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Nearshore marine paleoenvironmental reconstruction of southwest florida during the pliocene and pleistocene

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Title:
Nearshore marine paleoenvironmental reconstruction of southwest florida during the pliocene and pleistocene
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Book
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English
Creator:
Sliko, Jennifer
Publisher:
University of South Florida
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Tampa, Fla
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Subjects / Keywords:
Siderastrea
Pinecrest
Bermont
Phosphorus
Salinity
Dissertations, Academic -- Geology -- Masters -- USF   ( lcsh )
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non-fiction   ( marcgt )

Notes

Abstract:
ABSTRACT: Future climate change has been the subject of considerable speculation with scientists called upon to predict timing, magnitude, and impact of these changes. The Pliocene Warm Period serves as the best-available, pre-modern analog to predicted climate changes, and Pliocene climate anomalies are examined as possible scenarios for future climate change. Comparing modern conditions to the mean climate state of the Pliocene is essential for better constrained predictions of future climate change, and seasonal paleoenvironmental records provide a data set more analogous to instrumental observations and thereby reducing the uncertainty in modeled climate changes. This study first examines the potential of large gastropod shells as a paleoclimate proxy. Specimens of Busycon sinistrum, active in winter, and Fasciolaria tulipa, active in the summer, were collected alive from Tampa Bay and St. Joseph Bay in the hope of establishing a multi-year record of seasonality. The delta oxygen-18 time series of each shell were compared with predicted delta oxygen-18, based on local marine temperature variations, and both species cease shell growth during the winter months, despite opposing seasons of feeding activity. As none of the profiles provide information on winter environmental parameters, this sclerochronological system was replaced by work on pristine specimens of the scleractinian coral Siderastrea spp. Seasonal delta oxygen-18 and strontium/calcium time series from two Pliocene corals, collected from the Lower Pinecrest Member of the Tamiami Formation in southwest Florida, were used to calculate seawater delta oxygen-18 variations. Inferred salinity in the Pliocene has a reversed seasonal pattern from that of modern annual salinity variations, and is interpreted to be a response to an increase in winter precipitation, a teleconnection of the Pliocene "Super El Niño." Concentrations of variance in the typical ENSO frequency band are not apparent above the 95% confidence interval, suggesting that the Pliocene was dominated by a perennial, rather than an intermittent, El Niño-like state. Further geochemical analyses from both Pliocene and Pleistocene Siderastrea spp. corals indicate a high nutrient nearshore marine environment in south Florida. Marine phosphates, inferred from phosphorus/calcium analyses, were significantly higher in the Pliocene Tamiami Fm. than in the Early Pleistocene Caloosahatchee and Bermont Fms, and the decline in nutrients preceded local extinction by greater than 0.5 million years. Additionally, high-resolution phosphorus/calcium analyses of an individual coral reveal no evidence of seasonality required by a previously hypothesized upwelling-based nutrient delivery mechanism. The Pliocene nearshore marine environment in southwest Florida was characterized by higher nutrients than in the Pleistocene and precipitation patterns similar to modern El Niño teleconnections.
Thesis:
Dissertation (PHD)--University of South Florida, 2010.
Bibliography:
Includes bibliographical references.
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Mode of access: World Wide Web.
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by Jennifer Sliko.
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Title from PDF of title page.
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Document formatted into pages; contains X pages.

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ABSTRACT: Future climate change has been the subject of considerable speculation with scientists called upon to predict timing, magnitude, and impact of these changes. The Pliocene Warm Period serves as the best-available, pre-modern analog to predicted climate changes, and Pliocene climate anomalies are examined as possible scenarios for future climate change. Comparing modern conditions to the mean climate state of the Pliocene is essential for better constrained predictions of future climate change, and seasonal paleoenvironmental records provide a data set more analogous to instrumental observations and thereby reducing the uncertainty in modeled climate changes. This study first examines the potential of large gastropod shells as a paleoclimate proxy. Specimens of Busycon sinistrum, active in winter, and Fasciolaria tulipa, active in the summer, were collected alive from Tampa Bay and St. Joseph Bay in the hope of establishing a multi-year record of seasonality. The delta oxygen-18 time series of each shell were compared with predicted delta oxygen-18, based on local marine temperature variations, and both species cease shell growth during the winter months, despite opposing seasons of feeding activity. As none of the profiles provide information on winter environmental parameters, this sclerochronological system was replaced by work on pristine specimens of the scleractinian coral Siderastrea spp. Seasonal delta oxygen-18 and strontium/calcium time series from two Pliocene corals, collected from the Lower Pinecrest Member of the Tamiami Formation in southwest Florida, were used to calculate seawater delta oxygen-18 variations. Inferred salinity in the Pliocene has a reversed seasonal pattern from that of modern annual salinity variations, and is interpreted to be a response to an increase in winter precipitation, a teleconnection of the Pliocene "Super El Nio." Concentrations of variance in the typical ENSO frequency band are not apparent above the 95% confidence interval, suggesting that the Pliocene was dominated by a perennial, rather than an intermittent, El Nio-like state. Further geochemical analyses from both Pliocene and Pleistocene Siderastrea spp. corals indicate a high nutrient nearshore marine environment in south Florida. Marine phosphates, inferred from phosphorus/calcium analyses, were significantly higher in the Pliocene Tamiami Fm. than in the Early Pleistocene Caloosahatchee and Bermont Fms, and the decline in nutrients preceded local extinction by greater than 0.5 million years. Additionally, high-resolution phosphorus/calcium analyses of an individual coral reveal no evidence of seasonality required by a previously hypothesized upwelling-based nutrient delivery mechanism. The Pliocene nearshore marine environment in southwest Florida was characterized by higher nutrients than in the Pleistocene and precipitation patterns similar to modern El Nio teleconnections.
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Nearshore Marine Paleoenvironmental Reconstruction of Southwest Florida during the Pliocene and Pleistocene by Jennifer Leigh Sliko A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy D epartment of Geology College of Arts and Sciences University of South Florida Major Professor: Gregory S. Herbert, Ph.D. Peter Harries, Ph.D. Jonathan Wynn, Ph.D. Eric Oches, Ph.D. Terrence Quinn, Ph.D. Date of Approval: August 17, 2010 Keywords: S iderastrea Pinecrest, Bermont, Phosphorus, Salinity Copyright 2010, Jennifer Leigh Sliko

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Dedication To my grandfathers, Andrew Victor Sliko and Carmon Anthony Barone. Both of you were my inspiration.

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Ack nowledgements I would like to thank my advisor, Dr. Gregory S. Herbert, for giving me the opportunity to work on paleoclimate problems in Florida. I would also like to thank the rest of my committee members, Dr. Peter Harries, Dr. Jonathan Wynn, Dr. Eric Oches, and Dr. Terrence Quinn, for their support and advice with my research. Zachary Atlas' and Ethan Goddard's patient instruction and assistance with a variety of machines helped in geochemical data collection, and I thank them both. The fossils used in this research are housed at the Florida Museum of Natural History, and I thank Roger Portell for access. I am grateful for d iscussions with Kristine DeLong that greatly improved this project I thank all of my fellow graduate students in the Paleo Gr oup, for their support and help when I needed it the most. Thank you to all of my friends, for their patience and advice as I navigated the waters of graduate school. A special thanks also to Mary Haney, Mandy Stuck, and Connie Bryan for helping me navig ate through the layers of USF bureaucracy. I am also grateful to Sigma Xi, the Paleontological Society, the Geological Society of America, and the Everglades Geological Society for partially funding my research. I thank my parents, Victor and Carmen Slik o, and my sisters, Michelle and Carey, for their unending support as I pursued my degree. Finally, last but not least, thanks to you, Mike Meyer, for all of your support, patience, and love.

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i Table of Contents List of Tables ................................ ................................ ................................ ........ iv List of Figures ................................ ................................ ................................ ........ v Abstract ................................ ................................ ................................ ................ vi i Chapter 1: Introduction, Purpose, and Dissertation Organization ......................... 1 1.1 Introduction ................................ ................................ ........................... 1 1.2 Research Purpose ................................ ................................ ................ 3 1.3 Methods of Testing the Problem Dissertation Organization .............. 5 1.4 C hapter References ................................ ................................ .............. 9 Chapter 2: Background: Florida Precipitation Patterns, Nearshore Marine Nutrients, and Plio Pleistocene Fossiliferous Deposits ................................ .. 12 2.1 Introduction ................................ ................................ ......................... 12 2.2 Modern Florida Climate ................................ ................................ ...... 12 2.3 Teleconnections in M odern Florida Climate ................................ ....... 18 2.3.1 The Atlantic Multidecadal Oscillation ................................ .... 18 2.3.2 The North Atlantic Oscillation ................................ ................ 21 2.3.3 The Pacific Decadal Oscillation ................................ ............ 25 2.3.4 The El Ni–o Southern Oscillation ................................ .......... 26 2.3.5 ENSO, AMO, NOA, and PDO Interactions ........................... 32 2.4 Pliocene "Super El Ni–o" ................................ ................................ .... 33 2.5 Modern Nut rient Sources ................................ ................................ .... 36 2.6 Florida Shell Beds ................................ ................................ ............... 39 2.7 Florida Paleoenvironmental and Paleobiological Context .................. 42 2.8 Chapter References ................................ ................................ ............ 47 Chapter 3: Potential and Pitfalls of Obtaining Decadal Climate Records from Isotope Sclerochronology of Large Predatory Moll usks ......................... 59 3.1 Abstract ................................ ................................ ............................... 59 3.2 Introduction ................................ ................................ ......................... 60 3.3 Materials and Methods ................................ ................................ ....... 6 5 3.3.1 Collection Sites and Sampling Techniques ........................... 6 5 3.3.2 Stable Isotope Analysis ................................ ......................... 6 7 3.3.3 Environmental Data ................................ .............................. 6 8

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ii 3.3. 4 Predicted 18 O and 18 O water Determination .......................... 70 3.3.6 Statistical An alysis ................................ ................................ 71 3.4 Results ................................ ................................ ................................ 71 3.4.1 Shell Length ................................ ................................ .......... 71 3.4.2 Oxygen Isotope Geochemistry ................................ .............. 71 3.4. 3 Carbon Isotopes ................................ ................................ .... 7 4 3.5 Discussion ................................ ................................ ........................... 75 3.5.1 Applicability as climate proxies: Comparing 18 O shell and 18 O pred ................................ ................................ .............. 75 3.5.2 Estimation of Salinity Error ................................ .................... 78 3.5. 3 Seasonal Growth/Predation Habits ................................ ....... 80 3.5. 4 Longevity Estimates ................................ .............................. 83 3.5. 5 Carbon Isotopes ................................ ................................ .... 85 3.6 Conclusions ................................ ................................ ........................ 86 3.7 Chapter References ................................ ................................ ............ 88 Chapter 4: Seasonal Pliocene Teleconnections : Evidence from Florida Corals ................................ ................................ ................................ ............. 96 4.1 Abstract ................................ ................................ ............................... 96 4.2 Introduction ................................ ................................ ......................... 96 4.3 Methods and Results (Supplementary Information) ......................... 103 4.3.1 Testing Fossil Siderasstrea spp. Corals for Diagenic Alteration ................................ ................................ .. 103 4.3.2 Coral Sampling Procedures ................................ ................ 105 4.3.3 Stable Isotope and Trace Element Analysis ....................... 108 4.3. 4 Condensing Multiple Sample Pat hs and Depth to Time Conversions ................................ ................................ ............ 110 4.3. 5 Calculating 18 O SW ................................ .............................. 111 4.4 Results and Discussion ................................ ................................ .... 112 4. 5 A ppendix Time Series Analysis and 13 C Record ......................... 118 4. 6 Chapter References ................................ ................................ .......... 120 Chapter 5: Marine Phosphates in the Plio Pleistocene Beds of Southwest Flor ida: Implications for Nutrient Sources and Biotic Turnover .................... 128 5.1 Abstract ................................ ................................ ............................. 128 5.2 Introduction ................................ ................................ ....................... 128 5.3 Geologic Setting ................................ ................................ ............... 137 5.4 Methods ................................ ................................ ............................ 140 5.4.1 Sample Collection ................................ ............................... 140 5.4.2 Geochemical Analysis ................................ ......................... 143 5.4. 3 Age Model for Pliocene Seasonal Samples ........................ 144 5.4. 4 Statistical Analysis ................................ .............................. 145 5.5 Results ................................ ................................ .............................. 146 5.5.1 Comparing P/Ca Analysis Methodology ............................. 146

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iii 5.5.2 Bed Averaged P/Ca Comparisons between Formations ................................ ................................ ................... 147 5.5.3 Seasonal P/Ca Values in Fossil Corals .............................. 149 5.6 Discussion ................................ ................................ ......................... 151 5.6.1 Magnitude and Timing of Nutrient D ecline .......................... 151 5.6.2 Upwelling ................................ ................................ ............. 153 5.6.3 Terrestrial Nutrient Sources in the Pliocene ....................... 155 5.7 Conclusions ................................ ................................ ...................... 158 5.8 Appendix Modern Siderastrea spp. PO 4 SW P/Ca Calibration ...... 160 5.9 Chapter References ................................ ................................ .......... 166 Chapter 6 : Conclusions ................................ ................................ ..................... 174 Appendices ................................ ................................ ................................ ........ 176 Appendix A: Modern Gastropod Stable Isotope Data ............................. 177 Appendix B: Pliocene Siderastrea spp. Stable Isotope and Sr/Ca Data ................................ ................................ ................................ ........ 183 Appendix C: Pliocene and Pleistocene P/Ca Data from Siderastrea spp. ................................ ................................ ........... 200 Appendix D: Pliocene Seasona l P/Ca data from Siderastrea spp. ......... 205 About the Author ................................ ................................ ...................... End Page

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iv List of Tables Table 2.1 : Marine p hosphate concentrations from south Florida ........................ 35 Table 3.1: Measured and p redicted S ummer 18 O Minima and Winter 18 O Maxima for F. tulipa and B. sin istrum in Tampa Bay and St. Joseph Bay ................................ ................................ ................................ ................. 73 Table 4. 1 : 18 O coral results ................................ ................................ ................. 108 Table 4. 2 : Sr/Ca results ................................ ................................ ..................... 109 Table 5.1: Fossil m arine p hosphate v alues in south Florida ............................. 163 Table 5. 2 : Modern m arine p hosphate v alues in south Florida ........................... 164

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v List of Figures Figure 1 1: Site l ocation m ap ................................ ................................ ................. 7 Figure 2.1 a : Modern Florida statewide monthly precipitation (grey) and t emperature (black) averages from 1950 2010 ................................ ............ 13 Figure 2.1 b : Lag correlations between Florida statewide monthly precipitation and t emperature ................................ ................................ ........ 14 Figure 2.2 a : Modern t emperature and s alinity variations from the southwest Florida Gulf Coast ................................ ................................ ......... 16 Figure 2 2b : Lag correlations between Rookery Bay monthly temperature and salinity ................................ ................................ ................................ ..... 17 Figure 2.3: Atlantic Multidecadal Oscillation and Palmer Drought Sever ity Index ................................ ................................ ................................ ............... 19 Figure 2.4: North Atlantic Oscillation and Palmer Drought Severity Index .......... 23 Figure 2.5: Map of Ni–o regions ................................ ................................ .......... 27 Figure 2. 6 : S outhwest Florida a verage s easonal p recipitation ............................ 30 Figure 2. 7 : The Multivariate El Ni–o Southern Oscillation Inde x and the Palmer Drought Severity Index ................................ ................................ ...... 31 Figure 2. 8 : Lomb Periodogram of MEI and PDSI ................................ ................ 31 Figure 2. 9 : Pliocene to Recent SST r econstructions ................................ ........... 34 Figure 2. 10 : Linear regression between salinity and marine phosphate concentration in Rookery Bay ................................ ................................ ........ 39 Figure 2. 11 : Florida stratigraphic column ................................ ............................ 41

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vi Figure 3.1: Patterns of seasonal occupancy of B. sinistrum and F. tulipa from Baymouth Bay, Alligator Harbor, northwest Florida ............................... 6 4 Figure 3. 2 : Site l ocation m ap ................................ ................................ ............... 6 6 Figure 3. 3 : S ample locations ................................ ................................ ............... 6 7 Figure 3. 4 : Histo ric w ater q uality p arameters ................................ ...................... 6 9 Figure 3. 5 : Sample locations and isotope profiles for S. sinistrum and F. tulipa for Tampa Bay and St. Joseph Bay ................................ ...................... 74 Figure 3. 6 : Plot of 13 C versus 18 O for all shells ................................ ................ 75 Figure 3. 7 : B. carica growth curves ................................ ................................ ..... 84 Figure 4. 1: Southwest Florida mean seasonal precipitation .............................. 100 Figure 4. 2 : MEI, Florida PDSI, and Florida Temperature Anomaly ................... 101 Figure 4. 3 : XRD and SEM Analysis ................................ ................................ ... 104 Figure 4. 4 : UF 35438 Geochemical Data ................................ .......................... 106 Figure 4. 5 : UF 35931 Geochemical Data ................................ .......................... 107 Figure 4. 6 : Periodogram of UF 35438 geochemical records ............................. 119 Figure 5.1: Florida stratigraphic column ................................ ............................ 139 Figure 5.2: Site Location Map ................................ ................................ ............ 141 Figure 5.3: Bed averaged P/Ca for the Pliocene and Pleistocene Beds ........... 148 Figure 5.4: Geochemical seasonal variations ................................ .................... 150 Fi gure 5. 5 : Lomb Periodogram of Pliocene P/Ca time serie s ............................ 151 Figure 5. 6 : Relationship between modern PO 4 SW and salinity ........................ 156 Figure 5. 7 : Modern PO 4 SW P/Ca calibration for the Dry Tortugas .................. 162 Figure 5. 8 : Modern PO 4 SW site location map ................................ ..................... 164

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vii Nearsho re Marine Paleoenvironmental Reconstruction of Southwest Florida during the Pliocene and Pleistocene Jennifer Leigh Sliko Abstract Future climate change has been the subject of considerable speculation with scientists called upon to predict timing, magnit ude, and impact of these changes. !! The Pliocene Warm Period serves as the best available, pre modern analog to predicted climate changes, and Pliocene climate anomalies are examined as possible scenarios for future climate change. Comparing modern conditi ons to the mean climate state of the Pliocene is essential for better constrained predictions of future climate change, and seasonal paleoenvironmental records provide a data set more analogous to instrumental observations and thereby reducing the uncertai nty in modeled climate changes. This study first examines the potential of large gastropod shells as a paleoclimate proxy. Specimens of Busycon sinistrum, active in winter, and Fasciolaria tulipa active in the summer, were collected alive from Tampa Bay and St. Joseph Bay in the hope of establishing a multi year record of seasonality. The 18 O time series of each shell were compared with predicted 18 O, based on local marine temperature variations, and both species cease shell growth during the winter months, despite opposing seasons of feeding activity. As none of the

PAGE 11

viii profiles provide inf ormation on winter environmental parameters, this sclerochronological system was replaced by work on pristine specimens of the scleractinian coral Siderastrea spp. Seasonal 18 O and Sr/Ca time series from two Pliocene corals, collected from the Lower Pine crest Member of the Tamiami Formation in southwest Florida, were used to calculate seawater 18 O variations. Inferred salinity in the Pliocene has a reversed seasonal pattern from that of modern annual salinity variations, and is interpreted to be a respo nse to an increase in winter precipitation, a teleconnection of the Pliocene "Super El Ni–o." Concentrations of variance in the typical ENSO frequency band are not apparent above the 95% confidence interval, suggesting that the Pliocene was dominated by a perennial, rather than an intermittent, El Ni–o like state. Further geochemical analyses from both Pliocene and Pleistocene Siderastrea spp. corals indicate a high nutrient nearshore marine environment in south Florida. Marine phosphates, inferred from P /Ca analyses, were significantly higher in the Pliocene Tamiami Fm. than in the Early Pleistocene Caloosahatchee and Bermont Fms, and the decline in nutrients preceded local extinction by > 0.5 Ma. Additionally, high resolution P/Ca analyses of an individ ual coral reveal no evidence of seasonality required by a previously hypothesized upwelling based nutrient delivery mechanism. The Pliocene nearshore marine environment in southwest Florida was characterized by higher nutrients than in the Pleistocene and precipitation patterns similar to modern El Ni–o teleconnections.

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1 Chapter 1 Introduction, Purpose, and Dissertation Organization 1.1 Introduction Future c limate change has been the subject of considerable speculation with scientists called upon to predict timing magnitude and impact of these changes. The Inte rgovernmental Panel on Climate Change (IPCC) predicts an increase in average global surface air warming through the 21 st century, which could create adverse e ffects such as extreme weather systems, sea level rise, and migrating ecosystems (IPCC 2007). Atm ospheric greenhouse gasses are predicted to increase mean global temperatures, and forecasting how climate systems function with increased global temperatures is facilitated by examin ing how the Earth's climate functioned during previous intervals of eleva ted mean global temperature (e.g. Robinson et al., 2008; Federov et al., 2010). Furthermore, the effects of climate change vary regional ly and future policy changes will require region specific forecasts. In light of the recent decadal trend of global w arming and rise in atmospheric CO 2 the mid Pliocene Warm Period (PWP ; 3.0 3.3 Ma ) serves as a pre modern analog to predicted climate changes and PWP climate anomalies are often examined as possible scenarios for future climate change (Molnar and

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2 Cane, 2002; Ravelo et al., 2004, 2006; Federov et al., 2006, 2010; Robinson et al., 2008; Brierley et al., 2009 ; Haywood et al., 2009 ). The Pliocene was approximately 2 C to 3 C warmer than today ( Robinson et al., 2008 ) but global temperature distribution was different from the modern because n orthern high latitudes were warmer than today, while temperatu res in the tropics were similar (Ravelo et a l., 2004; Federov et al., 2006 ). Additionally, northern hemisphere glaciers were significantly reduced and the Cen tral American Seaway (CAS) was open enabling equatorial Pacific Atlantic Ocean exchange (Maier Reimer et al., 1990; Ravelo et al., 2004). However, despite these differences, the Pliocene was remarkably similar to modern climate when compared to other geo logically recent warm periods (such as the Eocene Thermal Maximum) in terms of the positions of the continents (Robinson, 2008) the thermal isolation of Antarctica (Zachos et al., 2001) and atmospheric CO 2 concentrations (Haywood et al., 2000, 2009) Th ese similarities enable the Pliocene to be a "possible, yet imperfect" analog for future global warming (Robinson et al., 2008 p. 501 ), but predictions about future climate change using PWP paleoclimate data must include estimation s of s ensitivity of regi onal teleconnections (environmental responses) to different boundary conditions. Will various regions respond to global warming in the same manner despite the different boundary conditions between the Pliocene, Pleistocene, and modern? High resolution (s easonal) paleoclimate records provide a robust test of this question.

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3 In addition to warmer global mean temperature a significant difference between the Pliocene and modern climate is the hypothesized lack of an east west temperature gradient in the equa torial Pacific Ocean, producing a permanent El Ni–o like state ("super El Ni–o") that dominated global climate during the PWP (Wara et al., 2005; Ravelo et al., 2006). A growing body of research suggests that the tropics (rather than high latitudes) affec t global climate (Ravelo et al., 2004) and many environmental patterns in the Pliocene that are differ ent from the modern are similar to modern El Ni–o climate anomalies (Molnar and Cane, 200 2, 2007). 1.2 Research Purpose The purpose of this research is to compare Pliocene precipitation patterns in southwest Florida with the modern to identify possible Pliocene ENSO variability. Additionally, this research examines nutrient patterns in the nearshore marine environment of southwest Florida through the Pli o Pleistocene transition in relation to existing diversity estimates in the Florida fossiliferous units. In this series of studies, high resolution regional climate variations interpreted from Pliocene and Pleistocene fossils exposed in Florida are examin ed and compared to modern climate. Comparing modern conditions to the mean climate state of the Pliocene and Pleistocene is essential for better constrained predictions of future climate change, providing a data set more analogous to instrumental observat ions and thereby reducing the uncertainty in modeled climate sensitivity.

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4 Previous research examining the paleoenvironmental conditions of the Florida P eninsula through ostracodes, pollen, and benthic foraminifer a assemblages have established that the cl imate of Florida was cooler and possibly wetter than present during the early to mid Pliocene, and mean temperatures increased to modern value s by the mid Pleistocene (Willard et al., 1993). While previous research has examined Pliocene temperature varia tions and general precipitation patterns, little is known about the seasonality of precipitation in the Pliocene and how it has changed through time. Modern precipitation in Florida is divided into dry winter and wet summer seasons (Kelly and Gore, 2008). Wetter conditions in the Pliocene could be the result of an increase in the amount and duration of summer precipitation, a slight decrease in summer precipitation coupled with an increase in winter precipitation, or an increase in both summer and winter precipitation. Warmer sea surface temperatures during the Pliocene may have increased local thunderstorm activity over southwest Florida Peninsula, thus increasing summer precipitation and prolonging the wet season (Hine et al., 2009). However, this hy pothesis contradicts previous research supporting cooler Pliocene temperatures in Florida (Willard et al., 1993). Instead of an increase in summer precipitation as proposed by Hine et al. (2009), I propose a slight decrease in Pliocene summer precipitatio n coupled with an increase in winter precipitation, similar to climate anomalies observed in Florida during strong modern El Ni–o events. This hypothesis is in accord with observed El Ni–o

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5 climate anomalies in the Pliocene (Molnar and Cane, 2007). A reco nstruction of seasonal trends in precipitation provides a test of these contradicting ideas. Additionally, the Pliocene nearshore marine environment in Florida is assumed to have be en nutrient rich followed by a decline in nutrients and thus productivity during the early Pleistocene (Allmon et al., 1996). W hile previous studies have describe d nutrient fluctuations in broad qualitative terms, this research quantitatively examines the evidence for nutrient decline as well as the seasonality of nutrient fl uctuations in nearshore marine lagoonal environment s of south Florida from the Pliocene. Th is question is particularly significant because the putative decline in nutrients is thought to have been a possible driver of a regional extinction event in the Gu lf of Mexico (Allmon et al., 1996) and Caribbean (O'dea et al., 2007) 1.3 Methods of Testing the Problem Dissertation Organization This research focuses on using fossil corals as seasonal salinity and nutrient prox ies for a Pliocene paleoenvironmental r econstruction and as Pliocene and Pleistocene "bulk" nutrient proxies, examini n g trends in marine phosphate concentration s through the Plio Pleistocene transition in southwest Florida The Florida shell beds, containing numerous well preserved mollusks an d a limited number of solitary and hermatypic corals, are an ideal system to provide paleoenvironmental reconstructions. Chapter 2 p rovid es a brief review of modern precipitation, salinity, and nutrient patterns while also examin ing average climate conditi ons in Florida and

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6 anomalies caused by several global phenomena This chapter also reviews the Florida Pliocene and Pleistocene fossiliferous beds. Chapter 3 examines the potential of large gastropod s hells as a paleoclimate proxy and describes how preda tion techniques affect shell growth and bias climate records. Using live specimens collected from St. Joseph Bay and Tampa Bay in Florida (locations "A" and "B" in F igure 1.1), Chapter 3 examines the use of two predatory gastropod species for paleoenviron mental analysis. This work represents early experimentation with a traditional isotope sclerochronological system that was ultimately replaced by work on pristine specimens of the scleractinian coral Siderastrea spp. Chapter 4 examines seasonal paleosali nity patterns in coral geochemical records from the Pliocene of Florida to test the presence of El Ni–o like teleconnections in southwest Florida. Scleractinian corals are commonly utilized in modern and historical environmental rec onstructions as proxies for sea surface temperature s and salinit ies ( e.g., Fairbanks and Dodge, 1979; Quinn et al., 1998; Linsley et al., 2000, 2006; Corrge, 2006 ). Previously determined calibrations quantify the relationship between temperature and Sr/Ca variations in Sideras trea spp. coral skeletons and between temperature, oxygen isotope variations in seawater, and oxygen isotope variations in Siderastrea spp coral skeletons (Moses et al., 2006; Maupin et al., 2008; DeLong et al., in prep).

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7 Figure 1 1 : Site l ocation m a p Florida is situated in the southeast North American continent, between the Gulf of Mexico and the North Atlantic Ocean (adapted from Florida Center for Instructional Technology, USF, 2009 ). Using fossil Siderastrea spp corals collected from the Richa rdson Road Shell Pit in southwest Florida (locati on "E" in Figure 1.1), Chapter 4 explores using these established proxies to determine Pliocene temperature and salinity patterns in southwest Florida, comparing them with modern El Ni–o teleconnection patte rns. Chapter 5 examines the seasonality of Pliocene nutrient input and Pliocene to Pleistocene nutrient decline. The seasonality data is used to test

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8 hypotheses about possible mode s of nutrient delivery to the nearshore marine system (e.g. upwelling, te rrestrial runoff). Additional ly, "bulk" nutrient levels from Pliocene and Pleistocene lagoonal systems are compared to establish the timing of nutrient decrease. The Pliocene corals used were collected from the Richardson Road Shell Pit (location E in F igure 1.1) and the Pleistocene corals were collected from the Cochran, Longan Lakes, Palm Beach Aggregates, and South Bay shell pits (locations F ," G ," H ," and I in F igure 1.1). Finally estimations of marine phosphate levels in the Pliocene and Ple istocene lagoonal systems are compared with similar modern environments from southwest Florida

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9 1.4 Chapter References Allmon, W, S Emslie, D Jones, G Morgan, 1996. Late Neogene oceanographic change along Florida's west coast: Evidence and mechanisms Journal of Geology 104:143 162 Brierley, CM, AV Federov, Z Liu, TD Herbert, KT Lawrence, JP LaRiviere, 2009. Greatly expanded tropical warm pool and weakened Hadley circulation in the Early Pliocene. Science 323:1714 1718 Chiang, JCH, 2009. The t ropics in paleoclimate. Annual Review of Earth and Planetary Science 37:263 297 Corrge, T, 2006. Sea surface temperature and salinity reconstruction from coral geochemical tracers. Palaeogeography, Palaeoclimatology, Palaeoecology 232:408 428 Croni n, T, G Dwyer, S Schwede, C Vann, H Dowsett, 2002. Climate variability from the Florida Bay sedimentary record: possible teleconnections to ENSO, PNA, and CNP. Climate Research 19:233 245 DeLong, KL, RZ Poore, J Flannery, CD Reich, CR Maupin, TM Quinn. In preparation. Do massive coral genera from the same reef record the same SST signal? A test from the Dry Tortugas, Florida Keys. To be submitted to Geophysical Research Letters Fairbanks, RG and RE Dodge, 1979. Annual periodicity of the 18 O/ 16 O and 13 C/ 12 C ratios in the coral Montastrea annularis. Geochimica et Cosmochimica Acta 43:1009 1020. Federov, AV, P Dekens, M McCarthy, AC Ravelo, P deMenocal, M Barreiro, R Pacanowski, S Philander, 2006. The Pliocene paradox (mechanisms for a p ermanent El Ni–o). Science 312:1485 1489 Federov, AV, CM Brierley, K Emanuel, 2010. Tropical cyclones and permanent El Ni–o in the early Pliocene epoch. Nature 463:1066 1070 Haywood, AM, PJ Valdes, BW Sellwood, 2000. Global scale palaeoclimate reconstruction o f the middle Pliocene climate using the UKMO GCM: initial results. Global and Planetary Change 25(3 4):239 256 Haywood, AM, HJ Dowsett, PJ Valdes, DJ Lunt, JE Francis, BW Sellwood, 2009. Introduction. Pliocene climate, processes and problems. Philosop hical Transactions of the Royal Society A 367:3 17

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10 Hine, AC, B Suthard, SD Locker, KJ Cunningham, DS Duncan, M Evans, RA Morton, RA, 2009. Karst subbasins and their relationship to cross Florida transport of Tertiary siliciclastics. In: Swart, PK, GP E berli, J McKenzie (Eds.), Perspectives in Sedimentary Geology: A Tribute to the Career of Robert Nathan Ginsburg, Sedimentology. IPCC, 2007. Climate change 2007: the physical science basis. Intergovernmental Panel on Climate Change, http://www.ipcc.ch/i pccreports/ar4 wg1.htm. Kelly, MH, and JA Gore, 2008. Florida river flow patterns and the Atlantic Multidecadal Oscillation. River Research and Applications 24:598 616 Linsley, BK, GM Wellington, DP Schrag 2000. Decadal s ea s urface t emperature v aria bility in the s ubtropical South Pacific from 1726 to 1997 A.D. Science 290(5494):1145 1148 Linsley, BK, A Kaplan, Y Gouriou, J Salinger, PB deMenocal, GM Wellington, SS Howe, 2006. Tracking the extent of the South Pacific Convergence Zone since the ear ly 1600s. Geochemistry, Geophysics, Geosystems 7(4): Q05003, d oi:10.1029/2005GC001115 Maupin, CR, TM Quinn, and RB Halley, 2008. Extracting a climate signal from the skeletal geochemistry of the Caribbean coral. Geochemistry, Geophysics, Geosystems 9: d oi:10.1029/2008GC002106 Maier Reimer, E, U Mikolajewicz, TJ Crowley, 1990. Ocean general circulation model sensitivity experiment with an open Central American Isthmus. Paleoceanography 5:349 366 Molnar, P, and MA Cane, 2002. El Ni–o's tropical cl imate and teleconnections as a blueprint for pre Ice Age climates. Paleoceanography 17(2): doi:10.1029/2001PA000663 Molnar, P, and MA Cane, 2007. Early Pliocene (pre Ice Age) El Ni–o like global climate: Which El Ni–o? Geosphere 3:337 365 Moses, CS, PK Swart, RE Dodge, 2006. Calibration of stable oxygen isotopes in Siderastrea radians (Cnidaria:Scleractinia): Implications for slow growing corals. Geochemistry, Geophysics, Geosystems 7:doi:10.1029/2005GC001196

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11 O'dea, A, JBC Jackson, H Fortunato, J T Smith, L D'Croz, KG Johnson, JA Todds, 2007. Environmental change preceded Caribbean extinction by 2 million years. Proceedings of the National Academy of Sciences 104(13):5501 5506 Quinn, TM, TJ Crowley, FW Taylor, 1996. New stable isotope results from a 173 year coral from Espiritu Santo, Vanuatu. Geophysical Research Letters 23(23):3413 3416 Ravelo, AC, DH Andreasen, M Lyle, AO Lyle, MW Wara, 2004. Regional climate shifts caused by gradual global cooling in the Pliocene epoch. Nature 429:263 267 Ravelo, AC, PS Dekens, M McCarthy, 2006. Evidence for El Ni–o like conditions during the Pliocene. GSA Today 16:4 11 Raymo, ME, D Rind, WF Ruddiman, 1990. Climatic effects of reduced Arctic sea ice limits in the GISS II general circulation model Paleoceanography 5(3):367 382 Robinson, MM, MA Chandle r, HJ Dowsett, 2008. Pliocene role in assessing future climate i mpacts. Eos Transactions, AGU 89(49):doi:10.1029/2008EO490001 Smith, SV, RW Buddemeier, RC Redalje, JE Houck, 1979. Strontium ca lcium thermometry in coral skeletons. Science 204:404 407 Wara, M, AC Ravelo, M Delany, 2005. Permanent El Ni–o like conditions d uring the Pliocene Warm Period. Science 309:758 761 Wefer, G and WH Berger, 1991. Isotope paleontology: growth and comp osition of extant calcareous species. Marine Geology 100:207 248 Williard, DA, TM Cronin, SE Ishman, RJ Litwin, 1993. Terrestrial and marine records of climatic and environmental changes during the Pliocene in subtropical Florida. Geology 21(8):679 68 2 Woodring, W, 1966. The Panama land bridge as a sea barrier. Proceedings of the American Philosophical Society 110:425 433 Zachos, J, M Pagani, L Sloan, E Tho mas, K Billups, 2001. Trends, rhythms, and aberrations in global climate 65 Ma to p resent. Science 292 (5517):686 693

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12 Chap ter 2 Background: Florida Precipitation Patterns, Nearshore Marine Nutrients, and Plio Pleistocene Fossiliferous Deposits 2.1 Introduction This dissertation focuses on establishing high resolution paleoclimate records for the Pliocene and Plei stocene nearshore marine environments of southwest Florida 1 Prior to examining climate (precipitation and nutrient) patterns in the Pliocene and Pleistocene fossil deposits in Florida, a review of those patterns in the modern environment is necessary to establish a baseline for comparison. Additionally, I present a brief review of the nature of the Florida Pliocene and Pleistocene fossiliferous beds and previous paleoenvironmental reconstructions. 2.2 Modern Florida Climate The Florida Peninsula north of Miami has a humid, subtropical climate, generally dominated by warm weather and summer dominated precipitation. The year is divided into the wet (June through September) and dry (October though May) seasons (Kelly and Gore, 2008), with ~60% of precipitat ion occurring during the 1 Recently, the boundary between the Pliocene and Pleistocene epochs has changed from 1.8 Ma to 2.58 Ma (Gibbard et al., 2010). All references to the Pliocene and Pleistocene epochs herein correspond to the newly ratified divisio n at 2.58 Ma.

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13 four months of the wet season. Additionally, statewide monthly precipitation and temperature, from the National Climatic Data Center (NCDC) of the National Oceanic and Atmospheric Administration (NOAA) (Figure 2.1a), are generally positive ly correlated. Figure 2.1a : Modern Florida statewide monthly precipitation (grey) and temperature (black) averages from 1950 2010, calculated by giving equal weight to stations within each climatic division. Data provided by the National Climatic Da ta Center (NCDC) of the National Oceanic and Atmospheric Administration (NOAA).

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14 Correlation coefficients are highest with no lag (r = 0.60), followed by a 1 month (r = 0.52) and 11 month lag (r = 0.52) (Figure 2.1b), demonstrating the synchronous relation ship between warm temperatures and increased precipitation. Figure 2.1b : Lag correlations between Florida statewide monthly precipitation and temperature. Correlation coefficients (in upper right box) are highest with no lag, a 1 month or 11 month lag. High reversed coefficients, representing an inverse correlation, are present with the 5 6 and 7 month lag. Data provided by the National Climatic Data Center (NCDC) of the National Oceanic and Atmospheric Administration (NOAA).

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15 Mimicking precipit ation patterns, 60% of annual river flow in the Florida Peninsula (south of the Suwannee River) occurs between the four summer months of June through September (Kelly and Gore, 2008). Flow peaks in the Myakka River (near Sarasota Florida in southwest Flor ida) at ~15 m 3 /sec, during mid July, whereas January flow in the same river is ~2 m 3 /sec (Kelly and Gore, 2008). Natural salinity patterns in the southwest Florida nearshore marine environments generally follow precipitation patterns, with the lowest sa linity occurring during the summer (wet) season (Figure 2.2a). However, unlike the relationship between precipitation and temperature, the inverse relationship between salinity and temperature is strongest (r = 0.47) when salinity is lagged 2 months behi nd temperature (Lag 10 in Figure 2.2b). The lowest marine salinity values are generally 2 months before the warmest temperatures, suggesting evaporation, along with precipitation, affect marine salinity in a complex relationship.

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16 Figure 2.2 a : Modern t emperature and salinity variations from the southwest Florida Gulf Coast. Rookery Bay sea surface temperature (SST) (black) and sea surface salinity (SSS) (grey) from 1998 2010. (Data provided by Southeast Environmental Research Center Water Quality Mo nitoring Network; SERC FIU.) Wet (summer) season precipitation is characterized by afternoon storms, which are driven by the localized high and low pressure zones over the sea and land, respectively (Duever et al., 1997). Sea breeze circulation initiates convection, and the resulting thunderstorm activity is then amplified by downdrafts from the initial convection activity (Cooper et al., 1982). The warm water that drives the summer rainfall patterns is part of the Western Hemisphere Warm Pool (WHWP). The WHWP is an area of surface water warmer than 28.5¡C that includes the eastern North Pacific (near Central America), the Caribbean, the Gulf of Mexico, and the western Atlantic Ocean (Wang and Enfield, 2001). The WHWP initiates in the spring (typically March)

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17 Figure 2.2b : Lag correlations between Rookery Bay monthly temperature and salinity. Correlation coefficients (in upper right box) are strongest with a 4 month lag (positive relationship) and an 11 month lag (precipitation proceeding temperature by 2 months) (inverse relationship). (Data provided by SERC FIU) and grows throughout the summer, with the largest extent of the pool apparent in August/September. Its size decreases during the fall and usually disappears by December (Wang and Enfield, 2001).

