USF Libraries
USF Digital Collections

Particulate carbon, nitrogen and phosphorus stoichiometry of south west Florida waters

MISSING IMAGE

Material Information

Title:
Particulate carbon, nitrogen and phosphorus stoichiometry of south west Florida waters
Physical Description:
Book
Language:
English
Creator:
Murasko, Susan Mary
Publisher:
University of South Florida
Place of Publication:
Tampa, Fla
Publication Date:

Subjects

Subjects / Keywords:
West Florida shelf
Redfield ratio
Nutrient limitation
Phytoplankton
Karenia brevis
Dissertations, Academic -- Marine Science -- Masters -- USF   ( lcsh )
Genre:
non-fiction   ( marcgt )

Notes

Summary:
ABSTRACT: The southwestern Florida shelf marine environment has often been characterized as oligotrophic, yet these waters can support large, high biomass, persistent phytoplankton blooms, including blooms of the toxin producing dinoflagellate Karenia brevis. Little is known regarding which major nutrient potentially limits primary production in these waters as both inorganic nitrogen and phosphorus concentrations are often near the limits of analytical detection and it is difficult to estimate what percentage of the dissolved organic pool is available for phytoplankton uptake. To assess the nutrient status of phytoplankton populations on the southwest Florida shelf, this project examines the particulate nutrient stoichiometry of ambient phytoplankton assemblages from 1998-2000 as part of the ECOHAB: Florida Program. Particulate C, N, P concentrations and particulate ratios display a large range of values across the West Florida Shelf (WFS).The average particulate stoichiometry is well above the classic Redfield ratio with a geometric mean of 410C:56N:1P. Frequency percentages of particulate ratio values to total sample number binned according to potential nutrient limitation indicate that 39% (C:N) of the data have values suggesting N limitation and that from 88% (N:P) to 95% (C:P) of the data have values which suggest P-limitation. It is difficult to discern whether phytoplankton biomass is truly P-limited as related to the nutrient regime on the WFS or whether detrital contributions, which can potentially be large on this shallow shelf, are skewing the N:P and C:P ratios towards higher values. Errors which could potentially be related to the different methodologies of determining C, N and P concentrations must also be considered when interpreting the particulate nutrient ratios. The data were also analyzed as subsets to determine near-shore to offshore, latitudinal, seasonal, inter-annual and K. brevis bloom versus non-bloom trends.The near-shore to offshore transect indicates decreasing concentrations of particulate C, N, P concentrations and increasing C:N, N:P, C:P ratios with increasing distance offshore. Particulate nutrient concentrations and particulate ratio values are very similar between the Tampa Bay, Sarasota and Fort Meyers transects indicating that these latitudes are not spatially distinct with regards to these variables. There does not appear to be any relationship between the particulate C, N, P concentrations or C:N, N:P, C:P ratios and rainfall as indicated by Spearman Ranking Correlation coefficients. However, there does appear to be monthly trends across the shelf where peak particulate nutrient concentrations and particulate ratio values occur during the spring, summer and fall. The average particulate nutrient concentrations and ratios differ for each year as well as each K. brevis bloom which occurred during the study period.In summary, the particulate C, N, P concentrations and particulate nutrient ratios vary both spatially and temporally on the WFS and are potentially related to the flexibility of phytoplankton uptake kinetics in response to the varying nutrient regimes of the WFS.
Thesis:
Thesis (M.S.)--University of South Florida, 2009.
Bibliography:
Includes bibliographical references.
System Details:
Mode of access: World Wide Web.
System Details:
System requirements: World Wide Web browser and PDF reader.
Statement of Responsibility:
by Susan Mary Murasko.
General Note:
Title from PDF of title page.
General Note:
Document formatted into pages; contains 164 pages.

Record Information

Source Institution:
University of South Florida Library
Holding Location:
University of South Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 002063952
oclc - 558730725
usfldc doi - E14-SFE0003036
usfldc handle - e14.3036
System ID:
SFS0027353:00001


This item is only available as the following downloads:


Full Text

PAGE 1

Particulate Carbon, Nitrogen and P hosphorus Stoich iometry of South West Florida Waters by Susan Mary Murasko A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science College of Marine Science University of South Florida Major Professor: Gabriel A. Vargo, Ph.D. Cynthia A. Heil, Ph.D. Edward S. VanVleet, Ph.D. Date of Approval: March 25, 2009 Keywords: West Florida Shelf, Redfield Ra tio, nutrient limitation, phytoplankton, Karenia brevis Copyright 2009 Susan M. Murasko

PAGE 2

ACKNOWLEDGMENTS I would like to thank my committe e members, Dr G abriel Vargo, Dr. Cynthia Heil and Dr. Ted VanVlee t, for their support, patience and encouragement throughout this endeavor. I would also like to thank Merrie Beth Neely, Danyelle Ault, Julie Havens and Robyn Conmy for help with sampling, data analysis and data processing and also the crew of the R/V Suncoaster. Special thanks to my parents and Marco Nery for their love and support throughout this project.

PAGE 3

i TABLE OF CONTENTS LIST OF TABLES……………………………………………………………………… iii LIST OF FIGURES…………………………………………………………………… vii ABSTRACT…………………………………………………………………………….xii CHAPTER ONE INTRODUCTION AND OBJECTIVES The Biological Pump………………………………………………………… 1 The Redfield Ratio…………………………………………………………… 2 Nutrient Limitation of Phytoplankton………………………………………..5 The Nutrients…………………………………………………………………. 8 Carbon……………………………………………………………………. 9 Nitrogen…………………………………………………………………. 10 Phosphorus……………………………………………………………...12 Scope of this Study………………………………………………………… 14 CHAPTER TWO: WEST FLORIDA SHELF STUDY AREA Physical Description………………………………………………………...16 Nitrogen and Phosphorus Sources………………………………………. 18 Summary of Nitrogen and Phosphorus Distributions……………………22 CHAPTER THREE: METHODOLOGY Sampling…………………………………………………………………….. 23 Chemical and Biological Measurements………………………………… 25 Particulate Nutrient Ratio Calculations…………………………………... 26 Statistics Methodology…………………………………………………….. 27 CHAPTER FOUR: RESULTS AND DISCUSSION Complications to the Interpretation of Particulate Nutrient Stoichiome try Interpretation…………………………………………. 29 General Particulate Nutr ient Distribution on the SW Florida Shelf……………………………………………………… 31 Spatial Considerations…………………………………………………….. 52 Near Shore to Offshore Trends……………………………………… 52 Latitudinal Trends……………………………………………………... 70 Temporal Considerations………………………………………………….. 80 Seasonal Trends………………………………………………………80 Inter-annual Trends…………………………………………………...99

PAGE 4

ii Karenia brevis……………………………………………………………... 108 Summary…………………………………………………………………... 113 REFERENCES……………………………………………………………………… 118 APPENDICES 134 Appendix A: Particulate Car bon, Nitrogen and Phosphorus Concentrations and Standard Devi ation (S.D.) from 19981999…………………………………................. ............... .............. ....... 135

PAGE 5

iii LIST OF TABLES Table 1. Central tendency and ranges for the surface particulate nutrient concentrations (S.D.) sampled from June 1998 through December 2001. All units are in (M)………………………………………………………… 32 Table 2. Central tendency and ranges of surface particulate nutrient ratios sampled from June 1998 through December 2001…………………………………………………... 36 Table 3. Summary of Spearman Rank Correlation coefficients (rs) for surface particulate C (M), N (M), P (M) concentrations, particulate nutrient molar ratios and Chl a g/L sampled from June 1998 through December 2001…………………………………………………... 40 Table 4. Literature summary of in situ particulate nutrient. ratios values presented are the average, with the range given in parentheses if available………………………... 42 Table 5. Literature summary of particulate nutrient ratios from phytoplankton cultures. Values presented are the average, with the range given in parentheses if available…………………………………………………………. 50 Table 6. Central tendency and ranges for the surface particulate nutrient concentration and particulate nutrient ratios sampled from June 1998 through December 2001 at the 10m, 30m, 50m and 200m isobaths……………………………………………………………. 57 Table 7. Particulate stoichiometry of surface waters at the 10m, 30m, 50m and 200m isobaths based on the mean and geometric mean of surface par ticulate nutrient ………………. 59 concentrations.

PAGE 6

iv Table 8. Summary of Spearman Rank Correlation coefficients (rs) for surface particulate C (M), N (M), P (M) concentrations and particulat e nutrient ratios at the 10m (N=106), 30m (N=103), 50m (N=101) and 200m (N=32) isobaths sampled from June 1998 through December 2001………………………………………… 64 Table 9. Frequency percentage (%) of surface particulate nutrient ratio values to total sample number within different isobaths with consi derations to the Redfield Ratio and nutrient limitation……………………………………... 68 Table 10. Central tendency measures and ranges of surface particulate nutrient concentrations and particulate nutrient ratios sampled from June 1998 through December 1999 for the Tampa Bay, Sarasota and Fort Meyers transects. The data include all stations sampled out to the 50m isobath for each transect……………. 71 Table 11. Surface particulate stoichiometry based on the geometric mean and median of the Tampa Bay, Sarasota and Fort Meyers transects. The data include all stations sampl ed out to the 50m isobath and 10m isobath for each transect……………………………... 72 Table 12. Frequency percentage (%) of surface particulate nutrient ratio values to total sample number within different transects with cons iderations to the Redfield Ratio and nutrient limitation. Each transect includes all station data from the 10m isobath to the 50m isobath……………………………………………………………...74 Table 13. Central tendency measures and ranges of surface particulate nutrient concentrations and particulate nutrient ratios of Tamp a Bay, Sarasota and Fort Meyers transects. The data include all stations sampled at the 10m isobath for each transect from June 1998 through Dece mber 2001………….................. 76 Table 14. Summary of Spearman Rank Correlation coefficients (rs) for surface particulate C (M), N (M), P (M) concentrations and particulat e nutrient ratios for the Tampa Bay (N=37), Sarasota (N=35) and Fort Meyers (N=33) sampled from June 1998 through December 2001…………………………………………………... 79

PAGE 7

v Table 15. Central tendency measures and ranges of surface particulate nutrient concentrations and nutrient ratios of the wet season (June to September) and the dry season (October to Ma y). The data include all stations sampled from June 1998 through December 2001………………………………………………………………...83 Table 16. Central tendency measur es and ranges of surface particulate Nutrient conc entrations and nutrient ratios of the wet Season (June to September) and the dry season (October to May) The data include the Tampa Bay, Sarasota and Fo rt Meyers stations at the 10m isobath sampled from June 1998 through December 2001…………………………………………………... 88 Table 17. Central tendency measures and ranges of surface particulate nutrient concentrations and nutrient ratios sampled from June 1998 through December 2001. The data only include t he months of June to December for each year in order to directly compare the study years…………………………………………………...100 Table 18. Surface particulate nutrient stoichiometry based on the mean and geometric mean. The data only include the months of June to December for each year in order to directly compare the study years…………… 101 Table 19. Central tendency meas ures and ranges of surface particulate nutrient ratios of K. brevis concentration, cells/L (0 includes sample with no K. brevis detected, 1,000-10,000 includes r egulatory limits for commercial shellfish bed closures, 10,000-100,000 includes low bloom conc entrations and >100,000 includes high bloom concent rations) sampled from June 1998 through December 2001. The stations with less than 1,000 K. brevis are only those stations that had a record of K. brevis present at some point during the study period…………………………………………. 109 Table 20. Average surface particula te C:N:P stoichiometry with K. brevis blooms from June 1998 through December 2001……………………………………………………………… 109

PAGE 8

vi Table 21. Summary of surface particulate nutrient ratios for each K. brevis bloom that occurred from June 1998 through December 2001………………………………… 110 Table 22. Particulate C, N and P content (S.E.) of K. brevis within blooms from June 1998 through December 2001…………....... .................. .................. ............ 111

PAGE 9

vii LIST OF FIGURES Figure 1. Map of ECOHAB:Fl orida study area and station locations…………………………………………………... ........... 24 Figure 2. Histogram of surface particulate nutrient A) carbon B) nitrogen and C) phosphorus concentration sampled from June 1998 through De cember 2001. The red bars identify concentration bins that are comprised entirely of samples collec ted from the 10m isobath. The hashed line indicate a change in scale…………………… 33 Figure 3. Relationship between su rface particulate C, N and P and either Chl a (Figures A, B, C) or K. brevis concentrations (Figures D, E, F) in samples comprising the bins fr om histogram Figure 2, indicating samples from the 10m isobath……………………… 34 Figure 4. Histogram of surface particulate nutrient ratios A) C:N B) N:P and C) C:P samp led from June 1998 through December 2001. Hash mar ks indicate a change in bin for A) from 2 to 4, B) from 10 to 100 and C). from 50 to 1000…………………………………………………… 37 Figure 5. Histograms of surface particulate nutrient ratios A) C:N B) N:P and C) C:P samp led from June 1998 through December 2001. The data are binned according to potential nutrient limitation as indicated by Redfield proportions of 106C:16N:1P. The % contribution of each bin to total samples is indicated as a % above the bar………………………………………………………………….. 44 Figure 6. Average surface particu late nutrient concentrations (Figures A, B, C) and particulate nutrient ratios (Figures D, E, F) in relation to distance offshore sampled from June 1998 through December 2001. The fitted line is the polynomial function………………………. 53