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18 2.3 Teleconnections in Modern Florida Climate The "normal" precipitation pattern in Florida is periodically altered by several global climate phenomena (explained in sections 1.4a through 1.4d) through teleconnections, which are "recurring and per sistent large scale pattern(s) of pressure and circulation anomalies that span vast geographical areas" (NOAA, 2010). Teleconnections arise from interactions between atmospheric and oceanic systems on both regional and global scales, affecting wind convec tion, precipitation, storm tracks, and temperature. For example, the mean temperature of the North Atlantic Ocean influences the drought potential of the mid North American continent (Enfield et al., 2001). In Florida, teleconnections and their influence on regional precipitation patterns are controlled by the Atlantic Multidecadal Oscillation (AMO) (Kelly and Gore, 2008), the North Atlantic Oscillation (NAO), the El Ni–o Southern Oscillation (ENSO) and the closely related Pacific/North American (PNA) tel econnection pattern, and, to a lesser extent, the Pacific Decadal Oscillation (PDO) (Hagemeyer 2006). 2.3.1 The Atlantic Multidecadal Oscillation The Atlantic Multidecadal Oscillation (AMO) is a measurement of sea surface temperature (SST) anomalies in the North Atlantic Ocean (Kerr, 2000). The anomalies, which are divided into warm and cool phases, vary up to 0.4 ¡C from the mean (Enfield et al., 2001). The historical record of the AMO, which extends back 146 years, shows a periodicity of ~70 years (~35 year cool phase followed by ~35 year warm phase) (Figure 2.3); however, when examined in pre

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19 instrument proxy records, AMO periodicity varies between 60 110 years (Delworth and Mann, 2000; Kerr 2000; Enfield et al., 2001; Gray et al., 2004; Knight et al., 2006). Figure 2.3 : Atlantic Multidecadal Oscillation and Palmer Drought Severity Index. Atlantic Multidecadal Oscillation (AMO) timeseries from 1850 to 2010 (black line is a 2 year binomial filter) plotted with the Palmer Drought Severity Index (PDSI). Shaded grey bars represent the 1930's ("Dustbowl") and 1950's periods of severe drought in central North America.(Data provided by Enfield et al., 2001 and NOAA.)

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20 The AMO has been linked to precipitation anomalies across most of the northern hemisphere, i ncluding North America, Europe, China, and northern Africa (Enfield et al., 2001; Gray et al., 2004; Lu et al., 2007; Shaunglin and Bates, 2007). During the warm (cool) phase of AMO, there is a decrease (increase) in precipitation in central North America and southern China, and an increase (decrease) in precipitation in peninsular Florida, the Sahel, and northern China. A negative correlation between precipitation and the AMO (warm AMO causing a decrease in precipitation) is extraordinarily expressed in Midwest and Southwest North America; for example, two of the most severe droughts there in the past century are associated with the previous warm phase of the AMO (shaded regions in Figure 2.3) (Enfield et al., 2001). However, while this negative precipi tation anomaly covers the entire Mississippi Valley, it only extends as far south as the Panhandle of Florida. South of the Suwannee River, precipitation increases ( and presumably local salinity decreases) during warm phases of the AMO, as measured by str eam and river discharge from 1940 1999 (Enfield et al., 2001; Kelly and Gore, 2008). Predicting shifts in AMO variability (from warm to cool phases) is difficult because multiple physical processes are identified as potential drivers of shifts in the A MO, including thermohaline circulation (THC) and the amount of sea ice and freshwater export from the Arctic to the North Atlantic Ocean (Dijkstra et al., 2006; Dima and Lohmann, 2007). An increase (decrease) in THC drives the

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21 AMO to a warm (cool) phase, as more (less) of the warm Gulf Stream flows into the North Atlantic (Timmerman et al., 1998; Dia et al., 2005; Dima and Lohmann, 2007). Additionally, sea ice and the resulting freshwater export from the Arctic Ocean can reduce THC (Dima and Lohmann, 2007 ). The relationships between drivers and AMO fluctuations are derived from instrumental data (Dima and Lohmann, 2007) and general climate models (GCM) (Dijkstra et al, 2006). The AMO and Pliocene Climate. In the early Pliocene, THC would have been weaker than present, driving the AMO into a relatively cool phase (Haywood and Valdes, 2004). In the mid Pliocene, the closing of the Central American Seaway (CAS) intensified the Loop Current and the Gulf Stream, thereby intensifying THC in the NW Atlantic Oce an (Huag and Tiedmann, 1998; Billups et al 1999; Billups, 2002; Haywood and Vlades, 2004). If the AMO is tied to THC, then the closing of the CAS and subsequent strengthening of THC should have instigated a modern "warmer" AMO, thus increasing precipitati on in peninsular Florida. THC variability is documented throughout the late Pliocene and Pleistocene through deep sea sediments and foraminifera assemblages (Dirscoll and Haug, 1998; Haug and Tiedmann, 1998; Haywood et al., 2000), potentially causing AMO oscillations with 60 110 year periodicities similar to what is apparent in historic and proxy records 2.3.2 The North Atlantic Oscillation The North Atlantic Oscillation (NAO) is an index of variance between the low pressure zone centered over the Arcti c and the high pressure zone over the

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22 subtropical Atlantic (van Loon and Rogers, 1978; Hurrell, 1995; Hurrell and van Loon, 1997; Hurrell, 2003; Stenseth et al., 2003; Hagemeyer, 2006). There is a 15 mbar pressure difference between the subtropical Atlant ic and the Arctic regions (Hurrell, 1995), and higher than normal pressures in the subtropical Atlantic combined with anomalously low pressures in the Arctic enhance the pressure gradient during a positive NAO. A negative NAO represents a minimal gradient between the two pressure zones. The modern instrument record extends back to 1864 (Figure 2.4) and shows 8 10 year periodicity in NAO oscillations (Hurrell et al., 2003). Historical records, tree rings, and Greenland Ice core records, however, extend ou r understanding of decadal NAO oscillations into the mid Holocene (Jones et al., 1998; Appenzeller et al., 1998; Cook, 2003). GCM's have further supported the presence of NAO oscillations into the Pleistocene and late Pliocene; however, most proxy records such as marine sediment cores, lack sufficient temporal resolution to reveal decadal variations in NAO (Haywood et al., 2000; Rind et al., 2005). Because NAO is a measure of winter pressure variability, typically only winter climate anomalies are examine d in the literature. The prevailing westerlies over the mid latitudes in the Northern Hemisphere are stronger during a positive NAO, causing a northward shift in Atlantic storm activity and consequently, increasing winter storm activity in Iceland and Sca ndinavia, but decreasing the severity of winter storms in Canada, Greenland, the Mid Atlantic region of North America, across the Iberian Peninsula, and in the Mediterranean

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23 Figure 2.4 : North Atlantic Oscillation and Palmer Drought Severity Index. North Atlantic Oscillation (NAO) index (black) based on the difference of normalized sea level pressure (SLP) during winter (December through March) between Lisbon, Portugal and Stykkisholmur/Reykjavik, Iceland from 1864 to 2010 (data from UCAR) plotted with th e PDSI (grey). (Data provided by NOAA). r egion (Visbeck et al., 2001; Hurrell, 2003). A negative NOA, instigated by a weak Arctic low and a weak Azores high, has the opposite effect, shifting Atlantic storm activity southward into Canada, the Mid Atlan tic region of North America, and Europe (Hurrell, 2003).

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24 The strong Azores high, associated with a positive NAO, extends westward over the southeast United States (north of Florida), creating a high pressure ridge that prevents winter storms from reachi ng the Florida peninsula and decreases winter precipitation (Hagemeyer, 2006; van Beynen et al., 2007). This enlarged high also decreases precipitation in southern Europe and northern Africa (Moulin et al., 1997; Hurrell, 1995). Conversely, a negative NA O is correlated to an increase in precipitation in Florida, southern Europe, and northern Africa (Hurrell, 1995; Hurell and Van Loon, 1997; Hurrell et al., 2003; Hagemeyer, 2006). The NAO and Pliocene climate. While an NAO signal has not been detected in any Pliocene proxy records (possibly due to the relatively low resolution Pliocene climate proxies), the boundary conditions of GCM's (including higher annual SST and reduced Northern Hemisphere glaciers) suggest an intensification of the Azores high an d the Arctic low characteristic of a positive NAO (Haywood et al., 2000), thus combin in g with a cooler AMO to result in decreas ed precipitation over the exposed part of the Pliocene Florida peninsula. In seasonal proxy precipitation records, a positive NA O would be detected as a decrease in winter precipitation. The positive NAO predictions are in agreement with a predicted northerly paleoposition of the Intertropical Convergence Zone (ITCZ) during the Pliocene and Miocene, as evident in eolian dust recor ds and planktonic foraminifera from deep sea cores in the Atlantic and Pacific Oceans (Rea, 1998; Billups et al., 1999). However, depending on the extent of its

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25 northerly migration, the ITCZ may have increased precipitation in Florida. After the closure of the CAS and approximately concurrent with the onset of Northern Hemisphere Glaciation, the ITCZ moved southward (Rea, 1998; Billups et al., 1999). 2.3.3 The Pacific Decadal Oscillation The Pacific Decadal Oscillation (PDO) is variation between SST ano malies in the North Pacific Ocean. During the warm (positive) mode of the PDO, the area of the eastern north Pacific Ocean adjacent to North America is anomalously warm, while cooler water spreads from the center of the Pacific Ocean to the western edge o f the North Pacific Ocean (Mantua et al., 1997). During the cool (negative) phase of the PDO, the opposite SST pattern is observed. Typical PDO periodicity ranges from 15 to 30 years, and the strongest teleconnections affect mid and high latitude regions of North America (Barlow et al., 2001; Mestas Nu–ez and Enfield, 2001). During a warm phase PDO, temperatures are above average in the northwest U.S. and below average in the southeast U.S., and precipitation in the southern U.S. is above average while b elow average in the NW and Great Lakes region. However, statistical correlations with precipitation anomalies suggest that the AMO plays a much larger role than PDO in North American precipitation patterns (Mestas Nu–ez and Enfield, 2001; Hagermeyer, 2006 ).

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26 2.3.4 The El Ni–o Southern Oscillation The El Ni–o Southern Oscillation (ENSO) is a quasi periodic coupled "ocean atmosphere system in the tropical Pacific with global impacts" (Cane, 2005, p. 227). The oceanic processes associated with ENSO are mani fest as changing SST (El Ni–o/La Ni–a) across the equatorial Pacific Ocean, while the atmospheric processes (the Southern Oscillation) reflect changing sea level pressure (SLP) caused by oscillating atmospheric masses between Darwin, Australia and Tahiti ( Cane, 2005). During "normal" conditions, SLP is controlled by a Walker atmospheric circulation cell over the equatorial Pacific, characterized by warm air rising in the western equatorial Pacific (WEP; creating regional low SLP) and cold air sinking in t he eastern equatorial Pacific (EEP; creating regional high SLP) (Bjerknes, 1969; Cane, 2005; Ravelo et al., 2006). Surface air then flows from the high pressure zone (in the EEP) to the low pressure zone (in the WEP) as easterly trade winds, which drives the westward flow of the oceanic equatorial current. This westward flow creates a thick, warm mixed layer in the WEP, which depresses the thermocline to depths of ~200 400 m, whereas in the EEP the thermocline is relatively shallow (~50 m; Ravelo et al., 2006). The easterly winds drive divergent upwelling in the EEP, causing SST to be cooler than in the WEP, resulting in an equatorial temperature gradient. The equatorial SST gradient strengthens the atmospheric low in the WEP and high in the EEP, thus

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27 st rengthening the easterly winds, resulting in a positive feedback system (Bjerknes, 1969; Cane, 2005; Ravelo et al., 2006). An El Ni–o event involves the breakdown of the Walker atmospheric circulation cell accompanied by weaker upwelling triggering a deep ening of the thermocline in the EEP and a decreased equatorial SST gradient (Cane, 2005; Ravelo et al., 2006). El Ni–o events are commonly characterized by the equatorial warming of SST in the Pacific, and these SST anomalies are grouped into four differe nt longitudinal areas of the tropical Pacific (Trenberth, 1997). The regions designated as Ni–o 1 and Ni–o 2 are commonly combined (referred to as Ni–o 1+2) and located in the EEP, between 80¡ and 90¡ W and 0¡ to 10¡ S (Figure 2.5) SST changes in Ni–o 3 and Ni–o 4 are both centered on the equatorial Pacific between 5¡ S and 5¡ N, and Ni–o 3 is located more eastward (90¡ and 150¡ W), whereas Ni–o 4 is located between 150¡ W and 160¡ E (Figure 2.5). Figure 2.5: Map of Ni–o regions. Map showing the loc ations of Ni–o 1+2, Ni–o 3, Ni–o 4, and Ni–o 3.4, which combines the western end of Ni–o 3 with the eastern end of Ni–o 4. (Figure adapted from NOAA Climate Prediction Center, http://www.cpc.noaa.gov/products/analysis_monitoring/ensostuff/nino_regions.sht ml)

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28 The highest SST anomalies for typical El Ni–o events are located in the Ni–o 3.4 region, near 160¡ W, however, for severe El Ni–o events (such as the 1997 1998 event), those anomalies migrate eastward toward the Ni–o 1 + 2 region, near South America (Trenberth, 1997; Molnar and Cane, 2007). The oscillation between El Ni–o and neutral or La Ni–a conditions relies on the strength of ocean atmosphere interactions and the delayed response of the equatorial thermocline (Webster and Yang, 1992; Wang, 2000; Cane, 2005). This coupling strength is dependent on a variety of factors, including surface wind strength, atmospheric heat generated by SST changes, and the depth of the thermocline (Wang, 2000; Cane, 2005). The complexity of these interactions affects both the frequency and amplitude of ENSO oscillations, numerically expressed as the Multivariate ENSO Index (MEI). The MEI is a spatially filtered average of sea level pressure, zonal and meridional surface wind, sea surface temperature, surface air tempe rature, and total cloudiness, calculated as the first principal component of the combined six fields (Wolter, 1987; Wolter and Timlim, 1993). Modern El Ni–o events, as measured by the positive phase of the MEI, occur approximately every 4 years, although ENSO oscillations vary between 2 7 year periodicities (Cane, 2005, Collins et al., 2010). ENSO oscillations have global ramifications, and these tropical driven teleconnections are possibly the most studied in climate research (e.g. Ropelewski and Halpe rt, 1986; Diaz et al., 2001; Nott et al., 2002; Emile Geay et

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29 al., 2007; Yoshida et al., 2007). A warm ENSO phase (El Ni–o) has the strongest affect on winter climate in the southeastern United States, and very little affect on summer climate (Cook et al. 2000; Enfield and Mestas Nu–ez, 2000; Diaz et al., 2001; Molnar and Cane, 2007). The warm phase of ENSO (an El Ni–o event) is also typically associated with the positive phase of the PNA (Hagemeyer, 2006), which is manifest as a large barometric pressur e difference between the southeastern United States and western Canada (Wallace and Gutzler, 1981). Today, increased rainfall in Florida during winter and spring is characteristic of conditions during an El Ni–o event and the positive phase of the PNA (Sc hmidt et al., 2001; Schmidt and Luther, 2002; Hagermeyer, 2006). Precipitation anomalies are particularly pronounced in southwest Florida between Tampa Bay and Charlotte Harbor (Carlson et al., 2003). During such an event, winter and spring rainfall in s outhwest Florida increases by 13% above normal winter/spring precipitation, and during a "severe" modern El Ni–o event, winter and spring rainfall increases by 85% above normal levels (Figure 2.6) (SWFWMD). During the strongest El Ni–o event in the past 6 0 years (the 1997 1998 event) winter (dry season) precipitation on the southwest Florida peninsula exceeded summer (wet season) precipitation by 56% (Figure 2.6) (SWFWMD).

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30 Figure 2.6 : Southwest Florida average seasonal precipitation. Averaged summer ( grey) and winter (black) precipitation for La Ni–a and El Ni–o years and "normal" years not associated with La Ni–a or El Ni–o events. The precipitation during the severe 1997 1998 El Ni–o event is separated from typical El Ni–o events. (Data provided by SWFWMD.) These ENSO driven precipitation anomalies in Florida also affect regional water resources and hazards in Florida. "Wet" and "dry spells" are quantified by the Palmer Drought Severity Index (PDSI), which accounts for precipitation, temperature, a nd the soil water holding capacity in defined regions (Palmer 1965). Most El Ni–o events since 1950 has coincided with an "extreme wet spell" (greater than 4 on the PDSI) in Florida (Figure 2.7), and total precipitation, the PDSI and the MEI are weakly co rrelated (r 2 = 0.13 for PDSI and MEI and r 2 = 0.02 for precipitation and MEI). Additionally, both the PDSI and MEI have periodicities in the 5.7, 5.5, 5.1, 3.7, and 2.9 year frequency bands (Figure 2.8).

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31 Figure 2.7 : The Multivariate El Ni–o Southern Osc illation Index and the Palmer Drought Severity Index. Multivariate El Ni–o Southern Oscillation Index (MEI) (black) from 1950 to 2010 plotted with the PDSI (grey). Grey bars represent El Ni–o events between 1950 and 2010. The grey bar denoted with a sta r represents the severe 1997 98 El Ni–o events. (Data provided by NOAA.) Figure 2.8: Lomb Periodogram of MEI and PDSI. The hatched line indicates the 95% confidence interval (white noise). Grey bars mark where both the MEI and PDSI have significant p eaks, at 5.7, 5.5, 5.1, 3.7, and 2.9 year frequencies.

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32 El Ni–o driven rainfall during the dry/cool season decreases fire hazards (Beckage et al., 2003), and fewer hurricanes make landfall in the southeastern United States during El Ni–o years (Bove et al., 1998) due to increased tropospheric vertical wind shear disrupting cyclone development (Gray, 1984). During the severe 97 98 El Ni–o event, rainfall increased fluvial input to the nearshore marine system, and the excessive terrestrial nutrients ca used widespread phytoplankton blooms along the southwest Florida Gulf Coast (Carlson et al., 2003). 2.3.5 ENSO, AMO, NOA, and PDO Interactions While the AMO, NAO, and PDO affect precipitation patterns in Florida, ENSO is the strongest driver of precipitati on anomalies in Florida. The 1997 98 strong El Ni–o event, when winter precipitation slightly exceeded summer precipitation, coincided with a warm AMO and a positive NAO, producing a cumulative effect of increased winter precipitation. However, despite s trong influences on precipitation patterns in the Mississippi Valley, AMO teleconnections in Florida are relatively weak compared to ENSO teleconnections (Enfield et al., 2001). For example, rainfall in the Lake Okeechobee region is positively correlated with ENSO events (i.e. south central Florida is wetter during El Ni–o years) regardless of the AMO phase (Enfield et al., 2001). Additionally, Hagemeyer (2006) examined Florida winter precipitation anomalies in regards to the ENSO, NAO, and PDO index. Bo th warm ENSO (El Ni–o) and positive NAO increase winter precipitation; however, a warm ENSO

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33 and negative NAO still show an increase in winter precipitation. While the AMO and NAO both increase winter season precipitation anomalies, ENSO is the dominant pr ecipitation driver for southern Florida (Enfield et al., 2001; Hagemeyer, 2006). 2.4 Pliocene "Super El Ni–o" Many researchers have proposed that the Pliocene Pacific Ocean lacked an east west temperature gradient and was in a perennial El Ni–o like state, commonly referred to as "El Padre" or a "super El Ni–o" (Cane and Molnar, 2001; Molnar and Cane, 2002; Wara et al., 2005; Ravelo et al., 2006; Federov et al., 2006; Haywood et al., 2006). Using oxygen isotopes and Mg/Ca ratios from foraminifera and the a lkenone unsaturation index in coccolithophore algae in sediment cores from the EEP and the WEP, Ravelo et al. (2006) reconstructed sea surface temperature and thermocline depth for the past 5 Ma (Figure 2.9). For the majority of the Pliocene, the equatori al thermocline was deep, and temperatures from both the EEP and WEP were similar, thus mimicking the conditions of a modern El Ni–o event (Wara et al., 2005; Ravelo et al., 2006; Haywood et al., 2006). The deep equatorial thermocline prevented the upwelli ng of cool water in the WEP, hindering the development of a longitudinal temperature gradient. However, the temporal resolution of the sediment cores used for SST reconstructions is such that it is impossible to differentiate between a permanent El Ni–o o r simply more frequent than modern episodic El Ni–o events (Bonham et al., 2009).

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34 Figure 2.9: Pliocene to Recent SST Reconstructions. (A) Planktonic foraminifera 18 O records from two western equatorial Pacific (WEP) locations and two eastern equatorial Pacific (EEP) locations. (B) Planktonic foraminifera Mg/Ca records from the western equatorial Pacific location (red) and eastern equat orial Pacific location (blue). (C) Sea surface temperature (SST) (¡C) estimates for the western equatorial Pacific (red) and eastern equatorial Pacific (blue) based on Mg/Ca records (shown in B) using Dekens et al. (2002) calibration and for the eastern eq uatorial Pacific (green) based on U k 37 measurements. (D) The west minus east SST difference record calculated by subtracting the site 847 Mg/Ca based SST record from the site 806 Mg/Ca based SST record (blue) and by subtracting the site 847 alkenone based SST record from the site 806 Mg/Ca based SST record (red). (Figure from Ravelo et al., 2006). The differences between Pliocene climate reconstructions and modern conditions are similar to differences associated with modern severe El Ni–o teleconnections ( Molnar and Cane, 2002, 2007). As such, seasonal precipitation reconstructions in southwest Florida should reflect an increase in winter

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35 precipitation and a slight decrease in summer precipitations, as observed in a modern severe El Ni–o event. The Pliocen e perennial El Ni–o is considered to be the "normal" state of the Pacific Ocean in periods of warm global mean temperatures, while the equatorial SST gradient and intermittent El Ni–o events characteristic of the modern Pacific Ocean and during the Pleisto cene and Holocene are only apparent during periods of cooler global temperatures (Ravelo et al., 2006). Cooler temperatures led to a strengthening of deepwater formation in the northern hemisphere and a shoaling of the thermocline in various parts of the ocean (Marlow et al., 2000; Federov et al., 2006). Once the thermocline started to shoal in the EEP, ~2 3 Ma, a wind driven upwelling region developed gradually over 0.5 to 1.0 Ma, causing surface SST in the EEP to decrease by 2.0 to 1.7 Ma. This ultimat ely led to a zonal temperature gradient across the tropical Pacific that is characteristic of modern "normal" conditions (Ravelo et al., 2004, 2006; Federov et al., 2006). Ocean atmosphere interactions strengthened the equatorial Walker circulation and i ncreased cloud cover over the Pacific, thereby increasing albedo and enhancing global cooling during the Plio Pleistocene transition. Changes in the Pacific Ocean, coupled with the closure of the CAS and subsequent strengthening of the Loop and Gulf Strea m Currents coincide with an expansion of northern hemisphere continental ice (Ravelo et al., 2004; Federov et al, 2010). Despite different boundary conditions from the Pliocene (such as open seaways

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36 and northern hemisphere glaciers), the current trend of global warming could cause the Pacific equatorial temperature gradient to destabilize and revert to Pliocene conditions (Federov et al., 2006). Global warming could lead to a permanent deepening of the thermocline in the EEP, shutting down upwelling, weak ening Walker Circulation, decreasing cloud cover (and albedo), and creating a new perennial EL Ni–o like state in the Pacific Ocean (Federov et al., 2006). 2.5 Modern Nutrient Sources Nitrogen (N) and phosphorus (P) are identified as limiting nutrients fo r nearshore marine communities along the southwest Florida coast (Lapointe, 1989; McCormick et al., 1996; Fourqurean and Zieman, 2002). Average marine phosphate (PO 4 SW ) concentrations range from 0.04 "mol/kg ( 1 # = 0 .04) in an open marine setting along th e Florida Shelf to 0.34 "mol/kg ( 1 # = 0 .5) in lagoonal coastal areas, with average concentrations reaching 5.64 "mol/kg ( 1 # = 3.7 ) in highly restricted, low circulation upper estuaries, suc h as Hillsborough Bay (Table 2.1 ) (EPCHC, SERC FIU).

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37 Table 2. 1 : Marine phosphate concentrations from south Florida. (Data provided by SERC FIU and EPCHC) Location PO 4 SW ( "mol/kg) n 1 # Biscayne Bay 0.036 4412 0.038 Florida Bay 0.045 211 0.042 Rookery Bay 0.34 3548 0.45 Ten Thousand Islands 0.24 432 8 0.24 Southwest Florida Shelf 0.041 2383 0.037 Dry Tortugas 0.031 740 0.048 Hillsborough Bay 5.64 2898 3.73 Old Tampa Bay 1.93 4002 2.13 Middle Tampa Bay 2.58 2969 3.19 Lower Tampa Bay 0.66 2334 0.85 Sources for nutrients in the nearshore marine s ystem of the southwest Florida coast include periodic upwelling, submarine groundwater discharge (SGD), and riverine input (Paluszkeiwicz et al., 1983; McCormick et al., 1998; Wetzel et al., 2005). Periodic upwelling along the west coast of Florida is ass ociated with cyclonic eddies separated from the Loop Current (Paluszkeiwicz et al., 1983; Hamilton and Lee, 2005). These cold core eddies separate from the Loop Current and meander shoreward of the Loop Current along the west Florida shelf (Vukovich, 198 6, 2007; ChŽrubin et al., 2006; Barth et al., 2008). The eddies are characterized by localized high planktonic productivity (Yoder et al.,

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38 1981) and high nutrients, such as PO 4 SW concentration of 0.40 "mol/kg at 100 m depth (Paluszkeiwicz et al., 1983). The karstic limestone bedrock of the Florida Platform creates a highly permeable aquifer system, and the hydraulic head of the aquifer drives SGD in the nearshore marine environment (Corbet et al., 1999; Taniguchi et al., 2002; McCoy and Corbett, 2009). Previously overlooked as significant contributors to coastal systems (e.g. Taniguchi et al., 2002), regions of SGD are now identified along the west Florida Gulf coast and in Florida Bay as sources for nearshore marine nutrients (Kayser 1995; Corbet et al. 1999; Wetzel et al., 2005; Kroeger et al., 2007). In Tampa Bay, saline groundwater PO 4 is 15 "mol/kg ( 1 # = 15 ), and nutrient fluxes due to SGD are substantial compared to river fluxes (Kroeger et al., 2007). During the wet season (June through Septe mber), riverine discharge is another nutrient source for nearshore marine environments along the southwest Florida coast (McCormick et al., 1998; Rudnick et al., 1999). As is evident in Rookery Bay (Figure 1.1), nutrient loading primarily associated with river discharge decreases as salinity increases (Figure 2.10) (SERC FIU). While an inverse relationship between PO 4 SW and salinity is statistically significant in Rookery Bay, anthropogenic alterations of the hydrologic regime of the estuary systems of s outhwest Florida can affect this relationship (Hecker, 2005). Modern nutrient delivery to the nearshore marine systems in SW Florida is heavily altered by anthropogenic influences, such as sewage and storm drain discharge,

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39 agricultural waste and runoff, a nd restricted flow due to structure and canal construction (Smith et al., 1989; Brewster Wingard and Ishman, 1999; Fourqurean and Robblee, 1999; Hecker, 2005). Figure 2.10 : Linear regression between salinity and marine phosphate concentration in Rookery Bay. (Data provided by SERC FIU). 2.6 Florida Shell Beds Pliocene and Pleistocene precipitation patterns and nutrients are inferred from the geochemical analysis of fossils from the Florida shell beds. The Plio Pleistocene shell beds of Florida were d eposited during an interval of dramatic global climate change and potentially record regional signals of teleconnection shifts, especially ENSO, through sedimentary, faunal, and geochemical proxies. Overall, the Florida shell beds consist of shelly sands limestones, and marls representative of nearshore marine environments and significantly exposed only at the numerous aggregate quarries of southern peninsula Florida. Most workers have divided these deposits into four formations based on biostratigraphy (Figure

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40 2.11) (Petuch, 1982; Vermeij, 2005; Lyons, 1991). Additionally, the fossil beds described from quarries in Sarasota (southwest Florida) have been further sub divided into 11 numbered beds (Petuch, 1982). The Pliocene Tamiami Formation consists o f the Sarasota Member (Petuch's bed 11 in Sarasota), the Buckingam Member (Petuch's bed 10 in Sarasota), and the Pinecrest Beds (Petuch's beds 9 2 in Sarasota). The Pinecrest Beds are sub divided into the Lower Pinecrest Member (beds 9 5 in Petuch, 19 82), and the upper Pinecrest Beds (beds 2 4 from Petuch, 1982), also referred to as the time equivalent Fruitville and Golden Gate Members (Vermeij, 2005). The lowermost Pleistocene (Gelasian) Caloosahatchee Formation (Petuch's bed 1 in Sarasota) overli es the Pinecrest beds, which is overlain by the lower Pleistocene (Gelasian and Calabrian) Bermont Formation (figure 2.11). The lower member of the Tamiami Formation is differentiated from the other shelly formations by relatively higher siliciclastic con tent and moldic aragonitic fauna, whereas the Bermont beds are differentiated from the Caloosahatchee by the mollusk fauna it contains (Lyons, 1991). Using isotope ratio dating (U series and Sr series) and biostratigraphic correlation with other dated fos siliferous deposits along the Atlantic coastal plain, ages are assigned to each of the units (Lyons, 1991). The Bermont Fm. was deposited between 1.1 to 1.6 Ma, the Caloosahatchee Fm. was deposited between 1.8 to 2.5 Ma, and the Pinecrest Member was depos ited from 3.0 to 3.5 Ma (Lyons, 1991).

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41 Figure 2.11 : Florida stratigraphic column. The Tamiami, Caloosahatchee, and Bermont Fms. are depicted (after Lyons et al., 2001). Each unit formed when sea level was higher than present, and the depositional en vironmental, based on ostracode, foraminiferal, and mollusk faunal assemblages (Petuch, 1982; Allmon, 1993; Willard et al., 1993), the occurrence of taphonomically abraded fossils indicative of depth above wave base (Emslie et al., 1996), and silica salts representing a lagoonal environment (Meyer et al., in prep). Previous research suggests that the agent of deposition for these dense shell beds was primarily storms, or that storms were only partly

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42 responsible, and what is seen today is the result of curr ent winnowing (Geary and Allmon, 1990; Ketcher and Allmon, 1993). Additionally, the high abundance of fossil shell s could have been due to an abundance of nutrients and overall high productivity (Petuch, 1982; Allmon et al., 1996; Allmon, 2001). The Pine crest Member, Caloosahatchee Fm., and Bermont Fm. contain abundant, exceptionally well preserved fossil material. In addition to a multitude of gastropod and bivalve species, several species of solitary corals are also found in each of these units, includ ing Siderastrea spp. corals. 2.7 Florida Paleoenvironmental and Paleobiological Context The Plio Pleistocene fossil beds found in Florida's deposits document a regional extinction event whose cause has been intensely debated for decades (e.g. Stanley, 19 86; Allmon et al., 1993; Petuch, 1995) Stanley (1986) ruled out a drop in sea level as a driver of extinction, citing lower survivorship among Western Atlantic fauna along a broad continental shelf than eastern Pacific (San Diego) fauna along a narrow co ntinental shelf. Following the drop in sea level, the Western Atlantic fauna had a larger area for survival than the eastern Pacific fauna; therefore the reduction of the nearshore marine environment caused by a drop in sea level would have had little eff ect on the survivorship of the Western Atlantic fauna. Stanley (1986) attributed the extinction event to cooler temperatures, specifically the initiation of the first cold air winter outbreaks at the onset of Northern Hemisphere glaciation. Stenothermal species in Florida suffered a heavy extinction because they were unable to shift their geographic

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43 range south of Florida into the Caribbean (Stanley, 1986). Since then, a consensus view has developed based on the idea that the ecosystems collapsed due to nutrient reduction and loss of primary producers. This idea builds off the work by Woodring (1966), who hypothesized that, following a reorganization of oceanic circulation after the closure of the CAS, food supply and nutrients would have declined in the Caribbean. Allmon et al. (1996) speculated that the source of high nutrients in the Florida Pliocene could be either a globally higher level of phosphogenesis during the Pliocene, a more nutrient rich Atlantic Ocean prior to closure of the CAS, and/or a l ocalized upwelling zone along the continental shelf in what is now southwest Florida. While all three mechanisms are viable scenarios for high Pliocene nutrients followed by a nutrient decline at the Plio Pleistocene boundary, biological and geochemical f ossil evidence from the Florida Pliocene beds are interpreted as indicative of a localized upwelling zone (Jones and Allmon, 1995; Allmon et al., 1996). The proposed paleoceanographic mechanism responsible for the hypothesized upwelling zone is similar to modern coastal upwelling zones associated with eastern boundary currents (EBC). An EBC in the Pliocene Gulf of Mexico would have flowed southward next to the western Florida peninsula. Likewise, mean wind flow direction was equatorward and the associate d Ekman transport pushed water offshore, causing coastal upwelling and allowing for bottom water to upwell onto the continental shelf (Allmon et al., 1996).

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44 Following the closure of the CAS, the Loop Current in the Gulf of Mexico strengthened (Maier Reim er et al., 1990; Allmon et al., 1996), which increased the coastal pressure gradient along the southwest Florida Gulf Coast. An increased coastal pressure gradient could depress the thermocline near the coast, thus dissipating localized upwelling, similar to conditions observed along the western Australian coast (Allmon et al., 1996). The strengthening of the Loop Current intensifies the eddy driven upwelling that is occasionally observed in the modern southwest Floirda Gulf coastal environment (Paluszkie wicz et al., 1983; Vukovich, 1986; He and Weisberg, 2003; Barth et al., 2008). However, nutrients delivery by this process is considered minimal compared to the hypothesized Pliocene EBC driven upwelling region (Allmon et al., 1996). The loss of this upw elling system would have decreased nutrient availability in the nearshore marine system, thereby instigating the biotic changes associated with the Plio Pleistocene boundary (Jones and Allmon, 1995; Allmon et al., 1996). While the upwelling hypothesis pr ovides one explanation for nutrient sources during the Pliocene, alternative methods of nutrient delivery to the nearshore marine system exist, and the evidence supporting the upwelling theory is somewhat "ambiguous" (Allmon et al., 1996, p. 145). For exa mple, Allmon et al. (1996) used the presence of several turritellid dominated assemblages (TDA) in the Pinecrest Member as evidence of upwelling. While previously thought only to represent areas of upwelling, TDA's have since been documented in

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45 carbonate and deltaic environments, which suggests they are not a good upwelling indicator (Allmon, 1988; Allmon and Cohen, 2003). Jones and Allmon (1995) also report stable isotopes from the mollusks Turritella apicalis (from a TDA in the upper Pinecrest/Caloosah atchee Fm.) Turritella gladeensis (from a TDA in the Pinecrest Member) Mercenaria campechiensis (from the middle of the Pinecrest Member), and Carolinapectin eboreus (from the middle of the Pinecrest Member) record upwelling signals. In general, an upwe lling region is characterized by cold water enriched in nutrients. That upwelling signal translates to 18 O enriched (higher) 18 O values coinciding with 13 C depleted (lower) 13 C values in the isotopic record of mollusk shells. However, this isotopic upwelling signature is not consistently found in Pinecrest shells and is also found with equal, if not increase d, frequency in younger material, suggesting that upwelling was not specifically indicative of the Pliocene in Florida (Jones and Allmon, 1995; Kasprak et al., 2007). The majority of the invertebrate evidence employed by Allmon et al. (1996) is simply indi cative of nutrient rich, cool water. While an upwelling system could explain this scenario, another mechanism that might drive a high influx of nutrients into the nearshore environment is heavy fluvial runoff. The Pliocene "Super El Ni–o" offers a mechan ism to increase winter precipitation (and, consequently, total annual precipitation) in the Pliocene. Miocene and Pliocene siliciclastic sediments draped over the carbonate bedrock in southwest Florida show signs of higher "pluvial" transport during those periods (Hine et al., 2009).

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46 During sea level highstands, sediments were deposited into prograding deltas on the carbonate bedrock throughout the central and southern Florida Peninsula (Hine et al., 2009). During periods of sea level lowstands, multipl e rivers drained into Tampa Bay and Charlotte Harbor, depositing deltaic sediments in those basins. No significant delta formation is apparent in Tampa Bay or Charlotte Harbor in the modern environment, suggesting that pluvial transport in the Miocene and Pliocene would have exceeded that which is observed today, presuming that regional precipitation is higher than observed in the modern environment (Hine et al., 2009). By the Pleistocene, a carbonate deposition system returned to south Florida, indicatin g the end of the pluvial transport of siliciclastic sediment across the Florida Platform (Hine et al., 2009). In addition to an increase in sediment transport, intensified terrestrial nutrient transport to the nearshore marine system may have been common i n the Miocene and Pliocene. As is evident in modern Florida Bay (Wetzel et al., 2005), groundwater may have been transported through the phosphorite bearing sediments of the Miocene Hawthorn Group, potentially bringing P to the nearshore marine system thr ough SGD or groundwater influenced river discharge. However, high nutrients in modern marine environments that create eutrophic conditions are usually characterized by lower species diversity ( Jrgensen and Richardson, 1996; Ršnnberg and Bonsdorff, 2004), contrary to the high species diversity observed in the late Pliocene fossil deposits (Allmon et al., 1993; Petuch, 1995).