PAGE 10

viii Figure7. Influence of distance from shore on surface particulate C, N, P concentrations (Figures A, B, C) and particulate nutrient ratios C:N, N:P, C:P (Figures D, E, F) sampled from June 1998 through December 2001…………………………………………………... 55 Figure 8. Relation between surface Chl a concentration and distance from shore. T he curve includes the data sampled from June 1998 through December 2001……………58 Figure 9. Scatter plots of surface particulate C, N and P concentrations at the 10m isobath (blue), 30m isobath (red), 50m isobath (green) and 200m isobath (turquoise) sampled from June 1998 through December 2001…………....... .................. .................. ...............61 Figure 10. Histogram of surface particulate C:N binned according to nutrient limitation as indicated by Redfield proportions (106C:16N) fo r the A) 10m isobath, B) 30m isobath, C) 50m isobath, D) 100m isobath and E) 200m isobath. C-limitati on is indicated by 0-4, near Redfield proportions by 410, N-limitation by 10-20 and severe N-limitation by 20+. The data include samples collected from June 1998 through December 2001. Note that the frequency dist ribution scale for the 200m isobath has been changed to a maximum of 15 due to a decrease in the number of samples at this site……………...65 Figure 11. Histogram of surface particulate N:P binned according to nutrient limitation as indicated by Redfield proportions (16N:1P) for t he A) 10m isobath, B) 30m isobath, C) 50m isobath, D) 100m isobath and E) 200m isobath. N-limitation is indi cated by 0-10, near Redfield proportions by 10-20, P-lim itation by 20-50 and severe P-limitation by 50+. The data include samples collected from June 1998 through December 2001. Note that the frequency dist ribution scale for the 200m isobath has been changed to a maximum of 30 due to a decrease in the number of samples at this site……………...66

PAGE 11

ix Figure 12. Histogram of surface particulate C:P binned according to nutrient limitation as indicated by Redfield proportions (106C:1P) for t he A) 10m isobath, B) 30m isobath, C) 50m isobath, D) 100m isobath and E) 200m isobath. C-limitat ion is indicated by 0-90, near Redfield proportions by 90-122, P-limitation by 122-212 and severe P-limit ation by 212+. The data include samples colle cted from June 1998 through December 2001. Note t hat the frequency distribution scale for the 100m and 200m isobath have been changed to a maximum of 30 due to a decrease in the number of sample s at these sites………………………….. 67 Figure 13. Histogram of surface particulate A) C:N, B) N:P and C) C:N ratios sampled from June 1998 through December 2001 binned according to potential nutrient limitation as indicated by the Redfield proportions of 106C:16N:1P. Tampa Bay (blue), Sarasota (red) and Fort Meyers (green)………………………………………… 73 Figure 14. Histogram of surface particulate A) C:N, B) N:P and C) C:N ratios at th e 10m isobath sampled from June 1998 through December 2001 binned according to potential nutrient limitation as indicated by the Redfield proportions of 106C:16N:1P. Tampa Bay (blue), Sarasota (red) and Fort Meyers (green)……………………………………………… 78 Figure 15. The monthly average rainfall at Tampa Bay, Sarasota and Fort Meyers for each month from 1998-2001. Data are from Florida State University http://www.coaps.fsu.edu/climate._ ................ ................ ......... 80 Figure 16. Scatter plots of surf ace particulate A) carbon, B) nitrogen and C) phosphorus concentrations during the wet season (pink) and dry season (blue) sampled from June 1998 through December 2001……………………… 82 Figure 17. Scatter plots of surf ace particulate A) carbon, B) nitrogen and C) phosphorus concentrations at the 10m isobath during the We t season (pink) and dry season (blue) sampled from June 1998 through December 2001…………………………………………………... 85

PAGE 12

x Figure 18. Relationship between m onth and surface particulate A) carbon, B) ni trogen and C) phosphorus concentrations sampled from June 1998 through December 2001…………....... ................ .............. ............. ....... 86 Figure 19. Relationship between m onth and surface particulate ratios A) C:N, B) N:P and C) C:P sampled from June 1998 through December 2001………………………………….. 87 Figure 20. Monthly average surf ace particulate C (blue), N (pink) and P (green) concentrations sampled from June 1998 through December 2001…………………………….89 Figure 21. Relationship betw een month and average surface particulate ratio A) C:N, B) N:P and C) C:P sampled from June 1998 through December 2001……………………… 90 Figure 22. Monthly average surf ace particulate C, N and P concentrations at the A) 10m, B) 30m, C) 50m and D) 200m isobaths sampled from June 1998 through December 2001. Particulate C (blue), particulate N (pink) and particulate P (green)…………………. 92 Figure 23. Monthly average surfac e particulate A) carbon, B) nitrogen and C) phosphorus concentrations along different isobaths sampled from June 1998 through December 2001. 10m isobath (blue), 30m isobath (red), 50m isobath (g reen) and the 200m isobath (turquoise)………………………………………………………… 93 Figure 24. Monthly average surface particulate A) C:N, B) N:P and C) C:P ratios along different isobaths sampled from June 1998 through December 2001. 10m isobath (blue), 30m isobath (red), 50m isobath (green) and the 200m isobath (turquoise)………………………………. 95 Figure 25. Monthly averages of surf ace particulate A) carbon, B) nitrogen and C) phosphorus concentrations for stations sampled from June through December of (blue), 1999 (red), 2000 (green) and 2001 (turquoise)………………………………………………………...103

PAGE 13

xi Figure 26. Monthly averages of su rface particulate A) C:N, B) N:P and C) C:P ratios for stations sampled from June through December of 1998 (blue), 1999 (red),) 2000 (green and 2001 (turquoise)…………………………….. 104 Figure 27. Averages surface parti culate A) carbon, B) nitrogen and C) phosphorus concentrati ons at each isobath for stations sampled from June through December of (blue), 1999 (red), 2000 (green) and 2001 (turquoise)………………………………………………………...106 Figure 28. Averages surface parti culate A) C:N, B) N:P and C) C:P ratios at each isobath for stations sampled from June through Dece mber of 1998 (blue), 1999 (red), 2000 (green) and 2001 (turquoise)……………… 107

PAGE 14

xii Particulate Carbon, Nitrogen and P hosphorus Stoichiometry of South West Florida Waters Susan Mary Murasko ABSTRACT The southwestern Florida shelf marine environment has often been characterized as oligotrophic, yet these waters can support large, high biomass, persistent phytoplankton blooms, includ ing blooms of the toxin producing dinoflagellate Karenia brevis. Little is known regarding which major nutrient potentially limits primary production in t hese waters as both inorganic nitrogen and phosphorus concentrations are often n ear the limits of analytical detection and it is difficult to estimate what per centage of the disso lved organic pool is available for phytoplankton uptake. To assess the nutrient status of phytoplankton populations on the southwest Florida shelf, this project examines the particulate nutrient stoichiometry of ambient phytoplankton assemblages from 1998-2000 as part of the ECOHAB: Florida Program. Particulate C, N, P concentrations and particulate ratios display a large range of values across the West Florida Shelf (WFS). The average particulate stoichiometry is well above the classic Redfield ratio with a geometric mean of 410C:56N:1P. Frequency percentages of particu late ratio values to total sample number binned according to potential nutrien t limitation indicate that 39% (C:N) of the data have values suggesting N limit ation and that from 88% (N:P) to 95%

PAGE 15

xiii (C:P) of the data have values which suggest Plimitation. It is difficult to discern whether phytoplankton biomass is truly P-lim ited as related to the nutrient regime on the WFS or whether detrital contribut ions, which can potentially be large on this shallow shelf, are skewing the N:P and C:P ratios towards higher values. Errors which could potentially be relat ed to the different methodologies of determining C, N and P concentrations must also be considered when interpreting the particulate nutrient ratios. The data were also analyzed as subsets to determine near-shore to offshore, latitudinal, seasonal, inter-annual and K. brevis bloom versus nonbloom trends. The near-shore to offshore transect indicates decreasing concentrations of particulate C, N, P concentrations and in creasing C:N, N:P, C:P ratios with increasing distance offshor e. Particulate nutrient concentrations and particulate ratio values are very si milar between the Tampa Bay, Sarasota and Fort Meyers transects indicating that t hese latitudes are not spatially distinct with regards to these variables. Ther e does not appear to be any relationship between the particulate C, N, P concent rations or C:N, N:P, C:P ratios and rainfall as indicated by Spearman Ranki ng Correlation coefficients. However, there does appear to be monthly trends acro ss the shelf where peak particulate nutrient concentrations and particulate ra tio values occur during the spring, summer and fall. The average particul ate nutrient concentrations and ratios differ for each year as well as each K. brevis bloom which occurred during the study period.

PAGE 16

xiv In summary, the particulate C, N, P concentrations and particulate nutrient ratios vary both spatially and temporally on the WFS and are potentially related to the flexibility of phytoplank ton uptake kinetics in response to the varying nutrient regimes of the WFS.

PAGE 17

1 CHAPTER ONE INTRODUCTION AND OBJECTIVES The Biological Pump The biological carbon is the sum of a suite of biological and physical processes that transport carbon from surfac e waters to the oceans interior. This mechanism plays an important role in t he cycling of nutrients in the global open oceans and is largely mediated by phyt oplankton production in the photic zone, export production rate of sinking partic ulate matter, remineralization rates at depth and upward eddy diffusion rates of dissolved inorganic nutrients back into the photic zone (Eppley and Peterson 1979; Karl et al. 2001). The dependence of each process on the other provides an effective feedback mechanism which ultimately drives the carbon (C) cycle and balances CO2 flux between the atmosphere and the oceans over large time sca les. In well lit surface waters the rates and intensities of these processes within the biological pump are influenced by the cycling and concentrations of nitrogen (N) and phosphorus (P) which are linked to the carbon cycle (Michaels et al 2001) through biological production (Wu et al. 2000). However, at depth, the more refractory C can become decoupled from the N and P cycles as they are remineralized at faster rates and “net carbon sequestration” can take place (Chr istian et al. 1997; Ka rl et al. 2001). In this manner, the biological pump serv es to “fractionate” the distributions of the conservative elements (Mg, Na, Co) and those which are non-conservative or biologically active (e.g. C, N, P) and a distinct “biochemical circulation” of

PAGE 18

2 nutrients is the result (Redfield et al. 1963). This is primarily because N and P are recycled between the dissolved and particulate pools on time scales much shorter than the mixing and residence time of waters in the basin (Harris 1986). These processes are critical in oli gotrophic oceans, often supplying the only source of “new” nutrients into these systems for phytoplankton uptake and assimilation (Dugdale and Goering 1967). In this case, the cycle of biological production, remineralization of that producti on at depth and the return of nutrients to surface waters primarily control the stoichiometry of C:N:P found within both the dissolved and particulate pools in the open ocean (Karl et al. 2001). In coastal and shallow marine environments, controls on C:N:P stoichiometry becomes much more complex as nutrient pathways (i.e. sources and sinks) and ecosystem community structure beco me much more varied and dynamic. The Redfield Ratio The classic work of Alfred Redf ield (1934, 1958, 1963) and Richard Fleming (1940), has provided scientists with a unifying concept of nutrient stoichiometry, which reflects the c ontinuous recycling of N and P between the particulate organic matter (POM) and the dissolved inorganic pool in the ocean (Gieder and La Roche 2002). Redfield documented the constancy of plankton C:N:P and the N:P of deep oc ean waters throughout the worlds oceans and more over, that the ratios of the two pools we re similar to each other (Redfield 1958; Redfield et al. 1963). Based on previous wo rks of C: N: P stoi chiometry, Redfield and co-researchers empirically derived by averaging available data an elemental