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47 2.8 Chapter references Allmon, WD, 1988. Ecology of recent turritellid gastropods (Prosobranchia, Turritellidae): Current knowledge and paleontological implications. Palaios 3:259 284 Allmon, WD, 1993. Age, environment and mode of deposition of the densely fossiliferous Pinecrest Sand (Pliocene of Florida): Implications for the role of biological productivity in shell bed formatio n, Palaios 8(2):183 201 Allmon, WD, 2001. Nutrients, temperature, disturbance, and evolution: a model for the late Cenozoic marine record of the western Atlantic. Palaeogeography, Palaeoclimatology, Palaeoecology 166:9 26 Allmon, WD, and PA Cohen, 20 03. Paleoecological significance of a turritellid gastropod dominated limestone in the Lower Cretaceous of Texas. GSA Abstracts with Programs 35:502 Allmon, WD, G Rosenberg, RW Portell, KS Schindler, 1993. Diversity of Atlantic coastal plain mollusks since the Pliocene. Science 260(5114):1626 1629 Allmon, WD, SD Emslie, DS Jones, GS Morgan, 1996. Late Neogene oceanographic change along Florida's west coast: Evidence and mechanisms. Journal of Geology 104:143 162 Appenzeller, C, TF Stocker, M Ank lin, 1998. North Atlantic Oscillation dynamics recorded in Greenland ice cores. Science 282(5388):446 449 Barlow, M, S Nigam, EH Berbery, 2001. ENSO, Pacific Decadal Variability, and U.S. summertime precipitation, drought, and stream flow. Journal of Climate 14:2105 2128 Barth, A., A. Alvera Azc‡rate, and R. H. Weisberg, 2008. A nested model study of the Loop Current generated variability and its impact on the West Florida Shelf, Journal of Geophysical Research 113 :doi:10.1029/2007JC004492 Bec kage, B, WJ Platt, MG Slocum, B Panko, 2003. Influence of the El Ni–o Southern Oscillation on fire regimes in the Florida Everglades. Ecology 84(12):3124 3130 Billups, K, AC Ravelo, JC Zachos, RD Norris, 1999. Link between oceanic heat transport, ther mohaline circulation, and the Intertropical Convergence Zone in the early Pliocene Atlantic. Geology 27(4):319 322

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48 Billups, K, 2002. Late Miocene through early Pliocene deep water circulation and climate change viewed from the sub Antarctic South Atlan tic. Palaeogeography, Palaeoclimatology, Palaeoecology 185:287 307 Bjerknes, J, 1969. Atmospheric teleconnections from the equatorial Pacific. Monthly Weather Review 97:163 172 Bonham, SG, AM Haywood, DJ Lunt, M Collins, U Sazlmann, 2009. El Ni–o Southern Oscillation, Pliocene climate and equifinality. Philosophical Transactions of the Royal Society A 367:127 156 Bove, MC, JB Elsner, CW Landsea, X Niu, JJ O'Brien,1998. Effect of El Ni–o on U.S. landfalling hurricanes, revisited. Bulletin of th e American Meteorological Society 79:2477 2482. Brewster Wingard, G, and SE Ishman, 1999. Historical trends in salinity and substrate in central Florida Bay: A paleoecological reconstruction using modern analogue data. Estuaries 22(2B):369 383 Cane, MA 2005. The evolution of El Ni–o, past and future. Earth and Planetary Science Letters 230:227 240 Cane, M, and P Molnar, 2001. Closing of the Indonesian seaway as a precursor to east African aridification around 3 4 million years ago. Nature 411:157 162 Carlson, PR, LA Yarbro, K Madley, H Arnold, M Merello, L Vanderbloemen, G McRae, MJ Durako, 2003. Effect of El Ni–o on demographic, morphological, and chemical parameters in Turtle Grass ( Thalassia testudinum ): An unexpected test of indicators. En vironmental Monitoring and Assessment 81:393 408 ChŽrubin, LM, Y Morel, EP Chassignet, 2006. Loop current ring shedding: The formation of cyclones and the effect of topography. Journal of Physical Oceanography 36:569 591 Cobb, KM, CD Charles, H Cheng RL Edwards, 2003. El Ni–o/Southern Oscillation and tropical Pacific climate during the last millennium. Nature 424:271 276 Collins, M, S An, W Cai, A Ganachaud, E Guilyardi, F Jin, M Jochum, M Lengaigne, S Power, A Timmermann, G Vecchi A Wittenberg 2010. The impact of global warming on the Tropical Pacific Ocean and El Ni–o. Nature Geoscience 3:391 397

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49 Cook ER, 2003. Multi proxy reconstructions of the North Atlantic Oscillation index: a critical review and a new well verified winter NAO index reconstruction back to AD 1400. In Hurrell, JW, Y Kushnir, G Ottersen, MH Visbeck (Eds.) The North Atlantic Oscillation. American Geophysical Union, Geophysical Monograph 134, AGU, pp. 63 79. Cook, ER, RD D'Arrigo, JE Cole, DW Stahle, R Villalba, 2000. T ree ring records of past ENSO variability and forcing In Diaz, HF, and V Markgraf, (Eds.) El Ni–o and the Southern Oscillation: Multiscale variability and global and regional impacts. Cambridge, Cambridge University Press, pp. 297 323. Cooper, HJ, M Gars tang, J Simpson, 1982. The diurnal interaction between convection and peninsular scale forcing over South Florida. Monthly Weather Review 110:486 503 Corbett, DR, J Chanton, W Burnett, K Dillon, C Rutkowski, J W Fourqurean, 1999. Patterns of Groundwat er Discharge into Florida Bay. Limnology and Oceanography 44(4):1045 1055 Delworth, TL, and ME Mann, 2000. Observed and simulated multidecadal variability in the Northern Hemisphere. Climate Dynamics 16:661 676 Dia, A, A Hu, GA Meehl, WM Washinton, WG Strand, 2005. Atlantic thermohaline circulation in a coupled general circulation model: Unforced variations versus forced changes. Journal of Climate 18: 3270 3293 Diaz, HF, MO Hoerling, JK Eischied, 2001. ENSO variability, teleconnections and clim ate change. International Journal of Climatology 21 :1845 1862 Dijkstra, HA, L te Raa, M Schmeits, J Gerrits, 2006. On the physics of the Atlantic Multidecadal Oscillation. Ocean Dynamics 56:36 50 Dima, M and G Lohmann, 2007. A Hemispheric Mechanism for the Atlantic Multidecadal Oscillation. Journal of Climate 20:2706 2719 Driscoll, NW and GH Haug, 1998. A short circuit in thermohaline circulation: A cause for Northern Hemisphere glaciation? Science 282:436 438. Duever MJ, JF Meeder, LC Meeder, JM McCollom, 1997. The climate of south Florida and its role in shaping the Everglades ecosystem In: Davis, SM and JC Ogden (Eds.), Everglades, the ecosystem and its restoration. Boca Raton, FL: St. Lucie Press, pp 225 248.

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50 Emile Geay, J, MA Cane, R Seager, A Kaplan, P Almasi, 2007. El Ni–o as a mediator of the solar influence on climate. Paleoceanography 22:doi:10.129/2006PA001304 Emslie, SD, WD Allmon, FJ Rich, JH Wrenn, SD de France, 1996. Integrated taphonomy of an avian death assemblage in marine sediments from the late Pliocene of Florida. Palaeogeography, Palaeoclimatology, Palaeoecology 124:107 136 Enfield, DB and AM Mestas Nu–ez, 2000. Global modes of ENSO and non ENSO sea surface temperature variability and their associations with c limate In Diaz, HF and V Markgraf (Eds.) El Ni–o and the Southern Oscillation: Multiscale variability and global and regional impacts: Cambridge, Cambridge University Press, p. 89 112. Enfield, DB, AM Mestas Nu–ez, PJ Trimble, 2001. The Atlantic Multidec adal Oscillation and its relationship to rainfall and river flows in the continental U.S. Geophysical Research Letters 28(10):2077 2080 EPCHC. Environmental Protection Commission of Hillsborough County, Water Monitoring Quality Sampling Information from 1974 to 2008. Federov, A, P Dekens, M McCarthy, AC Ravelo, P deMenocal, M Barreiro, R Pacanowski, S Philander, 2006. The Pliocene Paradox (Mechanisms for a Permanent El Ni–o). Science 312:1485 1489 Fedorov, AV, CM Brierley, K Emanuel 2010. Tropical cyclones and permanent El Ni–o in the early Pliocene epoch. Nature 463:1066 1071 Fourqurean, JW and MB Robblee, 1999. Florida Bay: A History of Recent Ecological Changes. Estuaries 22(2B):345 357 Fourqurean, JW and JC Zieman, 2002. Nutrient conten t of the seagrass Thalassia testudinum reveals regional patterns of relative availability of nitrogen and phosphorus in the Florida Keys USA. Biogeochemistry 61: 229 245 Geary, DH and WD Allmon,1990. Biological and Physical Contributions to the Accumul ation of Strombid Gastropods in a Pliocene Shell Bed. Palaios 5(3):259 272

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51 Gibbard, PL, MJ Head, MJC Walker, the Subcommission on Quaternary Stratigraphy, 2010. Formal ratification of the Quaternary System/Period and the Pleistocene Series/Epoch wit h a base at 2.58 Ma. Journal of Quaternary Science 25:96 102 Gray, ST, LJ Graumlich, JL Betancourt, GT Pederson, 2004. A tree ring based reconstruction of the Atlantic Multidecadal Oscillation since 1567 A.D. Geophysical Research Letters 31:doi:10.1029 /2004GL019932 Gray, WM, 1984. Atlantic seasonal hurricane frequency. Part 1: El Ni–o and 30 mb quasi biennial oscillation influences. Monthly Weather Review 112:1649 1668 Hagemeyer, BC, 2006. ENSO, PNA, and NAO scenarios for extreme storminess, rai nfall, and temperature variability during the Florida dry season. Proceedings of the 18th Conference on Climate Variability and Change, American Meteorological Society P2.4 Hamilton, P and TN Lee, 2005. Eddies and jets over the slope of the northeast G ulf of Mexico In: Sturges, W and A Lugo Fernandez den (Eds.), Circulation in the Gulf of Mexico: Observations and Models American Geophysical Union: Geophysical Monograph Series 161:123 142 Haywood, AM, and PJ Valdes, 2004. Modeling Pliocene warmth: c ontribution of atmosphere, oceans and cryosphere. Earth and Planetary Science Letters 218:363 377 Haywood, AM, BW Sellwood, PJ Valdes, 2000. Regional warming: Pliocene (3 Ma) paleoclimate of Europe and the Mediterranean. Geology 28(12):1063 1066 Hay wood, AM, PJ Valdes, V Peck, D Lunt, 2006. A permanent El Ni–o Like state during the Pliocene? AGU Fall Meeting Abstracts/Geophysical Research Abstracts 8:76 He, R and RH Weisberg, 2003. A Loop Current intrusion case student on the West Florida Shelf. Journal of Physical Oceanography 33:465 477 Hecker, J, 2005. Estuaries report card for southwest Florida. Conservancy of Southwest Florida, 203pp.

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52 Hine, AC, B Suthard, SD Locker, KJ Cunningham, DS Duncan, M Evans, RA Morton, RA, 2009. Karst subb asins and their relationship to cross Florida transport of Tertiary siliciclastics. In: Swart, PK, GP Eberli, J McKenzie (Eds.), Perspectives in Sedimentary Geology: A Tribute to the Career of Robert Nathan Ginsburg, Sedimentology. Huag, GH, and R Tiedema nn, 1998. Effects of the formation of the Isthmus of Panama on Atlantic Ocean thermohaline circulation. Nature 393:673 676. Hurell, JW, 1995. Decadal trends in the North Atlantic Oscillation: Regional temperatures and precipitation. Science 269(5224): 676 679 Hurell, JW, 2003. An overview of the North Atlantic Oscillation. In Hurrell, JW, Y Kushnir, G Ottersen, MH Visbeck (Eds.,) The North Atlantic Oscillation. American Geophysical Union, Geophysical Monograph 134, AGU, pp. 1 10 Hurell, JW, and H van Loon, 1997. Decadal variations in climate associated with the North Atlantic Oscillation. Climate Change 36:301 326 Hurrell, JW, Y Kushnir, G Ottersen, M Visbeck, 2003. An Overview of the North Atlantic Oscillation. The North Atlantic Oscillation : Climatic Significance and Environmental Impact Geophysical Monograph 134. Jones, DS, and WA Allmon, 1995. Records of upwelling, seasonality and growth in stable isotope profiles of Pliocene mollusk shells from Florida. Lethaia 28:61 74 Jones, PD, T Jonsson, D Wheeler, 1998. Extension to the North Atlantic Oscillation using early instrumental pressure observations from Gibraltar and southwest Iceland. International Journal of Climatology 17:1433 1450 Jrgensen, BB and K Richardson, 1996. Eutrophi cation: Definition, History and Effects. In: Jrgensen, BB and K Richardson (Eds.) Eutrophication in coastal marine ecosystems. Coastal and Estuarine Studies 52. Washington, DC: American Geophysical Union, Washington, DC: 1 19. Kasprak, AH, WA Weinlein, JL Sliko, PJ Harries, GS Herbert, EA Oches, RW Portell, and MC Coe, 2007. Stable isotopic investigation of coastal upwelling as an explanation for high Pliocene productivity on Florida's west coast. Geological Society of America Abstracts with Program 40 73 Kayser, RA, 1995. An investigation of climatic and environmental change during the middle Pliocene in southwest Florida using the elemental geochemistry of a pristine fossil coral. M.S. Thesis, University of South Florida, Tampa, FL, 71pp.

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53 Kelly, M H, and JA Gore, 2008. Florida river flow patterns and the Atlantic Multidecadal Oscillation. River Research and Applications 24:598 616 Kerr, RA, 2000. A North Atlantic climate pacemaker for the centuries. Science 288(5473):1984 1986 Ketcher, K and WD Allmon, 1993. Environment and Mode of Deposition of a Pliocene Coral Bed: Coral Thickets and Storms in the Fossil Record. Palaios 8(1):3 17 Knight, JR, CK Folland, AA Scaife, 2006. Climate impacts of the Atlantic Multidecadal Oscillation. Geophys ical Research Letters 31:doi:10.1029/2006GL026242 Kroeger, KD, PW Swarzenski, WJ Greenwood, C Reich, 2007. Submarine groundwater discharge to Tampa Bay: Nutrient fluxes and biogeochemistry of the coastal aquifer. Marine Chemistry 104:85 97 Lapointe, BE, 1989. Macroalgal production and nutrient relations in oligotrophic areas of Florida Bay. Bulletin of Marine Science 44(1):312 323 Lu, R, B Dong, H Ding, 2006. Impact of the Atlantic Multidecadal Oscillation on the Asian summer monsoon. Geophysica l Research Letters 33:doi:10.1029/2006GL027255 Lyons, WG, 1991. Post Miocene species of Latiris Montfort, 1810 (Molluscs: Fasciolariidae) of southern Florida, with a review of regional biostratigraphy. Bulletin of the Florida Museum of Natural History, Biological Sciences 35(3):131 208 Maier Reimer, E, U Mikolajewicz, TJ Crowley, 1990. Ocean general circulation model sensitivity experiment with an open Central American Isthmus. Paleoceanography 5:349 366 Mantua, NJ, SR Hare, Y Zhang, JM Wallace, R C Francis, 1997. A Pacific interdecadal climate oscillation with impacts on salmon production. Bulletin of the American Meteorological Society 78:1069 1079 Marlow, JR, CB Lange, G Wefer, A Rosell MelŽ, 2000. Upwelling intensification as part of the Pli ocene Pleistocene climate transition. Science 290:2288 2291

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54 McCormick, PV, PS Rawlik, K Lurding, EP Smith, FH Sklar, 1996. Periphyton Water Quality Relationships along a Nutrient Gradient in the Northern Florida Everglades. Journal of the North America n Benthological Society 15(4):433 449 McCormick, PV, RBE Shuford, JG Backus, WC Kennedy, 1998. Spatial and seasonal patterns of periphyton biomass and productivity in the northern Everglades, Florida, U.S.A. Hydrobiologia 362: 185 208 McCoy, CA and D R Corbett, 2009. Review of submarine groundwater discharge (SGD) in coastal zones of the Southeast and Gulf Coast regions of the United States with management implications. Journal of Environmental Management 90(1):644 651 Mestas Nu–ez, AM, and DB Enfie ld, 2001. Eastern Equatorial Pacific SST Variability: ENSO and Non ENSO Components and Their Climatic Associations. Journal of Climate 14:391 402. Meyer, MB, RW Portell, PJ Harries, J Schiffbauer, In preparation Paleoenvironmental reconstructions of P liocene southwest Florida using silica spheres. Molnar, P, and MA Cane, 2002. El Ni–o's tropical climate and teleconnections as a blueprint for pre Ice Age climates. Paleoceanography 17(2): doi:10.1029/2001PA000663 Molnar, P, and MA Cane, 2007. Early Pliocene (pre Ice Age) El Ni–o like global climate; Which El Ni–o? Geosphere 3(5):337 365 Moulin, C, CE Lambert, F Dulac, U Dayan, 1997. Control of atmospheric export of dust from North Africa by the North Atlantic Oscillation. Nature 387:691 694 N CDC Website. National Climatic Data Center. Data accessed at http://www7.ncdc.noaa.gov/CDO/CDODivisionalSelect.jsp#. NOAA Website. National Weather Service Climate Prediction Center. Last Updated May 8, 2008. Accessed at http://www.cpc.noaa.gov/data/tel edoc/teleintro.shtml. NOAA Website, 2010. Accessed at http://www.noaa.gov/. Nott, MP, DF Desante, RB Siegel, P Pyle, 2002. Influences of the El Ni–o/Southern Oscillation and the North Atlantic Oscillation on avian productivity in forests of the Pacific Northwest of North America. Global Ecology & Biogeography 11 :333 342

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55 Palmer, WC, 1965. Meteorological drought. Research Paper No. 45 U.S. Weather Bureau. 58pp. Paluszkiewicz, T, LP Atkinson, ES Posmentier, CR McClain, 1983. Observations of a Loop C urrent Frontal Eddy Intrusion onto the West Florida Shelf. Journal of Geophysical Research 88(C14):9639 9651 Petuch, EJ, 1982. Notes on the molluscan paleoecology of the Pinecrest Beds at Sarasota, Florida with the description of Pyruella, a stratigrap hically important new genus (Gastropoda: Melongenidae). Proceedings of the Academy of Natural Sciences of Philadelphia 134:12 30 Petuch, EJ, 1995. Molluscan diversity in the Late Neogene of Florida: Evidence for a two staged mass extinction. Science 2 70:275 277 Ravelo AC DH Andreasen, M Lyle, AO Lyle MW Wara, 2004. Regional climate shifts caused by gradual global cooling in the Pliocene epoch. Nature 429:263 267 Ravelo, AC, PS Dekens, M McCarthy, 2006. Evidence for El Ni–o like conditions dur ing the Pliocene. GSA Today 16:4 11 Rea, DK, 1998. The paleoclimatic record provided by eolian deposition in the deep sea: the geologic history of wind. Review of Geophysics 32(2):159 195 Rind, D, J Perlwitz, P Lonergan, J Lerner, 2005. AO/NAO respo nse to climate change: 2. Relative importance of low and high latitude temperature changes, Journal of Geophysical Research 110: doi:10.1029/2004JD005686 Rodbell, DT, GO Seltzer, DM Anderson, MB Abbott, DB Enfield, JH Newman, 1999. An 15,000 year record of El Ni–o driven alluviation in southwestern Ecuador. Science 283(5401):516 520 Ršnnberg, C and E Bonsdorff, 2004. Baltic Sea eutrophication: area specific ecological consequences. Hydrobiologia 514:227 241 Ropelewski, CF and MS Halpert, 1986. North American precipitation and temperature patterns associated with the El Ni–o/Southern Oscillation (ENSO). Monthly Weather Review 114:2352 2362 Rudnick, DT, Z Chen, DI Childers, JN Boyer, YDI Fontaine, 1999. Phosphorus and nitrogen inputs to Florid a Bay: The importance of the Everglades watershed. Estuaries 22:398 416

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56 SERC FIU. Data were provided by the SERC FIU Water Quality Monitoring Network, which is supported by the SWFWD/SERC Cooperative Agreement #4600000352 as well as EPA Agreement #X7 964 19603 3. Schmidt, N, and ME Luther, 2002. ENSO Impacts on Salinity in Tampa Bay, Florida. Estuaries 25:976 984 Schmidt, N, EK Lipp, JB Rose, ME Luther, 2001. ENSO Influences on Seasonal Rainfall and River Discharge in Florida. Journal of Climate 14: 615 628 Shuanglin, LI, GT Bates, 2007. Influence of the Atlantic Multidecadal Oscillation on the winter climate of East China. Advances in Atmospheric Sciences 24(1):126 135 Smith, TJ, JH Hudson, MB Robblee, GVN Powell, PJ Isdale, 1989. Freshwater f low from the Everglades to Florida Bay: a historical reconstruction based on fluorescent banding in the coral Solenastrea bouroni Bulletin of Marine Science 44(1):274 282 Stanley, SM, 1986. Anatomy of a Regional Mass Extinction: Plio Pleistocene Decim ation of the Western Atlantic Bivalve Fauna. Palaios 1:17 36 Stenseth, NC, G Ottersen, JW Hurrell, A Mysterud, M Lima, KS Chan, NG Yoccoz, B Adlandsvik, 2003. Studying climate effects on ecology through the use of climate indices: the North Atlantic Os cillation, El Ni–o Southern Oscillation and beyond. Proceedings of the Royal Society of London B:doi 10.1098/rspb.2003.2415 SWFWMD. Southwest Florida Water Management District Hydrologic Data. Taniguchi, M WC Burnett, JE Cable, JV Turner 2002. Inve stigation of submarine groundwater discharge. Hydrologic Processes 16:2115 2129 Timmermann, A, M Latif, R Voss, A Grštzner, 1998. Northern Hemisphere interdecadal variability: A coupled air sea mode. Journal of Climate 11: 1906 1931 Trenberth, KE, 1 997. The definition of El Ni–o. Bulletin of the American Meteorological Society 78(12):2771 2777 Tudhope, AW, CP Chilcott, M T McCulloch, ER Cook, J Chappell, R M Ellam, DW Lea, JM Lough, GB Shimmield 2001. Variability in the El Ni–o Southern Oscillati on through a glacial interglacial cycle. Science 291:1511 1517

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57 van Beynen, PE, Y Asmerom, V Polyak, L Soto, JS Polk, 2007. Variable intensity of teleconnections during the late Holocene in subtropical North America from an isotopic study of speleothem from Florida. Geophysical Research Letters 34: doi:10.1029/2007GL031046 van Loon, H and JC Rogers, 1978. The seesaw in winter temperatures between Greenland and northern Europe. Part I: General Description. Monthly Weather Review 106:296 310 Vermeij, GJ, 2005. One way traffic in the western Atlantic: causes and consequences of Miocene to early Pleistocene molluscan invasions in Florida and the Caribbean. Paleobiology 31(4):624 642 Visbeck, MH, JW Hurrell, L Polvani, HM Cullen, 2001. The North Atl antic Oscillation: Past, present, and future. Proceedings of the Natural Academy of Sciences 98(23): 12876 12877. Vukovitch, F, 1986. Aspects of the behavior of cold perturbations in the eastern Gulf of Mexico: A case study. Journal of Physical Oceanogr aphy 16:689 707 Vukovitch, FM, 2007. Climatology of Ocean Features in the Gulf of Mexico Using Satellite Remote Sensing Data. Journal of Physical Oceanography 37:175 188 Wallace, JM and DS Gutzler, 1981. Teleconnections in the geopotential height f ield during the Northern Hemisphere winter. Monthly Weather Review 109:784 812 Wang, C, 2000. A unified oscillator model for the El Ni–o Southern Oscillation. Journal of Climate 14:98 115 Wang, C and DB Enfield, 2001. The tropical Western Hemisphe re warm pool. Geophysical Research Letters 28(8):1635 1638 Wara, MW, AC Ravelo, ML Delany, 2005. Permanent El Ni–o Like Conditions During the Pliocene Warm Period. Science 309:758 761 Webster, PJ and S Yang, 1992. Monsoon and ENSO: Selectively inte ractive systems. Quarterly Journal of the Royal Meteorological Society 118:877 926 Wetzel, PR, AG van der Valk, S Newman, DE Gawlik, TT Gann, CA Coronado Molina, Dl Childers, FH Sklar, 2005. Maintaining tree islands in the Florida Everglades: Nutrient redistribution is the key. Frontiers in Ecology and the Environment 3(7):370 376

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58 Williard, DA, TM Cronin, SE Ishman, RJ Litwin, 1993. Terrestrial and marine records of climatic and environmental changes during the Pliocene in subtropical Florida. Geol ogy 21(8):679 682 Wolter, K, 1987. The Southern Oscillation in surface circulation and climate over the tropical Atlantic, Eastern Pacific, and Indian Oceans as captured by cluster analysis. Journal of Climate and Applied Meteorology 26: 540 558 Wolter K and MS Timlin, 1993. Monitoring ENSO in COADS with a seasonally adjusted principal component index. Proceedings of the 17th Climate Diagnostics Workshop Norman, OK p. 52 57. Woodring, W, 1966. The Panama land bridge as a sea barrier. Proceedings o f the American Philosophical Society 110:425 433 Yoder, JA, LP Atkinson, TN Lee, HH Kim, CR McClain, 1981. Role of Gulf Stream frontal eddies in forming phytoplankton patches on the outer southeastern shelf. Limnology and Oceanography 26(6):1103 1110. Yoshida, S, T Morimoto, T Ushio, Z Kawasaki, 2007. ENSO and convective activities in Southeast Asia and western Pacific. Geophysical Research Letters 34:doi:10.1029/2007GL030758

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59 Chapter 3 Potential and P itfalls of O btaining D ecadal C limate R ecords from I sotope S clerochronology of Large P redatory M ollusks 3.1 Abstract Stable isotope sclerochronology of mollusk shells has been used for seasonal scale paleoclimate reconstructi ons for decades, but the technique suffers from biological effects such as growth cessations, which potentially bias the seasonal record, and short life spans, which do not effectively record the sub decadal climate oscillations that are of primary interes t. In this study, we present stable isotope sclerochronology on tw o gastropod species, one active in the winter and the other active in the summer, from the Florida Gulf coast in the hope of establishing a multi year record of seasonality. In both Busyc on sinistrum and Fasciolaria tulipa, measured 18 O were similar to corresponding predicted 18 O summer values, but offset by 1.4 1.9 to corresponding predicted 18 O winter values. The oxygen isotope records the specimens reveal that both species cease shell growth during the winter months d espite o pposing seasons of feeding activity. F asciolaria tulipa a summer feeder, grows during its active predatory season, which makes available a thin, newly formed lip to be ever present for its wedging style predation on bivalve prey. Busycon sinistrum a wi nter feeder with a chipping style predation, does not grow during its active

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60 predatory season, instead growing and reinforcing its lip during what was once thought to be the dormant summer season. Neither stable isotope profile provides information on win ter environmental parameters. The timing of shell growth, which, in some cases, is influenced by predation style, should be co nsidered during interpretation of g eochemical information derived from mollusks 3 .2 Introduction Building off the pioneering wo rk of Epstein et al. (1951, 1953), mollusk shells have long been used as geochemical archives of key environmental variables needed for paleoclimate reconstructions, including temperature and its seasonality variability (e.g., Krantz, 1990; Bice et al., 19 96; Kirby et al., 1998; Andreasson and Schmitz, 2000; Kobashi et al., 2001; Surge et al., 2003; Schšne et al., 2004 ). M ollusks are useful for studying climate variation as they occur over a wide latitudinal distribution ranging from the tropics (e.g., Gea ry et al., 1992) to high latitudes (e.g., Schšne et al., 2004) and at depths varying from nearshore marine to abyssal (Wefer and Berger, 1991). Additionally, pristine non altered fossil mollusks offer a unique, high resolution paleoclimate perspective. U nlike other climate archives, such as deep sea sediment cores, which can average climate over century or millennia, the accretionary growth of mollusks can record seasonal and even monthly climate resolution (e.g., Schšne et al., 2005). Using mollusks she lls for paleoclimate reconstructions can make it possible to contrast winter vs. summer temperatures and precipitation ( e.g., Surge et al., 2003 ), pinpoint the seasonal timing and annual frequency of

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61 upwelling events (Jones and Allmon, 1995), and potential ly, for long lived mollusks such as Arctica i slandica reconstruct changes in seasonality over decadal timescales ( Buick and Ivany, 2004; Schšne et al., 2005 ) The mollusk 18 O record is generally in equilibrium with surrounding seawater (Wefer and Berg er, 1991), but as with all biological archives, the mollusk isotope record is imperfect, and isolating an environmental signal from the geochemical record requires an understanding of information loss due to shell growth cessation related to physiological tolerance, endogenous timekeeping mechanisms, and ontonogenic growth trends (Geary et al., 1992; Vermeij and Signor, 1992; Goodwin et al., 2001; Elliot et al., 2003; Schšne, 2008). Periodic shell g rowth cessation s can be stimulated by endogenous rhythms ( such as circadian increments mimicking tidal fluctuations) or by environmental perturbations (Hall et al., 1974; Palmer, 1995; Jones and Quitmyer, 1996; Rensing et al., 2001; Elliot et al., 2003 ). Some observed growth cessation s in modern mollusks are reg ular and relatively predictable, such as semidiurnal (tidally influenced) cessation s, seasonal (above/below a temperature thresho ld) cessations (e.g., Krantz et al., 1987), and during spawning; however, other periods of growth cessation are caused by spora dic environmental perturbations (such as nutrient fluxes) and are sometimes difficult to detect in fossil specimens (Schšne 2008). Calibration studies are ideal for determining whether and how these factors affect the fidelity of the mollusk isotope prox y record ( e.g., Elliot et a l., 2003; Gillikin et al., 2005; Schšne 2008).

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62 Most mollusks are assumed to grow skeletal material during "optimal" conditions of temperature and salinity levels and food availability (Frank, 1969; Palmer, 1992; Jones and Quitmye r, 1996; Kirby et al., 1998; Curtis et al., 2000; Elliot et al., 2003; Selders et al., 2009). Among other environmental and physiological variables which govern s hell growth, food availability is considered one of the most important for several marine org anisms, including the barnacles, Balanus glandula and Chthamalus dalli (Sanford and Menge, 2001), and the mollusks, Macoma balthica (Thompson and Nichols, 1988), Phacosoma japonicum ( Schšne et al., 2003 ) Strombus gigas ( Radermacher et al., 2009 ), and A r ct ica i slandica ( Schšne et al., 2005 ) For example, r egardless of temperature or salinity changes, A r ctica i slandica exhibit s a decrease in growth rates coinciding with a decrease in food availability ( Schšne et al., 200 5). However, growth during fasting is observe d in some organisms, such as Oncorhynchus ts hawytscha the pacific king salmon (Greene 1919, 1921) Prior to spawning, stored muscle fat is expended during migration (Greene 1919) and stored muscle protein and fat are used to increase gonad size ( Greene, 1921). The energetic cost associated with using this stored energy is presumably high, and ultimately leads to the organism's death after spawning (Greene, 1919). Nonetheless, the king salmon is an exception, and many animals typically exhibit a fasting response by limiting energy expenditures during periods of limited or no food availability (Westerterp, 1977; Guppy and Withers, 1999; Storey and Storey, 2004).

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63 Mollusk shell growth is energetically costly, and Nucella spp. gastropods must ingest 3.196 J for every 1 mg of shell produced, as determined from an ~90 day experiment and based on an assumed 66% energy assimilation efficiency (Palmer, 1992). During periods of dormancy, mollusks have a reduced metabolic rate (Guppy and Withers, 1999), an d conserving energy by a cessation of shell growth while dormant is sensible physiologically. As was observed in laboratory reared Nucella spp. gastropods (Palmer, 1992), shell growth may be correlated with energy consumption. If shell growth is directl y related to food availability, one potential method to increase the likelihood of producing an annual record of temperature variability involves c ombining the environmental records of mollusk s known through direct observation to feed in different seasons. Busycon sinistrum and Fasciolaria tulipa are predatory gastropod s found along the western Atlantic and Gulf Coasts with opposing seas ons of activity. Based on field observations in the nearshore marine environment in the Florida Panhandle (Paine, 1963) and in Tampa Bay ( Herbert, pers. comm .), B. sinistrum is abundant and actively feeds on the venerid bivalves Chione spp and Mercenaria spp. during the coldest winter months, whereas F. tulipa is abundant and actively feeds on thin shelled bivalves and oth er gastropods during the warmest summer months (Figure 3.1) If growth is concurrent with the predation activities of these two species, when they are obtaining food, then pairing the isotopic records of both gastropod species could provide a complete rec ord of annual seasonality.

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64 Figure 3.1: Patterns of seasonal occupancy of B. sinistrum (identified as B. contrarium in Paine, 1963) and F. tulipa from Baymouth Bay, Alligator Harbor, in northwest Florida, based on the average number of snails observed pe r hour per month (modified from Paine, 1963). In addition to compiling a complete record of seasonality, some gastropods have the potential to provide multi year and potentially decadal climate records outside of the tropics, based on a review of mollusk life histories (Powell and Cummins, 1985). Of the 101 mollusks examined by Powell and Cummins (1985), over 30% (n = 34) have maximum life spans > 10 years. Of the 34 species with decadal or longer life spans, over 50% (n = 18) are gastropods. Fasciolari a and Busycon genera were not included in Powell and Cummins' (1985) review, but f isherie s research indicates that the knobbed whelk Busycon carica a more temperate relative of B. sinistrum from the Atlantic coast of North America, can have a lifespan exc eeding 20 years ( Castagna and Kraeuter, 1994; Eversole et al., 2008; Power et al., 2009 ) Therefore, large Busycon spp. whelks, if they have similar growth rates to their more temperate relatives, may potentially provid e multi year records important for p aleoenvironmental studies

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65 3.3 Materials and Methods 3.3.1 Collection Sites and Sam pling Techniques Two gastropods, a specimen each of B. sinistrum and F. tulipa were collected live in January 2006 from Miguel Bay, near the mouth of Tampa Bay, along t he southwest Florida Gulf Coast. Two addition gastropods were collected live from slightly offshore of the Mosquito Trail (29.759¡ N, 85.391¡ W) outside of St. Joseph Peninsula State Park in St. Joseph Bay, along the northwest Florida Gulf Coast in June 2 007 (Figure 3.2). Both sets of specimens were collected from an intertidal zone in a water depth of approximately 0.5 m, on a fine sandy substrate, under the conditions of Special Activity License # 04SR 901 to G. Herbert (issued by the Florida Fish and W ildlife Conservation Commission). These sites were chosen based on latitudinal spread (one with more continental influence and one with less) and their proximity to long term water monitoring stations in two nearshore marine systems in a sub tropical envir onment. After collection, all specimens were subsequently frozen and the soft body parts were removed from their shells and preserved. The shells were submersed in a 3% sodium hypochlorite solution for 30 min then thoroughly rinsed in deionized water and scrubbed with a soft bristled brush to remove the periostracum and any encrusting organisms. After drying for at least 12 hrs a 0 .5 mm carbide dental drill bit was used to remove approximately 300 g of powdered aragonite from the upper < 0.5 mm of the shells for future isotopic analysis.

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66 Figure 3.2: Site location map. Location of the Environmental Protection Commission of Hillsborough County Water Monitoring Site #24 (star) and specimen collection location (circle) in Tampa Bay (1A) and F lorida Depa rtment of Environmental Protection Site LW5 (star) and specimen collection locations (circle) in St. Joseph Bay (1B) along the Florida Gulf Coast (adapted from Florida Center for Instructional Technology, USF, 2009). B. sinistrum is characterized by blun t knobs around the shoulders of its whorls. On the outermost whorl, ridges associated with each knob were assumed to represent periods of growth cessation, and one sample was collected from each side of the knob. On the inner whorls, representing early m id ontonogenic growth, we collected samples at a sampling interval of ~5 mm, between each knob (Figure 3.3). The samples collected from F. tulipa were taken in groves parallel to the growth lines at a sampling interval of ~5 mm in the juvenile portion of the shell and ~3 mm in the adult portion of the shell (Figure 3.3), because juvenile mollusk growth is typically faster than mature growth (Geiger, 2006). After the initial drilling, additional samples were re drilled on each specimen to increase sampling resolution near the interpreted seasonal highs and lows.

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67 Figure 3.3 : Sample locations. 3.3A Approximate sample locations on B. sinistrum (as viewed from the top of the shell) 3.3B Approximate sample locations on F tulipa. Scale bar = 1 cm. 3.3 .2 Stable Isotope Analysis After drilling, the aragonite samples were the n dried in a low temperature oven (~ 60 ¡ C) to remove any excess moisture. The samples from the Tampa Bay specimens were dissolved in 100% H 3 PO 4 at 7 0 ¡ C, and the resulting gas was ana lyzed on a Thermo Finnigan Delta+XL I sotope R atio M ass S pectrometer (IRMS) in dual inlet mode coupled to a Kiel III carbonate preparation system, located at the Paleoceanography, Paleoclimatology and Biogeochemistry Laboratory at the University of South F lo rida College of Marine Science Analytical precision based on daily measurements of NBS 19 (n > 500) over the 12 months preceding analysis is 0.06 for oxygen and 0.0 4 for carbon 1 Data are expressed in standard delta ( ) notation, where = [ ( 18 O/ 16 O sample ) / ( 18 O/ 16 O standard ) 1] x 1000 (3.1) for oxygen isotopes, and 13 C/ 12 C replaces 18 O/ 16 O in equation 3.1 for carbon isotopes. 1 In addition to daily measurements of NBS 19, a suite of standards is used to calibrate the IRMS several times annually. These standards (and their accepted values) include NBS 19 ( 18 O = 2.20; 13 C = 1.95), NBS 18 ( 18 O = 23.05; 13 C = 5.04), Carrera Marble (CM) 146 ( 18 O = 2.48; 13 C = 2.44), Atlantis II coral sample ( 18 O = 3.41; 1 3 C = 1.95), and Chi Cal ( 18 O = 11.67; 13 C = 7.90).

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68 The St. Joseph Bay samples were dissolved in > 100% H 3 PO 4 at 25 o C for 24 hrs. The resulting CO 2 cromatographically separated and focused and was then analyzed on a Thermo Finnigan Delta V Advantage IR MS in continuous flow mode coupled to a Gasbench II preparation device located in the Stable Isotope Lab oratory at the U niversity of South Florida Department of Geology. Analytical precision based on repeated measurements of the reference standard NBS 19 2 (n = 40) is 0.10 for oxygen and 0.06 for carbon. All values of 18 O and 13 C are reported in per mil units with respect to the Vienna PeeDee Belemnite (VPDB) isotopic standard. 3 .3. 3 Environmental Data The Tampa Bay specimens were collected ~2 km away from Marine Water Monitoring Site # 24 (27.588¡ N, 82.619¡ W) ( Figu re 3.2A ), maintained by the Environmental Protection Commission of Hillsborough County (EPC HC ). This station has monitor ed water quality parameters (including temperature and salinity) since 1974 and is the closest water monitoring station to the site of specimen collection. The St. Joseph Bay specimens were collected near the Mosquito Trail beach area. The Florida Department of Environmental Protection (FLDEP) collects water quality parameters from Site LW5 in St. Joseph Bay (29.760¡ N, 85.384¡ W), locat ed ~ 200 m from the Mosquito Trail location (Figure 3.2B ). At the EPCHC monitoring station, Tampa Bay bottom water temperatures at 3.5 m depth, rang ed from 31.3 to 12.2 ¡ C ( Figure 3.4 ), with a mean yearly 2 Accpeted value for NBS 19 is 2.20 for 18 O and 1.95 13 C.

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69 temperature of 23.9 ¡ C ( 1 # = 5.3 ¡ C ) between 2001 and 2005 At the FLDEP monitoring station, St. Joseph Bay bottom water t emperatures rang ed from 33.1 to 10.2 ¡ C (Figure 3.4 ) with an mean temperature of 21.7 ¡ C ( 1 # = 6.4 ¡ C ) between 2003 and 2008 Salinity at the Tampa Bay site ranged from 22.4 p su to 35.8 p su with a mean of 31.1 p su ( 1 # = 2.7 psu) In St. Joseph Bay, salinity ranged from 22.5 p su to 35.5 p su, with a mean of 30.5 psu ( 1 # = 2.9 psu) from 2003 to 2008 (Figure 3.3 ). The five ye ars of environmental data prior to colle ction for each site (2001 through 2006 for Tampa Bay, 200 3 to 200 8 for St. Joseph Bay) are presented (Figure 3.4 ) based on the approximate maximum lifespan of the collected specimens (Section 3.5.1 ). Figure 3. 4 : H istoric w ater q uality p arameters Sea surface temperature (black), sea surface salinity (dashed grey)), and calculated 18 O pred (grey) f or each collection site (data from the Environmental Protection Commission of Hillsborough County and from the Florida Department of Environmental Protection).

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70 3 .3. 4 Predicted 18 O and 18 O water Determination T o test if these predatory gastropods faithfully record the full range of summer and winter temperatures, we calculated the predicted seasonal range of 18 O aragonit e ( 18 O pred ) precipitated in environmental equilibrium for each site based on temperature measurements (T) and using a constant value for the 18 O of seawater ( 18 O SW ) using the Grossman and Ku (1986) equation for mollusks reorganized to solve for 18 O pred : 18 O pred = (20.6 T )/ 4.34 + 18 O SW (3.2) where 18 O pred is expressed relative to PDB and 18 O SW is expressed relative to SMOW. Monthly variations in 18 O SW were not measured at either water monitoring location. While 18 O SW can be derived f rom a regional linear relationship with salinity ( e.g., Surge et al., 2001; Elliot et al., 2003), no relationship between salinity and 18 O SW has been derived for the Tampa Bay or St. Joseph Bay sample sites For this reason, we use d constant values of 18 O SW derived from the Global Seawater Oxygen 18 Database (Schmidt et al., 1999). T h is database, constructed on a gridded dataset comprised of over 22,000 global 18 O SW measurements, was used to approximate mean 18 O SW values for the mouth of Tampa Bay ( 0.75 ) and St. Joseph Bay ( 0.50 ) Using a single, constant value for 18 O SW is a common, practical approach when performing paleotemperature reconstructions (e.g., Andreasson and Schmidz, 2000; Tripati et al., 2001).

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71 3.3.5 Statistical Analysis Corre lations between 18 O shel l and 1 3 C shell were compared using the Pearson's Product Moment Correlation Coefficient and p levels were set at 0.05 All analyses were performed using PAST software ( Hammer et al., 2001 ). 3 .4 Results 3.4.1 Shell Length Measur ed as shell length from apex to the tip of siphon, the B. sinistrum and F. tulipa specimens were between 120 and 150 mm long and 90 and 140 mm long, respectively. B. sinistrum ranges in size from ~100 mm to 450 mm long, and F. tulipa ranges from ~75 mm to 120 mm long, but can be up to 250 mm long (Abbott, 1954). As observed by Paine (1963), the average length of B. sinistrum and F. tulipa in northwest Florida is 250 mm and 170 mm, respectively, so the shells used in this study are smaller than the average sizes observed in that study. Samples were collected along the spiral growth direction of the shell, and in B. sinistrum this measured 334 mm and 299 mm long from the Tampa Bay and St. Joseph Bay specimens, respectively. In F. tulipa this measured 382 mm and 292 mm long from the Tampa Bay and St. Joseph Bay specimens, respectively. 3.4.2 Oxygen Isotope Geochemistry The mean 18 O shell value for F. tulipa from Tampa Bay is 0.6 (n = 50, 1 # = 0.9 ) and ranges from 2.2 to 2.1 The mean 18 O shell value for B sin is trum is 0.8 (n = 52, 1 # = 0.7 ) and ranges from 0.6 to 1.9 (Table 3.1 and Figure 3.5) The m ean annual 18 O shell profile amplitude s, representing

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72 maximum seasonal temperature variations, are 2.8 over 3.5 years ( 1 # = 0.9 ) for F. tulipa and 2.0 over 4.5 years ( 1 # = 0.4 ) for B. sinistrum in Tampa Bay The mean annual 18 O pred profile amplitude from Tampa Bay for the five years preceding sample collection is 3.7 ( 1 # = 0. 8 ) In St. Joseph Bay, t he mean 18 O shell value for F. tulipa is 0.7 (n = 43, 1 # = 0.6 ) and ranges from 0.8 to 2.1 The mean 18 O shell value for B sin is trum is 0.7 (n = 68, 1 # = 1.0 ) and ranges from 2.1 to 2.4 (Table 3.1 and Figure 3.5) In St. Joseph Bay, over a 3.5 year interval, the mean annual 18 O shell profile amplitudes for F. tulipa and B. sinistrum a re 2. 3 over 3.5 years ( 1 # = 0.24 ) and 3.1 over 3.5 years ( 1 # = 0. 2 ) respectively. The mean annual 18 O pred amplitude for St. Joseph Bay for the five years preceding sample collection is 4.3 ( 1 # = 0.3 ).

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73 Table 3.1: Measured and predicted Summer 18 O Minima and Winter 18 O Maxima for F. tulipa and B. sinistru m in Tampa Bay and St. Joseph Bay. Offset is measured from predicted values: a negative offset means the measured is isotopically lighter than predicted, and a positive offset means the measured is isotopically heavier than the predicted. Dashed line re presents no data collected. No data was collected in winter 2004 because the isotope record only extends back to summer 2004. No data was collected in summer 2007 because the organisms were collected from the field in June 2007 and did not grow during the warmest part of the year. Summer Winter Annual Range Location Species Year 18 O shell () 18 O pred () Offset (from predicted) () 18 O shell () 18 O pred () Offset (from predicted) () 18 O shell () 18 O pred () Offset (from predicted) () Tampa Bay F. tulipa 2003 1.6 1.7 0.2 2.2 2.6 0.5 3.7 4.4 0.6 2004 2.1 1.6 0.5 0.7 1.8 1.1 2.8 3.4 0.6 2005 2.0 1.7 0.4 0.1 2.7 2.8 1.9 4.4 2.5 Mean 1.9 1.7 0.2 0.9 2.4 1.5 2.8 4.1 1.2 B. sinistrum 2002 1.7 1.5 0.3 0.6 1.4 0.7 2.3 2.8 0.5 2003 1.8 1.7 0.1 0.3 2.6 2.9 1.5 4.4 2.8 2004 1.2 1.6 0.4 0.5 1.8 1.3 1.8 3.4 1.7 2005 1.9 1.7 0.2 0.4 2.7 2.3 2.3 4.4 2.1 Mean 1.7 1.6 0.0 0.3 2.1 1.8 2.0 3.7 1.8 St. J oseph Bay F. tulipa 2004 1.5 1.6 0.1 --2.5 ----4.1 --2005 1.2 1.4 0.2 0.8 2.9 2.1 2.0 4.3 2.3 2006 2.1 1.8 0.3 0.2 2.3 2.1 2.3 4.1 1.8 2007 --2.2 --0.9 2.6 1.7 --4.8 --Mean 1.6 1.7 0.1 0.7 2.6 1.9 2.3 4.3 2.1 B. sinistrum 2004 2.4 1.6 0.8 --2.5 ----4.1 --2005 1.2 1.4 0.2 2.1 2.9 0.8 3.3 4.3 1.1 2006 2.1 1.8 0.3 1.0 2.3 1.4 3.0 4.1 1.1 2007 --2.2 --0.6 2.6 2.1 --4.8 --Mean 1.9 1.7 0.1 1.2 2.6 1.4 3.1 4.3 1.3

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74 Figure 3. 5 : Sample locations and isotop e profiles for B. sinistrum and F. tulipa for Tampa Bay and St. Joseph Bay. The 18 O shell (black line) and 13 C shell (grey line) are plotted on an inverse y axis and distance is measured in mm from th e apex along the spiral growth axis. Dotted lines above (below) the 18 O profiles represent the predicted 18 O summer minima (winter maxima) for each year in Tampa Bay and St. Joseph Bay. Scale bar = 1 cm. 3.4. 3 Carbon Isotopes The shells from Tampa Bay are consistently more depleted in mean 13 C shel l than the St. Joseph Bay shells. The mean 13 C shel l is 2. 8 (n = 50, 1 = 0. 9 ) for F. tulipa and 3. 3 (n = 52, 1 = 0. 6 ) for B. sinistrum in Tampa

PAGE 86

75 Bay, whereas it is 0 9 (n = 43, 1 = 0. 6 ) for F. t ulipa and 1 0 (n = 68, 1 = 0. 5 ) for B. sinistrum in St. Joseph Bay (Figure 3.6) Furthermore, 13 C shel l is grouped by location rather than by species. There is a weak correlation between 13 C shell and 18 O shell in the shells from Tampa Bay ( r 2 = 0 .22 for F. tulipa and r 2 = 0.14 for B. sinistrum ) Likewise, the shells from St. Joseph Bay do not exhibit a strong correlation between 13 C shell and 18 O shell ( r 2 < 0.0 1 for F. tulipa and r 2 = 0.08 for B. sinistrum ) (regressions not shown in Figure 3.6) Figure 3. 6 : Plot of 13 C versus 18 O for all shells. 13 C shell and 18 O shell are not strongly correlated for any of the four specimens (see text for correlation coefficients). 3 .5 Discussion 3 .5.1 Applicability as Climate Proxies: Comparing 18 O shel l and 18 O pred Biogenic carbonate oxygen isotope fluctuations from shells in Florida are controlled primarily by temperature fluctuations (e.g., Elliot et al., 2003; Surge

PAGE 87

76 and Walker, 2006), although localized variations in the 18 O of seawater (! 18 O SW ) fr om river runoff, precipitation, and evaporation may also influence the amplitude of the measured 18 O oscillations in the biogenic carbonate ( 18 O shell ) (e.g., Surge et al., 2001). Typically, the 18 O shell time series yield seasonal oscillations with 18 O shell minima representing approximate maximum summer temperatures and 18 O shell maxima representing approximate minimum winter temperatures. As each specimen was collected alive at a known date, approximate seasonal dates, such as "summer 2005," could be assigned to each 18 O shell oscillation, based on the yearly summer temperature maxima and winter minima. Busycon sinistrum and F. tulipa from St. Joseph Bay and F. tulipa from Tampa Bay lived 3.5 years prior to collection. Busycon sinistrum from Tampa B ay lived 4.5 years prior to collection. The mean sample resolution is 16 samples per year for F. tulipa and 13 samples per year for B. sinistrum in Tampa Bay. The mean sample resolution is 16 samples per year for F. tulipa and 18 samples per year for B. s inistrum in St. Joseph Bay. This sampling resolution is higher than a monthly sampling resolution, and assuming mollusks follow the same model as corals, is sufficient to potentially capture the full annual range in monthly mean temperature recorded in ea ch shell (Quinn et al., 1996). To test if these predatory gastropods faithfully record the extent of summer and winter temperatures, we compare the maximum and minimum 18 O shell with 18 O pred for each year based on temperature measurements (Table 3.1). The mean annual 18 O shell minima representing summer, of F. tulipa and B.

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77 sinistrum are 0.2 and 0. 1 more depleted, respectively, than the corresponding 18 O pred summer values. The mean annual 18 O shell maxima representing winter, of F. tulipa and B. sinistrum are 1. 5 and 1.8 more depleted, respectively, than the corresponding 18 O pred winter values. As with the specimens from Tampa Bay, we compare 18 O shell with 18 O pred for St. Joseph Bay for each year based on temperature measurements (Table 3 .1). The average 18 O shell minimum of F. tulipa is 0.1 more enriched than 18 O pred summer values. The 18 O shell minimum of B. sinistrum is 0.1 more depleted than the 18 O pred summer values. The mean 18 O shell maxima of F. tulipa and B. sinistrum are 1 .9 and 1.4 more depleted, respectively, than the 18 O pred winter values. Comparing the yearly and mean summer minima and winter maxima for 18 O shell and 18 O pred (Figure 3. 4 and Table 3.1) demonstrates that F. tulipa growth is during the summer and co ncurrent with observed summer seasonal activity. Conversely, B. sinistrum does not grow in the winter months when it is active. The mean difference between summer 18 O shell and 18 O pred for all four specimens is 0.1 ( 1 = 0. 1 ), but the mean difference between winter 18 O shell and 18 O pred for all four specimens is 1. 7 ( 1 = 0. 3 ) This comparison between 18 O shell and 18 O pred indicates both species grow during the summer and cease growth during part of the winter. Additionally, the 18 O shell seas onal range for all four shells is at least 25% lower than the corresponding 18 O pred seasonal range.

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78 3. 5 2 Estimation of S alinity E rror The 18 O pred is based on temperature variations and uses a constant value for 18 O SW based on the Global Seawater Ox ygen 18 Database While practical, using a constant value for 18 O SW is a potential source of error in this study, because annual salinity variations are observed in both Tampa Bay and St. Joseph Bay ( S ection 3.3.1). Unlike temperature, lower salinity i s expressed as negative 18 O excursions due to the addition of isotopically light meteoric water, whereas higher salinity is expressed as positive 18 O excursions due to the preferential evaporation of 18 O and reduced input of meteoric water. In Tampa Ba y, s alinity is typically lower during the warmest part of the year, so the effects of salinity (low 18 O) and temperature (low 18 O) are additive. Therefore, the predicted seasonal highs and lows could be underestimated, and seasonal differences between 18 O pred and 18 O shell w ould be amplified if both temperature and salinity were used to calculate 18 O pred In this scenario, seasonal shell growth interruption may have occurred but could be overlooked in the isotope record T he 18 O shell summer minima o f both species are more depleted than the 18 O pred in all but one year, but 18 O shell exceeding 18 O pred during the summer is not unexpected as monthly salinity variations are not included in 18 O pred calculation s N either species' 18 O shell winter maxima reaches or exceeds the potentially underestimated 18 O pred for the winter in Tampa Bay, so we interpret this as a cessation of shell growth during the winter months.

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79 Like the Tampa Bay samples, the 18 O shell summer minima of both species from St. Joseph Bay are almost equivalent or more depleted than the 18 O pred in all but one year, but neither species is more enriched than the 18 O pred winter maxima. In St. Joseph Bay, salinity and temperature are not consistently inversely correlated, and during thos e periods of lower salinity during the winter months, the effects of salinity are subtractive 18 O pred could be overestimate d, and seasonal shell growth cessation may be inferred from the isotope record even if none existed To determine if 18 O pred is overestimated, especially during periods of inferred growth cessation during the winter months, 18 O SW is calculated based on existing 18 O SW salinity relationships from the northern extent of the Ten Thousand Islands region in southwest Florida (Surge et al., 2001), Cedar Key north of Tampa Bay (Yobbi, 1992), and Terrebonne Bay in the Mississippi Delta (Kirby et al., 1998). In each of these calibrations, 18 O SW increases by 0.12 0.13 for every 1 psu increase in salinity. In other words, a 1.0 increas e in 18 O SW represents a ~8.0 psu increase in salinity. The mean winter offsets of 18 O shell to 18 O pred are 1.3 for F. tulipa and 2.1 for B. sinistrum, which would represent a ~10.1 psu and ~16.5 psu change in salinity, respectively. The average annua l salinity range is less than 10 psu, and it is unlikely that any error in winter 18 O pred due to monthly salinity variations would equal or exceed the annual salinity range, given the agreement with summer 18 O shell and 18 O pred in both species. The diff erences between 18 O shell and 18 O pred winter maxima

PAGE 91

80 represent periods of growth cessation and are not a consequence of using a constant rather than fluctuating 18 O SW for 18 O pred Therefore, using a constant 18 O SW based on the Global Seawater Oxygen 18 Database and water temperature fluctuations for 18 O pred neither F. tulipa nor B. sinistrum grows during the coldest months of the year. While F. tulipa growth is concurrent with observed seasonal feeding activity, B. sinistrum does not grow during its "active" winter feeding season. The 18 O shel l profiles of both species are valuable summer paleotemperature proxies; however, neither species, independently or combined, would provide accurate winter paleotemperature estimates or a range in seasonality. 3 .5. 3 Seasonal Growth/Predation H abits Periodic growth is common in several Neogastropod species (Vermeij and Signor, 1992) and can be controlled by endogenous timekeeping mechanisms (biological clocks) (Schšne, 2008). Associating a biological causal m echanism to periodic growth in specific species is beneficial for the prediction of shell growth cessation in the fossil record. Therefor e, p redation activities of both species are considered as a possible driver of seasonal growth cessation F asciolaria tulipa is a gastropod with a wedging style of predation (Feifarek, 1987) found in the Gulf of Mexico and northwestern Atlantic coast Fasciolaria tulipa u ses its thin, toothed lip to wedge open the shells of bivalve prey ( Feifarek, 1987 ). F asciolaria tul ipa also consumes gastropod prey (Paine, 1963; Jory, 1982) and will occasionally "pirate" prey by dislodg ing another

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81 predator to utiliz e the exiting hole on the shell to feed (Paine, 1963), although neither of these methods is dependent on the lip for pene tration. F asciolaria tulipa bivalve predation often leaves little to no damage to the shell of its prey; however, the edge of the thin lip of F. tulipa occasionally is caught between the closing valves of the prey and chipped ( Wells, 1958; Paine, 196 3 ; Feifarek, 1987; Dunham et al., 2009). F asciolaria tulipa must wedge its lip into the body cavity area of a narrowly opened bivalve prey (Feifarek, 1987), and a newly formed, thin lip is ideal for F. tulipa predation. The optimal time for F. tulipa shel l growth is concurrent with the active summer feeding season in Florida, so the animal can maintain a thin wedging lip. Unlike F. tulipa B. sinistrum is a chipping style predator y gastropod found in the Gulf of Mexico and northwestern Atlantic coast ( P aine, 1963; Dietl, 2004 ). Busycon sinistrum uses the thick lip of its shell to attack bivalves by striking the prey's shell with its concave, reinforced lip ( Colton, 1908; Magalhaes, 1948; Paine, 1963; Dietl, 2003a,b, 2004 ). P redation can be damaging to B. sinistrum as is evident in lab oratory experiments and repair scars found on the lip of typical B. sinistrum specimens (Dietl, 2003a). Repair scars are divided into three categories and include minor chips in the "old growth" lip that do not decrease p redation performance, truncate embayed scars in new thin lip growth, and occasionally, wedge scalloped scars in recently secreted shell (Dietl, 2003a). Of these, truncate embayed scars are the most severe representing a significant time and energy investm ent in repair. An old growth, thickened lip that has not undergone recent extensions is ideal for B. sinistrum because it is less likely to

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82 break with its more aggressive style of chipping predation (Dietl, 2003a) Observations of B. sinistrum predation in a laboratory experiment reveal that, of the 1350 feeding observations, 92% (n = 1242) occurred during the old growth phase (Dietl, 2003a), which suggests whelks time their feeding to occur after lip thickening and avoid feeding during periods of lip ext ension, when the lip is razor thin, even though this is the time of rapid tissue growth and size increase. Therefore, t he optimal time for B. sinistrum growth is in the summer, well before the active feeding season in the winter, which allows the new raz or thin growing edge of the lip to thicke n and stre ng then, reducing the potential for shell breakage A review of scar frequency from the Pliocene and Pleistocene shell beds in Florida showed a decrease in truncate embayed scar frequency from 63% in the L ate Pliocene to 20% in the Late Pleistocene (Dietl, 2003b). As truncate embayed scars represent predation during the new growth phase, predation and shell growth were presumably more synchronous in the Pliocene than in the Pleistocene (Dietl, 2003a,b). O ver time, B. sinistrum appears to have increasingly mismatched its seasons of growth and feeding to allow for shell growth and thickening before predation. The opposite seasons of growth and feeding appear to be a relatively recent adaptation, possibly in response to increasingly thick prey (Dietl, 2003b). The seasonality of growth in B. sinistrum is therefore not related to observed seasonal predation activity, but the growth pattern observed in B. sinistrum can be explained by an interpretatio n of an energy optimization model based on its chipping predation style and possible predation pressure on B.

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83 sinistrum The energy optimization model is often applied to predator prey interactions as the optimal foraging theory, which predicts that organ isms will forage and consume food in such a way as to maximize their n et energy return (Charnov, 1976 ; Smith, 1978; Hughes, 1979; Rapport, 1980; Kitchell et al., 1981; P y ke, 1984; Brown and Kotler, 2004). Even though shell growth is energetically costly ( Palmer, 1992), especially during periods of fasting, asynchronous shell growth and feeding activities increases predation performance on hard shelled bivalve prey (Dietl, 2003b). The predation performance increase from the Pliocene could be the result of behavior selection of whelks that wait to feed until after the lip has thickened (Dietl, 2003b). Additionally, shell breakage caused by predation can decrease growth rate, leaving B. sinistrum vulnerable to durophagous predators (Dietl, 2003a). However, the frequency of durophagous repair scars and feeding induced repair scars are out of phase in the fossil record, suggesting B. sinistrum predation, not predators, drives whelk behavior (Dietl, 2003b). The energetic cost of growth associated with using en ergy stored in the muscle while fasting could be high, as was observed in the king salmon (Greene, 1919, 1921), but increased predation performance appears to outweigh the negative costs associated with shell growth while fasting. 3.5.4 Longevity Estimates Oxygen isotope profiles from invertebrate shells are also used in determinations of life history ( e.g., Jones et al., 1986; Ivany et al., 2003) Seasonal oscillations in the 18 O shel l records reveal that all four snails were less than five years old at the time of collection A growth curve for B. carica a

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84 congener of B. sinistrum calculated from marked and recaptured mixed sex whelks using the von Bertalanffy grow curve fr om South Carolina (Eversole et al., 2008), suggests that the two B. sinistrum were potentially ~20 40 years old at the time of collection (Figure 3.6). Another growth curve for B. carica generated from laboratory reared males from Virginia (Kraeuter et a l., 1989), suggests the two B. sinistrum may have been ~8 11 years old at the time of collection (Figure 3. 7 ). However, both of these curves were generated from populations in more northerly, cooler environments. The B. sinistrum specimens in this study were juveniles, but closer to the predicted age based on the Kraeuter et al. (1989) growth curve rather than the Eversole et al. (2008) curve. All four specimens are smaller than the maximum reported size by Abbott (1954), and larger specimens of both F. tulipa and B. sinistrum are observed in the nearshore marine environment in Florida (Paine, 1963). Larger and presumably older specimens could produce a longer multi year isotopic record. Figure 3. 7 : B. carica growth curves. Growth curves for B. ca rica reproduced from Eversole et al. (2008) and Kraeuter et al. (1989). Diamonds represent the placement of the two B. sinistrum on each curve based on size. Note the different scale in the x axis.

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85 3 .5. 5 Carbon Isotopes Carbon isotop ic variations are co ntrolled by the dissolved inorganic carbon (DIC) of sea water (Mook and Vogel, 1968; Fritz and Poplawski, 1974), the pH of seawater (Spero et al., 1997), and physical processes such as respiration (Tanaka et al., 1986; Klein et al., 1996; Gillikin et al., 2 007) and photosynthesis of symbionts, if present (McConnaughey, 1989; Rio et al., 1992). The 13 C shell values from St. Joseph Bay are generally more enriched than the 13 C shell values from Tampa Bay, and this group ing by locality rather than species sug gests that the carbon isotope values in these gastropods are controlled by environment (DIC or pH) rather than species specific vital effects ( Figure 3.6). In laboratory experiments, an increase in seawater pH (and [CO 3 2 ]) was correlated with a decrea se in 13 C (Spero et al., 1997). However, as the mean pH during the study period is 8.1 ( 1 = 0.1) (EPCHC; FLDEP) in both Tampa Bay and St. Joseph Bay, seawater pH appears to have little effect on 13 C shell values in these regions. Variations in 13 C DIC can b e inferred from secondary proxies, such as chlorophyll, representing primary productivity, and salinity, representing terrestrial 13 C DIC influx. Primary productivity alters 13 C DIC because the formation of organic matter preferentially incorporates 12 C d uring the metabolic reduction of carbon, thus enriching the seawater with 13 C (Sharp, 2007). However, based on measured chlorophyll levels from the water monitoring stations in Tampa Bay (5.6 #g/l; 1 = 3.5 # g/l) (EPCHC) and St. Joseph Bay (2.5 #g/l; 1 = 0.2 #g/l)

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86 (FLDEP), primary productivity appears higher in Tampa Bay, despite the lower 13 C shell values. Nearshore marine seawater 13 C DIC can also be controlled the mixing of marine and terrestrial water sources, dominated by the local terrestrial v egetation isotopic signal and bedrock (Boutton, 1991), and can be inferred from salinity variations (Chanton and Lewis, 1999; Surge et al., 2001). 13 C DIC variations in Apalachicola Bay in northwest Florida (Chanton and Lewis, 1999) and Ten Thousand Islan ds in southwest Florida (Surge et al., 2001) are positively correlated with salinity. However, salinity in Tampa Bay ( 31.1 p su; 1 = 2.7 psu) (EPCHC) is slightly higher than salinity in St. Joseph Bay ( 30.5 psu; 1 = 2.9 psu), despite lower 13 C shell val ues in Tampa Bay. The general depletion of 13 C in the Tampa Bay organisms compared to the St. Joseph Bay organisms does not appear to be related to pH, chlorophyll, or salinity differences between the two environments. However, other processes that af fect DIC, such as local CO 2 input from detrital decomposition (Boutton, 1991) are difficult to estimate with existing environmental data, and cannot be compared with 13 C shell values from Tampa Bay and St. Joseph Bay. 3 .6 Conclusions Geochemical informat ion derived from mollusks is potentially influenced by the timing of predation and shell growth. The 18 O shell profiles of the predatory gastropods B. sinistrum and F. tulipa in a sub tropical environment faithfully record summer temperature variations, b ut do not adequately record winter temperature variations. Fasciolaria tulipa a wedging style predator, utilizes its

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87 thin actively secreted lip during the summer predation season, thus grow is concurrent with previously observed feeding activities. Con versely, B. sinistrum, a chipping style predator benefits from a thickened and strengthened lip and does not grow during the winter feeding season. Shell growth occurs during previously assumed summer dormancy, which is unexpected considering the assumed metabolic depression during periods of fasting. The asynchronous feeding/growth patterns may be an evolutionary response to increase predation efficiency on the hard shelled prey of B. sinistrum (Dietl, 2003b). P eriods of growth cessation not concurrent with food availability are present in B. sinistrum T his documentation of an optimal growth strategy is u nique in predatory mollusks but likewise could be appli cable for whelk prey and other durophagous predators. Biology and ecology should be co nsidere d during interpretation of mollusk isotope records in paleoclimatic reconstructions.

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88 3.7 Chapter references Abbott, RT, 1954. American Seashells. Van Nostrand Reinhold, New York p. 236 and 242 Andreasson, FP, and B S chmitz, 2000. Temperature sea sonality in the early middle Eocene North Atlantic region: Evidence from stable isotope profiles of marine gastropod shells. GSA Bulletin 112(4):628 640 Bice, KL and MA Arthur, 1996. Late Paleocene Arctic Ocean shallow marine temperatures from mollusc stable isotopes. Paleoceanography 11(3):241 249 Boutton TW 1991 Stable carbon isotope ratios of natural materials II. Atmospheric, terrestrial, marine, and freshwater environments. In: Coleman, DC and B Fry (Eds.), Carbon isotope techniques Acad emic Press, San Diego, CA, p. 173 183 Brown, JS and BP Kotler, 2004. Hazardous duty pay and the foraging cost of predation. Ecology Letters 7:999 1014 Buick, DP and LC Ivany, 2004. 100 years in the dark: Extreme longevity of Eocene bivalves from Ant arctica. Geology 32(10):921 924 Carriker, MR, 1951. Observations on the penetration of tightly closing bivalves by Busycon and other predators. Ecology 32(1):73 83 Castagna, M and JN Kraeuter, 1994. Age, growth rate, sexual dimorphism and fecundity of knobbed whelk Busycon carica (Gmelin, 1791) in a western Mid Atlantic lagoon system, Virginia. Journal of Shellfish Research 13(2):581 585 Chanton, JP and FG Lewis, 1999. Plankton and dissolved inorganic carbon isotopic composition in a river domin ated estuary: Apalachicola Bay, Florida. Estuaries 22(3A):575 583 Charnov, EL, 1976. Optimal foraging, the Marginal Value Theorem. Theoretical Population Biology 9(2):129 136 Colton, HS, 1908. How Fulgur and Sycotypus e at o ysters, m ussels and c lams Proceedings of the Academy of Natural Sciences of Philadelphia 60(1):3 10 Curtis, LA, JL Kineley, NL Tanner, NL, 2000. Longevity of oversized individulas: growth, parasitism, and history in an estuarine snail population. Journal of Marine Biological Association of the United Kingdom 80:811 820

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89 Dietl, GP, 2003a. interaction strength between a predator and dangerous prey: Sinistrofulgur predation on Mercenaria Journal of Experimental Marine Biology and Ecology 289 : 287 301 Dietl, GP, 2003b. Coev olution of a marine gastropod predator and its dangerous bivalve prey. Biological Journal of the Linnean Society 80:409 436 Dietl, GP, 2004. Origins and circumstances of adaptive divergence in whelk feeding behavior. Palaeogeography, Palaeoclimatology Palaeoecology 208:279 291 Dunham, SR, GP Dietl, CC Visaggi, PH Kelley, 2009. Observations of Fasciolaria feeding behavior as a baseline for interpreting the trace fossil record of predation. Geological Society of America, Southeast Section Meeting Abstract St. Petersburg, FL. Elliot, M, PB deMenocal, BK Linsley, SS Howe, 2003. Environmental controls on the stable isotopic composition of Mercenaria mercenaria : Potential application to paleoenvironmental studies. Geochemistry, Geophysics, Geosyst ems 4(7), 1056, doi: 10.1029/2002GC000425. EPCHC. Environmental Protection Commission of Hillsborough County, Water Monitoring Quality Sampling Information from 1974 to 2008. Data accessed at http://www.epchc.org/surface_water_info.htm. Epstein, S, R Buc hsbaum, H Lowenstam, HC Urey, 1951. Carbonate water isotopic temperature scale. Bulletin of the Geological Society of America 62:417 426 Epstein, S, R Buchsbaum, H Lowenstam, HC Urey, 195 3 Revised c arbonate water isotopic temperature scale. Bulletin of the Geological Society of America 6 4 : 1315 1326 Eversole, AG, WD Anderson, JJ Isely, 2008. Age and growth of the knobbed whelk Busycon carica (Gmelin 1791) in South Carolina subtidal waters. Journal of Shellfish Research 27(2):423 426 Feifarek, BP 1987. Spines and epibonts as antipredator defenses in the thorny oyster Spondylus americanus Hermann. Journal of Experimental Marine Biology and Ecology 105:39 56 FLDEP Florida Department of Environmental Protection, St. Joseph Bay Aquatic Preserve, http://www.dep.state.fl.us/coastal/sites/stjoseph/

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90 Frank, PW, 1969. Growth rates and longevity of some gastropod mollusks on the coral reef at Heron Island. Oecologia 2:232 250 Fritz, P and S Poplawski, 1974. 18 O and 13 C in the shells of freshwater molluscs and their environments Earth and Planetary Science Letters 24(1):91 98 Geary, DH, TA Brieske, BE Bemis, 1992. The influence and interaction of temperature, salinity, and upwelling on the stable isotope profiles of Strombid gastropod shells Palaios 7:77 85 Geiger, DL 200 6. Marine Gastropoda. In: Sturm CF TA Pearce A ValdŽs (Eds.), The Mollusks: A Guide to their study, collection, and preservation American Malacological Society, Pittsburgh, PA, p. 295 312 Gillikin, DP, F de Ridde r, H Ulens, M Elskens, E Keppens, W Baeyens, F Dehairs, 2005. Assessing the reproducibility and reliability of estuarine bivalve shells (Saxidomus giganteus) for sea surface temperature reconstruction: Implications for paleoclimate studies. Palaeogeograp hy, Palaeoclimatology, Palaeoecology 228:70 85 Gillikin, DP, A Lorrain, L Meng F Dehairs, 2007. A large metabolic carbon contribution to the 13 C record in marine aragonite bivalve shells. Geochimica et Cosmochimica Acta 71:2936 2946 Goodwin, DH, KW Flessa, BR Schšne, DL Dettman, 2001. Cross calibration of daily growth increments, stable isotope variation, and temperature in the Gulf of California bivalve mollusk Chione cortezi : Implications for paleoenvironmental analysis. Palaios 16:387 398 Gre ene, CW, 1919. Biochemical changes in the muscle tissue of King Salmon during the fast of spawning migration. The Journal of Biological Chemistry 39:435 456. Greene, CW, 1921. Chemical development of the ovaries of the King Salmon during the spawning m igration. The Journal of Biological Chemistry 48:59 71 Grossman, EL and TL Ku, 1986. Oxygen and carbon isotope fractionation in biogenic aragonite: Temperature effects. Chemical Geology 59:59 74. Guppy, M and P Withers, 1999. Metabolic depression in animals: physiological perspetives and biochemical generalizations. Biological Review 74:1 40

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91 Hall Jr, C, WA Dollase, CE Corbat—, 1974. Shell growth in Tivela stultorum (Mawe, 1823) and Callista chione (Linnaeus, 1758) (Bivalvia): annual periodicity, latitudinal differences, and diminution with age. Palaeogeography, Palaeoclimatology, Palaeoecology 15:33 61 Hammer, , DAT Harper, PD Ryan, 2001. PAST: Paleontological s tatistics s oftware p ackage for e ducation and d ata a nalysis. Palaeontologia Electro nica 4(1): 9pp http://palaeo electronica.org/2001_1/past/issue1_01.htm Hughes, RN, 1979. Optimal diets under the energy maximization premise: the effects of recognition time and learning. The American Naturalist 113 (2):209 221 Ivany, LC, Wilkinson, B H, Jones, DS, 2003. Using stable isotopic data to resolve rate and duration of growth throughout ontogeny: An example from the surf clam, Spisula solidissima Palaios 18:126 137 Jones, DS, IR Quitmyer, 1996. Marking time with bivalve shells: oxygen is otopes and season of annual increment formation. Palaios 11:340 346. Jones, DS, DF Williams, C S Romanek 1986. Life h istory of s ymbiont b earing g iant c lams from s table i sotope p rofile s. Science 231(4733) : 46 48 Jory, DE, 1982. Predation by tulip snai ls, Fasciolaria tulipa on queen conchs, Strombus gigas M.S. thesis, University of Miami, Florida, 73pp Kirby, MX, TM Soniat, HJ Spero, 1998. Stable isotope record of Pleistocene and recent oyster shells ( Crassostrea virginica ). Palaios 13:560 569 Kitchell, JA, CH Boggs, JF Kitchell, JA Rice, 1981. Prey selection by naticid gastropods: experimental tests and application to the fossil record. Paleobiology 74:533 552 Klein R T KC Lohmann CW Thayer 1996. Sr/Ca and 13 C/ 12 C ratios in skeletal calc ite of Mytilus trossulus : Covariation with metabolic rate, salinity, and carbon isotopic composition of seawater. Geochimica et Cosmochimica Acta 60 : 4207 4221 Kraeuter, JN, M Castagna, R Bisker, 1989. Growth rate estimates for Busycon carica (Gmelin, 1 791) in Virginia. Journal of Shellfish Research 8(1):219 225 Krantz, DE, DF Williams, DS Jones, 1987. Ecological and paleoenvironmental information using stable isotope profiles from living and fossil molluscs. Palaeogeography, Palaeoclimtology, Palae oecology 58:249 266

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92 Krantz, DE, 1990. Mollusk isotope records of Plio Pleisotocene marine paleoclimate, U.S. Middle Atlantic Coastal Plain. Palaios 5:317 335 Kobashi, T, EL Grossman, TE Yancey, DT Dockery III, 2001. Reevaluation f conflicting Ecocen e tropical temperature estimates: Molluskan oxygen isotope evidence for warm low latitudes. Geology 29(11):983 986 Lowery, PL, JS Takahashi, 2004. Mammalian circadian biology:eludicating genome wise levels of temporal evoloution. Annual Review of Genom ics and Human Genetics 4:407 444 Magalhaes, H, 1948. An ecological study of snails of the genus Busycon at Beaufort, North Carolina. Ecological Monographs 18(3):377 409 McConnaughey, T, 1989. 13 C and 18 O isotopic disequilibrium in biological carbonat es: I. Patterns. Geochim ica et Cosmochimica Acta 53:151 162. Mook WG and JC Vogel 1968. Isotopic equilibrium between shells and their environment. Science 159 : 874 875 Paine, RT, 1963. Trophic relation ships of 8 sympatric predatory gastropods. Ecol ogy 44(1):63 73 Palmer, AR, 1992. Calcification in marine mollusks: How costly is it? Proceedings of the Academy of Natural Sciences 89:1379 1382 Palmer, JD, 1995. Review of the dual clock control of tidal rhythms and the hypothesis that the same cl ock governs both circatidal and circadian rhythms. Chronobiology International Journal 12:299 310 Powell, EN and H Cummins, 1985. Are molluscan maximum life spans determined by long term cycles in benthic communities? Oecologia 67(2):177 182 Power, AJ, CJ Seller, RL Walker, 2009. Growth and sexual maturity of the knobbed whelk, Busycon carica (Gmelin, 1791), from a commerciall harvested population in coastal Georgia. Occasional Papers of the University of Georgia Marine Extension Service 4, 29pp. Pyke, GH, 1984. Optimal foraging theory: a critical review. Annual Reviews in Ecological Systems 15:523 575. Quinn, TM, FW Taylor, TJ Crowley, SM Link, 1996. Evaluation of sampling resolution in coral stable isotope records: A case study using records from New Caledonia and Tarawa Paleoceanography 11 ( 5 ): 529 542

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93 Radermacher, P, BR Schšne, E Gischler, W Oschmann, J ThŽbault, J Fiebig, 2009. Sclerochronology a highly versatile tool for mariculture and reconstruction of life history traits of the queen conch, Strombus gigas (Gastropoda). Aquatic Living Resources 22:307 318 Rapport, DJ, 1980. Optimal foraging for complementary resources. The American Naturalist 116(3):324 346 Ray, M, and AW Stoner, 1995. Predation on tropical spinose gastropod: th e role of shell morphology. Journal of Experimental Marine Biology and Ecology 197:207 222 Rensing, L, U Meyer Grahle, P Ruoff, 2001. Biological timing and the clock metaphor: oscillatpry and hourglass mechanisms. Chronobiology International Journal 18 :329 369 Rio, M, M Roux, M Renard, E Schein, 1992. Chemical and isotopic features of present day bivalve shells from hydrothermal vents or cold seeps. Palaios 7:351 360 Sanford, E and BA Menge, 2001. Spatial and temporal variation in barnacle growth in a coastal upwelling system. Marine Ecology Progress Series 209:143 157 Schmidt, GA, GR Bigg, EJ Rohling, 1999. Global Seawater Oxygen 18 Database. http://data.giss.nasa.gov/o18data/ Schšne, BR, 2 008. The curse of physiology challenges and opportunities in the interpretation of geochemical data from mollusk shells. Geo Marine Letters 28:269 285 Sch šne, BR, K Tanabe, DL Dettman, S Sato, 2003. Environmental controls on shell growth rates and 18 O of the s hallow marine bivalve mollusk Phacosoma japonicum in Japan. Marine Biology 142:473 485 Schšne, BR A D Freyre Castro, J Fiebig, S D Houk, W Oschmann, I Kršncke 2004. Sea surface water temperatures over the period 1884 1983 reconstructe d from oxygen isotope ratios of a bivalve mollusk shell ( Arctica islandica southern North Sea) Palaeogeography, Palaeoclimatology, Palaeoecology 212: 215 232 Schšne, BR, SD Houk, AD Freyre C astro, J Fiebig, I Kršncke, W Dreyer, W Oschmann, 2005. Daily growth rates in shells of Arctica islandica: assessing subseasonal environmental controls on a long lived bivalve mollusk. Palaios 20:78 92

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9 4 Selders, K, GP Dietl, PH Kelley, D Surge, CC Visaggi, C Tobias, 2009. Using latitudinal differences in growth in crement formation in Mercenaria mercenaria to locate paleobiogeographic boundaries in the western North Atlantic. Geological Society of American, southeast section meeting abstract, St. Petersburg, FL. Sharp, Z, 2007. Carbon in the low temperature envir onment. In: Principles of stable isotope geochemistry Prentice Hall, Upper Saddle River, NJ, p. 149 171 Smith, JM, 1978. Optimization theory in evolution. Annual Reviews in Ecological Systems 9:31 56 Spero, HJ, J Bijma, DW Lea, BE Bemis, 1997. Eff ect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature 390:497 500. Storey, KB and JM Storey, 2004. Metabolic rate depression in animals: transcriptional and translational controls. Biological Review 79:207 233 Su rge, D and KJ Walker, 2006. Geochemical variation in microstructural shell layers of the southern quahog ( Mercenaria campechiensis ): Implications for reconstructing seasonality. Palaeogeography, Palaeoclimatology, Palaeoecology 237:182 190 Surge, D M K C Lohmann, DL Dettman, 2001. Controls on isotopic chemistry of the American oyster, Crassostrea virginica : implications for growth patterns. Palaeogeography, Palaeoclimatology, Palaeoecology 172:283 296 Surge, DM, KC Lohmann GA Goodfriend, 2003. Reco nstructing estuarine conditions: oyster shells as recorders of environmental change, Southwest Florida. Estuarine, Coastal and Shelf Science 57:737 756 Tanaka N MC Monaghan DM Rye 1986. Contribution of metabolic carbon to mollusk and barnacle shell carbonate. Nature 320 : 520 523 Thompson, JK and FH Nichols, 1988. Food availability controls seasonal cycle of growth in Macoma balthica (L.) in San Francisco Bay, California. Journal of Experimental Marine Biology and Ecology 116:43 61 Tripati, A, J Zachos, L Marincovich, K Bice, 2001. Late Paleocene Arctic coastal climate inferred from molluscan stable and radiogenic isotope ratios. Palaeogeography, Palaeoclimatology, Palaeoecology 170:101 113 Vermeij, GJ and PW Signor, 1992. The geographic, t axonomic, and temporal distribution of determinate growth in marine gastropods. Biological Journal of the Linnaean Society 47:233 247