PAGE 19

3 ratio of 106:16:1, by atoms and is now termed the “classic Redfield Ratio” (Redfield 1933; Redfield 1958). The cons istency of this ratio further suggests that the uptake and release of nutrients in t he ocean tend to occur in specific proportions (Karl et al. 2001; Micheals et al 2001). This observation led Redfield to the conclusion that the phytoplankt on ultimately control the chemical constituents in the ocean by adjusting t he N:P stoichiometry of the ocean by fixing atmospheric N to meet the metabolic needs of t he plankton (Redfield 1933; Redfield et al. 1963; Hecky and Kilham 1988; Tyrell 1999; Falkowski 2000; Micheals et al. 2001). In an effort to de scribe nutrient distribution in seawater, Redfield et al. (1963) invoked two c ausative principals; 1) the constrained (“inherently regular”) stoichiometry of the phytoplankton wh ich results from physiological requirements for growth and 2) the dynamic stoichiometry that results from an equilibrium between the physical and biological processes which determine the concentration of elements pr esent at any point in the sea. Falkowski (2000) describes the Redfield Ra tio as “the result of nested processes that have a molecular biological foundatio n, but are coupled to biogeochemical process on large spatial and long temporal scales”. The Redfield Ratio has provided res earchers with a general foundation on which has been based modeling efforts, laboratory experiments and field studies designed to understand nutrient dynami cs and biogeochemical processes in aquatic environments (Menzel and Ryther 1964; Goldman et al. 1979; Hecky and Kilham 1988; Karl et al. 2001; Michaels et al. 2001; Falkowski 2000; Sterner et al. 2008). Based on the idea that phytoplank ton assimilate C: N: P in specific

PAGE 20

4 proportions and that nutrients are recycled in the those same proportions, if the concentration of one element was known, it would be possible to calculate the concentrations of the other nutrients. General assump tions could also be made about nutrient cycling and recycling, prim ary production and export production (Michaels et al. 2001; Geider and La Roche 2002). As research continued with the Redf ield ratio as a guide, it became evident that under varying nutrient regime s, phytoplankton seem to only exhibit C:N:P in Redfield propor tions when cells are growing at or near the maximum rate under conditions of nutrient suffi ciency (Caperon and Meyer 1972; Droop 1974; Droop 1975; Goldman et al. 1979; Harris 1986; Hecky et al. 1993; Vaillancourt et al. 2003). Under these c onditions, growth is balanced where “all cellular components increase exponentially at the same rate” and “cellular composition remains fixed” (Shuter 1979) Therefore, the stoichiometry of phytoplankton should be reflective of nutri ent availability or limitation in both cultured and natural assemblages and can be employed to assess population dynamics as related to the concept of steady state (growth rate = uptake rate) versus exponential growth. The application of algal stoichiometry concepts is potentially important to the understanding of nutrient cycling as it pertains to the biological pump, biogeochemical cycling, atmospheric and oceanic CO2 exchange and algal growth management (Karl et al. 2001; Sterner et al. 2008).

PAGE 21

5 Nutrient Limitation of Phytoplankton The concept of a limiting nutrient was formulated in 1863 by an agricultural chemist, Justus von Leibig. His Law of t he Minimum states the “growth of a plant is dependent on the amount of foodstuff wh ich is presented to it in minimum quantity”. Expressed more simply, Leibig’ s Law suggests that “growth rate is determined by the availability of the most limiting substance” (Tyrell 1999). The seminal work of Leibig has remained as an important central concept of ecology and oceanography. In this manner, Lei big has been considered to be the “founding father of Ecological Stoichiometr y” (Sterner and Elser 2002). This limiting nutrient concept provides the bas is for modern modeling strategies which relate nutrient limitation and phytoplankt on growth. The Droop model (1974) is based on the premise that phytoplankton nu trient assimilation rates and related growth rates are determined by the internal nutrient stores of the organism and that nutrient limited growth is reflected in the particulate composition of the organism (Hecky and Kilham 1988; Geider and La Roche 2002). In contrast the Monad Model relates phytoplankton growth to external concentrations of dissolved nutrients (Hecky and Kilham 1988). Over the decades, the concept of t he “limiting nutrient” to phytoplankton growth has fueled many debates and insp ired many research projects. The current dogma is that lakes and stream s are predominately P-limited while oceans and estuaries are N limited (Goldman et al. 1979; Herbland et al. 1998). However there is much more evidence to support the former than the latter due to the complexities associated with t he size, long residence times and variable

PAGE 22

6 boundary layer in the ocean (Hecky and Kilh am 1988). Unlike in freshwater systems, where ecosystem wide expe riments have been conducted (Sommer 1990; Hecky et al. 1993), marine system assessments are largely confined to culture and bottle experiments in determi nation of the limiti ng nutrient (Hecky and Kilham 1988). Hecky and Ki lham (1988) and Smith ( 1984) suggest that these types of experiments have their limitations and results may not reflect processes that would occur in natural environments. Is the ocean N-limited or P-limited? There are two schools of thought on this: the geochemist point of view is t hat P limits primary production, while the biologist point of view where N limits primary production in the ocean (Tyrell 1999). The geochemists argue that when nitrogen becomes limiting, nitrogen fixers can utilize the abundant supply of N2 in the atmosphere to meet their requirements for growth. Remineralizat ion of this new biomass releases dissolved N, replenishing the supply of N available for phytoplankton uptake (Redfield 1958; Tyrell 1999). In contrast, ne w inputs of P in the ocean are largely limited to coastal inputs or up-welled deep ocean water and are a function of physical processes rather than a function of the biology and thus their rate of supply cannot be replenished as read ily. However, natural nutrient abundance data have shown that typically it is N that is in scarce supply relative to P (Tyrell 1999). It is also N additions that most often stimulat e phytoplankton growth in nutrient bioassays conducted with oligot rophic waters (Goldman 1976; Hecky and Kilham 1988; Tyrell 1999). In theory it seems that P should limit primary production in the ocean but “in practice” it seems that N is the “master limiting

PAGE 23

7 nutrient” (Tyrell 1999). This may be relat ed to timescale considerations where on geological time P limits production in the oceans, while on shorter scales, N limits production as related to t he biology of the system. Nutrient limited or non-nutrient limit ed growth of phytoplankton can be inferred by an examination of the C:N:P stoichiome try of the phytoplankton composition based on the c oncept that cellular C, N and P concentrations change in response to changing nutrient regimes (Nalewajko and Lean 1980). Fluxes of nutrients in the marine env ironment can be quite dynamic and are related to both biotic and abiotic processe s. Biological contro ls are perhaps the most influential in this respect and includ e the strength of t he biological pump as related to production and particle sinking velocities and the turnover times of N and P (Harris 1986) as related to the ef ficiency of the micr obial loop and the intensity of grazing activity. Physical in fluences on nutrient availability tend to be more episodic as many processes whic h effect nutrient distributions are dependent on climate conditions such as upwelling events (wind), horizontal advection (wind), stratification (tem perature and wind) and riverine inputs (precipitation). Other physical proc esses include nutrient movement along concentration differentials and redox cond itions. In response to this everchanging environment, phytoplankton have adapted the ability to adjust the quantity of metabolic and st orage components within the cell in order to sustain growth. As a resul t, the C: N ratio increases and th e N: P ratio decreases during N limitation while the C: P and N: P rati os increase when P is limiting. The Redfield Ratio provides a numerical benchmark to make this determination

PAGE 24

8 where N: P ratios greater than 16:1 implie s P limitation and N: P ratios less than 16:1 are indicative of N limitation. Fu rthermore, particle C:P can be employed to “set constraints on carbon sequestrati on” (Micheals et al. 2001) and the particulate C:N ratio provides “a relative measure of growth rate” (Donaghay et al.1978) as a response to the nutrient stat us of the cell (Eppley et al. 1973). Phytoplankton compositional C: N: P ratios thus provide a simple and powerful tool to determine phytoplankton nutritional state as it relates to nutrient availability and growth (Eppl ey et al. 1973; Hecky 1993). The Nutrients The major nutrients that are required by all phytoplankton for growth are carbon, nitrogen and phosphorus. In t he worlds oceans these elements continually cycle between the dissolved inorganic, dissolved organic and particulate organic (both living and nonliving particles) pools on timescales of minutes to days to thousands of year s and are driven by the biogeochemical processes both large and small that keep t hese elements continually cycling. It is the size of the nutrient pool (stor age capacity) and the rates of movement between these pools (turnover rate) rather than the absolute amounts of nutrients that are more important to understanding the roles of these biogeochemical processes as they relate to carbon sequestr ation over geological time or to global nutrient budgets or to “ecosystem function” and local nutrient availability (Harris 1986). On local spatial scales it is the availability of N and P that ultimately regulate phytoplankton growth rate, biom ass and bloom duration (Vargo et al.

PAGE 25

9 2008). Dugdale and Goering ( 1967) divided nitrogen into tw o forms, “new N” or “regenerated N”. “New” N ent ers the system from an external source and thus can contribute to new biomass (growth) “Regenerated” N originates within a system (eg. zooplankton grazing and excr etion and bacterial degradation) and can only maintain the present bioma ss, not produce new biomass (Dugdale and Goering 1967). All in all, “for natural populations to exist their cellular growth rate must exceed or equal losses to dilution, s edimentation, physi ological death and grazing” and “cellular growth rates are a function of nutrient supply” (Harris, 1986). Carbon In the marine environment, specia tion within the dissolved inorganic carbon pool is related to pH, alkalini ty and temperature which results in an equilibrium distribut ion between the CO2(aq), bicarbonate (HCO3 -) and carbonate ions (Harris 1986). The form of carbon wit hin this pool that is available for biological uptake is dissolved CO2 which is in equilibrium with atmospheric concentrations and can enter the oceans di rectly or by way of photosynthetic activity (Harris 1986). As a result of this endless source, dissolved inorganic carbon is found in much great er concentrations than the other essential nutrients and is rarely considered to be the limiti ng nutrient in marine waters. Although C is a bioactive element, its relative abundanc e results in longer turnover times in surface waters on time scales similar to physical processes and therefore C can

PAGE 26

10 be considered to behave more conservati vely than those of N and P (Harris 1986). The refractory nature of a portion of the dissolved organic C pool often results in its decoupling from the mo re labile N and P nutrient pools. Remineralization rates of N and P occur on significantly shorter time scales than for C, and often take place in shallo wer water column depths (Christian et al.1997; Hopkinson et al. 1997). This is related to the high N and P requirements of the microbial community and its pref erential remineraliz ation of N and P relative to C, and results in increasi ng C:N and C:P ratios of dissolved organic matter (DOM) with depth (Christian et al. 1997) The flexibility (deviation from the Redfield Ratio) of the stoi chiometry within the DOM pool is largely responsible for the oceans ability to store C. Nitrogen The nitrogen (N) cycle is very complex; many oxidation states of N exist as gains and losses of electrons to N compounds readily occur. The inorganic dissolved pool of N (DIN) in the aqueous en vironment includes the reactive forms NO3 -, NO2 -, NH4 + which are the preferred species for phytoplankton uptake, and dissolved N2 gas which is only available to a special group of organisms known as nitrogen fixers. Terrestrial sources of dissolved N, in cluding effluent from municipal waste water treatment plants, industry and agric ulture which enter the system via ground waters and rivers are important to coastal processes. In the open ocean,

PAGE 27

11 in-situ regeneration and higher trophic le vel digestion and excretion, N2 fixation, upwelling and eddy diffusion across the ther mocline provide the majority of N available for phytoplankton (Harris 1986) In oxygenated surface waters, nitrogen conversion is primarily the result of biological assi milation, grazing activity and heterotrophic bacterial regener ation within the euphotic zone (Harris 1986). These processes result in the release of NH4 + (ammonification) and the potentially bio-available co mponents of the dissolved organic pool of N (DON) which are urea and amino acids (McCarthy 1980; Bronk and Ward 1999; Cochlan and Bronk 2001; Glibert et al. 2004). In environments where concentrations of NO3 and NH4 + are low, it has been shown that urea could be a significant source of N to primary producers (Ant ia et al. 1991; Joint et al. 2001). Turnover times of DIN can be expected to be longer than for DIP as DON is more refractory than DOP (Walsh et al 2006) and N “must undergo changes in oxidation state before met abolism” (Harris 1986). Nitrification, denitrification and N2 fixation are also biologically mediated processes that play a very important role in N cycling and therefore N availability. Nitrification is an oxygen requiring process where a suite of bacterial decomposers oxidize NH4 + to NO2 to NO3 thus returning nitrogen into the preferred species for phytoplankt on uptake. This pathway of NO3 regeneration occurs quickly in both the water column and in oxygenated sediments and is in part responsible for the low concentrations of NH4 + and NO2 in marine waters (Harris 1986). Denitrification occurs in the absence of oxygen where facultative anaerobic bacteria reduce nitrates to gaseous nitrogen (Chempedia.com) and

PAGE 28

12 “represents a substantial loss of biol ogically availabl e N from the ocean (Ganeshram et al. 2002)”. The balance bet ween nitrification and denitrification is related to the flux of organic matter into bottom waters where increased flux means increased decomposition effort s resulting in oxygen depletion and increased denitrification and vice versa. N2 fixation is the process in which “N2 gas is combined, via the enzyme nitr ogenase, with free hydrogen molecules to produce NH4 + as the stable end product” (Chempedia.com) and is carried out by bacteria or the blue-green alga e referred to as cyanobacteria. This provides an important mechanism converting N from an unlimited source (atmosphere) into new biomass which upon decomposition prov ides a potential N source for non-N2 fixing phytoplankton. It has specifically been linked to K brevis bloom initiation and duration in oligotrophic Gulf waters (Lenes et al. 2001; Walsh and Steidinger 2001; Vargo et al. 2008). Phosphorus The phosphorus (P) cycle is less co mplex compared to the nitrogen cycle because phosphorus primarily exists as the (ortho-)phosphate ion PO4 3in both the aqueous environment and as cellular cons tituents (Harris 1986). In marine waters, the largest reservoir of P is typi cally within the particulate pool followed by DOP and the lowest concentrations are usually found within the DIP pool (Valiela 1995). The paucity within t he DIP pool is not only the result of phytoplankton uptake, but may be a result of the ease in which P complexes with other particles. P readily forms insoluble compounds with some metals under

PAGE 29

13 aerobic conditions which than sink out of the water column and become stored in the sediments (Valiela 1995). Sources of P to coastal areas are primarily terrogenous in origin and carried into marine environment through ri verine inputs, “direct discharge from industry and domestic sewage, surface runoff, erosion, leaching and groundwater transports and releas e from anaerobic sediments” (Anonymous 1994-1995). In contrast, in the open oc ean, P is predominantly supplied by insitu regeneration via zooplankton excreti on, grazing and the cycling of the microbial loop and also periodic upwe lling events (Nalewajko and Lean 1980). Turnover times of P can be quite rapid on the order of minut es to days depending on nutrient concentrations and P pool dist ributions (Nalewajko and Lean 1980). Phytoplankton primarily utilize orthophos phate for their metabolism and to manufacture cellular components, i.e. mainly phospholipids and nucleic acids (ribosomal RNA). PO4 3can be directly absorbed into the cell (Rivkin and Swift 1980), and no oxidation or reduction reacti ons are required for these processes (Harris 1986). This is an energy depend ent reaction which requires energy supplied from respiration or phot osynthesis (Nalewajko and Lean 1980). However, studies show that P uptake c an become saturated at low light levels when P is replete and that P uptake rates can be similar in both the light and dark phases (Nalewajko and Lean 1980). Some phytoplankton have the ability to take advantage of the large DOP pool by producing alkaline phosphatase, an extracellu lar enzyme that hydrolyzes organic monophosphate esters, releasing P that is available for assimilation by

PAGE 30

14 the cell (Perry 1974; Rivkin and Swift 1980; Graneli et al. 1999). An additional mechanism for P incorporation by phytoplankton has been suggested by Sanudo-Wilhelmy et al. (2004), where P that has been abiotically adsorbed or “scavenged” by phytoplankton cell surfaces can than be internalized by way of a “two-step kinetic process”. As yet it is unknown whether this process contributes significantly to the internal stores of P or just confounds phytoplankton stoichiometry studies which consider onl y total cellular P (Sanudo-Wilhelmy et al. 2004). The rate of P uptake is determined by the internal cellular P concentration of the phytoplankton (Fuhs et al. 1972) and the concentration and the N:P ratio of available nutrients. P uptake typi cally follows Michaelis-Menten kinetics (Nalewajko and Lean 1980). Algal cells which are P deficient have rapid assimilation rates when first given suffici ent P and uptake rates than decrease as cell P content increases (Healy and Hendzel 1980). When P is available in excess, phytoplankton have the ability to store P as polyphosphates in the cytoplasm and vacuoles of the cell, allowi ng for continued algal growth in the event that P becomes limiti ng (Nalewajko and Lean 1980). Scope of this Study The primary purpose of this study is to assess the nutrient status of the natural phytoplankton populations on t he Southwestern Florida shelf by comparing the particulate stoichiometry of carbon:nitrogen:phosph orus ratios of these assemblages to the Redfield Rati o of 106C:16N:1P. A secondary analysis

PAGE 31

15 of this data set will include the comparison of cross shelf transects (near-shore to offshore), latitudinal transects (north to south), the wet versus dry season, interannual (1998-2001) and bloom vers us non-bloom conditions of Karenia brevis and Trichodesmium.

PAGE 32

16 CHAPTER TWO WEST FLORIDA SHELF STUDY AREA Physical description The semi-enclosed western continental shelf of Florida is broad (extending 200km to the west) and relatively shallow due to a gently sloping topography (Yang and Weisberg 1998) with isobaths that generally parallel the coastline (Weisberg et al. 2000). The wide width of the WFS allows for the characterization of different regions as defined by distinctly different momentum balances (Weisberg et al. 2009). The near s hore region is part of the inner shelf and is directly impacted by estuarie s where salinity related baroclinicity influences circulation (Weisberg et al. 2005, 2009). The inner shelf (landward of the 50m isobath) is mostly affected by local wind forcing (Weisberg et al. 2000) and can be characterized by interacting surface and bottom Ekman layers (Weisberg et al. 2009). The mid-shelf (s eaward of 50m isobath) is where “along shelf momentum balance is in pure surface Ekman layer balance” and bottom stress is negligible (Weisberg et al. 2009) This region can experience flows which are opposite to those of the inner s helf as influenced by the partial closure of the WFS by the Florida Keys (Wei sberg et al. 2005). The outer shelf represents the transition between t he shelf and deep ocean processes. The WFS is wide enough so that the inner shelf and outer shelf do not overlap (Weisberg et al. 2009). The circulation pa tterns within the eastern Gulf of Mexico are the primary drivers of material fl ux across and within these regions of the

PAGE 33

17 WFS shelf and are primarily a result of isobath and coastline geometries, winds and buoyancy fluxes (He and Weisberg 2002; Weisberg et al. 2005, 2009), bounding Gulf waters and the Loop Current. The region experiences basically two seasons typical of a subtropical climate. Based on rainfall data (www.co aps.fsu.edu), the winter or dry season typically extends from October to May, with the summer or wet season from June to September. In response to shifts of the subtropical high pressure belt and associated changes in wind stress, seasonal patterns of shelf water circulation occur as well (Weisberg et al. 1996; Yang and Weisberg 1998). A brief and general summary of Yang and Weisberg (1998) is presented at this time. During the winter season, prevailing winds are from the north/northwest which results in a drop of coastal sea level as surface wate rs move westward. At this time, there are two opposing jets along the coast, one flowing south from the north and the other flowing north from the south, wh ich meet during March and October near the west-central Florida shelf. The mid shelf region is dominated by a strong northwestward jet along the 50m isobath. These winter conditions induce coastal upwelling, mid-shelf downwelling and a we ll-mixed water column. In contrast, prevailing winds in the summer are from the south/southeast and coastal sea surface elevation rises. Gulf circulati on is somewhat simpler at this time, with only a single northwestward flowing coasta l jet along the entire west coast. The shelf region is now dominated by downw elling conditions and the strong jet along the 50m isobath disappears. During both seasons, the shelf break is

PAGE 34

18 predominately influenced by northwestward moving topographic waves which results in alternating upwelling and dow nwelling conditions in this region. Due to low background inorganic nutrient concentrations (Heil 2000), this system is generally considered to be oligot rophic (Vargo et al. 2004; Bisset et al. 2005; Heil et al. 2007). Despite this characterization, the area has supported large and persistent blooms of diatoms (Neely et al. 2004), cyanobacteria (e.g. Trichodesmium spp), (Lenes et al. 2001) and the dinoflagellate Karenia brevis (Vargo et al. 2004). The source of nutrient s which fuel this primary production is currently unknown and much research is underway to gain insights into this enigma (Vargo et al. 2008). Nitrogen and Phosphorus Sources Primary production in the SW Florida coastal zone is influenced by new nutrients entering the Gulf of Mexico via numerous rivers and tributaries which drain into the Tampa Bay and Charlotte Ha rbor estuaries and the gated flow of the Caloosahatchee River which periodica lly receives the overflow of Lake Okeechobee. The nutrient loads associ ated with these watersheds originate from residential development, industry, agriculture, cattle ranching and the Miocene Hawthorne phosphatic deposits (H eil et al. 2007). The “sandy soils, conductive aquifers and permeable coastal sediments” of these watersheds are conditions conducive to submarine ground water discharge into coastal waters which can carry nutrient loads with conc entrations similar to riverine inputs (Kroeger et al. 2006). These sources tend to carry greater loads of inorganic

PAGE 35

19 phosphorus than inorganic nitrogen and the es tuaries within the study area are generally considered to be N-limited or P-enriched, with low DIN:DIP ratios (Wang et al. 1999; Heil et al. 2001; Var go et al. 2001, 2008). Other nutrient inputs to coastal waters include overl and runoff, discharge from storm water systems, wastewater treatm ent plants, industrial and domestic point sources (Wang et al. 1999; Poor et al. 2001). As anthropogenic activity continua lly increases on Florida’s west coast, atmospheric deposition should potentially be an important source of new N but not P, to the coastal marine environmen t. A study conducted by Poor et al. (2001) found that average total wet and dry deposition of nitrogen (NH4 +, HNO3, NO3 -) to the Tampa Bay estuary duri ng 1996-1999 contributed approximately 22.0% of the nitrogen to this region. Data collected at the Mote Marine Lab and the Gandy Bridge during 20002002 had deposition rates of N and P that were 12 orders of magnitude lowe r than estuarine inputs and were not significant sources of nutrients to coastal zones prim arily due to dilution effects (Vargo et al. 2008). The shallow southwestern Florida shelf supports a diverse autotrophic and heterotrophic benthic community and as su ch, benthic flux of remineralized N and P out of the sediments into the water column could be an important source of nutrients to this system (Vargo et al. 2008) Modeled values of benthic flux report that ammonia flux rates ar e more significant relative to P fluxes out of the sediment (Vargo et al. 2008). Wang et al (1999), reports that the release of NH3 and PO4 3from the sediments in Tampa Bay exceeded all external loads.

PAGE 36

20 Nutrient flux out of the Tampa Ba y and Charlotte Harbor estuaries and the Caloosahatchee River can be an important source of TN and TP to coastal marine waters, especially when river input s are high during the late summer and fall. During this time, tributaries of bot h Tampa Bay and Charlotte Harbor have high concentrations of silica (see Froe lich et al. 1985, Vargo et al. 1991). Therefore, Si concentrations can be us ed as a non-conservative indicator for estuarine discharge into the coastal zone. Inorganic PO4 3and DOP are elevated at the 10m isobath and show a distinct seasonal pattern that coincides with river flow (Vargo et al. 2008). When estimates of N and P within the daily volume of water flowing out of the Tampa Bay and Charlotte Harbor estuaries and subsequent dilution calculations are cons idered, estuarine outflows are generally “confined to the areas immediat ely offshore of the estuary” (Vargo et al. 2008). The inner west Florida shelf experi ences periodic upwelling events where interacting surface and bottom Eckman laye rs move deeper nutrient rich waters shoreward across isobaths as part of an Ekman-Geostrophic adjustment to wind forcing along the coast (Weisberg et al. 2000) At the shelf break, nutrient rich slope waters are occasionally upwelled (reaching the 30m isobath) in response to intrusions of the Loop cu rrent onto the outer shelf of the Gulf of Mexico and local wind events (Heil et al. 2001; Vargo et al. 2008). Although this water rarely reaches the surface, the entrained nutri ents could potentially fuel near bottom diatom populations which dev elop during summer stratifica tion (Heil et al. 2001). This mechanism indirectly provide nutrients to surface water as the remineralization products of this bi omass eventually reach the photic zone

PAGE 37

21 through vertical mixing in the fall (Vargo et al. 2008). Across shelf transport of upwelling waters provides an important albei t sporadic source of new nutrients to the photic zone and creates an effective link between shelf break and near shore nutrient sources (He and Weisberg 2002). Moving seaward, away from coastal influences, the balance between the phytoplankton uptake from the soluble poo l and regeneration of the nutrient from the particulate pool becomes an increas ingly important fa ctor regulating production in these oligotrophic waters. N2 fixation by cyanobacteria, metabolic activity of grazers (zoo plankton and flagellates) and in situ regeneration (microbial loop) are the likely biologica l processes recycling nutrients in GOM offshore waters. Blooms of Trichodesmium spp. blooms periodically occur within 75 km of the west coast of Florid a and have been linked to the wind driven Saharan dust events which de posit large amounts of iron to Gulf waters during the summer months (Lenes et al. 2001, 2008). Iron is a critical component of nitrogenase, the enzyme responsible for N2 fixation. Therefore, iron has the potential to limit N2 fixation in offshore environments (Lenes et al. 2001) but typically not in coastal environments where iron is delivered into the marine environment via rivers (Ingle and Martin 1971). Trichodesmium ssp. has been reported to excrete inorgani c N and P as well as DON (Lenes et al. 2001, 2008; Mullholland et al. 2004; Glibert and Bronk 1994). In turn, these “new” sources of N and P would potentially become available to other cells including the harmful algae K. brevis (Mullholland et al. 2004; Gliber t and Bronk 1994; Havens 2004).