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95 Wefer, G and WH Berger, 1991. Isotope paleontology: growth and composition of extant calcareous species. Marine Geolog y 100:207 248 Wells, HW, 1958. Predation of Pelecypods and Gastropods by Fasciolaria hunteria (Perry). Bulletin of Marine Science of the Gulf and Caribbean 8:152 166 Westerterp, K, 1977. How rats economize: Energy loss in starvation. Physiological Zoology 50(4):331 362 Yobbi, D, 1992. Effects of tidal and ground water levels on the discharge and water quality of springs in coastal Citrus and Hernando Counties, Florida. U.S. Geological Survey Water Resources Investigations Report 94(4254), 32 pp

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96 Chapter 4 Seasonal Pliocene ENSO Teleconnections: Evidence from Florida Corals 4.1 Abstract The temporal resolution of most Pliocene records are too coarse to capture interannual variability, leading to conflicting conclusions about the variabilit y of the Pliocene El Ni–o like system. Reconstructed seasonal sea surface temperature and salinity variations from well preserved Pliocene corals in Florida exhibit an increase in winter precipitation, characteristic of a modern severe El Ni–o event, howe ver, concentrations of variance in the typical ENSO frequency band above the 95% confidence interval are not apparent in this high resolution proxy data. Sustained, rather than intermittent, Pliocene El Ni–o like conditions are a likely driver for the inc reased winter precipitation patterns observed in these high resolution climate records. 4.2 Introduction The El Ni–o Southern Oscillation (ENSO) has global impacts on regional temperature and precipitation patterns through atmospheric teleconnections (e.g Ropelewski and Halpert 1987; Yoshida et al., 2007), and increasing global temperatures are expected to change the frequency and severity of ENSO variability (Diaz et al., 2001; Cane, 2005; Collins et al., 2005; Emile Geay et al., 2007; Collins et al., 2010) However, simulations in general circulation models

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97 (GCM) of ENSO variability with higher mean global temperatures give inconsistent results, with contrasting predictions of perennial El Ni–o like conditions, perennial La Ni–a like conditions, or no long term changes (Collins et al., 2005). Furthermore, because globally warm temperatures and higher atmospheric CO 2 are unprecedented in recent human history, the short instrument record available provides little useful insight. Paleoceanographic investi gations are needed to establish long term trends in ENSO variability, such as an increase or decrease in El Ni–o frequency, and are important for climate forecasting and regulatory planning. The data from these investigations are beneficial for testing an d improving GCM's to reduce the uncertainty in future ENSO predictions. Previous research using paleontological, biochemical, and geochemical SST proxies (e.g. Dowsett and Robinson, 2009 and research done by the Pliocene Research, Interpretation, and Syn optic Mapping group) indicates that the Pliocene was significantly warmer than today, and the Pliocene Warm Period (PWP) can be considered a contemporaneous analogue to the predicted effects of modern global warming, characterized by continental positions and ice sheet configurations similar to modern geography (e.g. Robinson et al., 2008; Brierley et al., 2009). Future global warming could drive the Pacific Ocean to revert to the mean Pliocene state, which was characterized by warmer global temperatures, an expanded tropical warm pool, and a perennial El Ni–o like state in the Pacific Ocean (Wara et al. 2005; Ravelo et al. 2004, 2006; Federov et al., 2006, 2010; Brierley et al, 2009). Landmark studies (Chaisson and Ravelo, 2000; Wara et al.,

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98 2005; Ravelo et al., 2006) demonstrate a relatively homogeneous equatorial east west temperature regime for the Pacific Ocean similar to severe El Ni–o events (Molnar and Cane, 2007). This sustained El Ni–o like system in the Pliocene Pacific Ocean is also thought to have had similar global climatic teleconnections as modern El Ni–o events despite differences in key boundary conditions, such as an open Central American Seaway and reduced Northern Hemisphere Glaciation, between the modern and Pliocene environments (Can e and Molnar, 2001; Molnar and Cane, 2002, 2007). However, the interannual variability the Pliocene El Ni–o like system is uncertain. The temporal resolution of most Pliocene teleconnection records is too coarse to capture decadal to sub annual variations that define the modern ENSO. An alternative explanation of the Pliocene Pacific Ocean is that warmer than modern sea surface temperatures (SST) persisted in the eastern equatorial Pacific (EEP) with ENSO variability similar to modern fluctuations (Haywoo d et al., 2007; Bonham et al., 2009). Also, some of the global teleconnection data used to confirm the existence of El Ni–o like teleconnections during the Pliocene have been interpreted other ways. Cooler than modern temperatures in the Gulf of Mexico r egion during the Pliocene (Cronin and Dowsett, 1996; Willard et al., 1993), for example, are also consistent with a regional upwelling zone (Allmon et al., 1996). The global teleconnection paleo proxy data used to support a perennial El Ni–o during the Pliocene has also been brought into question from version 3 of the Hadley Centre coupled model (HadCM3), which found that most perennial El

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99 Ni–o like teleconnections can be reproduced with a warming of SST in the EEP with ENSO variability or even with a f ixed east west SST gradient in the Pacific (Bonham et al., 2009). However, the Gulf of Mexico region, including Florida, in the HadCM3 predicts warmer temperatures (Bonham et al., 2009) than indicated by paleoclimate data (Cronin and Dowsett, 1996; Willar d et al., 1993) in both a variable ENSO and forced constant SST gradient scenario. Likewise, the HadCM3 model also predicts reduced precipitation over the Gulf of Mexico (Bonham et al., 2009), which is inconsistent with modern El Ni–o precipitation anomal ies in Florida, a dominant signal of ENSO variability in the region ( Carlson et al., 2003; Hagemeyer, 2006; Kelly and Gore, 2008). Modern El Ni–o teleconnections in peninsular Florida manifest as an anomalous increase in dry season (winter) precipitation ( Carlson et al., 2003; Hagemeyer, 2006; Kelly and Gore, 2008) and are related to the severity of the El Ni–o event. During "typical" El Ni–o events (Chapter 2, p. 26), the greatest SST anomalies in the equatorial Pacific are between 180 ¡ and 160 ¡ W. In peninsular Florida, there is a 13% increase in winter precipitation (October through May) coupled with a 3% decrease in summer precipitation (June through September) associated with typical El Ni–o events (precipitation data from the Southwest Florida Wate r Management District (SWFWMD); Figure 4.1). The SST anomalies in the equatorial Pacific are closer to South America during "severe" El Ni–o events. During the severe 1997 98 El Ni–o event, there was an 85% increase in winter precipitation coupled with a 14% decrease in summer precipitation in peninsular Florida (SWFWMD; Figure 4.1) The Florida Palmer

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100 Drought Severity Index (PDSI) 1 and monthly averaged precipitation are both weakly correlated to the Multivariate ENSO Index (MEI) 2 (r 2 = 0.13 for PDSI a nd r 2 = 0.02 for precipitation; Figure 4.2). Additionally, winter precipitation surpassed summer precipitation in southwest Florida during the strong 1997 98 El Ni–o (SWFWMD data). This El Ni–o event is considered to be similar to the hypothesized perenn ial "Super El Ni–o" event in the Pliocene (Molnar and Cane, 2007). Figure 4.1 : Southwest Florida mean seasonal precipitation. Mean summer (grey) and winter (black) precipitation for La Ni–a and El Ni–o years and "normal" years with no La Ni–a or El Ni– o events. Winter precipitation during the severe 1997 1998 El Ni–o event is 85% higher than normal winter years, and is separated from typical El Ni–o events. (Data provided by SWFWMD.) 1 The PDSI is an index indicating the severity of a wet or dry sp ell discounting anthropogenic affects. 2 The MEI is a weighted combination of sea level pressure, surface wind, sea surface temperature, surface air temperature, and total cloudiness over the tropical Pacific.

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101 Figure 4.2: MEI, Florida PDSI, and Florida Temperature Anomaly. Variations in the Multivariate ENSO Index (MEI), the Florida Palmer Drought Severity Index (PDSI) and temperature anomalies from 1950 2009. Black line represents 2 year binomial filter of temperature anomalies. Shaded bars repres ent El Ni–o events during same time periods, and a "severe wet spell" (greater than 4 on the PDSI) occurs during every El Ni–o event in Florida. Star denotes the severe 1997 98 El Ni–o events. The 1997 98 event is considered to have similar teleconne ctions as the Pliocene perennial El Ni–o like state (Molnar and Cane, 2007). El Ni–o precipitation anomalies in Florida are characterized by seasonal scale variations, and high resolution records of Pliocene ENSO teleconnections are crucial to document th e frequency and magnitude of periodic ENSO variations, if they exist. Multi decadal, subannual records can differentiate between the perennial El Ni–o, perennial La Ni–a, and variable ENSO Pliocene scenarios. If the Pliocene Pacific Ocean had ENSO variat ions similar to the modern (Haywood et al., 2007; Bonham et al., 2009), we hypothesize a

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102 southwest Florida precipitation pattern similar to what is observed in the instrumental record. Here, we present a seasonal record of Pliocene SST and sea surface sa linity (SSS) from SW Florida. Through geochemical records of two pristine Siderastrea spp. corals found in Bed 6 of the Pliocene Pinecrest Member shell beds in Sarasota on the southwest coast of Florida, we present an analysis of persistent Pliocene El Ni –o like seasonal precipitation patterns in the Gulf of Mexico. Corals provide ideal seasonal, multi decadal climate proxy records with annual banding which provides a non geochemical chronologic control and a skeletal structure which incorporates a variet y of isotopic and minor element components ideal for paleoclimatic reconstructions (e.g., Emiliani et al., 1978; Fairbanks and Dodge, 1979; Quinn et al., 1998; Linsley et al., 2000, 2006; Corrge, 2006). Modern Siderastrea spp corals colonize areas avoid ed by other coral species due to their capacity to tolerate salinity fluctuations, turbid waters, and shallow burial during times of increase sediment input (Lirman et al., 2003; Lirman and Manzello, 2009). The tendency for Siderastrea spp. corals to grow slowly (2 6 mm/year) (Moses et al., 2006; Maupin et al., 2008) results in a dense crystal structure, which lowers their susceptibility to diagenic alteration (Moses et al., 2006) and, thus, makes them ideal candidates for fossil geochemical studies. Use of oxygen isotopic composition of corals as a high resolution proxy for SST and/or SSS is commonly employed in Holocene tropical paleoclimatic studies (e.g. Weber and Woodhead, 1972; Leder et al, 1996; Quinn et al., 1996a, 1998; Linsley et al., 2000, 200 6; Corrge, 2006). Previous research has

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103 documented the SST 18 O coral and SST Sr/Ca relationships for Siderastrea spp. corals in the Caribbean and Gulf of Mexico (Gischler and Oschmann, 2005; Moses et al., 2006; Maupin et al. 2008; DeLong et al., in prep). The method of determining the 18 O of seawater (! 18 O SW ) from Sr/Ca and 18 O coral to reconstruct SSS has been used in various coral based paleoclimate reconstructions (McCulloch et al., 1994; Gagan et al., 1998; Ren et al., 2002; Kilbourne et al., 2004; Cahyarini et al., 2008). We apply these established geoch emical methods to test for the presence of seasonal scale El Ni–o teleconnections in Florida in the Pliocene. 4.3 Methods and Results (Supplementary Information) 4.3.1 Testing Fossil Siderastrea spp. Corals for Diagenic Alteration Two corals, UF 35931 and UF 35438, were selected from the Florida Museum of Natural History Invertebrate Paleontology Collection for geochemical analysis. Both corals were collected from Bed 6 of the Late Pliocene Pinecrest Member of the Tamiami Formation at Richardson Road Shell Pit in Sarasota, Florida. Prior to geochemical analysis of the coral samples, sections of UF 35438 were analyzed with XRD and SEM to test for the presence of diagenic alteration. Pieces of the coral skeleton were crushed to a fine powder in preparation f or analysis. X ray powder diffraction patterns of all samples were analyzed in a Rigaku Miniflex powder diffractometer, equipped with a Cu anode, operating at 45kV and 40mA. Spectra were measured from 17 o to 62 o with a step size of 2 Peaks at 29.5 o (2 ) were interpreted as calcite peaks, while peaks a 26.2 o and

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104 27.4 o were interpreted as aragonite peaks (Davies and Hooper, 1963). No samples had peaks above background at 29.5 o (2 ); therefore the amount of calcite in the coral samples is minimal (Figure 4.3A). The coral skeletons were also analyzed for secondary aragonite overgrowth using a Scanning Electron Microscope (SEM). Secondary aragonite is a re growth of aragonite crystals on the coral skeleton, and in some cases, secondary a ragonite can grow less than 15 years after living tissue vacates the skeleton (Enmar et al., 2000; Hendy et al., 2007). Scanning electron microscope images were collected from gold coated slivers of the coral skeleton collected from several locations thro ughout the coral colony. Multiple images were collected from several coral slivers (Figure 4.3B) with only a minimal amount of secondary aragonite present. 4.3.2. Coral Sampling Procedures Figure 4.3 : XRD and SEM Analysis. 4.3A: Select results of XRD analysis, without a "calcite peak" at 29.5 o 4.3B: SEM photos of M2 coral, showing s ections of the pristine aragonite skeleton. Scale bar = 500 # m

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105 Both corals were sliced into 0.5 cm thick slabs, x rayed, and so nicated in deionized water for 30 minutes. The coral slab was then mounted to a computer aided triaxial sampling platform and samples for paired stable isotope/trace element analysis were drilled from the coral thecal walls using a 1.4mm dental drill bit along continuous paths following the methodology described in detail by Quinn et al. (1996b). Sample paths were selected where corallite walls most parallel to the lengthwise axis of the slab were present. Samples collected along corallite walls will cap ture a constant growth and thus continuous time increments (DeLong et al., 2007). Specimen UF 35438 exhibited noticeable growth breaks in the slab; therefore, multiple paths were sampled to avoid these breaks while constructing a continuous record (sectio n 4.3.4). One sample was collected every 0.25 mm along the sample path, for approximately six samples per year as estimated by density bands in x radiographs (Figures 4.4 and 4.5)

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106 Figure 4.4: UF 35438 Geochemical Data. 4.4A: Photograph of UF 35438 cora l slab with yellow bars representing the 5 sa mple paths. 4.4B: X radiograph of same coral. 4.4C: Sr/Ca, 18 O coral and calculated 18 O SW for M2 Coral, interpolated to 6 samples per year in the 81 year long record. Black lines represent 2 year binomial filters for each dataset. Error bars for each analysis ( + 0.012 mmol/mol for Sr/Ca, + 0.10 for 18 O coral and + 0.12 for 18 O SW ) is located in the upper right corner. 4.4D: Correlation between calculated 18 O SW and Sr/Ca, significant above the 95% confidence interval (df = 162). Scale bar = 1 cm

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107 Figure 4.5: UF 35931 Geochemical Data: 4.5A: Photo of UF 35931 with yellow bar representing sample path. 4.5B: X radiograph same coral. 4.5C: Sr/Ca, 18 O coral and calculated 18 O SW variations in M1 coral. Black lines represent 2 year binomial filters for each dataset. Error bars for each analysis ( + 0.012 mmol/mol for Sr/Ca, + 0.10 for 18 O coral and + 0.12 for 18 O SW ) is located in the upper right corner. 4 .5 D: Correlation between calculated 18 O SW and Sr/Ca, significant above the 95% confidenc e interval (df = 50). Scale bar = 1 cm

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108 4.3.3 Stable Isotope and Trace Element Analysis Stable isotope analyses were performed on ~200 # g of powdered aragonite split from the original sample and dried in low temperature oven (~60 o C) to remove any excess m oisture. The samples were then dissolved in > 100% H 3 PO 4 at 25 o C for 24 hours. The resulting CO 2 cromatographically separated and focused was then analyzed on a Thermo Finnigan Delta V Advantage Isotope Ratio Mass Spectrometer in continuous flow mode coup led to a Gasbench II preparation device, located in the Stable Isotope Laboratory at the University of South Florida in Tampa, Florida. Data are expressed in standard delta ( !) notation, where = [( 18 O/ 16 O sample )/( 18 O/ 16 O standard ) 1] x 1000 (4.1) Ana lytical precision is 0.10 for oxygen, and + 0.06 for carbon, based on repeated measurements of the reference standard NBS 19 (1 n = 135), using a value of 2.20 for 18 O and 1.95 for 13 C All values are reported in per mil units () with respect to the Vienna PeeDee Belemnite (VPDB) isotopic standard (Table 4.1). Table 4.1: 18 O coral results. Descriptive statistics of the stable isotope analysis for both corals. 18 O coral Maximum Minimum Mean 1 Mean Seasonal Range n (samples) n (years) UF 35438 1.44 4.63 3.02 0.37 0.31 484 81 UF 35931 2.11 3.69 2.95 0.35 0.49 139 25

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109 Analyses of Sr/Ca were performed by dissolving ~200 # g of powder into 2% HNO 3 to dilute the sample to ~20 ppm Ca. Measurements of sample Sr /Ca ratios were made using a Perkin Elmer 4300 Dual View Inductively Coupled Plasma Optical Emission Spectrometer (ICP OES) located in the Paleoceanography, Paleoclimatology and Biogeochemistry Laboratory at the University of South Florida in St. Petersbu rg, Florida. The Sr/Ca of a gravimetrically prepared standard solution (IGS) was measured between each dissolved sample in order to correct for instrumental drift and noise (Schrag, 1999). The average corrected precision of IGS was 0.008 mmol/mol (1 n = 85), based on batches of 5 consecutive measurements performed at the beginning and end of each 50 sample batch of samples. A second standard consisting of homogenized powder from Porites lutea coral dissolved in 2% HNO 3 was analyzed for Sr/Ca between ev ery fifth sample analyzed. The average precision of this second standard was 0.012 mmol/mol (1 n=120). All values are reported in mmol/mol units (Table 4.2). Table 4.2: Sr/Ca results. Descriptive statistics of the trace element analysis for both corals. Sr/Ca Maximum (mmol/mol) Minimum (mmol/mol) Mean (mmol/mol) 1 (mmol/ mol) Mean Season al Range (mmol/mol) n (samples) n (years) UF 35438 9.236 8.731 9.041 0.080 0.039 484 81 UF 35931 9.198 8.829 9.010 0.088 0.140 139 25

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110 4.3.4 Condensing Multiple Sample Paths and Depth to Time Conversion On both corals, a chronology was established by cross dating the paths following the method used by DeLong et al. (2007). Relative time was assigned to each path by matching Sr/Ca minima with SST maxima (and vice versa) on an idealized dated sinusoidal temperature record using AnalySeries software (Pai llard et al., 1996) and linearly interpolated to even bi monthly time intervals. A visual comparison between the density bands in the x radiograph and geochemical years confirmed the accuracy of the age conversion. Following relative time assignment, sam ples from UF 35931 aligned on a 25 year long time series. Specimen UF 35438 had several noticeable partial growth breaks in the slab, so, to avoid growth breaks and to assess geochemical reproducibility within the coral, four overlapping paths were drilled along the growth axis of the M2 coral. A fifth overlapping record was drilled to resample a five year section of geochemical data missing in the middle of the timeseries due to instrument malfunction (Figure 4.4). All of these paths were converted to re lative time as described above. The five time domain paths were then aligned for the final coral time series. Matching Sr/Ca variations between sections along the growth axis of the coral were aligned in overlapping portion of each path. Correlations bet ween the overlapping sections of the Sr/Ca record were compared using the Pearson's Product Moment Correlation Coefficient (Hammer and Harper, 2006) in Past (Hammer et al., 2001), and tested at the 5% significance level ( p < 0.05). All five

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111 overlapping se ctions were strongly correlated (r 2 > 0.75), confirming the continuity between the different sample tracts and geochemical reproducibility. Following relative time assignment, samples from UF 35438 aligned on an 81 year long time series. 4.3.5 Calculatin g 18 O SW We calculate SSS variations using the method described by Ren et al. (2002), assuming Sr/Ca variations are a function of only SST and 18 O coral variations are a function of both SST and 18 O SW We subtract the mean from both Sr/Ca and 18 O coral timeseries because the strontium and oxygen isotope content of seawater in the Pliocene is poorly constrained. We use equation 4.2, derived from Ren et al. (2002), to calculate 18 O SW 18 O SW = 18 O coral 0.21 / o C ((Sr/Ca)/0.039 mmol/mol/ o C) (4.2) T he slope for Sr/Ca SST ( 0.039 mmol/mol/ o C) is derived from a modern S. siderea in the Gulf of Mexico (Maupin et al., 2008). As the contribution for 18 O SW to 18 O coral has not been quantified for the Dry Tortugas, the location of the modern S. siderea calibration, we use an average slope generally accepted for biogenic carbonate 18 O SST ( 0.21 / o C ) ( Epstein et al., 1953; Weber and Woodhead, 1972; McConnaughey, 1989; Shen et al., 1992; Wellington et al., 1996; Ren et al., 2002). The relative error f or 18 O SW is + 0.13, propagated from the analytical errors in Sr/Ca and 18 O coral and the errors from each slope calculation. This error estimate does not necessarily reflect the actual error of the 18 O sw reconstruction, which would be the sum of the er ror propagation plus noise

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112 related to any non climatic factors that may influence the proxies. While we cannot calibrate error related to noise, the error propagation provides important constraints on 18 O sw reconstructions. 4.4 Results and Discussion The Sr/Ca variations are a function of only SST, but the 18 O coral variations are a function of both SST and 18 O SW However, the contribution of SST to 18 O coral variations is limited based on the reduced shared variance of the 18 O coral and Sr/Ca timeserie s (11% and 56% for UF 35438 and UF 35931). Estimated 18 O sw (SSS) and Sr/Ca (SST) are negatively correlated (r 2 = 0.46, df = 162, p <0.05 for UF 35438; r 2 = 0.58, df = 50, p < 0.05 for UF 35931) ( Figures 4.4 and 4.5), suggesting the Pliocene fossil corals experienced lower salinity during the colder months. The pattern of lower 18 O sw values during the cooler months and higher 18 O sw values during the warmer months is apparent in 60 years in the 81 year long (74%) and 23 years in the 25 year long (92%) cor al records (Figures 4.4 and 4.5). The negative correlation of 18 O sw (SSS) and Sr/Ca (SST) suggests that either winter precipitation was higher than summer or winter and summer precipitation were approximately equal, with intensive evaporative processes i n the summer responsible for the higher salinity in the warmer months. The modern (historic) climate of peninsular Florida is characterized by summer dominated precipitation and a dry winter season, and this trend of lower winter salinity is the opposite of observations in modern Florida, except during severe El Ni–o events ( Carlson et al., 2003; Hagemeyer, 2006; Kelly and Gore, 2008).

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113 Modern summer precipitation in peninsular Florida is primarily delivered by thunderstorm convection (Cooper et al., 1982; Obeysekera et al., 1999). During the Pliocene, when mean sea level was 5 m 40 m higher than present (Raymo et al., 2009), the areal extent of the Florida Peninsula was reduced, which could have reduced the frequency of summer thunderstorm convection and consequently, precipitation. Reduced summer precipitation, coupled with intensive evaporative processes, could result in the "reversed" SSS patterns apparent in the Pliocene geochemical proxies. However, this explanation only applies if the paleoenviro nment where the stacked corals lived was a back barrier lagoon with restricted circulation. An increase in winter precipitation could also cause the reversed seasonal SSS patterns, and several global climate phenomena anomalously increase winter precipitat ion in peninsular Florida, including the warm phase of the Atlantic Multidecadal Oscillation (AMO), the negative phase of the North Atlantic Oscillation (NAO), and the warm phase of ENSO (Enfield et al., 2001). A warm AMO and a negative NAO are unlikely g iven existing Pliocene boundary conditions. A warm AMO coincides with an increase in thermohaline circulation (THC) (Dima and Lohmann, 2007), but during the Pliocene, a warm AMO is unlikely given the proposed relatively weaker thermohaline circulation in the North Atlantic at that time (Haywood and Valdes, 2004). A negative NAO, characterized by a minimal gradient between a weak Azores high and a weak Icelandic Low (Hurrell et al., 2003), is also unlikely given the proposed strong Azores high and Icelandi c low in Pliocene model reconstructions (Haywood et al.,

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114 2000). ENSO is the strongest driver of modern precipitation anomalies in the Florida peninsula (Hagemeyer, 2006), and the proposed perennial Pliocene El Ni–o (the warm phase on ENSO) is a probable e xplanation for the increase in winter precipitation and lower salinity during the winter months. T he Sr/Ca, 18 O coral and estimated 18 O sw records are also examined for variability in signal frequency. The temporal resolution of previous Pliocene sediment core records of a perennial El Ni–o like state are too coarse to capture decadal to sub annual v ariations that define the modern ENSO. Alternative explanations for Pliocene climate anomalies involve warmer than modern SST in the EEP with ENSO variability similar to modern fluctuations as is apparent the climate module simulation, instead of a perenn ial El Ni–o like state (Haywood et al., 2007; Bonham et al., 2009). The S r/Ca, 18 O coral and estimated 18 O sw do not display concentrations of variance in the typical ENSO frequency band (2 7 years; e.g., Cane, 2005; Collins et al., 2010) above the 95% confidence interval (Figure 4.6 in Appendix 4.1). Likewise, t he 13 C rec ord does not have a periodicity (6 year) in the typical ENSO frequency band above the 95% confidence interval (Figure 4.6, Appendix 4.1), but coral 13 C records can represent several different proxies (e.g., McConnaughey, 1989). A previously published hig h resolution Pliocene coral stable isotope record has frequencies in the typical ENSO band for both 18 O and 13 C, but the most prominent peaks occur in the 13 C record, interpreted as variability in cloudiness cycles (Roulier and Quinn, 1995).

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115 Precipitat ion anomalies are well documented as a strong El Ni–o teleconnection in Florida ( Carlson et al., 2003; Hagemeyer, 2006; Kelly and Gore, 2008). Variations in SSS controlled by changes in seasonal precipitation patterns would reflect the presence or absence of ENSO variability. The negative correlation of 18 O sw and Sr/Ca and inferred low winter SSS suggests higher winter precipitation, similar to modern El Ni–o teleconnections. The lack of ENSO like frequencies in the Sr/Ca, 18 O coral and estimated 18 O sw records suggest a permane nt, rather than intermittent event. Therefore the precipitation pattern inferred from SW Florida Pliocene seasonal salinity variations are compatible with previous conclusions of high SST in the EEP and a relatively homogeneous equatorial east west temper ature regime for the Pacific Ocean (Chaisson and Ravelo, 2000; Wara et al., 2005; Ravelo et al., 2006) similar to severe El Ni–o events (Molnar and Cane, 2007). However, the multi decadal, sub seasonal coral SSS records contradict previous research sugge sting a Pliocene La Ni–a scenario (Rickaby and Halloran, 2005) and GCM's suggesting Pliocene ENSO fluctuations (Haywood et al., 2007; Bonham et al., 2009). Bonham et al. (2009) suggests global anomalies similar to modern El Ni–o teleconnections can be ach ieved in both a perennial El Ni–o and variable ENSO scenarios in the HadCM3, except for the Gulf of Mexico region. Increased winter precipitation in southeast North America linked to modern El Ni–o events is not reproduced in the HadCM3, but Bonham et a l. (2009) cites poor spatial resolution in the paleoclimate data, indicating the only

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116 evidence for a wetter Pliocene climate in that region is from Texas (Thompson, 1991), which is replicated in the HadCM3. The precipitation patterns inferred from the new high resolution coral records from Florida are not replicated in the HadCM3, and suggest the model results, at least for the northeastern Gulf of Mexico, are inaccurate. The high resolution proxy data from the northeastern Gulf of Mexico does not indicat e drier conditions, as predicted by the HadCM3 (Bonham et al., 2009), but is consistent with the previously proposed perennial El Ni–o like phenomenon (e.g., Ravelo et al., 2006) with teleconnections similar to a severe modern El Ni–o event (Molnar and Can e, 2007). Assuming the Pliocene El Ni–o like state produced teleconnections similar to the strong 1997 98 El Ni–o event (Molnar and Cane 2007), summer precipitation would have been slightly less than modern, winter precipitation would have surpassed summ er, and combined annual precipitation in Florida would have been higher than the present. Previous geomorphological data also suggests high annual precipitation rates and pluvial conditions inferred from prograding deltas across the Florida Platform durin g the Pliocene (Hine et al., 2009), which are uncommon in the modern environment. Deposits of quartz pebbles in southwest Florida likewise confirm enhanced river transport (Cunningham et al., 2003; Hine et al., 2009). Increased annual precipitation may h ave also increased nutrient runoff, thereby supporting the highly productive nearshore marine community represented in the Pliocene shell beds of southwest Florida.

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117 T he Pliocene is considered a close analogue to future global warming, despite different boundary conditions (e.g., open seaways) from the modern (Robinson et al., 2008). If an increase in mean global temperature destabilizes the equatorial Pacific thermal gradient, similar to the Pliocene perennial El Ni–o like state (Ravelo et al., 2006), t hen global El Ni–o teleconnections could increase in frequency and severity, thus changing regional climate patterns, similar to what is reconstructed for in the Pliocene. In Florida, modern El Ni–o teleconnections result in a decrease in winter vegetable production (Hansen et al., 1999) and widespread phytoplankton blooms along the southwest Florida Gulf Coast from excessive terrestrial nutrient influx (Carlson et al., 2003). Using climate proxies with seasonal scale resolution is useful to address issue s important for climate forecasting and regulatory planning. U nderstanding regional climate variations during the Pliocene will increase the confidence of predictability of these teleconnections in models of future climate change.

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118 4.5 Appendix Time S eries Analysis and 13 C Record Coral 13 C is controlled by the dissolved inorganic carbon (DIC) reservoir in seawater at the time of carbonate precipitation and CO 2 diffusion into the calcification space, which varies with coral respiration and photosynthetic activities of endosymbiotic algae. Respiration lowers 13 C, but its effect on 13 C is minimal in corals (McConnaughey, 1989). Photosynthesis raises 13 C (McConnaughey, 1989), and coral 13 C records have been interpreted as a proxy for sunlight intensity/availability and cloudiness (e.g., Weber et al., 1976; Fairbanks and Dodge, 1979; Roulier and Quinn, 1995). However, the amount CO 2 that diffuses into the calcification space affecting DIC increases as pH increases (McConnaughey, 2003), so the 13 C records of corals l iving in low pH (more acidic) seawater would be less affected by photosynthesis than corals living in high pH seawater. The Pliocene Sr/Ca, 18 O, estimated 18 O sw and 13 C records do not have periodicities in the typical ENSO frequency band of 2 7 yea rs. However, because there are multiple potential sources for 13 C variations (changes in sunlight variability and changes in seawater DIC variations), multiple interpretations of the 13 C proxy are plausible and not limited exclusively to ENSO teleconnec tions.

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119 Figure 4.6 : Periodograms of UF 35438 geochemical records. Sr/Ca, 18 O, estimated 18 O sw and 13 C do not have significant periods in the typical ENSO frequency band (2 7 years) above the red noise 95% confidence interval. Note log scale of y axi s.

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127 Yoshida, S, T Morimoto, T Ushio, Z Kawasaki 2007. ENSO and convective activities in Southeast Asia and western Pacific. Geophysical R esearch Letters 34:L21806, doi:10.1029/2007GL030758

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128 Chapter 5 Marine Phosphates in the Plio Pleistocene Beds of Southwest Florida: Implications for Nutrient Sources and Biotic Turnover 5.1 Abstract Marine phosphate concentrations, estimated from the g eochemical analyses of pristine fossil corals fr om the Pliocene and Pleistocene shell beds of southwest Florida were significantly higher in the Pliocene Tamiami Fm. than in the Early Pleistocene Caloosahatchee and Bermont Fms. T he Plio Pleistocene boundary in southwest Florida was marked by nutrient decline several million years after the previously documented nutrient decline in the western Caribbean, suggesting a local rather than a regional source for Pliocene marine phosphate s Additionally, high resolution P/Ca analyses of Pliocene coral reveal no evidence of seasonality required by hypothesized nutrient delivery mechanisms. Nonetheless, a s in the Caribbean, nutrient decline preced ed local extinction by > 0.5 Ma 5.2 Introduction The Pliocene shell beds of southwest Florida contain some of the most fos sil rich deposits in the world, and paleontological evidence indicates that nearshore habitats in this region during at least part of the Pliocene were

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129 nutrient rich and highly productive (Allmon et al., 1996). Following the Pliocene, many invertebrate an d vertebrate taxa in Florida (Stanley, 1986; Allmon et al., 1993; Petuch, 1995) and adjacent regions (Vermeij and Petuch, 1986; Jackson and Johnson, 2000) became extinct. The timing and number of Late Neogene extinctions in Florida has been debated. Pre vious research suggested (1) an initial extinction event at ~3.2 Ma followed by several pulses over the next 1 million years (Stanley, 1986), (2) a drop in diversity at the Plio Pleistocene boundary balanced with high origination rates (Allmon et al., 1993 ), and (3) a two staged drop in diversity at 2.5 Ma and 1.8 Ma (Petuch, 1995). However, recent research, using rigorous standardized bulk sampling techniques to correct for sampling biases, points to a single extinction event at ~1.8 Ma (Herbert et al., 2 008). Several possible causes for the reduction in diversity have been proposed, including loss of habitat due to changes in sea level (Petuch, 1982), the onset of Northern Hemisphere Glaciation (Stanley, 1986; Petuch, 1982, 1995), and nutrient decline (Jo nes and Allmon, 1995; Allmon et al., 1996; Allmon, 2001). Stanley (1986) ruled out a drop in sea level as a driver of extinction, citing lower survivorship among Western Atlantic fauna along a broad continental shelf than eastern Pacific (San Diego) fauna along a narrow continental shelf. Following the drop in sea level, the Western Atlantic fauna had a larger area for survival than the eastern Pacific fauna; therefore the reduction of the nearshore marine environment caused by a drop in sea level would h ave had little effect on the

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130 survivorship of the Western Atlantic fauna (Stanley, 1986). Stanley (1986) attributed the extinction event to cooler temperatures, specifically the initiation of the first cold air winter outbreaks at the onset of Northern Hem isphere glaciation. Stenothermal species in Florida suffered a heavy extinction because they were unable to shift their geographic range south of Florida into the Caribbean (Stanley, 1986). An alternative explanation is the idea that the ecosystems collap sed due to nutrient reduction and loss of primary producers (e.g., Allmon et al., 1996; Allmon, 2001). This idea builds off the work by Woodring (1966), who hypothesized that, following a reorganization of oceanic circulation after the closure of the Cent ral American Seaway (CAS), food supply and nutrients would have declined in the Caribbean. Foraminifera stable isotope evidence (Keigwin, 1982), changes in foraminifera assemblages (Collins, 1996), percent sediment carbonate (O'Dea et al., 2007), and high mean annual temperature range estimated from bryozoans as a proxy for upwelli ng (O'dea et al., 2007) suggest that shallow waters in the Caribbean may have been more nutrient rich prior to the closure of the CAS. However, the evidence for nutrient decline in the Caribbean predates the biological changes observed in the Caribbean by ~2 million years (O'Dea et al., 2007), which indicates that either extinction lagged environmental change by some intrinsic biological mechanism or that some other, as yet unkno wn, mechanism was involved.

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131 In Florida, paleobiological evidence suggests the timing of nutrient decline possibly occurred later and much closer to the time of the extinction event at ~2 Ma. For example, in the Pinecrest Beds, which were deposited 3.5 to 2.5 Ma, there are several indicator taxa normally associated with cold, nutrient rich waters, such as t urritellid gastropod dominated assemblages (TDAs), seabirds and marine mammals (cetaceans, pinnipeds, etc.), and an absence of organisms that prefer olig otrophic waters, such as calcareous algae and hermatypic corals (Allmon et al., 1996). Some of this evidence, however, is potentially misleading and could be interpreted other ways. For example, TDAs have been reported from both eutrophic and oligotrophi c (carbonate dominated) strata (Allmon and Knight, 1993; Allmon and Cohen, 2003) and may also form due to taphonomic processes alone, such as current driven accumulation (Herbert and Harries, personal observation). Also, and as recognized by Allmon et al. (1996), high density of fossils in the pre extinction shell beds that was purported to indicate high productivity (i.e. high nutrient concentrations ) also characterizes younger strata deposited during times when nutrient concentrations were supposedly muc h lower. Additionally, high nutrients in modern marine environments that create eutrophic conditions are usually characterized by lower species diversity ( Jrgensen and Richardson, 1996; Ršnnberg and Bonsdorff, 2004), contrary to the high species diversit y observed in the late Pliocene fossil deposits (Allmon et al., 1993; Petuch, 1995; Herbert et al., 2008).