PAGE 38

22 Summary of Nitrogen and Phosphorus Distributions The Tampa Bay and Charlotte Harbor estuaries are characterized by low DIN concentrations (less than 0.5 M) and high DON concentrations with values measured in 2001 of ~44-56 M (Vargo et al. 2008). A study conducted by Heil et al. during the dry season of 2003 has shown that the inorganic N pool is typically dominated by NH4 + and is found in the highest concentrations at the mouth of Tampa Bay and inside Charlotte Harbor, an area which also exhibits the greatest concentration of DON (Heil et al. 2007). Coastal standing stocks of DIP and DOP are of similar magnitude and show seasonal peaks in the late summer and fall as related to increase rive r flow during this time (Vargo et al. 2008). The Caloosahatchee River had higher average concentrations of TN and TP relative to Tampa Bay and C harlotte Harbor during 1998-2001. Typically offshore (greater than the 10m isobath) concentrations of DIN and DIP are low, ranging from ~0.02-0.2 M and ~0.025 -0.24 M respectively. Such values are in contrast to conc entrations of organic N ~8-14 M and organic P ~0.2-0.5 M which are present at mu ch higher concentrations (Vargo et al. 2008). I refer the reader to Vargo et al. (2008), Walsh et al. (2006) and Heil et al. (2007) for a more detailed description of the nutrient distribution on the West Florida Shelf.

PAGE 39

23 CHAPTER THREE METHODOLOGY Sampling The Florida Ecology and Oceanography of Harmful Algal Blooms (ECOHAB) program was a mu lti-institutional collabora tion, multi-agency (National Science Foundation, National Oceani c and Atmospheric Administration, Environmental Protection Agency) project examining the dynami cs of the Florida Karenia brevis Red Tide which consisted of several major components. As part of the hydrological ECOHAB component, m onthly field surveys were conducted aboard the R/V Suncoaster from June 1998 through De cember 2001 in the Southwestern Gulf of Mexico off the c oast of Florida. The study site was determined in relation to where K. brevis was usually first observed, which is ~27 N latitude between Tampa Bay and C harlotte Harbor (Walsh et al. 2006) (Figure 1) Three East to West transects were sampled monthly from 1998 to 2001, 1) outside the mouth of Tampa Bay (St. Petersburg), 2) Sarasota and 3) Fort Meyers. Stations were sampled synoptical ly approximately every 9.2 kilometers out to the 50m isobath along all transects over a 4 day period. The stations along the Sarasota transect were extended out to the 200m isobath. Seawater samples were obtained from 12L Niskin bottles attached to an aluminum-framed rosette/CTD package whic h also provided continuous vertical profiles of chlorophyll fluorescence, tem perature, salinity and density. Surface

PAGE 40

24 hydrologic data were collected from a deck mounted underway flow through system which ran continuously throughout each cruise. This system provided system where surface temperature, salin ity, chlorophyll fluor escence, density, particle scattering and light transmissi on data matched with latitude and longitude. Therefore the surface data provided the ab ility to construct surface maps of all parameters. Longitude(W) USF Ft. Myers Sarasota TampaFLORIDA GULF OF MEXICOTampa Bay Transect Sarasota Transect Ft. Myers Transect 28.00Latitude(N)28.50 27.50 26.50 27.00 26.00 -84.00-83.30-83.00-82.50-82.00-81.50 Longitude(W) USF Ft. Myers Sarasota TampaFLORIDA GULF OF MEXICOTampa Bay Transect Sarasota Transect Ft. Myers Transect 28.00Latitude(N)28.50 27.50 26.50 27.00 26.00 -84.00-83.30-83.00-82.50-82.00-81.50 Fi g ure 1. Ma p of ECOHAB: Florida stud y area and station locations.

PAGE 41

25 Chemical and Biological Measurements For Chlorophyll a (Chl a ) analysis, 250 ml of whole seawater was filtered onto 25mm Whatman GF/F filt ers in duplicate. The filt ration chimney was rinsed with 0.2 m filtered seawat er, then the GF/F filter was folded in half and immersed in 10 ml of methanol contained in a 10 ml plastic centrifuge tube, vortexed for approximately 2 seconds, capped and frozen at -15 C. Immediately prior to analysis, samples were then allo wed to equilibrate to room temperature and centrifuged for 10 minutes at 80 rpms. The fluorescence of the resultant supernatant was determined using a Turner 10AU fluorometer and Chl a and phaeopigments content were determined as given by Holm-Hansen et al.1965). For analysis of particulate phosphate, 500 ml of seawater was pre-filtered using 153 m mesh to eliminate lar ge zooplankton and t han filtered onto replicate pre-combusted (450 C for 2.5 hour s) 25mm GF/F filters and frozen in fired (450 C 2.5 hours) scintillation vi als at -15 C. The samples were subsequently processed following the Solorzano and Sharp (1980) method and particulate phosphate concentrate s were measured on a Beckman spectrophotometer. To determine particulate carbon and nitr ogen, seawater was pre-filtered using a 153 m mesh to eliminate large zooplankton and filtered in duplicate onto a pre-combusted (450 C, 2.5 hours) 15mm GF/F filter using a sample volume which gave the filter adequate color for the analysis. T he filter was than treated with 2-3ml of 10% HCl in f iltered seawater to remove inorganic carbon, rinsed

PAGE 42

26 with filtered sea water then placed in fir ed foil (450 C, 2.5 hours),frozen at -20 C, followed by lyophilization and storage at -20 C over desiccant. Particulate carbon and nitrogen were measured by hi gh temperature combustion/oxidation of a whole filter using a Carla Erba Elemental Analyzer. Karenia brevis was counted live within 3 hour s of sampling. One ml samples were placed in a glass well plate and the number of K. brevis cells was determined using an Olympus dissecting microscope. Trichodesmium spp concentration was determined by filtering between 1-4 L of seawater onto a 47mm Whatman GF/F f ilter. The filter was than placed in a 47mm plastic Petri dish. The number of in dividual trichomes and colonies (puffs and tufts) were counted on ship using an Olympus dissecting microscope. Monthly precipitation data were obtained from http://www.coaps.fsu.edu for Tampa Bay, Fort Meyers and Sarasota areas. Data from these sites were then averaged to provide an overa ll area precipitation average. Particulate Nutrient Ratio Calculations The mass of particulate carbon and nitr ogen values were calculated from the combustion of replicate filters so average C:N ratios and accompanying standard deviation for that ratio could be determined. Particulate phosphate however, was determined by a different method, and theref ore the mass of particulate carbon, nitrogen and phosphate were first averaged for each station, with N: P and C: P ratios calculated without the statistical appl ication of standard

PAGE 43

27 deviation. All particulate ratios present ed are molar ratios as determined by the equation: [(Mass (mg)/Volume filtered (L) 1000)/Formula Weight]. Statistical Methodology Data were statistically analyzed using SigmaPlot (version 11). Data were compiled in Microsoft Exce l and imported into SigmaP lot. Kolmogorov-Smirnov goodness of fit analysis and skewness and kurtosis Z scores were used to assess the distribution of the data. A Spearman Rank Order Correlation was performed on all particulate nutrient conc entration and calculated nutrient ratio data as well as Chl a data. Spearman Rank Order Correlation is a nonparametric test that co mputes the correlation coefficient to quantify the relationship between two variables without specifying dependent and independent variables. This test was performed on data where the residuals are not normally distributed and/or have non-constant variances. This test is based on ranks rather than ar ithmetic means. To analyze nutrient data for potential detrital contribut ion and parameter relationships, data were also analyzed us ing simple linear regressions in SigmaPlot. Results of linear regressions were used to produce scatter plots of the residuals and normal probability distri bution of the residuals and observed versus predicted values. Central Tendency Analyses were also performed on log transformed and non-transformed particulate nutrient concent ration and calculated particulate ratio

PAGE 44

28 data using Excel. Central Tendency A nalyses provided the mean, geometric mean (Gmean), minimum (min), maximum (max) and median.

PAGE 45

29 CHAPTER 4 RESULTS AND DISCUSSION Complications to the Interpreta tion of Particulate Nutrient Stoichiometry Particulate nutrient concentration quantif ies how much C, N and P is in the particulate pool at a given time or place and should primarily be related to the physical processes of nutrient delivery. Theoretically surface particulate ratios should be related to phytoplankton bioma ss and reflect phytoplankton uptake and growth dynamics as related to nutrient availability. Particulate C, N and P are useful to include when discussing particula te nutrient ratios as these values can help explain why a ratio changes concentra tion in relation to the elements that comprise that ratio. However, interpreting in situ particulate nutrient data and particulate nutrient stoichiometry is c hallenging because it is often unknown exactly what comprises the particulate nutrient fractions being measured. For this study, particulate nutrients are operatio nally defined as t he total particulate material that is in the size range from 0.7 m to 153 m. It is known that the detrital component of the particulate pool varies in both quantity and chemical compos ition (Menzel and Ryther 1964; Sharp et al. 1980; Valiela 1985; Hecky et al. 1993; Hessen et al. 2003) and that the contribution of detrital nutrients can confound nutrient stoichiometry interpretation. In oligotrophic waters where phytoplankton biom ass is low, the detrital contribution can be large (Harris 1986), but potentially has a similar particulate stoichiometry

PAGE 46

30 to phytoplankton as turn over rates of bot h fractions are rapid (Hecky et al.1993). In contrast, in coastal environments where phytoplankton biomass is higher, detrital contributions can become less im portant as living cells contribute a greater portion to the particulate pool (Steele and Baird 1961; Harris 1986). However, the chemical composition has mo re potential to vary due to inputs from sources other than phytoplankton includi ng decaying submerged vegetation (e.g. seagrass), macro-algae, resuspension of bottom material and te rrestrial sources which have higher proportions of particulate C and N relative to P than those of phytoplankton cells (Hecky et al. 1993). Without other complimentary analysis, whether the particulate nutrient ratios ar e truly reflective of living phytoplankton cellular material is unknown. Another aspect of this study whic h complicates data interpretation concerns the potential for the underesti mation/overestimation of particulate P relative to the underestimation/overestima tion of particulate C and N due to the different methodologies used for each (S ee Chapter 3). If the method for measuring particulate C and N concent ration either overestimates or underestimates C and N values concurrent ly, the C:N ratio would remain the same. However, the complication arises when interpreting N:P and C:P ratios. The underestimation/overestimation of eit her particulate C and N or P would not be expected to be of the same magnit ude or possibly the same direction and could significantly skew the particulate N:P and C:P ratios leading to erroneous conclusions.

PAGE 47

31 It should be mentioned that samplin g was continuous from June 1998 through December 2000 and resumed in Ap ril of 2001 through December 2001. This could potentially bias the data when calculating the mean, ranges and median of the particulate constituents and ratios as this was not taken into consideration at this time. General Particulate Nutrient and Nu trient Ratio Distributions on the SW Florida Shelf Surface particulate nutrient data colle cted over the sampling period from 1998-2001 displayed a large range for each el ement (Table 1). Particulate C ranged form 1.05 to 503.20 M (geometri c mean=20.820.69), particulate N ranged from 0.05 to 330.88 M (geometri c mean=2.851.08) and particulate P ranged from 0.001 to 0.071 M (geometric mean=0.05 0.91). Particulate N concentrations displayed the greatest variability, encompassing 4 orders of magnitude. The spread of particulate nut rient concentrations values across the wide range are not normally distributi on and are heavily skewed toward higher values (Figure 2). A variety of tests performed for norma lity of the untrans formed and natural log transformed data including Kolmogor ov-Smirnov goodness of fit, skewness and kurtosis Z-scores, confirmed that surf ace particulate C, N and P values were not normally distributed. Results of stat istical analysis showed that particulate C (normal log transformed) was the most nor mally distributed variable of all the parameters presented, only failing to conform to kurtosis or the “peakedness” test

PAGE 48

32 Table 1. Central tendency and ranges fo r the surface particulate nutrient concentrations (S.D.) sampled from June 1998 through December 2001. All units are in (M). ________________________ _____________________ ___________________ C N P ________________________ _____________________ ___________________ N 828 828 828 Mean 26.60(26.55) 6.14(15.24) 0.08(0.09) Geometric Mean 20.82(0.69) 2.85(1.08) 0.05(0.91) Minimum value 1.05 0.05 0.001 Maximum value 503.20 330.88 0.71 Median 20.08 2.56 0.04 ________________________ _____________________ ___________________ of the distribution. This suggests that particulate C concentrations across the shelf are less inclined to have extreme values relative to particulate N or P. This seems to make sense in that the potent ial for the more biologically active elements, N and P, to vary is much greater than the potential for C to vary. It is also interesting to note that particulate N has a frequency distribution which is different from particulate C and P, which s hare a similar distribution. This may be related to biological processes or the sensitivity of the el emental analyzer in detecting N at low concentrations. Interestingly, the right tails of these distributions are comprised entirely of samples collected adjacent to the mouths of Tampa Bay and Charlotte Harbor or along the 10 m isobath for which some stations had Karenia brevis concentrations greater than 1,000 cells/L (Figure 2). This implies that contributions from coastal inputs and K. brevis biomass has a large influence particulate nutrient stoichiometry at this isobath and seem to be responsible for

PAGE 49

33 0 100 200 300 400 500 0.020.080.140.200.260.320.380.440.500.560.620.680.74 0 100 200 300 2468101214161820222426283032343638>38 0 100 200 300 102030405060708090100>100A C B Frequency DistributionP (M) N (M) C (M) 0 100 200 300 400 500 0.020.080.140.200.260.320.380.440.500.560.620.680.74 0 100 200 300 400 500 0.020.080.140.200.260.320.380.440.500.560.620.680.74 0 100 200 300 2468101214161820222426283032343638>38 0 100 200 300 2468101214161820222426283032343638>38 0 100 200 300 102030405060708090100>100 0 100 200 300 102030405060708090100>100A C B Frequency DistributionP (M) N (M) C (M) Figure 2. Histogram of surface partic ulate nutrient A) carbon, B) nitrogen, and C) phosphorus concentrations sampled from June 1998 through December 2001. The red bars identify concentration bins that are comprised entirely of samples collected from the 10m isobath. The hashed lines indicate a change in scale. All units in M.

PAGE 50

34 20.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 0100020003000400050006000C ( mg/L) R 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 0100020003000400050006000N (mg/L)y = 0.0006x + 0.12432= 0.5608 y = 1E-09x + 0.0098 R= 0.4352y = -10.307x + 1.8039 = 0.0004 y = 6E-07x + 1.121 R= 0.9999 20.000 0.005 0.010 0.015 0.020 0.025 0100020003000400050006000P (mg/L) y = 0.1116x + 0.0107 R2= 0.0305 0.000 0.005 0.010 0.015 0.020 0.025 0.0000.0050.0100.0150.0200.0250.030P(mg/L)K. brevis (cells/L) Chl a (mg/L)R 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 0.0000.0020.0040.0060.0080.010C (mg/L) y = -193.46x + 2.2095 R2= 0.5648 0.00 0.50 1.00 1.50 2.00 2.50 0.0000.0010.0020.0030.0040.005N (mg/L)A B C D E F 20.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 0100020003000400050006000C ( mg/L) 20.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 0100020003000400050006000 20.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 0100020003000400050006000C ( mg/L) R 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 0100020003000400050006000N (mg/L) R 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 0100020003000400050006000 R 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 0100020003000400050006000N (mg/L)y = 0.0006x + 0.12432= 0.5608 y = 0.0006x + 0.12432= 0.5608 y = 1E-09x + 0.0098 R= 0.435 y = 1E-09x + 0.0098 R= 0.4352y = -10.307x + 1.8039 = 0.00042y = -10.307x + 1.8039 = 0.0004 y = -10.307x + 1.8039 = 0.0004 y = 6E-07x + 1.121 R= 0.9999 y = 6E-07x + 1.121 R= 0.9999 R= 0.9999 20.000 0.005 0.010 0.015 0.020 0.025 0100020003000400050006000P (mg/L) 20.000 0.005 0.010 0.015 0.020 0.025 0100020003000400050006000 20.000 0.005 0.010 0.015 0.020 0.025 0100020003000400050006000P (mg/L) y = 0.1116x + 0.0107 R2= 0.0305 0.000 0.005 0.010 0.015 0.020 0.025 0.0000.0050.0100.0150.0200.0250.030P(mg/L) y = 0.1116x + 0.0107 R2= 0.0305 0.000 0.005 0.010 0.015 0.020 0.025 0.0000.0050.0100.0150.0200.0250.030 y = 0.1116x + 0.0107 R2= 0.0305 0.000 0.005 0.010 0.015 0.020 0.025 0.0000.0050.0100.0150.0200.0250.030P(mg/L)K. brevis (cells/L) Chl a (mg/L)R 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 0.0000.0020.0040.0060.0080.010C (mg/L)R 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 0.0000.0020.0040.0060.0080.010 R 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 0.0000.0020.0040.0060.0080.010C (mg/L) y = -193.46x + 2.2095 R2= 0.5648 0.00 0.50 1.00 1.50 2.00 2.50 0.0000.0010.0020.0030.0040.005N (mg/L) y = -193.46x + 2.2095 R2= 0.5648 0.00 0.50 1.00 1.50 2.00 2.50 0.0000.0010.0020.0030.0040.005 y = -193.46x + 2.2095 R2= 0.5648 0.00 0.50 1.00 1.50 2.00 2.50 0.0000.0010.0020.0030.0040.005N (mg/L)A B C D E F\ Figure 3. Relationship between surf ace particulate C, N and P and Chl a (Figs. A, B,C) or K. brevis concentrations (Figs. D, E, F) in samples comprisi ng the bins from histogram Fig. 2, i ndicating samples from the 10m isobath.

PAGE 51

35 the high values which occur with low frequen cy relative to non-coastal stations or non-bloom conditions on the WFS. A shar ed spatial distribution justifies the validity of these numbers, and excludes t heir potential exclusio n based solely on the fact that they lie outside the range of most of the data. Particulate C and P values show no linear relationship to Chlorophyll a (Chl a ) (Figure 3) with R2=0.0004 for C and R2 = 0.0305 for P. The lack of a relationship may be the result of detrital contributions influencin g the particulate stoichiometry of coastal stations, despite the high biomass associ ated with near shore stations and bloom conditions. However, there does seem to be a positive linear relationship between C (R2=0.9990), N (R2=0.5608) and P (R2=0.4350) with Karenia brevis cell concentration (Figure 3) which provi des justification to include those data points in the analysis. It appears that particulate C, N and P concentrations increase with increasing K. brevis concentration as biomass increases. The surface particulate C, N and P molar ratios collected over the sampling period from 1998-2001 also displa yed a large range of values across the WFS (Table 2). Particulate C:N ranged from 0. 09-98.82 (geometric mean=7.690.97), N:P ranged from 0.59-789.08 (geometr ic mean=54.600.96) and C:P ranged from15.134431.17 (geometric m ean=407.480.82). The surface particulate molar ratios of C:N, N:P and C: P are not normally distributed as given by the failure to pass Kolmogorov-Smirnov goodness of fit,

PAGE 52

36 Table 2. Central tendency and ranges of surface particulate nutrient ratios sampled from June 1998 through December 2001. ________________________ _____________________ ___________________ C:N N:P C:P C:N:P ________________________ _____________________ ___________________ N 831 812 817 Mean 11.53(21.88) 90.07(1 75.20) 569.36(726.53) 332:77:1 Geometric Mean 7.69(0.97) 54.60(0.96) 407.48(0.82) 410:56:1 Minimum value 0.09 0.59 15.13 Maximum value 98.82 789.08 4431.17 Median 8.48 46.91 394.63 502:64:1 ________________________ _____________________ ___________________ skewness and kurtosis Z-scores tests for no rmality (Figure 4). The large range in the data requires these histograms to be presented on two scales to accommodate those samples of higher values but less frequency (see caption Figure 4). It is interesting to note t hat the data for the pa rticulate N:P and C:P ratios (Fig 4, B and C) display a more normal distribution when considering the bulk of the data (N:P bins 10 to 100 and C:P bins 50 to 1000) relative to the bulk of the nutrient constituents (C N and P) and the C:N ratio. The large range in the particulate nutri ent constituents is evidence of the wide variety of processes on the WFS wh ich can potentially influence nutrient inputs and availability for phytoplankton upt ake. These include: proximity to coastal inputs, N2 fixation, upwelling events, vert ical structure of the water column (e.g. thermal strati fication), wind events, salinity fronts, hydrography of different regions and seasonality. Thes e processes, along with the ability of phytoplankton to adapt to the nutrient regime of their environment, may be responsible for the wide range within the particulate ratios over space and time.

PAGE 53

37 Figure 4. Histogram of su rface particulate nutrient ra tios A) C:N, B) N:P and C) C:P sampled from June 1998 through De cember 2001. Hash marks indicate a change in bin for A) from 2 to 4, B) from 10 to 100 and C) from 50 to 1000 A 0 50 100 150 2814202632386090 0 20 40 60 80 100 120 140 1030507090200400600800 0 20 40 60 80 100 502003505006508009503000Frequency DistributionC:N N:P C:P B C A 0 50 100 150 2814202632386090 0 20 40 60 80 100 120 140 1030507090200400600800 0 20 40 60 80 100 502003505006508009503000Frequency DistributionC:N N:P C:P B C 0 50 100 150 2814202632386090 0 20 40 60 80 100 120 140 1030507090200400600800 0 20 40 60 80 100 502003505006508009503000Frequency DistributionC:N N:P C:P B C

PAGE 54

38 This could also explain in part, the non-norma l distribution of this data set, where the values comprising the right tail of both histograms (Figure 2, 3) could potentially be related to more infrequent events such as phytoplankton blooms, large detrital contributions to coastal stati ons as a result of increased river flow or pulsed nutrient inputs in response to c limatic forcing (e.g. wind events). Variability of particulate nutrient ratios is not confined to the WFS. Studies of natural phytoplankton assemblages conduc ted by Karl et al. (2000, 2001) at station ALOHA and BATS and a review of the GEOSECS data by Micheals (2001) have indicated that nutri ent stoichiometries based on in situ samples are not constant and can vary substantially. Phytoplankton culture experiments also have shown that phytoplankton exhibit fl exible particulate stoichiometry in response to different nutrient and light regimes (Rhee 1974, 1978; Epply et al. 1974; Goldman et al. 1979; Perry 1976; Goldman 1986). The West Florida Shelf from June 1998 through December 2001 had a geometric mean particulate C:N:P stoichio metry of 332:77:1 (Table 2), which is very different from the cl assic Redfield ratio of 106: 16:1 (Redfield 1934, 1958) or the more recent work of Montegut-C opin and Montegut-Copin (1983) who report a global average of 103:16.1: 1. The geometric mean of 7.69 for the surface particulate C:N ratio is close to the Redf ield ratio of 6.66 and the global average of 7.70 reported by Bertilsson et al ( 2003) (Table 2). However particulate N:P and C:P have geometric means of 54. 60 and 407.48 respectively, and do not compare with other values found in t he literature for nat ural phytoplankton assemblages (Table 3) nor to the Redfie ld ratios of N:P and C:P of 16 and 106

PAGE 55

39 respectively. The closest values in the literature to the current WFS results are those reported for P-limited phytoplank ton culture experiments (Table 4). Reported N:P and C:P ratios of marine phyto plankton grown in P limited cultures are well above the Redfield ratio. Prochlorococcus Synechococcus and Thalassiosira pseudonana are part of the phytoplankton assemblage found in WFS waters and reported N:P values r anged from 61.1 to 109.0 and C:P values ranged from 464.0 to 779.0 when grown under P-limited conditions (Perry 1976;Bertillsson et al. 2003; Wawrik and Paul 2004). These findings suggest that on average, the WFS seemed to be predominately P-lim ited during the sampling period. Surface particulate nutrient rati os have been binned according to categories derived from their potential nutri ent status (no limit ation with values close to Redfield, nutrient limited and seve rely nutrient limited) (Figure 5) as suggested by Hecky et al. (1993), Downing (1997), Tyrell (1999) and Grieder and La Roche (2001). 43.4% of the data ar e near Redfield proportions for C:N and are either not nutrient limit ed or growing at their maxi mal rates, while 26.4% of the data are N-limited and 11.9% are severe ly N-limited. 18. 3% fall into the category of C-limitation; however this is most likely due to light limitation. The N:P ratios have only 9.7% of the data near Redfield with 40.4% suggesting Plimitation and 48.2% suggesting severe Plimitation. The ratio of C:P have 83.76% of the data categorized as severe ly P-limited and only 2.32% are near the Redfield Ratio. The fact that 86% of the N:P and 94.87% of the C:P nutrient