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132 One of the only geochemical studies to examine nutrient concentrations in Florida from the Pliocene is a record of Ba/Ca ratios in the coral Solenas trea bourni (Kay s er, 1995). This study found that nutrient concentrations prior to the extinction ranged from two times higher than to roughly equivalent with those of modern corals (Kayser, 1995). While coralline Ba/Ca has been used as a proxy for relat ive changes in upwelling intensity (Lea et al., 1989; Fallon et al., 1999), this proxy has also been linked to elevated riverine discharge (McCulloch et al., 2003; Lewis et al., 2007). However, the coral Ba/Ca technique is not calibrated for limiting nutr ients, which directly control biological productivity, and there has been no geochemical studies comparing limiting nutrients in the Florida shell beds before and after the extinction event. Nitrogen (N) and phosphorus (P) are two nutrients that limit macr oalgal growth in Florida nearshore marine environments along the Florida Gulf Coast (Lapointe, 1989; Smith et al., 1999; Fourqurean and Zieman, 2002; Fourqurean and Cai, 2001). N:P ratios in seagrass indicate variations in N and P limitation along the Flo irda Gulf Coast, with P as the primary limiting nutrient in Florida Bay but N limitation dominant in Charlotte Harbor (Fourqurean and Cai, 2001). In Tampa Bay, N:P ratios in seagrass indicate weak N limitation (Fourqurean and Cai, 2001), and restrictions of both N and P loading into Hillsborough Bay in the upper end of Tampa Bay were followed by an almost immediate reduction in plankton biomass (Smith et al., 1999). Quantifying past variations in either of these limiting nutrients and the timing of change s is needed to test whether an

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133 environmental shift to more oligotrophic conditions possibl y triggered the Florida extinctions. Coral P/Ca variations provide a measurement of the limiting nutrient P through marine phosphate (PO 4 SW ) variations. Recent resea rch has successfully calibrated skeletal phosphorus (P/Ca) variations in corals ( Porites spp. and Pavona spp.) from the Gulf of Panama with PO 4 SW (equations 5.1 and 5.2) (LaVigne et al., 2008; LaVigne et al., 2010). The linear relationship between coral P /Ca and PO 4 SW documented in other coral species (LaVigne et al., 2010) suggests a linear relationship between P/Ca and PO 4 SW in Siderastrea spp. corals as well. P/Ca Porites lobata ( mol/mol) = (21.1 + 2.4) PO 4 SW ( mol/kg) + ( 14.3 + 3.8) (5.1) P/Ca P avona gigantea ( mol/mol) = (29.2 + 1.4) PO 4 SW ( mol/kg) + (33.4 + 2.7) (5.2) In these modern corals, P is incorporated as both "intracrystalline" (organic plus inorganic P bound between or within individual aragonite crystals) and "non intracrystall ine" (coral tissue, endolithic algae, fungi, and bacteria) (LaVigne et al., 2008). Below the residual tissue layer, "intracrystalline" skeletal P/Ca can be used to reconstruct fluctuations in PO 4 SW (LaVigne et al., 2008). In this study, we analyze P/Ca from Pliocene and Pleistocene fossil Siderastrea spp. corals to examine the abundance of limiting nutrients and the timing of their purported decline in Florida. By examining nutrient concentrations from corals collected from the three major stratigraphi c units of interest for the

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134 Florida extinction (Late Pliocene Pinecrest Member of the Tamiami Fm., Earliest Pleistocene Caloosahatchee Fm., and the late Early Pleistocene Bermont Fm.), the timing of a nutrient change can also be compared with the timing of extinction. Based on the most recent assessment that the extinctions occurred in a single pulse at ~1.8 Ma (Herbert et al., 2008) and the consensus view that the event was triggered by a decline in nutrients (Allmon et al., 1996), we expect to find a dec rease in P/Ca concentrations in corals around ~1.8 Ma or the boundary between the Caloosahatchee and Bermont Fms. With high resolution seasonal scale analyses of P/Ca and Sr/Ca we are also able to test some of the hypothesized nutrient delivery mechanisms Previous research suggested that the source of high nutrients in the southwest Florida Pliocene nearshore marine environment was either a globally higher P concentration a more nutrient rich Atlantic Ocean prior to closure of the CAS that would have le t in nutrients from the Pacific, or local upwelling along the continental shelf in what is now southwest Florida (Allmon et al., 1996). The age of most phosphorite deposits in the southeastern United States, including Florida, implies highest P availabili ty in the shallow shelf environment from the Late Oligocene to the Late Mi ocene (Compton et al., 1990), at least three million years prior to the deposition of the Pinecrest Member shell beds and nearly four million years prior to the extinctions. However global P accumulation rates, as interpreted from the sediment record, shows a strong peak at 5 6 Ma followed by

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135 a sharp decline to 1 2 Ma (Filippelli and Delaney, 1994), which better matches the timing of the extinctions. At the same time, stable isoto pe geochemical evidence from the Florida Pliocene beds have been interpreted as indicative of a localized upwelling zone (Jones and Allmon, 1995; Allmon et al., 1996). In the Pliocene, as in modern coastal upwelling zones associated with eastern boundary currents (EBC), mean wind flow direction was equatorward and the associated Ekman transport pushed water offshore, causing coastal upwelling onto the continental shelf (Allmon et al., 1996). Following the closure of the CAS, there was a reorganization of currents in the Caribbean (Maier Reimer et al., 1990), and an assumed strengthening of the Loop Current in the Gulf of Mexico (Bruner, 1984). The strengthened Loop Current would have likely increased the coastal pressure gradient along the southwest Flori da Gulf Coast, depressed the thermocline near the coast, and dissipated local upwelling (Allmon et al., 1996). The strengthening of the Loop Current would have intensified eddy driven upwelling that is occasionally observed in the modern southwest Floirda Gulf coastal environment (Paluszkiewicz et al., 1983; Vukovich, 1986; He and Weisberg, 2003; Barth et al., 2008). However, nutrients delivery by eddy driven upwelling is considered minimal compared to the hypothesized Pliocene EBC driven upwelling region (Allmon et al., 1996). Previous geochemical evidence of local Pliocene upwelling includes stable isotope variations from several mollusks, including Turritella gladeensis, Turritella

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136 apicalis, Mercenaria campechiensis and Carolinapectin eboreus (Jones an d Allmon, 1995). In general, an upwelling region is characterized by cold water enriched in nutr ients. That upwelling signal translates to enriched (higher) 18 O values coinciding with depleted (lower) 13 C values in the isotopic record of mollusk shells sampled serially along the axis of growth. In the Pliocene mollusk shells studied, an upwelling signal consistently appears during the transition period from warm summer months to cool winter months (Allmon et al., 1996). However, the i sotopic upwelling signature observed in some Florida Pliocene mollusks (Jones and Allmon, 1995; Allmon et al., 199 6) is not consistently found in the isotopic analyses of Pliocene Mercenaria spp. shells and is also found with equal, if not increased, frequency in younger material (Kasprak et al., 2007) suggesting either a flawed isotopic model or that u pwelling was n ot ubiquitous in Florida during the Pliocene. Kayser (1995) suggested an alternative hypothesis of terrestrial nutrient sources in the Pliocene nearshore marine environment of southwest Florida, but could not unequivocally identify the mechanism. High res olution P/Ca analysis from a Siderastrea spp. fossil coral from the Pliocene beds in southwest Florida provide an opportunity to examine the seasonal timing of nutrient pulses to the nearshore marine environment, thus testing the upwelling hypotheses. Uti lizing Sr/Ca as a sea surface temperature (SST) proxy for Siderastrea spp. (after Maupin et al., 2008; DeLong et al., in prep.) and coupling Sr/Ca and 18 O to calculate the 18 O of seawater (! 18 O SW ) (Chapter 4), we compare not only the

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137 seasonality of marin e phosphate addition to the nearshore marine environment (through P/Ca) but also its correlation with 18 O SW (a proxy for sea surface salinity (SSS) and rainfall and evaporative processes). 5.3. Geologic Setting While fossil beds in Florida span most of th e Cenozoic, this study uses individual Siderastrea spp. corals from the Late Pliocene Pinecrest Member of the Tamiami Fm., the Earliest Pleistocene Caloosahatchee Fm., and the Late Early Pleistocene Bermont Fm. (Figure 5.1) in south Florida. These beds co nsist of shelly sands, limestones, and marls representative of nearshore marine environments and are significantly exposed only at the numerous aggregate quarries of the southern Florida peninsula (Petuch, 1982; Lyons, 1991). Using isotope ratio dating (U series and Sr series) and biostratigraphic correlation with other dated fossiliferous deposits along the Atlantic coastal plain, the Pinecrest Member was deposited from 3.0 to 3.5 Ma, the Caloosahatchee Fm. was deposited between 1.8 to 2.5 Ma, and the Ber mont Fm. was deposited between 1.1 to 1.6 Ma (Lyons, 1991). The Pinecrest Beds are sub divided into the lower Pinecrest Member of the Tamiami Fm. (beds 9 5 from Petuch, 1982), and upper Pinecrest Beds (beds 4 2 from Petuch, 1982), also referred to as the coeval Fruitville and Golden Gate Members (Vermeij, 2005). The Pliocene corals analyzed i n this studied are from bed 6 of the lower Pinecrest Member. Each unit formed when sea level was higher than present. The depositional environmental represents a shallow water to mid shelf environment,

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138 a determination based on ostracode, foraminiferal, and mollusk assemblages (Petuch, 1982; Allmon, 1993; Willard et al., 1993), the occurrence of taphonomically abraded fossils indicative of depth above wave base (Em slie et al., 1996), and silica salts representative of a lagoonal environment (Meyer et al., in prep). Additionally, the Siderastrea spp. corals have two distinct morphologies, "stacked pancake" and "ball," both of which represent a coastal environment. The corals with the stacked pancake morphology are convex, dome shaped coral colonies, indicative of a low energy, possibly lagoonal environment, with sporadic high sedimentation rate events (Yonge, 1935; Lasker, 1980; Cuevas et al., 2008). The defining f eature of the stacked pancake Siderastrea spp. corals is the repeating, but apparently infrequent and irregular growth breaks in which part of the coral colony died and was regenerated from the remaining polyps near the top of the dome. This mortality pat tern is consistent with occasional events of high sedimentation rates that would have buried the lower portion of the colony. The ball shaped corals formed in a shallow shelf environment with wave velocities similar to modern wave velocities on the east coast of Florida (Sorauf and Harries, 2009). Based on the abundance of fine grained sediment and lack of winnowing in the lower Bermont Fm. where some of the ball Siderastrea spp. corals were collected, Sorauf and Harries (2009) hypothesized that the se corals grew on bare patches in seagrass dominated shoal environments.

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139 Figure 5.1 : Florida stratigraphic column. The Tamiami Fm., Upper Pinecrest Beds, Caloosahatchee Fm., and Bermont Fm. are dep icted (after Lyons et al., 2001). Both coral morphologies represent slightly different environments but are found in the same fossil deposits, suggesting either adjacent microhabitats or that one or both types of coral morphology were transported prior to deposition. Regardless of the amount of transport prior t o deposition, both morphologies are ideal for recording the timing and level of nutrient input in two distinct coastal environments.

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140 5.4 Methods 5.4.1 Sample Collection To compare mean nutrient concentrations for each formation, replicate bulk carbonate s amples were collected from ball and stacked pancake Siderastrea spp. corals for trace element analysis. These corals included Siderastrea spp. from bed 6 of the Pinecrest Member of the Tamiami Fm. (from Richardson Road Shell Pit), the Caloosahatchee Fm. ( from Cochran Shell Pit and Longan Lakes), and the Bermont Fm. (from Palm Beach Aggregates, South Bay 2, Capelletti Brothers, and Belle Glade shell pits) (Figure 5.2). Corals with stacked pancake and ball morphologies were analyzed from each of the units. From the Pinecrest Member, 18 stacked pancake and two ball corals were sampled. From the Caloosahatchee Fm., two stacked pancake and 18 ball corals were sampled. From the Bermont Fm., four stacked pancake and 16 ball corals were sampled. Each coral was sliced in half and sonicated in deionized water for 30 min. After thoroughly drying the coral halves, samples were collected with a ha nd held drill with a 0.5 mm diameter carbide drill bit. Samples were collected from three locations on each coral corresponding to early mid and late ontogenetic growth. Each sample location consisted of a 2 mm by 3 mm box designed to capture one hig h density (winter) and one low density (summer) growth band, which represents ~1 year of growth (Knutson et al., 1972), along a single corallite, based on visual confirmation of the corallite width and previous

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141 Figure 5 .2 : Site l ocation m ap. Florida is situated on the southeast North American continent, between the Gulf of Mexico and the North Atlantic Ocean. Fossils were collected from several locations in southern Florida. Modern marine phosphate data from Rookery Ba y is described in section 5.6.2. (Adapted from Florida Center for Instructional Technology, USF, 2009. ) estimates of Siderastrea spp. growth rates (M oses et al., 2006; Maupin et al., 2008). To reduce the effects of brief anomalous nutrient excursions, the three samples from each coral were then averaged to calculate a mean P/Ca value for each coral. These values were then used to test for differences in mean nutrient concentrations between formations. In addition to examining mean P/Ca values between formations, seasonally resolved samples were collected from one Pliocene Siderastrea spp. coral with a stacked pancake morphology from bed 6 of the Pinec rest Member of the Tamiami Fm. to test the Allmon et al. (1996) autumn upwelling hypothesis. Testing of the seasonal timing of nutrient input into nearshore coastal habitats

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142 requires subannual temporal resolution in coral geochemical proxy records, which can be accomplished by micro sampling individual growth bands. The Pinecrest Member coral was sliced into a 0.5 cm thick slab, x rayed, and sonicated in deionized water for 30 min. The coral slab was then mounted to a computer aided triaxial sampling pl atform and samples for paired stable isotope (! 18 O) /trace element analysis were drilled from the coral thecal walls using a 1.4mm dental drill bit along continuous paths following the methodology described in detail by Quinn et al. (1996). Sample paths were selected where corallite walls mo st parallel to the lengthwise axis of the slab were present. Samples collected along corallite walls will capture a constant growth and thus continuous time increments (DeLong et al., 2007). One sample was collected every 0.25 mm along the sample path, c orresponding to approximately six samples per year of skeletal extension as estimated by the existence of annual cycles in the geochemical data (Chapter 4). B elow the organic tissue layer, samples treated in a chemical solution designed to remove non int racrystalline material gave results similar to samples that were sonicated in deionized water, demonstrating that ~90% of P is incorporated in the intracrystalline phase (LaVigne et al., 2008). Thus, sonicating in deionized water is sufficient to remove t he majority of non intracrystalline phosphorus in the fossil corals, and P trapped in the intracrystalline portion of the coral skeleton can be examined as fluctuations in P/Ca along the growth axis of the coral skeleton (LaVigne et al., 2008). Assuming t he Pliocene Siderastrea

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143 spp. corals incorporate P in the same manner as the modern Pavona spp. and Porites spp. corals, treating each sample in a chemical solution is an unnecessary extraneous step, and sonicating the coral skeleton in deionized water s houl d be sufficient to examine P/Ca variations in fossil Siderastrea spp. 5.4.2 Geochemical Analysis A subset of samples were prepared and analyzed for P/Ca following the methodology described in LaVigne et al. (2010) for an initial test to determine if P/Ca concentrations in fossil corals were above machine detection limits. Some of these samples were then re analyzed following the methodology described below to test if the different methods of acid digestion biased the results. The samples were prepared and analyzed for P/Ca similar to the methodology described by LaVigne et al. (2010), but with a different type of digestive acid. In order to minimize differential plasma matrix effects between samples during analysis (de Villiers et al., 1994; Rosenthal et al., 1999), 200 "g of powdered coral was dissolved into 100 "L of concentrated, OPTIMA grade 1 N Hydrochloric Acid (HCL) spiked with 40 ppb Indium (In) to a achieve a 40 mM Ca solution. Samples were further diluted to 2 mM Ca (5% HCl with 2 ppb In) sol ution with 950 L of 18.2 M# cm Millipore distilled, diluted water for analysis on a Perkin Elmer Elan DRC II Quadrupole Inductively Coupled Plasma Mass Spectrometer housed at the G eochemistry Lab oratory at the University of South Florida Department of Geology Indium was used to measure and correct for machine drift and noise.

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144 Sample concentration was calibrated from two sets of laboratory prepared standards (for multiple trace elements and for calcium). For the trace element standards, five sets of standard concentratio ns were spiked with CaCO 3 Puratronic¨ from Alfa Aesar (stock # 43073, lot # B02U036) for matrix matching. Precision, based on the average corrected value of P/Ca ratios of a matrix matched prepared limestone consistency standard (JLs 1 from the Geological Survey of Japan) measured every 10 samples, was 10.1 "mol/mol (1 $ n = 214). A second set of matrix matched consistency standards, consisting of homogenized powder from a Pliocene Siderastrea spp. coral was analyzed randomly throughout each set of analyse s, and the average precision of was 6.03 "mol/mol (1 $ n = 54). Stable isotope (! 18 O), Sr/Ca, and estimated 18 O of seawater (! 18 O SW ) variations were determined in seasonally resolved samples following the methodology described in detail in Chapter 4. 5.4 .3 Age Model for Pliocene Seasonal Samples Relative time was assigned to the paired P/Ca, Sr/Ca, and coral 18 O depth series of the Pliocene seasonal samples (Chapter 4) by matching Sr/Ca minima with SST maxima (and vise versa) on an idealized dated sinuso idal temperature record, using Analy S eries software (Paillard et al., 1996) and linearly interpolated to even bi monthly time intervals. A visual comparison between the density bands in the x radiographs and geochemical years confirmed the accuracy of the age conversion.

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145 The coral exhibited noticeable growth breaks i n the slab, and multiple sample paths were drilled to avoid these breaks. The overlapping records were aligned to ensure a continuous record throughout the coral (Chapter 4). The 81 year ch ronology was established by cross dating the paths following the method used by DeLong et al. (2007). 5.4.4 Statistical Analysis Several different statistical tests were used to assess the relationship between different sets of data. A student's t tes t (Hammer and Harper, 2006) was used to compare P/Ca values analyzed using HCl (section 5.4.2) with a previous published methodology for P/Ca analysis using HNO 3 (LaVigne et al., 2010). Additionally, the two datasets were compared using the Pearson's Prod uct Moment Correlation Coefficient (Hammer and Harper, 2006). A student's t test was also used to compare mean P/Ca concentrations between the Pinecrest Member, the Caloosahatchee Fm., and the Bermont Fm. samples. Correlations between modern PO 4 SW and sa linity a nd between the Pinecrest Member coral seasonal P/Ca, Sr/Ca, and calculated 18 O SW were compared using the Pearson's Product Moment Correlation Coefficient. For the student's t test and the Pearson's Product Moment Correlation, p values below 0.05 were c onsidered statistically significant. These analyses were performed using PAST software (Hammer et al., 2001). Finally, a spectral analysis of the P/Ca time series conducted to test for seasonal periodicity was performed using the Lomb Periodogram method in Redift (Press et al., 1992, Schulz and Mudelsee, 2002 ).

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146 A red noise line was calculated at p = 0.05 and peaks rising above that line were considered statistically significant. 5.5 Results 5.5.1. Comparing P/Ca Analysis Methodology Previous research ex amining P/Ca variations in modern corals used a slightly different methodology for sample analysis (LaVigne et al., 2010). Previously analyzed coral samples were digested with diluted HNO 3 prior to analysis while coral samples described in this chapter w ere digested with HCl prior to analysis on a different machine with lower sensitivity than that used by LaVigne et al. (2010) To confirm that samples digested in HCl (methodology described in section 5.4.2) are comparable to samples digested in HNO 3 (met hodology described in LaVigne et al., 2010), a subset of samples (n = 28, including 5 duplicates) were split for preparation and analysis following the methodology and instrumentation described by LaVigne et al. (2010). The differences between the two dat asets were not statistically significant (student's t test, p = 0.52), and therefore we can co nclude that the results from thi s study are not biased by the use of HCl digestion techniques. The samples prepared using HNO 3 ranged from 82.7 "mol/mol to 139.6 mol/mol and had a mean P/Ca value of 102.2 "mol/mol (1 $ = 17.5). The samples prepared using HCl ranged from 76.5 "mol/mol to 144.4 "mol/mol and had a mean P/Ca value of 105.3 "mol/mol (1 $ = 18.1). Additionally, the two datasets were significantly corre lated (r 2 = 0. 81 ). Despite using two different types of digestive acids (HNO 3

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147 vs. HCl), P/Ca values are statistically similar, and the methodology described in section 5.4.2 is comparable to the methods employed by LaVigne et al. (2010). 5.5.2 Bed Avera ged P/Ca Comparisons between Formations Of the stacked pancake corals, the P/Ca values of specimens collected from the Pinecrest Member range from 77.6 "mol/mol to 245.9 "mol/mol, with a mean of 151.0 "mol/mol (n = 18 corals, 1 $ = 39.5). The P/Ca from the Caloosahatchee Fm. range from 57.2 "mol/mol to 95.8 "mol/mol, with a mean of 76.5 "mol/mol (n = 2 corals, 1 $ = 27.2). The P/Ca from the Bermont Fm. range from 52.2 "mol/mol to 67.8 "mol/mol, with a mean of 60.4 "mol/mol (n = 4 corals, 1 $ = 6.4) (Figure 5.3). The mean P/Ca values of stacked pancake corals from the Pinecrest Member and the Bermont Fm. are statistically different (student's t test, p < 0.05). However, the mean P/Ca values of the stacked pancake corals from the P inecrest Member and the Caloosahatchee Fm. (student's t test, p = 0.06) and of the Caloosahatchee Fm. and the Bermont Fm, (student's t test, p = 0.28) are not statistically different Of the ball corals, the P/Ca from the Pliocene Pinecrest Member range from 104.6 "mol/mol to 116.6 "mol/mol, with a mean of 110.6 "mol/mol (n = 2 corals, 1 $ = 8.5). The P/Ca from the Caloosahatchee Fm. range from 47.5 "mol/mol to 139.7 "mol/mol, with a mean of 77.7 "mol/mol (n = 18 corals, 1 $ = 20.9). The P/Ca from the Bermont Fm. range from 58.2 "mol/mol to 118.2 "mol/mol, with a mean of 85.1 "mol/mol (n = 16 corals, 1 $ = 16.9) (Figure 5.3).

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148 Figure 5.3 : Bed averaged P/Ca for the Pliocene and Pleistocene Beds. The P/Ca is separated by coral morphology (ball or stacked pancake) and by unit (Pinecrest Member, Caloosahatchee Fm., or Bermont Fm.). The bed averaged Pliocene Pinecrest Member is generally higher than the bed averaged Pleistocene Caloosahatchee and Ber mont Fms., but statistical significance is limited by low sample numbers in the ball Pinecrest and stacked pancake Caloosahatchee corals (see text for statistical results). Differences between the mean P/Ca values of ball corals from the Pinecrest Member, the Caloosahatchee Fm., and the Bermont Fm. are not significant (student's t test, p = 0.06 for Pinecrest Caloosahatchee, p = 0.06 for Pinecrest Bermont, and p = 0.27 for Caloosahatchee Bermont). The limited number of ball Pinecrest Member and stacked pancake Caloosahatchee Fm. corals weakens the comparative statistical tests. However, a general trend of higher nutrients in the Pinecr est Member followed by lower nutrients in both the Caloosahatchee and Bermont Fm. is apparent in both ball

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149 and stacked pancake coral datasets. Further sampling of additional corals is not expected to reverse the trend observed in these data. 5.5. 3 Seasona l P/Ca Values in Fossil Corals The seasonal resolution P/Ca record from one Pliocene Pinecrest Member Siderastrea spp. coral ranges from 58.9 "mol/mol to 383.0 "mol/mol, with a mean P/Ca value of 155.7 "mol/mol (n = 484, 1 $ = 49.4) (Figure 5.4) Previousl y analyzed Sr/Ca and estimated 18 O SW (Chapter 4) determined from splits of the same samples as the P/Ca analyses provide temperature and salinity references for seasonal fluctuations in P/Ca (Figure 5.4). P/Ca, Sr/Ca, and 18 O SW are not significantly cor related (Pearson's correlation, r 2 < 0.0 1 for P/Ca with Sr/Ca and r 2 < 0.0 1 for P/Ca with 18 O SW ) and suggest nutrient fluctuations do not vary as a simple function of SST or SSS. LaVigne et al. (2008, 2010) found that upwelling events in the Gulf of Panama are recorded in coral geochemical records as concurrent increases in P/Ca, interpreted as an increase in PO 4 SW and Sr/Ca, interpreted as a decrease in SST. While 29 peaks 1 $ or more above the mean in the Florida Pliocene coral are apparent in t he 81 year fossil P/Ca record, only 14 (17%) appear during periods of cooler temperatures ( F igure 5.4). Of the 12 peaks in P/Ca above 2 $ eight (10%) are associated with periods of cooler temperatures. E liminating all peaks over 1 $ from the dataset does not improve the correlation between P/Ca, Sr/Ca and 18 O SW

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150 Figure 5.4 : Geochemical seasonal variations. A: Photograph of the Pinecrest Member Siderastrea spp coral with the five sample tracks highlighted. B: X radiograph of the same coral. C: Geochemical data (P/Ca, Sr/Ca, and 18 O SW ) from the Pliocene coral interpolated to 6 samples per year (grey line) with a 2 year binomial filter (black line). Error ba rs for each analysis (2$, P/Ca: 20.2 "mol/mol, Sr/Ca: 0.024 mmol/mol, 18 O SW : 0.24) are located in the upper right corner of each graph. Scale bare = 1 cm.

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151 The periodogram of the P/Ca time series (Figure 5.5), which tests for recurring frequencies in the dataset, shows no concentration of variance in the 1 year (seasonal) frequency domain in above the 9 5% confidence interval. However, a concentration of variance at a frequency of 0.06, representing 16.3 20.0 year recurring frequenc y is apparent. Figure 5.5 : Lomb Periodogram of Pliocene P/Ca t ime s eries. The hatched line indicates the 95% confidence interval ( red noise). No significant peak emerges at the 1 year frequency, but one significant peak is apparent, at the 0.06 (17.9 year) frequency 5.6 Discussion 5.6.1 Magnitude and Timing of Nutrient Decline Fossil coral geochemical eviden ce provides a direct proxy for nutrients, specifically PO 4 SW in the Pliocene and Pleistocene depositional environments of sou th Florida. Bed averaged P/Ca concentration s were 0 .5 to 1.5 times higher in the Pliocene Pinecrest Member than in the Pleistocen e Caloosahatchee and Bermont Fms. Additionally, Pliocene Siderastrea spp. coral P/Ca is an order of magnitude higher than P/Ca in modern Siderastrea spp. corals from the Dry Tortugas (LaVigne and Sliko unpublished data). The P/Ca in fossil Siderastrea s pp. corals from the Pinecrest Member shell bed demonstrates that PO 4 SW was

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152 high in the late Pliocene in southwest Florida, followed by a decline of this important limiting nutrient which is in agreement with previous estimations of nutrient concentrations from Allmon et al (1996) Based on the stacked pancake morphology corals, the timing of nutrient decline is after the Pliocene Pinecrest Member of the Tamiami Fm. and at least before the onset of the Bermont Fm. The sample size for bed averaged P/Ca in the Caloosahatchee Fm. is small (n = 2 corals), and therefore the decline in nutrients between the Pinecrest Member and the Caloosahatchee Fm. bed averaged P/Ca is not statistically significant. However, as the bed averaged P/Ca of the Caloosahatchee and Bermont Fms. is similar for the stacked pancake corals, we propose a tentative timing for nutrient decline between the Pinecrest Member and Caloosahatchee Fm. A similar pattern o f nutrient decline is observed in the ball morphology corals. Mean P/Ca values in ball corals from the Caloosahatchee and Bermont Fms., where sample sizes are sufficient, are statistically similar, representing environments with similar PO 4SW concentratio ns The Pinecrest Member ball corals are not statistically different from the Caloosahatchee or Bermont Fm. corals. However, the Pinecrest mean P/Ca value is higher than the Caloosahatchee mean P/Ca value, and we attribute apparent statistical similariti es to a small Pinecrest Member sample size (n = 2 corals). Future research involves analyzing more Pinecrest ball corals to test the proposed

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153 timing of nutrient decline at the Pinecrest Member Caloosahatchee Fm. boundary. An extinction event is evident between the Early Pleistocene Caloosahatchee and Bermont Fms. (Herbert et al., 2008). Based on the conservative timing of a nutrient decline between the Pinecrest Member and the Caloosahatchee Fm. (roughly 2.5 Ma), environmental (PO 4 SW ) changes pr ecede the extinction event by at least 0.5 M a A lag between extinction and environmental change is also observed in the Plio Pleistocene Caribbean fauna (O'Dea et al., 2007). However, the environmental changes apparent in the Caribbean (4.25 3.45 ma) pre date the nutrient decline observed at 2.5 Ma in southwest Florida by at least a million years, suggesting a different trigger for environmental change in the Caribbean (e.g., closing of the CAS) (O'Dea et al., 2007) compared to southwest Florida. Exam ining the processes responsible for the higher Pliocene nutrients and decline at the Plio Pleistocene boundary warrants further investigation. 5.6.2 Upwelling Previous research suggests that if nutrients were higher during the Pliocene in southwest Flori da, the source of those nutrients could be either a globally higher level of P during the Pliocene, a more nutrient rich Atlantic Ocean prior to closure of the Central American Seaway (CAS), and/or a localized upwelling zone along the continental shelf in what is now southwest Florida (Allmon et al., 1996). Isotope sclerochronology of mollusk shells from the

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154 Pliocene Pinecrest Member has been interpreted to support the latter mechanism (Jones and Allmon, 1995; Allmon et al., 1996). The timing of environme ntal change in the Caribbean, concurrent with the closure of the CAS (O'Dea et al., 2007), predates the timing of nutrient decline in southwest Florida, which also suggests that the nutrient source in the southwest Florida nearshore marine environments was local and not regional or global. However, more recent efforts to document local upwelling from isotope sclerochronology records of Florida mollusks have produced equivocal results (Kasprak et al., 2007). Using multi decadal seasonal nutrient reconst ructions, this study offers a conclusive test of the seasonal upwelling hypothesis using new geochemical data from corals. If seasonal autumn upwelling was the dominant nutrient source for the nearshore marine system, peaks in the P/Ca record should acco mpany all cold (fall winter) Sr/Ca excursions. Not only do over half of the peaks above 1 $ in the P/Ca record occur during warm Sr/Ca excursions, but 67 of the 81 years of cold Sr/Ca excursions have no P/Ca peaks above 1 $ associated with them. While eight of the 12 peaks above 2 $ are associated with cold Sr/Ca excursions, these peaks represen t ~10% of the entire 81 year record and do not represent consistent seasonal autumn upwelling. The P/Ca peaks above 2 $ could be the result of periodic eddy driven upwelling. In the modern environment, cold core eddies from the Loop Current that drive per iodic upwelling occur in the eastern Gulf of Mexico approximately twice a year (Vukovitch, 2007). However, the

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155 hypothesized weaker Loop Current in the Pliocene (Bruner, 1984; Maier Reimer et al., 1990 ) would have produced fewer eddies and eddy driven upwe lling events (Allmon et al., 1996). Likewise, Pliocene coral P/Ca and Sr/Ca are not significantly correlated, demonstrating reduced seasonality, as nutrient fluctuations do not vary with SST. The P/Ca timeseries exhibits no concentration of variance in th e 1 year (seasonal) frequency domain above the 95% confidence interval, suggesting nutrient influx was not driven by a distinctive recurring annual event. As was concluded in the previous Ba/Ca record from a different Pliocene coral (Kayser, 1995), the P/Ca record presented here does not unequivocally support a seasonal upwelling mechanism of nutrient delivery to the Pliocene southwest Florida coastal environment. Therefore, alternative mechanisms for nutrient delivery, such as submarine groundwater di scharge and riverine input similar to what is observed in the modern nearshore marine environments of southeast Florida (Fourqurean et al., 1995; Corbet et al., 1999; Kroeger et al., 2007), are explored as possible mechanisms. 5.6. 3 Terrestrial Nutrient S ources in the Pliocene Marine phosphate is delivered to modern nearshore marine systems in southwest Florida via riverine input, submarine groundwater discharge (SGD), and occasional upwelling events ( Paluszkeiwicz et al., 1983; McCormick et al., 1998; Wet zel et al., 2005 ). In Rookery Bay (Figure 5.2), marine phosphate concentrations are inversely correlated with salinity (r 2 = 0. 40 ) (Figure 5.6),

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156 indicating that terrestrial input, via rivers or SGD, is a primary nutrient delivery mechanism. However, nutr ient delivery to the nearshore marine system is heavily altered by anthropogenic influences, such as sewage and storm drain discharge, agricultural waste, and restricted flow due to structure an d canal construction (Smith et al., 1989; Brewster Wingard and Ishman, 1999; Fourqurean and Robblee, 1999; Hecker, 2005). Figure 5.6 : Relationship between modern PO 4 SW and salinity. A statistically significant correlation between modern marine phosphate (P O 4 SW ) and salinity from Rookery Bay in southwest Florida suggests terrestrial nutrient sources. Statistical analysis is described in section 5.4.5. (Data provided by SERC FIU.) Previous research establishes the inverse relationship between Pliocene coralline Sr/Ca (SST) and 18 O SW (SSS) (Chapter 4), suggesting an increase in Pliocene winter precipitation, similar to the strong, 1997 98 El Ni–o event. Contrary to what is observed in the modern environment, where summer and winter are also considered the wet and dry seasons, respectively, Pliocene precipitation was slightly higher in the winter than in the summer. However, as is observed in the modern 1997 98 El Ni–o event, summer precipitation was not

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157 abnormally low ( Figure 4.1 in Chapter 4), and total annual Pliocene precipitation was possibly wetter than what is observed in the modern (Hine et al., 2009). Increased annual precipitation would have increased pluvial transport to the nearshore marine environment, concurrent with the proposed prograding deltaic system in southwest Florida during the Pliocene (Cunningam et al., 2003; Hine et al., 2009). Pliocene age quartz pebbles found in southwest Florida also suggest increased fl uvial transport compared to the modern (Cunningam et al., 2003). C oral P/Ca and 18 O SW are not significantly correlated, and nutrient fluctuations are not related to SSS fluctuations. The lack of correlation between P/Ca and both SSS and SST proxies, coupled with the absence of annual frequency variations in the P/Ca ti meseries, eliminates the possibility of annual seasonal precipitation as a nutrient source in the nearshore marine syst em. An alterative hypothesis of Pliocene precipitation patterns suggests continuous yearly precipitation, and a reduced seasonality in t errestrial runoff and nutrient input, which would not be correlated to annual SST or SSS. Modern nearshore marine salinity variations are driven by an increase (decrease) in summer (winter) precipitation (Figure 2.2b in Chapter 2). Conversely, in the Plio cene, salinity was lower in the winter and higher in the summer, estimated from seasonal 18 O SW variations (Chapter 4). T he range of Pliocene 18 O SW is lower than the modern 18 O SW range from the northern end of Ten Thousand Islands in southwest Florida ( Surge et al., 2001) by 0.5, representing a 3.8 psu decrease in average seasonal salinity range in the

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158 Pliocene. The reduced Pliocene salinity range could be the result of intense summer evaporation driving salinity variations rather than seasonal precipi tation. Assuming summer evaporation controlled SSS variations in the Pliocene and seasonal precipitation changes were minimal, nutrient influx related to terrestrial runoff and SGD would be relatively continuous throughout the year and not correlated to S ST or SSS variations. Additionally, small seasonal changes in P/Ca could be smoothed by the bi monthly sample resolution of the record. However, without an independent estimate of Pliocene evaporation rates, this hypothesis is speculative at best. T he la ck of correlation between P/Ca and both SSS and SST proxies, coupled with the absence of annual frequency variations in the P/Ca timeseries does not unequivocally support a terrestrial nutrient source, and suggests either relatively constant annual and/or random nutrient influx to the nearshore marine system 5.7 Conclusions The Pinecrest Member of the Tamiami Fm. represents a high nutrient environment, followed by a nutrient decline at the Plio Pleistocene boundary. This decrease is later than observed env ironmental changes in the Caribbean, suggesting a local, rather than regional, nutrient source. The decrease in nutrients at the Plio Pleistocene boundary also precedes the extinction event observed in southwest Florida. The question of the high Pliocene nutrient source, however, remains unresolved. The lack of an annual frequency pattern in the P/Ca timeseries with no correlation to SST suggests upwelling was not the

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159 primary nutrient source in the Pliocene Pinecrest Member of the Tamiami Fm. Additional ly, the lack of correlation of P/Ca to SST or SSS suggests either continuous annual and/or random episodic nutrient addition.

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160 5.8 Appendix Modern Siderastrea spp. PO 4 SW P/Ca Calibration If Pliocene and Pleistocene marine PO 4 SW could be calculated from coral P/Ca and compared with modern values, a quantitative assessment comparing modern environments with the Pliocene and Pleistocene PO 4 SW would be possible. To determine a genus specific calibration of Siderastrea spp. P/Ca with PO 4 SW geochemical dat a (Sr/Ca and P/Ca) was collected from a modern Siderastrea siderea coral the Dry T ortugas (DeLong et al., in prep; LaVigne and Sliko, unpublished data). Dates were assigned to each sample based on correlation of Sr/Ca variations with measured SST (DeLong et al., in prep). Samples representing ~2.5 years of growth were then compared to water quality data provided by the SERC FIU Water Quality Monitoring Network (SERC FIU). The least squares method of linear regression was used to assess the relationship b etween modern coral P/Ca and PO 4 SW concentrations in the Dry Tortugas. P levels below 0.05 were considered statistically significant, and the regression analysis was performed using Microsoft Excel 2008 for Mac, version 12.2.4 ( 2007 Microsoft Corporatio n). Previously resolved calibrations between modern PO 4 SW and P/Ca in Porites spp. and Pavona spp. corals from Isla Contadora exhibit a positive linear relationship with similar slopes (equations 5.1 and 5.1) (LaVigne et al., 2010). P/Ca in the modern Si derastrea siderea from the Dry Tortugas compared with PO 4 SW also exhibits a positive linear relationship with a slope similar to previous P/Ca PO 4 SW calibrations. P/Ca values corresponding to measured PO 4 SW

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161 ranged from 12.1 "mol/mol to 15.8 "mol/mol, with a mean of 14.9 mol/mol (n = 9, 1 $ = 1.2) The slope and y intercept were calculated from the linear regression to create the following calibration (Equation 5.3, Figure 5.7). P/Ca Siderastrea siderea ( mol/mol) = (18.1 + 5.2) PO 4 SW ( mol/kg) + ( 14.3 + 1.9) (5.3) Based on the Dry Tortugas PO 4 SW concentration range (0.02 0.1 "mol/kg ), the error associated with the above calibrations, and analytical error for P/Ca (2 mol/mol) we calculated 0.01 "mol/kg error on PO 4 SW reconstructed from S. siderea P/C a. However, the brevity of the analyzed coral record (2.5 years) coupled with the scarcity of marine water quality data (collected 4 times annually) limits the statistical strength of the linear regression between the two datasets (r 2 = 0.02) ( F igure 5.7). Nonetheless, the slope and y intercept calculated for the modern Siderastrea spp. P/Ca PO 4 SW relationship is similar to the slope and y intercept of previously published P/Ca relationships for Porites spp. and Pavona spp. given the short study period.

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162 Figure 5.7 : Modern PO 4 SW P/Ca calibration for the Dry Tortugas. Linear regression was calculated from local PO 4 SW (x axis) and Siderastrea siderea coral P/Ca (y axis; see text). The bed averaged mean PO 4 SW for the fossil corals are higher in the Pi necrest Member corals and lower in the Caloosahatchee and Bermont Fms. corals (Table 5.1). Similar to the bed averaged mean PO 4 SW estimates of seasonal marine phosphate from the lower Pinecrest Member of the Tamami Fm. range from 2.5 "mol/kg to 20.4 "mol /kg, with a mean of 7.8 "mol/kg ( n = 484, 1 $ = 2.7)

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163 Table 5.1 : Fossil m arine p hosphate v alues in south Florida. Coral Estimated PO 4 SW ( "mol/kg) n 1 $ Stacked Pancake Morphology Bermont Fm. 2.5 4 0.4 Caloosahatchee Fm. 3.4 2 1.5 Pinecrest Member 7.6 18 2.2 Ball Morphology Bermont Fm. 3.9 16 0.9 Caloosahatchee Fm. 3.5 18 1.2 Pinecrest Member 5.3 2 0.5 Based on the calibration derived from a modern S. siderea from the Dry Tortugas, the calculated marine phosphate values for both the Pliocene and Pleistocene beds are an order of magnitude higher than what is observed in modern comparable nearshore marine environments around the southern Florida Peninsula (0.04 "M/kg 0.31 "M/kg) ( Figure 5.8 and T able 5.2). Some modern environments with high PO 4 SW such as Hillsborough Bay, Ol d Tampa Bay, and Middle Tampa Bay, are low energy with anoxic bottom water subjected to anthropogenic influences, such as sewage and storm drain discharge, agricultural waste, and restricted flow (Baskaran et al., 2007; Kroeger et al., 2007; Swarentzi et a l., 2007) While the Pliocene calculated PO 4 SW is similar to modern PO 4 SW in parts of Tampa Bay, the proposed paleoenvironmental reconstruction for the Pliocene is not comparable with modern Tampa Bay.

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164 Figure 5.8: Modern PO 4 SW site location map. Coll ection sites for south Florida PO 4 SW listed in Table 5.2. (Adapted from the Florida Center for Instructional Technology, USF, 2009). Table 5.2 : Modern m arine p hosphate v alues in south Florida. (Data provided by SERC FIU and EPCHC). Location PO 4 SW ( "mol/kg) n 1 $ Biscayne Bay 0.036 4412 0.038 Florida Bay 0.045 211 0.042 Rookery Bay 0.34 3548 0.45 Ten Thousand Islands 0.24 4328 0.24 Southwest Florida Shelf 0.041 2383 0.037 Dry Tortugas 0.031 740 0.048 Hillsborough Bay 5.64 2898 3.73 Old Tampa Bay 1.93 4002 2.13 Middle Tampa Bay 2.58 2969 3.19 Lower Tampa Bay 0.66 2334 0 .85

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165 Based on previous estimations of paleodepth for the Pinecrest Member of the Tamiami Fm. (section 5.3), the modern lagoonal environments are considered analogous to the southwest Florida Pliocene environment. While modern lagoonal PO 4 SW in southwest Florida is higher than i n Florida Bay Biscayne Bay, and the southwest Florida Shelf PO 4 SW the calculated Pliocene and Pleistocene PO 4 SW is still an order of magnitude higher than what is observed in the modern environment. However, as with the P/Ca data, there is a sharp decre ase in calculated PO 4 SW at the Pinecrest Caloosahatchee, supporting previous theories of a nutrient decline at the (current) Plio Pleistocene boundary. The modern global surface PO 4 SW varies from 0.0 "M/kg to 2.9 "M/kg, with the highest values found in hig h latitudes and in the eastern equatorial Pacific (Garcia et al., 2005). However, the data presented in the World Ocean Atlas (Garcia et al., 2005) mostly represent ocean PO 4 SW and are packaged in 1 o grids and possibly smooth locally high PO 4 SW such as in the southwest Florida lagoonal systems. While the calculated PO 4 SW for the Pliocene is higher than observed global PO 4 SW we suggest that the calculated high PO 4 SW is the result of a low energy, high nutrient environment.