PAGE 56

40 Table 3. Literature summary of in situ particulate nutrient ratios. Values presented are the average, with the range given in parentheses if available. ________________________ _____________________ ___________________________ _________________________ Particulate Nutrient Ratio Location Depth C:N N:P C:P Reference ________________________ ___________________________ ____________________ __________________________ Global Average Pelagic N.A. 37* Downing, 1997 Pelagic N.A. 7.7 (3.8-12.5) 16.4 (5.0-34.0) 114.0 (35.0-221.0) Bertilsson et al., 2003 Benthic Microalgae 20 35 700 Atkinson and Smith 1983 Atlantic Ocean Oceanic Sargasso Sea 1-20 m 31.0 225.0 Ammerman et al., 2003 Atlantic Ocean 1-30 m 8.6 17.0 112.0 Sterner et al., 2008 Bermuda 0-4 m 15.0 235.0 Sterner et al., 2008 Western North** E.Z. 12.5 59.0 Menzel and Ryther, 1964 Western North*** E.Z. 5.3 91.0 Menzel and Ryther, 1964 Subtropical West# 5.7 14.0 80.0 Sanudo-Wilhelmy et al., 2004 Coastal Bay of Biscay M.L. 6.5 33.5 217.0 Herbland et al., 1993 Norway 0-10 m 7.6 19.0 137.0 Sterner et. al., 2008 Oslofjord 2-8 m 9.2 17.0 154.0 Sterner et al., 2008 Riga Bay 9.9 18.0 171.0 Sterner et al., 2008 Pacific Ocean Oceanic North Pacific Gyre 8.2 (6.9-48.0) Sharp et al., 1980 Central North Pacific Gyre 0-70 m 8.8 18.0 152.0 Perry, 1976 Bering Sea 8.2 (3.9-17.5) Tanoue and Handa, 1979 East China Sea E.Z. 6.7 Hung et al., 2003 Sea of Japan Surface 9.3 19.0 153.0 Sterner et al., 2008

PAGE 57

41 Table 3. (Continued). ________________________ _____________________ ___________________________ _________________________ Particulate Nutrient Ratio Location Depth C:N N:P C:P Reference ________________________ _____________________ ___________________________ _________________________ Coastal Santa Catalina Basin 1-75 m 5.5 6.0 33.3 Holm-Hansen et al., 1966 Mediterranean Sea 4200’N, 445’E# 1-75 m 9.7 23.1 225.0 Copin-Montegut and CopinMontegut, 1983 4200’N, 445’E 10 m 6.2 21.5 133.9 Copin-Montegut and CopinMontegut, 1983 Antarctic Ocean Ross Sea 0-10 m (5.2-16.0) Smith et al., 2000 Polar Front$ 5 m 5.7 22.6 130.2 Copin-Montegut and CopinMontegut, 1983 Artic Ocean Kara Sea 0-8 m 7.8 15.0 108.0 Sterner et al., 2008 Indian Ocean Southern 5 m 6.5 26.0 101.0 Sterner et al., 2008 West Tropical 0-10 m 7.2 18.0 130.0 Copin-Montegut and CopinMontegut, 1983 Gulf of Mexico West Florida Shelf& 0 m 10.2 16.8 Heil et al., 2000 West Florida Shelf 0 m 11.53, 7.69 90.07, 54.6 569.36, 407.48 This study ________________________ _____________________ ________________________ _________________________ N.A.: not applicable; E.Z.: Euphotic zone; M.L.: Mixed Layer; *from liter ature review; **January; ***April; # value for field collected Trichodesmium ; ## August; May; maximum value; &Diatom bloom; Geometric mean

PAGE 58

42 Table 4. Literature summary of particul ate nutrient ratios from phytoplankton cultur es. Values presented are the average, with the range given in parentheses if available. ________________________ _____________________ ___________________________ _________________________ Nutrient Particulate Nutrient Ratio Species Conditi ons C:N N:P C:P Reference ________________________ _____________________ __________________ __________________ ________________ Marine Phytoplankton Replete 7.7 (4.0-17.0) 10.1 (5.0-19.0) 7.5 (27.0-135.0) Geider and La Roche, 2002 Dunaliella tertiolecta ** P-limited 12.5 48.0 600.0 Goldman et al., 1979 Dunaliella tertiolecta *** P-limited 10.1 32.0 325.0 Goldman et al., 1979 Dunaliella tertiolecta ** N-limited 17.0 5.0 85.0 Goldman et al., 1979 Dunaliella tertiolecta# N-limited 7.0 5.0 35.0 Goldman et al., 1979 Monochrysis lutheri ** P-limited 11.3 115.0 1,300.0 Goldman et al., 1979 Monochrysis lutheri ** P-limited 7.1 15.0 106.0 Goldman et al., 1979 Prochlorococcus E.G. (8.5-9.9) (15.9-24.4) (156.0-215.0) Bertillsoon et al., 2003 6 strains Prochlorococcus MED4 P-replete 5.7 21.2 121.0 Bertillsson et al., 2003 Prochlorococcus MED4 P-limited 7.4 62.3 464.0 Bertillsson et al., 2003 Synechococcus WH8012 P-replete 5.4 24.0 130.0 Bertillsson et al., 2003 Synechococcus WH8012 P-limited 7.5 96.9 723.0 Bertillsson et al., 2003 Synechococcus WH8103 P-replete 5.0 33.2 165.0 Bertillsson et al., 2003 Synechococcus WH8103 P-limited 7.1 109.0 779.0 Bertillsson et al., 2003 Synechococcus WH8103 E.G. 10.0 15.0 150.0 Bertillsson et al., 2003 Synechococcus WH7804 E.G. 8.9 13.3 113.0 Bertillsson et al., 2003 Chyrsochromulina N:P 1:1 11.8 9.8 115.0 J ohansson and Graneli, polylepis 1998 Chyrsochromulina N:P 4:1 10.2 11.6 117.0 J ohansson and Graneli, polylepis 1998 Chyrsochromulina N:P 16:1 7.7 16.0 122.0 J ohansson and Graneli, polylepis 1998 Chyrsochromulina N:P 80:1 8.7 21.0 182.0 J ohansson and Graneli, polylepis 1998

PAGE 59

43 Table 4. (Continued). ________________________ _____________________ ___________________________ _________________________ Nutrient Particulate Nutrient Ratio Species Conditi ons C:N N:P C:P Reference ________________________ _____________________ ___________________________ _________________________ Chyrsochromulina N:P 160:1 8.6 29.5 253.0 Johansson and Graneli, polylepis 1998 Trichodesmium sp. N-deplete 7.2(5.0-10.0) Mullholland and Capone, 2001 Trichodesmium sp. P-replete 95.0 Sanudo-Wilhelmy et al., 2004 Trichodesmium sp. P-limited 207.0 Sanudo-Wilhelmy et al., 2004 Thalassiosira P-limited 5.8 37.2 220.0 Perry, 1976 pseudonana## Thalassiosira P-limited 10.7 61.1 665.0 Perry, 1976 pseudonana Thalassiosira N-limited 5.7 9.7 63.4 Perry, 1976 pseudonana## Thalassiosira N-limited 10.0 8.3 84.3 Perry, 1976 pseudonana Thalassiosira N-limited 14.8 84.3 90.5 Perry, 1976 pseudonana$ Thalassiosira N-limited 12.6 5.0 63.0 Goldman et al., 1979 psuedonana** Thalassiosira N-limited 7.1 15.0 106.0 Goldman et al., 1979 pseudonana# _______________________________________________________________________________________________________________________________ _______________________________________ E.G: Exponential growth; species not indicated; ** 10% growth rate; ***50% growth rate; # 90% growth rate; ##=0.041h-1; =0.017h,1; $ =0.0085h-1

PAGE 60

44 0 100 200 300 400 500 0-1010-2020-5050+ 2% 10% 40% 48%N-limited Near Redfield Ratio P-limited Severely P-limited 0 100 200 300 400 0-44-1010-2020+Near Redfield Ratio Severely N-limited N-limited C-limited18% 43% 27% 12%A BNear Redfield Ratio P-limited Severely P-limited C-limited 0 200 400 600 800 0-9090-122122-212212+ 3% 2% 11% 84%CFrequency DistributionC:N N:P C:P 0 100 200 300 400 500 0-1010-2020-5050+ 2% 10% 40% 48% 0 100 200 300 400 500 0-1010-2020-5050+ 2% 10% 40% 48%N-limited Near Redfield Ratio P-limited Severely P-limited 0 100 200 300 400 0-44-1010-2020+Near Redfield Ratio Severely N-limited N-limited C-limited18% 43% 27% 12%A BNear Redfield Ratio P-limited Severely P-limited C-limited 0 200 400 600 800 0-9090-122122-212212+ 3% 2% 11% 84%CNear Redfield Ratio P-limited Severely P-limited C-limited 0 200 400 600 800 0-9090-122122-212212+ 3% 2% 11% 84%CFrequency DistributionC:N N:P C:P Figure 5. Histogram of surf ace particulate nutrient rati os A) C:N, B) N:P and C) C:P sampled from June 1998 through Dece mber 2001. The data are binned according to potential nutrient limitation as indicated by Redfield proportions of 106C:16N:1P. The % contribution of each bin to total samples is indicated as a % above the bar.

PAGE 61

45 ratios are well above the expected Redfie ld ratio further s uggests that the WFS was largely P-limited over the cour se of the sampling period. Although the world’s oceans are thought to be primarily N-limited, there appears to be some systems which at times exhibit P-limited conditions. Data from the North Pacific subtropical gyre s uggests that this system has shifted from an N-limited environment to a P-limited environment ov er the past two decades, as evidenced by enhanced N2 fixation and relatively high N:P ratios of the particulate pool (Karl et al. 2000). Similar findings are reported for the northwestern Atlantic (Sargasso Sea) western and north-eastern tropical Atlantic, western sub-tropi cal Atlantic and eastern At lantic (Angola Basin) (Herbland et al. 1998; Ammerman et al 2003). Carlson and Graneli (1999) suggest that P can limit productivity in t he northern Adriatic S ea, as P stimulated phytoplankton growth in bioassay expe riments. The Mediterranean Sea is another marine environment which appears to be a P-controlled system (Berland et al. 1980). Inorganic nutrient conc entrations, together with incubation experiments, suggest that the southeas tern Mediterranean is strongly P-limited (Krom et al. 1991) and high pulse uptak e capacity and subsaturated uptake in phytoplankton suggest P deficiency dur ing the summer in the northwest Mediterranean (Thingstad et al. 1998). P-limitation can result when there are greater input s of “new” N ( sensu stricto Dugdale and Goering 1967) relative to P sources (e.g. from N2 fixation) or by low inorganic P availability relative to inorganic N. A study by Zehr (2002 ) has shown that N2 fixation by picoplankton could be a major, previously overlooked,

PAGE 62

46 source of new N in oligotrophic oceani c environments, in addition to N supplied by Trichodesmium Both types of cyanobacteria are found on the WFS. The presence of Trichodesmium on filters was not noted duri ng sampling. However, the N2 fixing picocyanobacteria may still have contributed significantly to samples. M. Mullholland ( pers. comm.) has measured N2 fixation in <2.0 m fraction on the WFS, suggesting that N2 fixing picoplankton are present in this system. P-limitation on the WFS could also possibly be related to the physical properties of P compounds. Phosphorus has a tendency to adhere to other particles (Harris 1986; Sanudo-Wilhelmy et al. 2004) and thus could potentially sink out of the photic zone, become seques tered in the sediments and therefore made unavailable for remineralization in surface waters (Harris 1986). To partially explain why the eastern Medi terranean exhibits P-limited conditions, Krom et al. (1991) has sugges ted that Saharan Dust which has a high affinity for dissolved PO4 3-, could effectively remove this nut rient as it sinks though the water column. The WFS also receives atmospheric deposition of Saharan Dust and may in part explain some of the findings in this study. However, this is unlikely given the shallow depth of the WFS and the strong influence of wind driven circulation in the region (Mitchum and St urges 1982). Van Mooy et al. (2006, 2009) have demonstrated the ability of picocyanobacteria to substitute non-P membrane lipids for phospholipids in environ ments where P sources are scarce. This would skew phytoplankton C:N:P stoich iometry away from the Redfield ratio and increase cellular C and N relative to P, but allow phytoplankton to still meet their metabolic needs in the face of low dissolved P concentrations. These