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166 5.9 Chapter References Allmo n, WD, 1993. Age, e nvironment and m ode of d eposition of the d ensely f ossiliferous Pinecrest Sand (Pliocene of Florida): Implications for the r ole of b iological p roductivity in s hell b ed formation. Palaios 8(2):183 201 Allmon, WD, 2001. Nutrients, temp erature, disturbance, and evolution: a model for the late Cenozoic marine record of the western Atlantic. Palaeogeography, Palaeoclimatology, Palaeoecology 166:9 26 Allmon, WD, and JL Knight, 1993. Paleoecological significance of a turritelline gastrop od dominated assemblage in the Cretaceous of South Carolina. Journal of Paleontology 67(3):355 360 Allmon, WD, and PA Cohen, 2003. Paleoecological significance of a turritelline gastropod dominated limestone in the Lower Cretaceous of Texas. GSA Abstr acts with Programs 35:502 Allmon, WD, G Rosenberg, RW Portell, KS Schindler, 1993. Diversity of Atlantic coastal plain mollusks since the Pliocene. Science 260(5114):1626 1629 Allmon, WD, SD Emslie, DS Jones, GS Morgan, 1996. Late Neogene oceanograp hic change along Florida's west coast: Evidence and mechanisms. Journal of Geology 104:143 162 Barth, A, A Alvera Azc‡rate, RH Weisberg, 2008. A nested model study of the Loop Current generated variability and its impact on the West Florida Shelf, Jour nal of Geophysical Research 11 3 : C05009 d oi:10.1029/2007JC004492 Baskaran, M, and PW Swarzenski, 2007. Seasonal variation on the residence times and partitioning of short lived radionuclides ( 237 Th, 7 Be and 210 Pb) and depositional fluxes of 7 Be and 210 P b in Tampa Bay, Florida. Marine Chemistry 104:27 42 Brewster Wingard, G, and SE Ishman, 1999. Historical trends in salinity and substrate in Central Florida Bay: A paleoecological reconstruction using modern analogue data. Estuaries 22(2B):369 383 Br uner, CA, 1984. Evidence for increased volume transport of the Florida current in the Pliocene and Pleistocene. Marine Geology 54:223 235 Collins, LS, 1996. Environmental changes in Caribbean shallow waters relative to the closing Tropical American Se away In: Jackson, JBC, AF Budd, AG Coates (Eds.), Evolution and Environment in Tropical America Chicago: The University of Chicago Press, Chicago, p. 130 167

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170 LaVigne, M, MP Field, E Anagnostou, AG Grottoli, GM Wellington, RM Sherrell, 2008. Skeletal P/Ca tracks upwelling in Gulf of Panama coral: Evidence for a new seawater p hosphate proxy. Geophysical Research Letters 35: L05604, d oi: 10.1029/2007GL031926 LaVigne, M, KA Matthews, AG Grottoli, KM Cobb, E Anagnostou, G Cabioch, RM Sherrell, 2010. Coral skeleton P/Ca proxy for seawater phosphate: Multi colony calibration with a contemporaneous seawater phosphate record. Geochimica et Cosmochimica Acta 74:1282 1293 Lea, DW, GT Shen, EA Boyle, 1989. Corralline barium records temporal variability in equatorial Pacific upwelling. Nature 340:373 376 Lewis, SE, GA Shields BS Kamber, JM Lough, 2007. A multi trace element coral record of land use changes in the Burdekin River catchment, NE Australia. Palaeogeography, Palaeoclimatology, Palaeoecology 246:471 487 Lyons, WG, 1991. Post Miocene species of Latiris Montfort, 1810 (Molluscs: Fasciolariidae) of southern Florida, with a review of regional biostratigraphy. Bulletin of the Florida Museum of Natural History, Biological Sciences 35(3):131 208 Maier Reimer, E, U Mikolajewicz, TJ Crowley, 1990. Ocean general circulation model sensitivity experiment with an open Central American Isthmus. Paleoceanography 5:349 366 Maupin, CR, TM Quinn, RB Halley, 2008. Extracting a climate signal from the skeletal geochemistry of the Caribbean coral Siderastrea siderea Geochemistry, Geophysics, Geosystems 9 : Q12012, d oi:10.1029/2008GC002106 McCormick, PV, RBE Shuford, JG Backus, WC Kennedy, 1998. Spatial and seasonal patterns of periphyton biomass and productivity in the northern Everglades, Florida, U.S.A. Hydrobiologia 362: 185 2 08 McCulloch, M, S Fallon, T Wyndham, E Hendy, J Lough, D Barnes, 2003. Coral record of increased sediment flux to the inner Great Barrier Reef since European settlement. Nature 421:727 730 Meyer, MB, RW Portell, PJ Harries, J Schiffbauer, In prepara tion Paleoenvironmental reconstructions of Pliocene southwest Florida using silica spheres.

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171 Moses, CS, PK Swart, RE Dodge, 2006. Calibration of stable oxygen isotopes in Siderastrea radians (Cnidaria: Scleractinia): Implications for slow growing corals Geochemistry, Geophysics, Geosystems 7: Q09007, doi:10.1029/2005GC001196 O'dea, A, JBC Jackson, H Fortunato, JT Smith, L D'Croz, KG Johnson, JA Todds, 2007. Environmental change preceded Caribbean extinction by 2 million years. Proceedings of the Nat ional Academy of Sciences 104(13):5501 5506 P aillard, D, L Labeyrie, P Yiou, 1996. Macintosh program performs time series analysis, Eos Trans. AGU, 77:379 Paluszkiewicz, T, LP Atkinson, ES Posmentier, CR McClain, 1983. Observations of a Loop Current frontal eddy intrusion onto the West Florida Shelf. Journal of Geophysical Research 88(C14):9639 9651 Petuch, EJ, 1982. Notes on the molluscan paleoecology of the Pinecrest Beds at Sarasota, Florida with the description of Pyruella a stratigraphically important new genus (Gastropoda: Melongenidae). Proceedings of the Academy of Natural Sciences of Philadelphia 134:12 30 Petuch, EJ, 1995. Molluscan diversity in the Late Neogene of Florida: Evidence for a two staged mass extinction. Science 270:275 277 Press, WH, BP Flannery, SA Teukolsky, WT Vetterling, 1992. Numerical recipes in C: The art of scientific computing, p. 398 447. Cambridge University Press, Cambridge. Quinn, TM, FW Taylor, TJ Crowley, SM Link, 1996. Evaluation of sampling resoluti on in coral stable isotope records: A case study using records from New Caledonia and Tarawa. Paleoceanography 11(5):529 542 Rosenthal Y, MP Field, RM Sherrell, 1999. Precise determination of element/calcium ratios in calcareous samples using Sector Fi eld Inductively Couple Plasma Mass Spectrometry. Analytical Chemistry 71:3248 3253 Ršnnberg, C and E Bonsdorff, 2004. Baltic Sea eutrophication: area specific ecological consequences. Hydrobiologia 514:227 241 Schulz M and M Mudelsee, 2002. REDF IT: Estimating red noise spectra directly from unevenly spaced paleoclimatic time series. Computers and Geosciences 28:421 426

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172 SERC FIU. Data were provided by the SERC FIU Water Quality Monitoring Network, which is supported by the SWFWD/SERC Cooperative Agreement #4600000352 as well as EPA Agreement #X7 96419603 3. Data accessed at http://serc.fiu.edu/wqmnetwork/. Smith, TJ, JH Hudson, MB Robblee, GVN Powell, PJ Isdale, 1989. Freshwater flow from the Everglades to Florida Bay: a historical reconstruct ion based on fluorescent banding in the coral Solenastrea bouroni Bulletin of Marine Science 44(1):274 282 Smith, VH, GD Tilman, JC Nekola, 1999. Eutrophication: impacts of excess nutrient inputs on freshwater, marine, and terrestrial ecosystems. Env ironmental Pollution 100:179 196 Sorauf, JE and PJ Harries, 2009. Rotatory colonies of the corals Siderastrea radians and Solenastrea spp. (Cnidaria, Scleractinia), from the Pleistocene Bermont Formation, South Florida, USA. Palaeontology 52(1):111 126 Stanley, SM, 1986. Anatomy of a regional mass extinction: Plio Pleistocene decimation of the Western Atlantic bivalve fauna. Palaios 1:17 36 Surge, D, KC Lohmann, DL Dettman, 2001. Controls on isotopic chemistry of the American oyster, Crassostrea virginica : implications for growth patterns. Palaeogeography, Palaeoclimatology, Palaeoecology 172:283 296 Swarentzi, PW and K Yates, 2007. Tampa Bay as a model estuary for examining the impact of human activities on biogeochemical processes: An introd uction. Marine Chemistry 104:1 3 Vermeij, GJ, 2005. One way traffic in the western Atlantic: causes and consequences of Miocene to early Pleistocene molluscan invasions in Florida and the Caribbean. Paleobiology 31(4):624 642 Vermeij, GJ and EJ Petu ch, 1986. Differential extinction in tropical American molluscs: endemism, architecture, and the Panama Land Bridge. Malacologia 27(1):29 41 Vukovitch, F, 1986. Aspects of the behavior of cold perturbations in the eastern Gulf of Mexico: A case study. Journal of Physical Oceanography 16:689 707 Vukovitch, FM, 2007. Climatology of Ocean Features in the Gulf of Mexico Using Satellite Remote Sensing Data. Journal of Physical Oceanography 37:175 188

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173 Wetzel, PR, AG van der Valk, S Newman, DE Gawlik, TT Gann, CA Coronado Molina, Dl Childers, FH Sklar, 2005. Maintaining tree islands in the Florida Everglades: Nutrient redistribution is the key. Frontiers in Ecology and the Environment 3(7):370 376 Williard, DA, TM Cronin, SE Ishman, RJ Litwin, 1993. Terrestrial and marine records of climatic and environmental changes during the Pliocene in subtropical Florida. Geology 21(8):679 682 Woodring, WP, 1966. The Panama land bridge as a sea barrier. Proceedings of the American Philosophical Societ y 110 (6):425 433 Yonge, CM, 1935. Studies on the biology of Tortugas Corals, II. Variation in the Genus Siderastrea Papers from Tortugas Laboratory 29:200 208

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174 Chapter 6 Conclusions The Pliocene is considered analogous to the predicted consequences of future climate change. However, the temporal resolution of most Pliocene paleoclimate records is too coarse to capture decadal to sub annual variations. Large gastropods found in the Pliocene fossiliferous deposits in Florida were first used to explore their potential as high resolution paleoclimate records. However, the shells of two predatory gastropods, B usycon sinistrum and Fasciolaria tulipa are ina ppropriate for paleoenvironmental reconstructions. While both species' shells faithfully record summer temperatures, neither record winter temperatures. The geochemical analyses of pristine Pliocene Siderastrea spp. corals indicate that salinity variati ons inferred from calculated seasonal seawater 18 O are different from modern salinity seasonal variations. The correlation of lower annual salinity with lower temperatures is interpreted to be a response to an increase in winter precipitation, a teleconnection of the Pliocene "Super El Ni–o." Addit ional geochemical analyses from Pliocene and Pleistocene Siderastrea spp. corals demonstrate that marine phosphate was higher in the Pliocene Lower Pinecrest Member of the Tamiami Formation than in the Pleistocene Caloosahatchee and Bermont Fms.

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175 The near shore marine environment in southwest Florida is characterized as a high nutrient environment with precipitation patterns similar to modern El Ni–o events (increased winter precipitation). The Pliocene nearshore marine environment is different from the mo dern nearshore marine environment of southwest Florida, which is relatively nutrient poor and with predominately summer precipitation. Characterizing the seasonal environmental characteristics of regional Pliocene environments can improve the accuracy of climate models that ultimately help to anticipate future changes in the environment.

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176 Appendices

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177 Appendix A: Modern Gastropod Stable Isotope Data Fasciolaria tulipa from Tampa Bay Sample ID mm from Protoconch 18 O shell () 13 C shell () F 40 20.5 0.32 3.95 F 39 28 0.10 4.12 F 38 50.5 0.10 4.04 J 11 59 2.17 3.32 F 37 68.5 1.46 3.98 J 10 75 0.84 4.15 F 36 82.5 0.42 3.45 F 35 101 0.14 3.61 F 34 120.5 0.05 3.19 J 9 124 0.51 3.08 F 33 127.5 0.31 3.19 J 8 132 0.12 3.52 F 32 136.5 0.09 3.27 F 31 147 0.07 3.25 F 30 154 0.39 3.30 F 29 162.5 0.84 3.15 F 28 171 0.48 3.63 J 6 176 1.55 4.06 F 27 181.5 1.50 4.16 J 5 188 1.11 4.41 F 26 195.5 0.65 3.88 J 4 202 0.09 3.25 F 25 210.5 0.74 2.81 J 3 220 0.37 2. 74 F 24 232 0.01 2.62 F 23 257 0.30 2.07 F 22 280.5 0.71 1.65 F 21 308 0.74 1.63 J 2 316 2.05 2.76 F 20 324 1.38 2.35 J 1 326 1.64 2.32 F 19 328.5 1.00 2.44 F 18 332.5 0.12 2.91 F 17 337 0.77 2.18 F 16 34 0.5 0.69 1.73 F 15 344 0.38 1.36 F 14 348 0.82 2.44 F 13 350 0.90 2.43 F 12 353 1.22 2.22 F 11 355.5 1.07 2.51 F 10 359 1.24 2.20 F 9 362.5 1.18 2.50 F 8 365 0.92 2.67 F 7 367.5 1.77 1.45

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178 Appendix A (continue d): Modern Gastropod Stable Isotope Data Fasciolaria tulipa from Tampa Bay Sample ID mm from Protoconch 18 O shell () 13 C shell () F 6 369.5 1.73 1.55 F 5 371 2.04 1.89 F 4 373.5 1.71 1.35 F 3 375.5 1.54 1.41 F 2 377.5 1.21 1.16 F 1 382 0.76 1.75 Busycon sinistrum from Tampa Bay Sample ID mm from Protoconch 18 O shell () 13 C shell () W 1 0 0.56 2.12 W 2 6 0.07 2.36 W 3 13.5 0.12 2.58 W 4 21 0.34 2.84 W 5 30 0.61 3.04 W 6 37.5 0.21 3.25 W 7 40 0.33 2.82 W 8 43.5 0.24 2.77 W 9 46.5 0.61 3.01 W 10 49 1.01 3.06 W 11 52 0.94 3.03 W 12 55 1.35 3.31 W 13 59.5 1.71 3.46 W 14 63 0.68 3.76 W 15 66.5 1.09 3.29 W 16 70.5 1.10 2.97 W 17 76 0.67 2.93 W 1 8 80 0.97 3.31 W 19 86 0.30 3.59 W 20 92.5 0.82 3.63 W 21 99.5 0.93 4.40 W 22 106 0.58 3.30 W 23 114 1.63 3.74 W 24 122 1.82 4.16 W 25 131 1.37 4.10 W 26 137 1.51 4.19 W 27 144 1.25 3.77 W 28 149 1.04 3.7 5 W 29 158 0.24 3.84 W 31 168 0.52 3.12 W 32 173 0.00 3.52 W 33 178.5 0.02 3.01 W 34 184.5 0.41 3.45 W 35 195 0.75 3.08

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179 Appendix A (continued): Modern Gastropod Stable Isotope Data Fasciolar ia tulipa from St. Joseph Bay Sample ID mm from Protoconch 18 O shell () 13 C shell () PF 1 1 0.31 1.09 PF 2 7 0.44 0.19 PF 3 12.5 0.35 0.40 PF 4 16.5 0.18 0.80 PF 5 19.5 0.79 0.56 PF 6 22.5 0.65 0.05 PF 7 26 1.21 0.70 PF 8 29 1.53 1.70 PF 9 32 1.05 0.92 PF 10 36.5 1 .53 1.55 PF 11 40 1.48 1.24 PF 12 43.5 1.23 1.32 PF 13 46 0.87 1.27 PF 14 48.5 0.66 1.41 PF 15 51.5 0.55 1.48 PF 16 57 0.11 1.25 PF 17 60.5 0.02 1.27 PF 18 63 0.03 1.24 PF 19 69 0.80 0.48 PF 20 75 0.33 1.07 PF 21 80 0.05 2.12 PF 22 84.5 0.60 1.12 Busycon sinistrum from Tampa Bay Sample ID mm from Protoconch 18 O shell () 13 C shell () W 36 200 1.23 3.89 W 37 205.5 1.01 4.11 W 38 211.5 1.18 3.48 W 39 221 1.21 3.79 W 41 229.5 0.33 3.94 W 42 237.5 0.11 3.08 W 43 246.5 0.06 2.57 W 44 256 0.40 2.77 W 45 261 0.49 3.29 W 46 265.5 0.49 3.29 W 47 268.5 1.49 3.16 W 48 272.5 1.33 3.17 W 49 276.5 1.88 3.99 W 50 295.5 1.85 2.50 W 51 300.5 1.68 3.28 W 52 318.5 1.26 2.14 W 53 323 0.99 2.52 W 54 334 1.13 2.30

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180 Appendix A (continued): Modern Gastropod Stable Isotope Data Fasciolaria tulipa from St. Joseph Bay Sample ID mm from Protoconch 18 O shell () 13 C shell () PF 23 90 0.56 1.34 PF 24 98 0.74 0.75 PF 25 106.5 0.85 1.71 PF 26 115.5 0.94 0.91 PF 27 123.5 1.06 0.72 PF 28 133 1.04 0.86 PF 29 140 0.84 0.52 PF 30 150 1.05 0.21 PF 31 153 1.20 0.23 PF 32 162 0.71 0.62 PF 33 166.5 0.56 0.69 PF 34 173.5 0.59 1.02 PF 35 182 0.57 0.57 PF 36 192 0.23 0.86 PF 37 210 0.83 1.19 PF 38 228 1.53 1.10 PF 39 242.5 2.11 1.36 PF 40 254 1.25 1.46 PF 41 264.5 0.94 0.66 PF 42 289.5 0.93 0.25 PF 43 291.5 0.98 0.71 Busycon sinistrum from St. Joseph Bay Sample ID mm from Protoconch 18 O shell () 13 C shell () SS 1 2 2.27 0.46 SS 2 4.5 2.37 0.44 SS 3 7.5 1.66 0.32 SS 4 12.5 2.37 0.38 SS 5 14.5 1.93 0.45 SS 6 17.5 1.48 0.43 SS 7 20 1.68 0.49 SS 8 22 1.72 0.53 SS 9 23.5 1.53 0.67 SS 10 26 1.95 0.78 SS 11 28.5 1.54 0.83 SS 12 30 1.36 0.49 SS 13 33 1.67 0.65 SS 14 35 1.64 0.67 SS 15 37 1.22 0.26 SS 16 39.5 1.53 1.10 SS 17 42 1.13 1.12 SS 18 44 1.32 1.25 SS 19 46 1.19 1.92 SS 20 48 1.03 1.03

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181 Appendix A (continued): Modern Gastropod Stable Isotope Data Busycon sinistrum from St. Joseph Bay (cont.) Sample ID mm from Protoconch 18 O shell () 13 C shell () SS 21 49.5 0.08 1.55 SS 22 51 0.84 1.66 SS 23 54 0.22 1.35 SS 24 57 0.02 1.64 SS 25 60 0.29 1.77 SS 26 62 0.19 1.44 SS 27 65 1.67 1.34 SS 28 68.5 2.07 0.81 SS 29 73 1.47 0.91 SS 30 78 0 .87 1.57 SS 31 83 0.73 1.53 SS 32 89.5 0.11 1.61 SS 33 97 0.24 1.02 SS 34 103 0.68 1.47 SS 35 109.5 0.57 1.27 SS 36 116 0.76 0.76 SS 37 122.5 0.99 0.69 SS 38 129.5 0.77 1.00 SS 39 137 0.99 0.71 SS 40 141 0.92 0.62 SS 41 146.5 0.92 0.76 SS 42 151.5 0.96 0.71 SS 43 156.5 1.18 0.15 SS 44 161 0.65 0.01 SS 45 165.5 0.36 0.67 SS 46 172 0.30 0.37 SS 47 176.5 0.46 0.75 SS 48 180.5 0.23 0.75 SS 49 186 0.95 1.08 SS 50 193 0.5 5 0.61 SS 51 198.5 0.45 0.80 SS 52 204 0.77 1.80 SS 53 210 0.98 1.21 SS 54 217 1.65 1.77 SS 55 224 1.41 1.08 SS 56 231 1.35 0.85 SS 57 235 1.86 1.41 SS 58 239.5 1.96 1.61 SS 59 245 2.08 1.38 SS 60 249 1.01 1.28 SS 61 254.5 0.99 0.77 SS 62 260 0.54 0.65 SS 63 265.5 0.60 0.66 SS 64 270 0.41 0.69

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182 Appendix A (continued): Modern Gastropod Stable Isotope Data Busycon sinistrum from St. Joseph Bay (cont.) Sample ID mm from Protoconch 18 O shell () 13 C shell () SS 65 272.5 0.56 1.60 SS 66 278 0.48 1.56 SS 67 287.5 0.19 0.73 SS 68 298.5 0.77 0.32

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183 Appendix B: Pliocene Siderastrea spp. Stable I sotope and Sr/Ca D ata UF35438 Track A Re lative Year Sr/Ca (mmol/mol) 18 O () 13 C () Calculated 18 O SW () 81.73 8.855 3.08 1.84 0.86 81.56 8.842 3.02 1.46 0.99 81.40 8.868 3.20 1.34 0.67 81.23 8.907 3.29 1.28 0.37 81.06 8.929 3.07 1.13 0.47 80.90 8.931 3. 09 1.16 0.44 80.73 8.902 3.35 1.34 0.34 80.56 8.802 3.44 1.47 0.79 80.40 8.811 3.27 1.31 0.91 80.23 8.918 2.90 1.33 0.70 80.06 9.152 2.51 1.05 0.18 79.90 9.139 2.62 1.45 0.21 79.73 9.109 3.12 1.75 0.54 79.56 8.965 3.18 1.82 0.17 79.40 8.975 2.99 1.00 0.31 79.23 9.079 2.58 0.91 0.16 79.06 9.120 2.86 1.19 0.35 78.90 9.115 3.20 1.29 0.66 78.73 8.918 3.26 1.17 78.56 8.902 3.53 1.25 78.40 9 .003 3.18 0.56 78.23 9.020 2.83 0.04 78.06 9.080 2.44 0.31 77.90 8.967 2.49 1.00 77.73 8.921 3.05 1.94 77.56 8.869 3.27 2.28 77.40 8.908 3.08 2.24 77.23 8.974 2.86 2.16 77.06 9.001 3.15 2.29 76.90 9.000 3.37 2.37 76.73 8.960 3.45 2.39 76.56 8.888 3.54 2.41 Overlap onto Track B 76.40 8.914 3.49 2.28 UF35438 Track B Relative Year Sr/Ca (mmol/mol) 18 O () 13 C () Calculated 18 O SW () 78.73 8.908 3.22 1.29 0.44 78.56 8.871 3.55 1.01 0.31 78.40 8.945 3.09 0.47 0.37 78.23 9.018 2.71 0.51 0.35 78.06 9.060 2.83 1.27 0.01 77.90 8.977 2.94 2.18 0.34

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184 Appendix B (cont ): Pliocene Siderastrea spp. Stable I sotope and Sr/Ca D ata UF35438 Track B Relative Year Sr/Ca (mmol/mol) 18 O () 13 C () Calculated 18 O SW () 77.73 8.921 3.15 2.44 0.44 77.56 8.856 3.43 2.39 0.51 77.40 8.889 3.18 1.91 0.57 77.23 8.948 3.25 1.88 0.19 77.06 8.974 3.47 2.13 0.17 76.90 8.948 3.45 2.19 0.01 76.73 8.922 3.42 2.25 0.16 76.56 8.898 3.39 2.29 0.32 76.40 8.914 3.26 1.84 0.37 76.23 9.057 2.77 1.35 0.08 76.06 9.107 2.84 1.34 0.26 75.89 9.059 3.16 1.27 0.32 75.73 8.956 3.50 1.56 0.10 75.56 8.932 3.33 1.39 0.20 75.39 9.032 2.80 1.00 0.19 75.23 9.120 2.55 0.91 0.04 75.06 9.187 2.57 1.11 0.42 74.89 9.090 3.15 1.72 0 .47 74.73 8.992 3.62 1.86 0.42 74.56 8.967 3.50 1.55 0.16 74.39 9.051 2.71 1.07 0.17 74.23 9.163 2.48 1.30 0.20 74.06 9.172 3.01 1.25 0.78 73.89 9.161 3.40 1.52 1.11 73.73 9.012 3.42 1.56 0.32 73. 56 8.957 3.12 1.55 0.27 73.39 9.059 2.84 1.45 0.00 73.23 9.047 3.03 2.08 0.12 73.06 9.126 3.56 2.01 1.08 72.89 8.999 3.54 1.89 0.38 72.73 8.922 3.52 2.18 0.06 72.56 8.906 3.42 1.79 0.24 72.39 8.960 3.02 1.28 0.35 72.23 9.075 2.88 1.65 0.12 72.06 9.103 3.11 1.83 0.50 71.89 9.018 3.52 2.00 0.46 71.73 8.942 3.58 1.78 0.10 71.56 8.918 3.13 1.20 0.47 71.39 8.999 2.80 1.33 0.36 71.23 9.046 2.78 1.41 0.13 71.06 9.067 3.00 1.45 0.20 70.89 9.056 3.46 1.58 0.60 70.73 8.982 3.64 1.77 0.38 70.56 8.942 3.52 1.71 0.05

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185 Appendix B (cont ): Pliocene Siderastrea spp. Stable I sotope and Sr/Ca D ata UF35438 Track B Relative Year Sr/Ca (mmol/ mol) 18 O () 13 C () Calculated 18 O SW () 70.39 9.015 3.11 0.90 0.03 70.23 9.122 2.64 0.97 0.13 70.06 9.124 2.62 1.16 0.12 69.89 9.099 3.20 1.38 0.57 69.73 9.045 3.46 1.50 0.55 69.56 8.999 3.33 1.22 0.17 69.39 9.059 2.97 0.87 0.13 69.23 9.086 3.02 1.11 0.32 69.06 9.108 3.32 1.29 0.74 68.89 9.050 3.54 1.36 0.65 68.73 8.994 3.53 1.25 0.34 68.56 8.932 3.23 0.96 0.30 68.39 9.024 2.85 0.85 0.18 68.23 9.0 63 2.84 0.95 0.02 68.06 9.088 3.02 1.07 0.33 67.89 9.060 3.55 1.21 0.72 67.73 8.998 3.78 1.20 0.61 67.56 8.943 3.56 0.93 0.09 67.39 9.001 3.16 0.71 0.00 67.23 9.059 2.85 0.86 0.01 67.06 9.079 2.66 1. 30 0.07 66.89 9.034 2.73 1.47 0.25 66.73 8.989 2.80 1.63 0.42 66.56 8.959 2.86 1.78 0.52 66.39 9.009 2.91 1.90 0.20 66.23 9.040 3.06 1.89 0.11 66.06 9.051 3.23 1.80 0.34 65.89 9.023 3.23 1.65 0.19 65 .73 9.001 3.20 1.48 0.04 65.56 9.001 3.02 1.24 0.13 65.39 9.009 2.87 1.07 0.24 65.23 9.036 2.78 1.13 0.19 65.06 9.051 2.76 1.20 0.13 64.89 9.011 3.06 1.38 0.04 64.73 8.997 3.32 1.54 0.15 64.56 8.975 3.31 1.49 0.02 64.39 9.025 2.83 0.85 0.20 64.23 9.149 2.38 0.77 0.02 64.06 9.181 2.38 1.33 0.20 63.89 9.100 3.27 1.51 0.65 63.73 9.080 3.46 1.53 0.74 63.56 9.040 3.12 1.12 0.18 63.39 9.059 2.79 0.78 0.05 63.23 9.073 2.58 0.94 0.18

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186 Appendix B (cont ): Pliocene Siderastrea spp. Stable I sotope and Sr/Ca D ata UF35438 Track B Relative Year Sr/Ca (mmol/mol) 18 O () 13 C () Calculated 18 O SW () 63.06 9.067 2.51 1.34 0.29 62.89 8.991 2.77 1.81 0.44 62.73 8.967 3.03 2.11 0.30 62.56 8.968 3.20 2.14 0.13 62.39 8.977 2.99 1.46 0.29 62.23 9.018 2.80 1.25 0.26 62.06 9 .058 2.69 1.29 0.16 61.89 9.049 2.80 1.51 0.10 61.73 9.039 2.91 1.72 0.04 61.56 9.037 3.02 1.87 0.06 61.39 9.061 3.17 1.82 0.34 61.23 9.086 3.31 1.77 0.61 61.06 9.103 3.50 1.69 0.90 60.89 9.089 3.75 1. 54 1.07 60.73 9.038 3.55 1.35 0.60 60.56 9.003 3.25 0.92 0.11 60.39 9.076 2.82 0.69 0.07 60.23 9.142 2.68 0.93 0.28 60.06 9.161 2.72 1.36 0.43 59.89 9.089 3.31 1.71 0.63 59.72 9.042 3.29 1.75 0.36 59.56 9.024 2.94 1.30 0.09 59.39 9.120 2.56 1.28 0.05 59.22 9.159 2.57 1.47 0.27 59.06 9.164 2.77 1.69 0.49 58.89 9.111 3.08 1.73 0.52 58.72 9.037 3.22 1.49 0.26 58.56 9.019 3.13 1.08 0.07 58.39 9.0 56 2.72 0.61 0.14 58.22 9.212 2.39 0.97 0.37 58.06 9.218 2.68 1.26 0.70 57.89 9.192 3.00 1.39 0.88 57.72 9.118 3.16 1.21 0.64 57.56 9.066 3.02 0.94 57.39 9.106 2.95 1.04 57.22 9.047 3.02 1.09 57.06 9.104 3.14 1.01 56.89 9.084 3.40 1.00 56.72 9.040 3.41 0.92 56.56 9.044 3.27 0.81 56.39 9.052 2.95 0.68 56.22 9.132 2.90 0.81 56.06 9.117 2.98 0.97 Overlap onto Track E 55.89 9.038 3.25 1.09

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187 A ppendix B (cont ): Pliocene Siderastrea spp. Stable I sotope and Sr/Ca D ata UF35438 Track E Relative Year Sr/Ca (mmol/mol) 18 O () 13 C () Calculated 18 O SW () 57.56 9.067 2.93 1.12 0.13 57.39 9.076 3.47 1.61 0.72 57.22 9.087 3.54 0.91 0.85 57.06 9.084 2.55 0.97 0.16 56.89 9.080 2.72 1.15 0.01 56.72 9.039 3.22 1.23 0.27 56. 56 9.014 3.31 0.88 0.22 56.39 9.057 2.11 0.39 0.75 56.22 9.092 2.24 0.50 0.43 56.06 9.108 3.36 0.82 0.78 55.89 9.058 4.02 1.08 1.18 55.72 9.060 4.09 1.02 1.25 55.56 9.007 3.22 0.39 0.10 55.39 8.925 3.3 5 2.03 0.22 55.22 8.956 4.08 2.85 0.68 55.06 9.038 3.31 2.53 0.35 54.89 9.088 2.35 2.15 0.34 54.72 9.076 2.10 1.93 0.65 54.56 9.028 2.02 2.08 0.99 54.39 8.980 2.19 2.31 1.08 54.22 8.975 2.80 2.60 0.49 54.06 9.091 3.01 2.48 0.35 53.89 9.135 3.15 2.28 0.72 53.72 8.952 3.29 2.07 53.56 8.996 3.23 1.95 53.39 9.035 3.12 1.84 53.22 9.064 3.01 1.74 53.06 8.997 2.67 1.37 Overlap onto Track C 52.89 9.049 2. 37 1.22

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188 Appendix B (cont ): Pliocene Siderastrea spp. Stable I sotope and Sr/Ca D ata UF35438 Track C Relative Year Sr/Ca (mmol/mol) 18 O () 13 C () Calculated 18 O SW () 57.56 9.060 2.94 1.10 57.39 9.007 2.97 1.90 57.22 9.058 2.98 1.84 Overlap onto Track B 57.06 8.956 3.00 1.79 55.72 9.090 2.94 1.10 55.56 9.014 2.97 1.90 55.39 8.926 2.98 1.84 55.22 8.964 3.00 1.79 55.06 9.008 3.01 1.73 54.89 9.108 3.03 1.69 54.72 9.082 3.07 1.67 54.56 8.998 3.10 1.64 54.39 9.000 3.14 1.61 54.22 9.0 15 3.18 1.59 54.06 9.092 3.21 1.56 Overlap onto Track E 53.89 9.085 3.25 1.53 53.72 8.995 3.29 0.73 0.11 53.56 8.957 2.99 1.56 0.40 53.39 8.956 3.02 2.07 0.38 53.22 9.005 2.82 1.80 0.31 53.06 9.034 3.38 1.96 0.40 52 .89 9.037 3.20 1.99 0.24 52.72 9.040 2.93 2.15 0.01 52.56 8.963 2.94 2.16 0.42 52.39 8.903 2.96 2.02 0.72 52.22 8.930 3.23 1.80 0.30 52.06 9.055 2.89 1.51 0.03 51.89 9.100 2.90 1.42 0.28 51.72 9.017 3.19 1.60 0.13 51.56 8.951 3.07 1.59 0.36 51.39 8.998 2.90 1.50 0.27 51.22 9.090 3.00 1.68 0.32 51.06 9.142 3.18 1.80 0.78 50.89 9.098 3.27 1.88 0.64 50.72 8.994 3.26 1.92 0.07 50.56 8.966 3.27 1.88 0.07 50.39 9.033 3.14 1.72 0.16 50.22 9.153 2.84 1.44 0.50 50.06 9.172 2.73 1.51 0.49 49.89 9.170 2.80 1.76 0.55 49.72 9.016 3.01 2.25 0.07

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189 Appendix B (cont ): Pliocene Siderastrea spp. Stable I sotope and Sr/Ca D ata UF3543 8 Track C Relative Year Sr/Ca (mmol/mol) 18 O () 13 C () Calculated 18 O SW () 49.56 8.927 3.07 2.47 0.48 49.39 8.924 2.90 2.29 0.67 49.22 8.969 2.70 2.19 0.62 49.06 9.079 2.76 2.26 0.03 48.89 9.079 2.79 2.37 0.05 48.72 9.000 2.91 2.40 0.25 48.56 8.921 3.03 2.43 0.56 48.39 8.909 2.96 2.33 0.69 48.22 8.963 2.49 2.04 0.87 48.06 9.088 2.53 1.96 0.16 47.89 9.081 3.03 1.99 0.31 47.72 8.983 2.84 1.73 0.42 47.56 8.908 3.03 1.89 0.63 47.39 8.902 2.98 1.7 7 0.71 47.22 8.932 2.52 1.21 1.00 47.06 8.891 2.32 1.01 1.43 46.89 8.877 2.47 1.11 1.36 46.72 9.000 2.72 1.22 0.44 46.56 9.073 3.04 1.25 0.27 46.39 9.208 3.17 1.50 1.13 46.22 9.207 3.21 1.63 1.16 46. 06 9.103 3.16 1.43 0.55 45.89 9.145 2.82 1.39 0.44 45.72 9.173 2.48 1.36 0.25 45.56 9.184 2.63 1.31 0.46 45.39 9.216 2.84 1.26 0.84 45.22 9.203 3.00 1.25 0.93 45.06 9.137 3.10 1.31 0.68 44.89 9.045 3 .17 1.32 0.25 44.72 9.029 3.13 1.18 0.12 44.56 9.012 3.09 1.04 0.00 44.39 9.036 2.96 0.93 0.01 44.22 9.072 2.68 0.87 0.10 44.06 9.098 2.61 1.01 0.02 43.89 9.096 3.00 1.14 0.36 43.72 9.021 3.41 0.96 0.36 43.56 8.999 3.46 1.09 0.29 43.39 9.002 2.61 1.26 0.54 43.22 9.079 2.76 1.46 0.02 43.05 9.141 2.61 1.53 0.21 42.89 9.083 2.71 1.78 0.01 42.72 9.064 3.21 2.28 0.39 42.55 8.962 3.37 2.30 0.00 42.39 8. 939 3.16 2.11 0.32

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190 Appendix B (cont ): Pliocene Siderastrea spp. Stable I sotope and Sr/Ca D ata UF35438 Track C Relative Year Sr/Ca (mmol/mol) 18 O () 13 C () Calculated 18 O SW () 42.22 9.053 2.68 1.52 0.20 42.05 9.046 2.75 1.58 0.16 41.89 8.998 3.07 1.70 0.10 41.72 8.936 3.29 1.78 0.21 41.55 8.907 3.16 1.64 0.50 41.39 8.930 2.97 1.53 0.57 41.22 8 .972 2.77 1.59 0.54 41.05 9.014 2.57 1.65 0.52 40.89 9.016 2.49 1.73 0.58 40.72 8.996 2.67 1.85 0.51 40.55 8.951 2.87 1.82 0.55 40.39 8.950 2.94 1.65 0.49 40.22 8.977 2.71 1.27 0.57 40.05 9.046 2.62 1.26 0 .29 39.89 9.044 2.68 1.40 0.24 39.72 8.998 3.07 1.66 0.10 39.55 8.929 3.13 1.79 0.41 39.39 8.932 2.50 1.72 1.03 39.22 8.971 2.67 1.52 0.64 39.05 9.047 2.62 1.38 0.29 38.89 9.043 2.61 1.31 0.32 38.72 9.0 09 2.83 1.40 0.28 38.55 8.956 2.95 1.48 0.45 38.39 8.993 2.93 1.45 0.26 38.22 9.053 2.69 1.20 0.19 38.05 9.109 2.76 1.31 0.18 37.89 9.098 2.97 1.52 0.34 37.72 9.031 3.19 1.63 0.20 37.55 8.979 2.94 1.43 0.33 37.39 9.019 2.54 1.28 0.52 37.22 9.043 2.29 1.27 0.64 37.05 9.039 2.62 1.64 0.33 36.89 9.032 2.96 1.85 0.03 36.72 9.011 3.27 1.80 0.17 36.55 8.982 2.99 1.78 0.26 36.39 8.988 2.82 1.73 0.41 36.22 9 .028 2.49 1.34 0.52 36.05 9.127 2.48 1.26 0.00 35.89 9.091 2.46 1.48 0.21 35.72 9.000 2.96 1.71 0.20 35.55 8.931 3.20 1.55 0.34 35.39 8.930 3.17 1.60 0.37 35.22 9.049 2.81 1.36 0.09 35.05 9.125 2.41 1.11 0 .08

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191 Appendix B (cont ): Pliocene Siderastrea spp. Stable I sotope and Sr/Ca D ata UF35438 Track C Relative Year Sr/Ca (mmol/mol) 18 O () 13 C () Calculated 18 O SW () 34.89 9.099 2.62 1.27 0.01 34.72 9.053 3.08 1.41 0.21 34.55 9.014 3.12 1.56 0.03 34.39 9.013 3.31 1.57 0.22 34.22 9.061 2.91 1.30 0.07 34.05 9.072 2.78 1.20 0.00 33. 89 9.054 2.96 1.27 0.09 33.72 8.996 3.28 1.36 0.10 33.55 8.970 3.26 1.26 0.06 33.39 8.984 3.06 1.09 0.19 33.22 9.024 2.88 0.95 0.15 33.05 9.065 2.74 0.91 0.07 32.89 9.037 2.71 1.05 0.25 32.72 8.993 3.20 1.38 0.00 32.55 8.946 3.53 1.64 0.08 32.39 9.047 3.26 1.40 0.35 32.22 9.110 2.55 1.09 0.01 32.05 9.119 2.69 1.20 0.17 31.89 9.115 3.12 1.16 0.58 31.72 9.041 3.27 1.21 0.33 31.55 8.953 3.24 1.41 0.18 31.39 8.986 3.03 1.49 0.21 31.22 9.046 2.67 1.44 0.24 31.05 9.088 2.88 1.56 0.20 30.89 9.070 3.17 1.73 0.39 30.72 8.986 3.29 1.78 0.06 30.55 8.941 3.24 1.61 0.24 30.39 8.971 3.21 1.42 0.11 30.22 9.026 2.90 1.37 0.12 30.05 9.047 3.01 1.33 0.10 29.89 9.041 3.10 1.38 0.17 29.72 9.024 3.25 1.36 0.22 29.55 8.995 3.27 1.27 0.08 29.39 9.019 2.91 0.93 0.15 29.22 9.121 2.48 0.63 0.02 29.05 9.140 2.36 0.61 0.0 4 28.89 9.128 2.51 0.67 0.04 28.72 9.104 2.80 0.60 0.20 28.55 9.084 2.83 0.75 0.12 28.39 9.100 2.83 0.92 0.21 28.22 9.120 2.75 1.24 0.23 28.05 9.146 2.80 1.26 0.43 27.89 9.089 2.93 1.15 0.25 27.7 2 9.045 3.02 1.27 0.10

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19 2 Appendix B (cont ): Pliocene Siderastrea spp. Stable I sotope and Sr/Ca D ata UF35438 Track C Relative Year Sr/Ca (mmol/mol) 18 O () 13 C () Calculated 18 O SW () 27.55 9.021 3.13 1.26 0.08 27.39 9.094 3.17 1.16 0.51 27.22 9.124 2.73 1.00 0.24 27.05 9.148 2.50 1.07 0.14 26.89 9.128 2.96 0.99 0.48 26.72 9.042 3.34 0.80 26.55 9.020 3.24 0.68 26.39 9.014 3.00 0.67 26.22 9.086 2.74 0.42 26.05 9.044 2.26 0.53 25.88 9.073 1.92 0.85 25.72 9.067 2.07 0.87 25.55 9.031 2.23 0.89 25.38 9.003 2.36 0.91 25. 22 9.063 2.39 0.87 25.05 9.144 2.42 0.82 24.88 9.140 2.48 0.80 24.72 9.086 2.77 0.93 24.55 9.034 2.87 1.10 24.38 8.988 2.84 1.28 24.22 9.002 2.78 1.37 24.05 9.020 2.72 1.47 23.88 8.997 2.67 1.55 23.72 8.952 2.79 1.49 23.55 8.900 3.27 1.43 23.38 8.931 3.33 1.31 23.22 8.992 2.96 1.07 Overlap onto Track D 23.05 9.011 2.22 1.10 UF35438 Track D Relative Year Sr/Ca (mmol/mol) 18 O () 13 C () Calculated 18 O SW () 26.72 9.058 2.92 0.75 0.07 26.55 9.055 3.39 0.83 0.52 26.39 9.038 3.21 0.86 0.26 26.22 9.053 2.95 1.12 0.07 26.05 9.057 2.82 1.37 0.04 25.88 9.055 2.86 1.55 0.01 25.72 9.052 3.29 1.43 0.41 25.55 9.016 3.50 1.40 0.43 25.38 8.987 2.87 1.18 0.37 25.22 9.065 2.76 1.08 0.05

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193 Appendix B (cont ): Pliocene Siderastrea spp. Stable I sotope and Sr/Ca D ata UF35438 Track D Relative Year Sr/Ca (mmol/mol) 18 O () 13 C () Calculated 18 O SW () 25.05 9.115 2.65 1.10 0.11 24.88 9.133 2.53 1.24 0.08 24.72 9.087 3.25 1.05 0.56 24.55 9.072 3.54 0.90 0.77 24.38 8.995 3.52 1.24 0.33 24.22 9.002 3.15 1.17 0.00 24 .05 9.029 2.81 1.05 0.20 23.88 9.077 2.51 0.86 0.24 23.72 8.992 2.73 1.46 0.48 23.55 8.908 3.36 1.35 0.30 23.38 8.898 3.47 1.41 0.24 23.22 8.944 3.22 1.67 0.24 23.05 8.993 3.39 1.57 0.20 22.88 8.995 3.23 1.66 0.05 22.72 8.997 3.46 1.52 0.29 22.55 8.989 3.46 1.35 0.24 22.38 8.970 3.24 1.16 0.08 22.22 9.021 3.10 1.38 0.05 22.05 9.058 3.11 1.52 0.26 21.88 9.080 3.28 1.57 0.55 21.72 9.066 3.36 1.58 0.55 21.55 9.036 3.39 1.59 0.42 21.38 8.989 3.36 1.61 0.14 21.22 9.028 2.70 1.24 0.31 21.05 9.065 3.16 1.57 0.35 20.88 9.096 3.57 1.71 0.93 20.72 9.054 3.34 1.58 0.47 20.55 9.021 3.24 1.38 0.19 20.38 8. 999 3.29 1.09 0.13 20.22 9.059 2.91 0.98 0.07 20.05 9.088 2.70 1.05 0.01 19.88 9.080 2.68 1.28 0.04 19.72 9.098 2.65 1.57 0.02 19.55 9.062 2.96 1.56 0.13 19.38 9.005 3.04 0.96 0.09 19.22 9.010 2.96 1. 17 0.14 19.05 9.023 3.13 1.46 0.09 18.88 9.025 3.38 1.37 0.36 18.72 8.993 3.41 1.38 0.20 18.55 8.965 3.31 1.31 0.04 18.38 8.944 3.08 1.14 0.38 18.22 9.029 2.98 0.91 0.03 18.05 9.023 2.89 1.17 0.15 17 .88 9.034 3.05 1.42 0.07

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194 Appendix B (cont ): Pliocene Siderastrea spp. Stable I sotope and Sr/Ca D ata UF35438 Track D Relative Year Sr/Ca (mmol/mol) 18 O () 13 C () Calculated 18 O SW () 17.72 8.999 3.23 1.42 0.07 17.55 8.978 3.21 1.33 0.07 17.38 8.954 3.07 1.09 0.34 17.22 8.967 2.97 1.13 0.37 17.05 8.981 2.87 1.17 0.40 16.88 8.994 2.77 1.21 0.42 16.72 8.973 2.79 1.34 0.51 16.55 8.951 2.82 1.48 0.60 16.38 8.929 2.85 1.62 0.70 16.22 8.949 3.07 1.56 0.37 16.05 8.970 3.30 1.49 0.02 15.88 8.970 3.31 1.45 0.01 15.72 8.970 3.32 1.42 0.01 15.55 8.964 3.18 1.28 0.18 15.38 8.958 3.03 1.14 0.36 15.22 9.029 2.86 1.18 0.15 15.05 9.076 2.83 1.24 0.08 14.88 9.094 2.97 1.33 0.31 14.72 9.076 3.16 1.40 0.41 14.55 9.048 3.27 1.45 0.36 14.38 9.006 3.26 1.45 0.13 14. 22 9.013 2.89 1.24 0.20 14.05 9.026 2.80 1.14 0.22 13.88 9.043 3.05 1.15 0.12 13.72 9.037 3.12 1.09 0.16 13.55 9.012 3.45 1.10 0.35 13.38 8.976 3.34 0.96 0.05 13.22 8.996 3.13 0.96 0.05 13.05 9.025 3.05 0.95 0.02 12.88 9.064 3.13 0.94 0.31 12.72 9.060 3.29 1.07 0.46 12.55 9.016 3.35 1.16 0.28 12.38 9.002 3.19 0.89 0.04 12.22 9.027 3.13 0.91 0.11 12.05 9.055 3.06 0.94 0.19 11.88 9.082 3.00 0.97 0.2 8 11.72 9.060 2.96 0.98 0.12 11.55 9.036 2.92 0.99 0.05 11.38 9.012 2.88 0.99 0.22 11.22 9.026 2.94 1.03 0.08 11.05 9.041 3.00 1.07 0.06 10.88 9.056 3.07 1.10 0.21 10.72 9.019 3.14 1.16 0.09 10.55 8 .988 3.15 1.19 0.07

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195 Appendix B (cont ): Pliocene Siderastrea spp. Stable I sotope and Sr/Ca D ata UF35438 Track D Relative Year Sr/Ca (mmol/mol) 18 O () 13 C () Calculated 18 O SW () 10.38 8.966 3.08 1.21 0.26 10.22 8.981 3.06 1.16 0.20 10.05 8.999 3.04 1.11 0.13 9.88 9.016 3.01 1.06 0.06 9.72 9.010 2.87 1.14 0.24 9.55 9.004 2.77 1.22 0.37 9.38 9.001 2.74 1.28 0.42 9.21 9.015 2.77 1.27 0.31 9.05 9.029 2.82 1.26 0.19 8.88 9.044 2.86 1.24 0.07 8.71 9.011 2.92 1.26 0.18 8.55 8.976 3.03 1.32 0.26 8.38 8.952 3.11 1.32 0.31 8.21 8.957 3.03 1.15 0.36 8. 05 8.977 2.68 0.99 0.60 7.88 8.986 2.67 1.09 0.57 7.71 8.963 3.21 1.53 0.15 7.55 8.951 3.43 1.41 0.01 7.38 8.946 3.43 1.30 0.03 7.21 8.974 3.19 1.19 0.11 7.05 9.016 3.05 1.31 0.02 6.88 9.044 3.03 1.50 0. 11 6.71 9.035 3.08 1.54 0.10 6.55 8.994 3.08 1.39 0.11 6.38 8.956 2.97 1.11 0.43 6.21 8.990 2.94 1.16 0.28 6.05 9.013 2.93 1.20 0.16 5.88 9.016 2.95 1.18 0.13 5.71 8.996 3.21 1.38 0.03 5.55 8.968 3.3 6 1.38 0.03 5.38 8.961 3.27 1.19 0.09 5.21 9.057 2.87 0.75 0.02 5.05 9.082 2.52 1.00 0.20 4.88 9.101 2.96 1.49 0.34 4.71 9.088 3.26 1.42 0.58 4.55 8.964 3.38 1.30 0.03 4.38 8.956 3.12 0.93 0.27 4. 21 8.952 2.97 0.86 0.44 4.05 8.973 2.96 0.77 0.35 3.88 9.020 3.08 0.66 0.03 3.71 9.001 3.17 0.68 0.02 3.55 8.978 3.26 0.71 0.01 3.38 8.955 3.35 0.74 0.05 3.21 8.978 3.21 0.65 0.07

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196 Appendix B (cont ): Pliocene Siderastrea spp. Stable I sotope and Sr/Ca D ata UF35438 Track D Relative Year Sr/Ca (mmol/mol) 18 O () 13 C () Calculated 18 O SW () 3.05 9.033 2.99 1.06 0.01 2.88 9.052 2.97 0.98 0.09 2.71 9.029 3.07 0.98 0.06 2.55 9.031 2.96 0.81 0.03 2.38 8.988 2.94 0.80 0.28 2.21 9.039 2.91 1.16 0.04 2.05 9.056 2.92 0.79 0.06 1.88 9.077 2.84 0.87 0.10 1.71 9.057 2.83 0.88 0.02 1.55 9.035 2.85 0.97 0.12 1.38 9.014 2.92 1.17 0.17 1.21 9.034 2.81 1.03 0.16 UF35931 Relative Year Sr/Ca (mmol/mol) 18 O () 13 C () Calculated 18 O SW () 24.12 9.038 2.96 1.31 0.15 23.95 9.001 3.15 1.12 0.13 23.79 9.035 2.94 1.14 0.12 23.62 9.096 2.67 1.26 0.20 23.45 9.121 2.81 1.43 0.49 23.29 9.098 3.03 1.38 0.57 23.12 9.039 3.22 1.17 0.42 22.95 8.985 3.27 1.26 0.16 22.79 8.992 3.24 1.05 0.17 22.62 9.111 2.99 1.09 0.60 22.45 9.195 2.45 1.50 0.56 22.29 9.193 2.19 1.61 0.28 22.12 9.170 2.33 1.54 0.30 21.95 9.097 2.74 1.46 0.28 21.79 9.067 2.87 1.27 0.23 21.6 2 9.090 2.70 1.05 0.19 21.45 9.163 2.44 1.11 0.36 21.29 9.129 2.53 1.73 0.25 21.12 8.981 3.12 1.91 0.02 20.95 8.852 3.43 1.57 0.46 20.79 8.862 3.30 1.40 0.53 20.62 8.926 2.96 1.41 0.50 20.45 9.010 2.68 1.58 0.29 2 0.29 9.033 2.64 1.69 0.20 20.12 8.968 3.10 1.83 0.12 19.95 8.917 3.08 1.73 0.44 19.79 8.885 3.13 1.54 0.57 19.62 8.925 2.98 1.42 0.48

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197 Appendix B (cont ): Pliocene Siderastrea spp. Stable I sotope and Sr/Ca D ata UF35931 Relative Year S r/Ca (mmol/mol) 18 O () 13 C () Calculated 18 O SW () 19.45 9.035 2.68 1.52 0.14 19.29 9.061 2.72 1.61 0.05 19.12 8.975 3.04 1.64 0.13 18.95 8.913 3.08 1.64 0.46 18.79 8.948 2.78 1.38 0.55 18.62 9.018 2.69 1.38 0.23 18.4 5 9.088 2.60 1.38 0.09 18.29 9.100 2.50 1.62 0.06 18.12 9.070 2.99 1.85 0.37 17.95 8.954 3.49 1.64 0.19 17.79 8.902 3.42 1.38 0.18 17.62 8.948 3.15 1.07 0.18 17.45 9.050 2.74 0.98 0.01 17.29 9.024 2.85 1.09 0.04 17.12 9.014 2.96 1.04 0.01 16.95 8.972 3.08 0.95 0.11 16.79 8.981 3.09 0.84 0.05 16.62 9.023 2.95 0.81 0.06 16.45 9.094 2.83 0.99 0.36 16.29 9.115 2.86 1.10 0.50 16.12 9.086 2.94 1.09 0.41 15.95 9.048 3.13 1.05 0 .38 15.79 9.037 3.20 0.96 0.39 15.62 9.051 3.16 0.82 0.43 15.45 9.064 3.12 0.67 0.46 15.29 9.051 3.17 0.73 0.45 15.12 9.018 3.28 0.91 0.35 14.95 8.985 3.23 0.86 0.11 14.79 8.996 3.14 0.86 0.09 14.62 9.044 3.00 0.98 0.23 14.45 9.096 2.78 1.34 0.31 14.29 9.076 3.12 1.47 0.54 14.12 9.006 3.49 1.36 0.50 13.95 8.901 3.66 1.23 0.06 13.79 8.894 3.46 1.05 0.19 13.62 8.955 3.10 1.08 0.19 13.45 9.021 2.94 1.27 0.03 13.29 9.001 3.04 1.32 0.02 13.12 8.969 3.38 1.12 0.17 12.95 8.952 3.45 0.95 0.14 12.79 9.005 3.14 0.90 0.14 12.62 9.109 2.76 1.00 0.37 12.45 9.174 2.47 1.15 0.45 12.29 9.132 2.72 1.33 0.45

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198 Appendix B (cont ): Pliocene Siderastre a spp. Stable I sotope and Sr/Ca D ata UF35931 Relative Year Sr/Ca (mmol/mol) 18 O () 13 C () Calculated 18 O SW () 12.12 9.046 3.11 1.31 0.35 11.95 8.963 3.30 1.07 0.05 11.79 8.943 3.18 0.82 0.18 11.62 9.012 2.80 0.81 0.16 11.45 9.118 2.60 1.21 0.26 11.29 9.065 2.94 1.42 0.29 11.12 9.005 3.28 1.07 0.28 10.95 8.958 3.15 0.83 0.12 10.79 9.011 2.76 0.93 0.20 10.62 9.129 2.50 1.12 0.22 10.45 9.147 2.45 1.17 0.28 10.29 9.069 2.85 1.35 0.22 10.12 8.974 3.26 1.29 0.08 9.95 8.922 3.42 1.09 0.07 9.79 8.997 3 .02 0.95 0.02 9.62 9.114 2.57 0.91 0.21 9.45 9.155 2.52 1.15 0.39 9.29 9.089 2.68 1.30 0.17 9.12 8.978 3.06 1.21 0.10 8.95 8.911 3.41 0.96 0.13 8.79 8.909 3.40 0.81 0.15 8.62 8.939 3.20 0.82 0.18 8.45 8.954 3.11 1.06 0.18 8.29 8.948 3.06 1.41 0.27 8.12 8.934 3.07 1.73 0.34 7.95 8.901 3.12 1.78 0.49 7.79 8.921 2.91 1.55 0.57 7.62 9.026 2.56 1.46 0.31 7.45 9.138 2.24 1.55 0.02 7.29 9.145 2.19 1.77 0.01 7.12 9.046 2.52 1.72 0 .24 6.95 8.951 2.80 1.52 0.51 6.79 8.918 2.88 1.17 0.62 6.62 8.968 2.70 0.97 0.51 6.45 9.111 2.53 1.28 0.15 6.29 9.095 2.52 1.58 0.04 6.12 9.044 2.59 1.43 0.18 5.95 8.971 2.77 1.43 0.43 5.79 8.968 2.79 1.21 0.42 5.62 9.010 2.74 1.15 0.24 5.45 9.065 2.85 1.12 0.20 5.29 9.057 2.81 1.15 0.12 5.12 9.003 2.91 1.10 0.10 4.95 8.967 2.69 1.00 0.53

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199 Appendix B (cont ): Pliocene Siderastrea spp. Stable I sotope and Sr/Ca D ata UF35931 Relative Year Sr /Ca (mmol/mol) 18 O () 13 C () Calculated 18 O SW () 4.79 8.989 2.46 0.93 0.63 4.62 9.076 2.63 1.15 0.05 4.45 9.103 2.61 1.34 0.18 4.29 8.988 2.97 1.32 0.13 4.12 8.928 3.27 1.28 0.17 3.95 8.895 3.36 1.10 0.27 3.79 8.896 3.33 1.02 0. 31 3.62 8.899 3.24 1.06 0.38 3.45 8.941 3.08 1.06 0.29 3.29 8.950 3.05 1.02 0.27 3.12 8.933 3.09 0.97 0.32 2.95 8.917 3.14 0.92 0.37 2.79 8.950 3.04 0.95 0.27 2.62 9.017 2.85 1.04 0.08 2.45 9.083 2.66 1.13 0.12 2 .29 9.097 2.73 1.20 0.27 2.12 8.988 3.06 1.07 0.04 1.95 8.891 3.36 0.86 0.30 1.79 8.943 3.30 0.70 0.06 1.62 9.032 2.98 0.98 0.14 1.45 9.077 2.76 1.30 0.18 1.29 9.029 2.88 1.32 0.02 1.12 8.941 3.12 1.28 0.25 0.95 8.862 3.33 1.14 0.50

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200 Appendix C : Pliocene and Pleistocene P/Ca Data from Siderastrea spp. Formation Sample ID Coral Morphology P/Ca ( "mol/mol) Coral Averaged P/Ca ( "mol/mol) Bermont UF56940 A Ball 71.8 Bermont UF56940 B Ball 90.8 76.4 Bermont UF56940 C Ball 66.5 Bermont UF56948 A Ball 61.3 Bermont UF56948 B Ball 52.7 60.5 Bermont UF56948 C Ball 67.6 Bermont UF115124 A Ball 89.9 Bermont UF115124 B Ball 81.4 90.3 Bermont UF115124 C Ball 99.7 Bermont UF15132 A Ball 7 2.9 Bermont UF15132 B Ball 71.4 69.9 Bermont UF15132 C Ball 65.5 Bermont UF115136 A Ball 50.1 Bermont UF115136 B Ball 66.9 58.2 Bermont UF115136 C Ball 57.7 Bermont UF115135 A Ball 68.5 Bermont UF115135 B Ball 90.8 90.7 Bermont UF115135 C Ball 112.9 Bermont UF115137 A Ball 83.6 Bermont UF115137 B Ball 80.8 85.2 Bermont UF115137 C Ball 91.1 Bermont UF115139 A Ball 81.9 Bermont UF115139 B Ball 74.3 81.4 Bermont UF115139 C Ball 88.0 Bermont UF115131 A Ball 116.8 Bermont UF 115131 B Ball 101.7 102.6 Bermont UF115131 C Ball 89.4 Bermont UF56363 A Ball 82.9 Bermont UF56363 B Ball 62.0 70.4 Bermont UF56363 C Ball 66.2 Bermont UF115125 A Ball 130.5 Bermont UF115125 B Ball 76.8 104.0 Bermont UF115125 C Ball 104.7 Bermont UF56357 A Ball 98.9 Bermont UF56357 B Ball 78.5 78.1 Bermont UF56357 C Ball 57.0 Bermont UF115134 A Ball 143.2 Bermont UF115134 B Ball 55.2 87.3 Bermont UF115134 C Ball 63.5 Bermont UF15890 A Ball 99.1 Bermont UF15890 B Ball 96.8 118.2 Bermont UF15890 C Ball 158.6

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201 Appendix C (cont ): Pliocene and Pleistocene P/Ca Data from Siderastrea spp. Formation Sample ID Coral Morphology P/Ca ( "mol/mol) Coral Averaged P/Ca ( "mol/mol) Bermont UF115126 A Ball 66.1 Bermont UF115126 B Bal l 71.6 81.3 Bermont UF115126 C Ball 106.2 Bermont UF14880 A Ball 125.7 Bermont UF14880 B Ball 65.9 107.9 Bermont UF14880 C Ball 132.0 Bermont UF115121 A Stacked 66.9 Bermont UF115121 B Stacked 71.9 67.5 Bermont UF115121 C Stacked 63.8 Ber mont UF56356 A Stacked 89.4 Bermont UF56356 B Stacked 52.7 60.9 Bermont UF56356 C Stacked 40.7 Bermont UF19524 A Stacked 44.8 Bermont UF19524 B Stacked 57.4 52.2 Bermont UF19524 C Stacked 54.4 Bermont UF115134 A Stacked 61.7 Bermont UF1151 34 B Stacked 63.3 60.7 Bermont UF115134 C Stacked 57.1 Formation Sample ID Coral Morphology P/Ca ( "mol/mol) Coral Averaged P/Ca ("mol/mol) Caloosahatchee UF23648 A Ball 63.5 Caloosahatchee UF23648 B Ball 71.2 71.7 Caloosahatchee UF23648 C Ball 80 .5 Caloosahatchee UF41908 A Ball 77.3 Caloosahatchee UF41908 B Ball 140.3 139.9 Caloosahatchee UF41908 C Ball 202.1 Caloosahatchee UF35108 A Ball 110.2 Caloosahatchee UF35108 B Ball 68.9 89.3 Caloosahatchee UF35108 C Ball 88.8 Caloosahatch ee UF25687 A Ball 82.1 Caloosahatchee UF25687 B Ball 113.7 82.5 Caloosahatchee UF25687 C Ball 51.7 Caloosahatchee UF14987a A Ball 77.8 Caloosahatchee UF14987a B Ball 83.0 78.0 Caloosahatchee UF14987a C Ball 73.1 Caloosahatchee UF36068a A Ball 67.3 Caloosahatchee UF36068a B Ball 77.1 71.1 Caloosahatchee UF36068a C Ball 68.8 Caloosahatchee UF23648 A Ball 80.9 Caloosahatchee UF23648 B Ball 123.1 91.9 Caloosahatchee UF23648 C Ball 71.7

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202 Appendix C (cont ): Pliocene and Pleistocene P/ Ca Data from Siderastrea spp. Formation Sample ID Coral Morphology P/Ca ( "mol/mol) Coral Averaged P/Ca ("mol/mol) Caloosahatchee UF14987b A Ball 63.8 Caloosahatchee UF14987b B Ball 76.8 74.7 Caloosahatchee UF14987b C Ball 83.6 Caloosahatchee UF1236 88 A Ball 92.0 Caloosahatchee UF123688 B Ball 53.2 75.7 Caloosahatchee UF123688 C Ball 81.8 Caloosahatchee UF157720 A Ball 86.5 Caloosahatchee UF157720 B Ball 72.0 81.4 Caloosahatchee UF157720 C Ball 85.8 Caloosahatchee UF36068b A Ball 59.8 Caloosahatchee UF36068b B Ball 57.2 58.6 Caloosahatchee UF36068b C Ball 58.8 Caloosahatchee UF35108 A Ball 65.5 Caloosahatchee UF35108 B Ball 54.0 57.5 Caloosahatchee UF35108 C Ball 53.0 Caloosahatchee UF41908 A Ball 57.2 Caloosahatchee UF4 1908 B Ball 39.1 47.5 Caloosahatchee UF41908 C Ball 46.2 Caloosahatchee UF23648a A Ball 56.6 Caloosahatchee UF23648a B Ball 99.4 98.8 Caloosahatchee UF23648a C Ball 140.3 Caloosahatchee UF35110a A Ball 67.0 Caloosahatchee UF35110a B Ball 69.2 68.0 Caloosahatchee UF35110a C Ball 67.9 Caloosahatchee UF35110b A Ball 83.8 Caloosahatchee UF35110b B Ball 75.9 77.7 Caloosahatchee UF35110b C Ball 73.4 Caloosahatchee UF153364 A Ball 38.6 Caloosahatchee UF153364 B Ball 33.7 48.9 Caloosa hatchee UF153364 C Ball 74.4 Caloosahatchee UF23648b A Ball 81.8 Caloosahatchee UF23648b B Ball 71.0 85.2 Caloosahatchee UF23648b C Ball 102.9 Caloosahatchee UF14987c A Stacked 132.8 Caloosahatchee UF14987c B Stacked 95.8 95.8 Caloosahatchee UF14987c C Stacked 58.7 Caloosahatchee UF127475 A Stacked 76.7 Caloosahatchee UF127475 B Stacked 48.9 57.2 Caloosahatchee UF127475 C Stacked 46.2

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203 Appendix C (cont ): Pliocene and Pleistocene P/Ca Data from Siderastrea spp. Formation Sample ID Coral Morphology P/Ca ( "mol/mol) Coral Averaged P/Ca ( "mol/mol) Pinecrest UF53145 A Stacked 153.6 Pinecrest UF53145 B Stacked 113.1 170.9 Pinecrest UF53145 C Stacked 246.1 Pinecrest UF35520 A Stacked 152.6 Pinecrest UF35520 B Stacked 182.2 1 63.0 Pinecrest UF35520 C Stacked 154.2 Pinecrest UF35929 A Stacked 69.7 Pinecrest UF35929 B Stacked 77.6 77.6 Pinecrest UF35929 C Stacked 85.6 Pinecrest UF32189 A Stacked 382.2 Pinecrest UF32189 B Stacked 139.3 214.1 Pinecrest UF32189 C Stac ked 120.7 Pinecrest UF41392 A Stacked 118.3 Pinecrest UF41392 B Stacked 148.5 132.4 Pinecrest UF41392 C Stacked 130.4 Pinecrest UF35524a A Stacked 159.4 Pinecrest UF35524a B Stacked 141.2 146.6 Pinecrest UF35524a C Stacked 139.0 Pinecrest UF35524b A Stacked 157.3 Pinecrest UF35524b B Stacked 108.2 124.2 Pinecrest UF35524b C Stacked 107.0 Pinecrest UF35524c A Stacked 140.4 Pinecrest UF35524c B Stacked 106.2 117.8 Pinecrest UF35524c C Stacked 106.8 Pinecrest UF41392 A Stacked 13 1.9 Pinecrest UF41392 B Stacked 125.3 131.8 Pinecrest UF41392 C Stacked 138.2 Pinecrest UF38138 A Stacked 126.3 Pinecrest UF38138 B Stacked 149.0 161.1 Pinecrest UF38138 C Stacked 207.9 Pinecrest UF38273 A Stacked 111.4 Pinecrest UF38273 B Stacked 116.6 113.3 Pinecrest UF38273 C Stacked 111.7 Pinecrest UF32187 A Stacked 118.7 Pinecrest UF32187 B Stacked 143.3 195.6 Pinecrest UF32187 C Stacked 324.9 Pinecrest UF53131 A Stacked 124.4 Pinecrest UF53131 B Stacked 173.8 245.9 Pine crest UF53131 C Stacked 439.5 Pinecrest UF35522 A Stacked 159.9 Pinecrest UF35522 B Stacked 174.8 164.5 Pinecrest UF35522 C Stacked 158.7

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204 Appendix C (cont ): Pliocene and Pleistocene P/Ca Data from Siderastrea spp. Formation Sample ID Coral Mor phology P/Ca ( "mol/mol) Coral Averaged P/Ca ( "mol/mol) Pinecrest UF32188 A Stacked 134.0 Pinecrest UF32188 B Stacked 137.7 135.9 Pinecrest UF32188 C Stacked 136.0 Pinecrest UF171641 A Stacked 122.4 Pinecrest UF171641 B Stacked 145.9 132.3 Pinec rest UF171641 C Stacked 128.5 Pinecrest UF35438 A Stacked 128.0 Pinecrest UF35438 B Stacked 129.1 127.4 Pinecrest UF35438 C Stacked 125.0 Pinecrest UF35931 A Stacked 257.1 Pinecrest UF35931 B Stacked 110.5 164.1 Pinecrest UF35931 C Stacked 12 4.5 Pinecrest UF46858 A Ball 126.2 Pinecrest UF46858 B Ball 91.4 104.6 Pinecrest UF46858 C Ball 96.2 Pinecrest UF35520 A Ball 111.0 Pinecrest UF35520 B Ball 115.7 116.6 Pinecrest UF35520 C Ball 123.1

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205 Appendix D : Pli ocene Seasonal P/Ca Data from Siderastrea spp. Relative Year P/Ca ( "mol/mol) Relative Year P/Ca ( "mol/mol) Relative Year P/Ca ( "mol/mol) 81.73 291.4 74.56 145.4 67.39 185.5 81.56 252.7 74.39 150.7 67.23 210.0 81.40 242.1 74.23 154.9 67. 06 222.7 81.23 258.5 74.06 146.5 66.89 215.3 81.06 251.6 73.89 168.5 66.73 196.7 80.90 219.9 73.73 168.2 66.56 178.2 80.73 205.4 73.56 157.4 66.39 182.4 80.56 218.6 73.39 155.5 66.23 199.0 80.40 240.3 73.23 282.2 66.06 183.8 80.23 239.2 73.06 137.0 65.89 177.3 80.06 166.2 72.89 154.6 65.73 176.9 79.90 147.9 72.73 180.6 65.56 200.1 79.73 150.8 72.56 191.0 65.39 234.8 79.56 168.6 72.39 189.0 65.23 211.6 79.40 221.8 72.23 185.0 65.06 161.6 79.23 222. 1 72.06 158.7 64.89 140.5 79.06 311.5 71.89 149.8 64.73 138.7 78.90 383.0 71.73 172.4 64.56 139.9 78.73 241.6 71.56 164.0 64.39 144.1 78.56 171.9 71.39 196.2 64.23 149.0 78.40 163.8 71.23 195.1 64.06 161.6 78.23 158.6 71.06 194.0 63.89 161.9 78.06 154.6 70.89 170.2 63.73 158.9 77.90 150.6 70.73 151.6 63.56 157.5 77.73 157.5 70.56 145.7 63.39 154.6 77.56 142.3 70.39 142.8 63.23 162.4 77.40 155.7 70.23 144.9 63.06 260.5 77.23 143.5 70.06 147.1 62 .89 248.4 77.06 152.5 69.89 149.2 62.73 176.9 76.90 150.7 69.73 137.7 62.56 188.4 76.73 148.9 69.56 167.8 62.39 194.6 76.56 147.0 69.39 179.8 62.23 197.6 76.40 149.4 69.23 178.3 62.06 200.5 76.23 170.0 69.06 176.7 61.89 198.0 76.06 159.2 68.89 156.9 61.73 192.0 75.89 142.3 68.73 160.8 61.56 186.0 75.73 152.9 68.56 154.5 61.39 177.4 75.56 143.9 68.39 132.1 61.23 167.2 75.39 134.9 68.23 135.9 61.06 157.1 75.23 140.2 68.06 176.6 60.89 143.9 75.06 145 .5 67.89 132.5 60.73 173.5 74.89 134.0 67.73 150.3 60.56 228.3 74.73 132.5 67.56 166.4 60.39 213.6

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206 Appendix D (cont.) : Pliocene Seasonal P/Ca Data from Siderastrea spp. Relative Year P/Ca ( "mol/mol) Relative Year P/Ca ( "mol/mol) Re lative Year P/Ca ( "mol/mol) 60.23 166.6 53.06 242.7 45.89 98.9 60.06 179.1 52.89 321.6 45.72 73.5 59.89 189.1 52.72 229.9 45.56 72.7 59.72 249.4 52.56 171.1 45.39 73.2 59.56 155.1 52.39 161.8 45.22 68.7 59.39 125.8 52.22 148.2 45.06 60.9 59.22 128.2 52.06 131.2 44.89 196.7 59.06 130.7 51.89 119.8 44.72 98.9 58.89 132.8 51.72 127.1 44.56 151.1 58.72 134.8 51.56 138.3 44.39 90.3 58.56 136.8 51.39 121.5 44.22 80.7 58.39 163.4 51.22 129.1 44.06 171.2 58.22 185.1 51.06 163.3 43.89 313.6 58.06 171.7 50.89 167.2 43.72 145.9 57.89 158.1 50.72 171.1 43.56 102.7 57.72 173.9 50.56 208.2 43.39 149.4 57.56 96.0 50.39 203.7 43.22 196.2 57.39 113.9 50.22 178.3 43.05 178.7 57.22 113.4 50.06 186.6 42.89 121.3 57.06 132.2 49.89 163.3 42.72 113.1 56.89 137.4 49.72 190.3 42.55 110.6 56.72 143.0 49.56 184.6 42.39 130.9 56.56 125.8 49.39 146.9 42.22 323.5 56.39 92.2 49.22 113.1 42.05 203.0 56.22 116.7 49.06 85 .7 41.89 80.0 56.06 133.3 48.89 71.5 41.72 77.0 55.89 132.2 48.72 70.9 41.55 73.2 55.72 108.0 48.56 172.8 41.39 74.0 55.56 100.7 48.39 191.9 41.22 69.9 55.39 95.6 48.22 118.8 41.05 66.1 55.22 103.2 48.06 107.9 40.89 63.1 55 .06 98.1 47.89 97.0 40.72 64.5 54.89 97.8 47.72 87.9 40.55 78.1 54.72 104.0 47.56 78.9 40.39 94.9 54.56 90.3 47.39 127.8 40.22 84.1 54.39 100.8 47.22 219.5 40.05 74.4 54.22 142.3 47.06 240.4 39.89 193.1 54.06 129.9 46.89 169 .2 39.72 159.8 53.89 114.5 46.72 97.9 39.55 87.2 53.72 150.0 46.56 73.2 39.39 69.8 53.56 166.5 46.39 86.0 39.22 58.9 53.39 176.3 46.22 90.2 39.05 63.1 53.22 196.1 46.06 103.9 38.89 94.3

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207 Appendix D (cont.) : Pliocene Seasonal P/Ca Data from Siderastrea spp. Relative Year P/Ca ( "mol/mol) Relative Year P/Ca ( "mol/mol) Relative Year P/Ca ( "mol/mol) 38.72 93.1 31.55 139.5 24.38 151.2 38.55 95.2 31.39 127.0 24.22 145.9 38.39 106.3 31.22 130.8 24.05 142.4 38.22 84.6 31.05 133.1 23.88 145.3 38.05 93.4 30.89 134.4 23.72 148.9 37.89 89.7 30.72 142.1 23.55 211.0 37.72 77.0 30.55 271.0 23.38 167.2 37.55 91.7 30.39 343.4 23.22 135.3 37.39 90.8 30.22 158.5 23.05 165.2 37.22 81.6 30.05 147 .1 22.88 193.0 37.05 85.2 29.89 166.1 22.72 143.4 36.89 115.4 29.72 127.6 22.55 193.0 36.72 148.9 29.55 143.3 22.38 244.5 36.55 120.6 29.39 135.4 22.22 230.6 36.39 110.2 29.22 134.9 22.05 216.7 36.22 107.0 29.05 130.4 21.88 210.6 36.05 207.9 28.89 157.4 21.72 226.0 35.89 91.0 28.72 148.2 21.55 304.0 35.72 96.7 28.55 248.0 21.38 322.3 35.55 105.6 28.39 192.2 21.22 169.2 35.39 137.1 28.22 155.4 21.05 136.6 35.22 90.4 28.05 175.8 20.88 138.6 35.05 109.1 27.89 206.3 20.72 132.7 34.89 87.5 27.72 236.8 20.55 138.5 34.72 88.9 27.55 228.6 20.38 149.3 34.55 107.9 27.39 211.1 20.22 163.9 34.39 122.6 27.22 193.6 20.05 126.4 34.22 110.1 27.05 210.3 19.88 98.0 34.05 133.3 26.89 240.4 19.72 129.9 33.89 120.7 26.72 282.5 19.55 150.7 33.72 90.0 26.55 258.4 19.38 143.7 33.55 87.0 26.39 219.7 19.22 131.4 33.39 89.3 26.22 181.0 19.05 131.6 33.22 95.5 26.05 160.2 18.88 140.3 33.05 114.6 25.88 172.4 18.72 135.1 32.89 88.5 25.72 153.3 18.55 134.3 32.72 88.1 25.55 190.8 18.38 124.1 32.55 87.3 25.38 196.9 18.22 115.9 32.39 89.2 25.22 195.9 18.05 156.2 32.22 90.6 25.05 194.8 17.88 159.4 32.05 100.9 24.88 193.7 17.72 165.4 31.89 1 58.5 24.72 170.9 17.55 163.9 31.72 211.9 24.55 152.1 17.38 143.4

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208 Appendix D (cont.) : Pliocene Seasonal P/Ca Data from Siderastrea spp. Relative Year P/Ca ( "mol/mol) Relative Year P/Ca ( "mol/mol) Relative Year P/Ca ( "mol/mol) 17.22 151. 5 10.05 184.4 2.88 137.8 17.05 159.7 9.88 200.9 2.71 116.9 16.88 165.3 9.72 227.6 2.55 118.3 16.72 165.2 9.55 218.3 2.38 136.0 16.55 165.2 9.38 203.0 2.21 141.6 16.38 165.1 9.21 186.4 2.05 129.1 16.22 165.1 9.05 169.9 1.88 100.9 16.05 161.3 8.88 201.0 1.71 108.6 15.88 149.7 8.71 293.7 1.55 116.3 15.72 147.2 8.55 176.1 1.38 130.5 15.55 164.3 8.38 146.9 1.21 155.7 15.38 192.2 8.21 216.9 15.22 242.8 8.05 213.2 15.05 249.9 7.88 144.4 14.88 229.7 7.71 170.9 14.72 172.6 7.55 178.9 14.55 144.1 7.38 170.2 14.38 128.3 7.21 141.3 14.22 126.2 7.05 146.2 14.05 124.0 6.88 151.2 13.88 113.3 6.71 156.1 13.72 110.4 6.55 161.0 13.55 14 0.2 6.38 163.0 13.38 156.5 6.21 160.5 13.22 206.3 6.05 158.0 13.05 193.3 5.88 157.4 12.88 177.2 5.71 159.6 12.72 181.3 5.55 157.4 12.55 186.9 5.38 156.1 12.38 180.8 5.21 160.3 12.22 174.8 5. 05 158.0 12.05 168.7 4.88 155.8 11.88 162.7 4.71 171.8 11.72 156.6 4.55 188.4 11.55 150.5 4.38 171.1 11.38 144.5 4.21 153.8 11.22 138.4 4.05 116.1 11.05 132.4 3.88 102.1 10.88 132.3 3.71 121.0 10.72 142.7 3.55 139.9 10.55 153.1 3.38 134.4 10.38 163.6 3.21 96.5 10.22 174.0 3.05 138.4

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About the Author Jennifer Leigh Sliko was raised in Lancaster County, Pennsylvania by two caring parents, along with her two younger sisters. She attended Warwic k High School in Lititz, PA, graduat ing second in her class. She dual majored in Mari ne Science and Geoscience at Rider University, in Lawrenceville, New Jersey, where she graduated Magna Cum Laude. After graduating from Rider University, Jennifer spent a several years working for the New Jersey Department of Environmental Protection as a geologist in the Office of Dredging and Sediment Technology. In 2005, she began her graduate studies at the University of South Florida with Gregory S. Herbert, earning her Ph.D. in December 2010 in Geology. Jennifer lives with her fiancŽ Mike in wester n Virginia and is employed at the Virginia Polytechnic Institute and State University in the Department of Geosciences as an adjunct instructor. Currently, she is developing and teaching the department's first online courses.