PAGE 63

47 organisms are some of the dominant s pecies on the WFS and this mechanism could potentially explain the low concent rations of particulate P seen across the shelf. Further confounding plankton stoich iometry interpretation is the idea presented by Sanudo-Wilhelmy (2004) of a pool of P which adheres to the external structure of phytoplankton cells but is not internalized into cellular components. Although interesting, this does not help explain why particulate P concentrations are so low on the WFS. The idea that the WFS is primarily P-limited seems unlik ely, as DIN:DIP ratios are generally low and suggest N-limit ation (Heil et al. 2007). Furthermore, zooplankton excretion can be an impor tant source of regenerated N and especially P to the WFS. It has been esti mated that zooplankton excretion could potentially supply all the P required to support K brevis populations of 106 cells/L (Vargo et al. 2008). However DON:DOP ra tios are generally high (Heil et al. 2007) and support the conclusions drawn from the particulate nutrients. Alkaline phosphatase activity (APA) has been detected across the shelf and suggests that phytoplankton are utilizing DOP, whic h can be a response to a P-limited conditions. It has also been suggested that Trichodesmium populations can draw down inorganic and organi c stocks of P, leading to P-limitation within the bloom (Sanudo-Wilhelmy et al. 2001; Lenes et al. 2008). The fact that 48% of t he N:P and 84% of the C:P ratios suggesting severe P-limitation, presents a bit more of a conundrum. Expl anations may very well lie within the methodology. It is possible that the molybdenum blue method (see Methods section) underestimates parti culate P concentrations where the

PAGE 64

48 potential for P to adhere to the glass scint vial or filter during processing does exist. It is also probable that some cellula r material was lost during the filtration process due to cell breakage, which would ha ve a larger effect on particulate P than C or N values as this element is found in lower concentrations within the cells. Another possibility is that correct ions for the filter contributions (filter blanks) may be high due to contamination or other hidden factors. It has also been suggested that P uptak e by zooplankton with high P demands could result in P limitation of the surr ounding waters (Hessen et al. 2003). As these grazers were filtered out during the sampling proc ess, they could potentially represent a missing portion of the particulate P pool. The detrital contribution to the parti culate pool is variable both in its chemical structure and quant ity. It has been suggested by Menzel and Ryther (1964) that one approach to correcting particulate nut rient data for detrital contributions is to regress particu late nutrients against another and Chl a and the particulate nutrient ratios against Chl a This type of analysis was not appropriate when applied to the enti re data set. The parameters (nontransformed data and natural log trans formed data) do not share a linear relationship, slope of the regression did not predict the mean, residuals are not normally distributed (normal probability pl ot), scatter plots of residuals showed structure and predicted versus obs erved values were not linear. The inability to correct for the detrital contributi on to the particulate pool could potentially result in the largest erro r within the data set. The C:N:P ratios of benthic marine plants (seagrass and macroalgae) are more depleted in P relative

PAGE 65

49 to C and N than phytoplankton and have a median atomic ratio of 700:35:1 (Atkins and Smith 1983). These plants ar e a major component of the benthos within the shallow WFS and could contribute significant detrital material to the water column influencing the particulate ratios of this study. Upon the decomposition of organic matter, P is ut ilized more rapidly than N and C (Menzel and Ryther 1964) and if detrital contribut ions were large during the sampling period, this could also skew the particulate nutrient ratios towards less P relative to C and N, potentially result ing in the extreme values of the N:P and C:P ratios seen on the WFS during the study period. Ka rl et al. (2001) noted that during the summer and fall at station ALOHA there was an increase of non-living particulate matter, which was accompanied by an increase of particulate N but not particulate P. This resulted in elevated par ticulate N:P ratios during that period. This observation further supports the idea t hat a lack of particulate P in detrital matter can skew particulate ratio interpre tation to P-limitation, at least during times of high phytoplankton production. Spearman Rank Order Correlation show that all the particulate nutrient parameters (C, N, P and Chl a ) have positive correlation coefficients and therefore tend to increase together. The particulate nutrients all have similar correlation coefficients of approximately 0.500 (Table 5), indicating that these parameters are related to some degree. C and N are weakly associated with Chl a and have similar correlation coefficients of 0.330 and 0.316 respectively. The variables with the stro ngest relationship to Chl a is particulate P (rs =0.752), further supporting the idea that particula te P concentrations may have a stronger

PAGE 66

50 association with live cells as the turnover time of P is much faster than turnover times for C or N.. This, and the high par ticulate N:P and C:P ratios suggests that, as in fresh water syst ems, P controls biomass. Table 5. Summary of Spearman Rank Order Correlation coefficients (rs) for surface particulate C (M), N (M), P (M) concentration s, particulate nutrient ratios and Chl a (g/L) sampled from June 1998 through December 2001. ________________________ _____________________ __________________ Paired Variables N rs __________________ ________________________ _____________________ C, N 837 0.472 N, P 818 0.487 C, P 818 0.520 C, Chl a 795 0.330 N, Chl a 795 0.316 P, Chl a 789 0.752 C, C:N 833 0.160 C, C:P 812 0.110 N, C:N 833 -0.711 N, N:P 813 0.519 P, N:P 813 -0.389 P, C:P 818 -0.721 C:N, N:P 807 -0.565 C:N, C:P 812 0.355 N:P, C:P 811 0.448 ________________________ ____________________________ Spearman Ranking Correlation Coefficient s for the particulate nutrients as related to the particulate ratios give some interesting resu lts (Table 5). The results indicate that the C:N ra tios are more associated with N (rs = -0.711) than C (rs =0.160). The negative sign of this coeffi cient is due to the fact that N is the denominator of the ratio, so as N increases the C:N ratio decreases and vice

PAGE 67

51 versa. The results also indicate that the C:P ratios are more related to P (rs = -7.21) than C (rs = 0.110). This supports t he premise that particulate C concentrations are more constant across th e shelf relative to the more variable particulate N and P concentrations. This is reasonable as C is not considered to be a limiting nutrient on the WFS. Particulate N (rs = 0.519) also seems to be more related to the N:P ratio than P (rs = -0.389) and could reflect the greater potential for inorganic N sources to vary across the WFS as a result of N2 fixing activity. The lack of strong relationships of the variable pairs presented in Table 5, is expected, as this data set includes t he results of all stations sampled across the WFS for each month in each year. Environmental processes at each isobath in each month over each year would be ex pected to vary and this variance would be reflected in the stoichiome try of the particulate nutrient s. In short, the scale of the sampling approach used in this study mi ght be too broad to discern individual factors influencing particulate nutrient ratios.

PAGE 68

52 Spatial Considerations Near-Shore to Offshore Trends It is reasonable to assume t hat different circulation patterns and associated nutrient concentra tions within each region of the WFS would influence phytoplankton uptake rates of C, N and P, and therefore different particulate concentrations and ratios across these zones. Underlying this assumption and further confounding data interpretation, is the probability that both phytoplankton populations and detritus are tr ansported onto different r egions of the shelf via wind and currents (e.g. via the bottom Ek man layer, see Weisberg et al. 2009), and their nutrient stoichiometries may be more reflective of their origin or transit path rather than present lo cation. Thus particulate nutrient composition of phytoplankton may be indicative of cell history and transport as well as present nutrient availability and limitation. The relationships of the average surfac e particulate nutrients and ratios at each sampled distance offshore are we ll described by polynomial functions (Figure 6). The surface particulate C, N and P show surprisingly similar curves but of different magnitudes. This sugges ts that a similar regulating mechanism may be fundamentally acting on all three nut rients but to varying degrees. There is an initial decline in concentration from the 10m isobath (0 km offshore) out to the 30m isobath (~50 km offshore), wher e concentrations become level before decreasing again at the shelf break (~200km o ffshore). It is interesting to note

PAGE 69

53 0 5 10 15 20 25 y = -0.0442x2+ 11.809x + 161.42 R2= 0.8311 0 200 400 600 800 1000 050100150200Distance offshore (km) Distance offshore (km)32y = -2E-05x+ 0.0058x-0.5852x + 39.05 R2= 0.8805 0 20 402 3y = -1E-07x+ 4E-05x-0.0042x + 0.1767 R2= 0.94143y = 1E-07x-5E-05x+ 0.0085x-0.5211x + 13.271 R2= 0.785 20 5 10 0.00 0.05 0.10 0.15 050100150200 y = -0.0006x2+ 0.1412x + 8.281 R2= 0.393 y = 9E-07x4-0.0004x3+ 0.0535x2-1.533x + 74.117 R2= 0.6323 0 50 100 150 200C(M) N(M) P(M) C:N N:P C:PA B C D E F 0 5 10 15 20 25 y = -0.0442x2+ 11.809x + 161.42 R2= 0.8311 y = -0.0442x2+ 11.809x + 161.42 R2= 0.8311 0 200 400 600 800 1000 050100150200Distance offshore (km) Distance offshore (km)32y = -2E-05x+ 0.0058x-0.5852x + 39.05 R2= 0.880532y = -2E-05x+ 0.0058x-0.5852x + 39.05 R2= 0.8805 0 20 402 3y = -1E-07x+ 4E-05x-0.0042x + 0.1767 R2= 0.9412 3y = -1E-07x+ 4E-05x-0.0042x + 0.1767 R2= 0.9413y = -1E-07x+ 4E-05x-0.0042x + 0.1767 R2= 0.941 y = -1E-07x+ 4E-05x-0.0042x + 0.1767 R2= 0.94143y = 1E-07x-5E-05x+ 0.0085x-0.5211x + 13.271 R2= 0.785 20 5 10 0.00 0.05 0.10 0.15 050100150200 y = -0.0006x2+ 0.1412x + 8.281 R2= 0.393 y = -0.0006x2+ 0.1412x + 8.281 R2= 0.393 y = 9E-07x4-0.0004x3+ 0.0535x2-1.533x + 74.117 R2= 0.6323 y = 9E-07x4-0.0004x3+ 0.0535x2-1.533x + 74.117 R2= 0.6323 0 50 100 150 200C(M) N(M) P(M) C:N N:P C:PA B C D E F Figure 6. Average of surface particulate nutrient concentrations (Figures A, B, C) and partFigure 17. Scatter plots of surface particulate A) carbon, B) nitrogen and C) phosphorus concentration s at the 10m isobath of the Tampa Bay, Sarasota and Fort Meyers stations during the we t season (pink) and dry season (blue) sampled from June

PAGE 70

54 that Lester et al. (2008) has shown t hat the 30m isobath is a transition zone where the zooplankton community contains mixed populations of coastal and offshore species. This isobath appears to also be a transition zone from high particulate nutrient concentrations to low concentrations. Therefore, it seems possible that the particulate nutrient concentrations are driving zooplankton assemblages via regulation of food supply. The mean surface particulate ratios of C:N, N:P and C:P also share similar curves but instead steadily increase to a maximum value ~125km offshore and than decr ease slightly at th e 200m isobath. Particulate C, N and P across the WFS display a wide range of concentrations (M) from the coast to the shelf break, with the greatest variability found at the coastal stations (Figure 7). This is expec ted as these stations are directly impacted by estuarine and rive rine inputs, where nutrient and detrital fluxes are more dynamic. In contrast, the C:N and C:P molar ratios (Figure. 7) exhibit greater scatter at distances gr eater than 50km from the coast. This suggests a decoupling of processes r egulating particulat e C from those regulating particulate N and P with di stance offshore which can occur under nutrient limiting conditions. It has been shown that phytopl ankton will store C when other nutrients are found in short suppl y (Fuhs et al. 1972). This could also be related to changes in the contribution of detrital material to the particulate concentration. Detrital material is co mposed of recalcitrant C, which could contribute a greater portion to the particulate as phytoplankton biomass decreases off-shore. In c ontrast, the range of particulate N:P ratios exhibit less

PAGE 71

55 0 20 40 60 80 100 050100150200 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 050100150200Distance offshore (km)P (M) N (M) 0 200 400 600 800 1000 050100150200 0 1000 2000 3000 4000 5000 050100150200 0 50 100 150 200 250 300050100150200C:N N:P C:PAAB C D E F 0 50 100 150 200 250 300050100150200C (M) 0 20 40 60 80 100 050100150200 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 050100150200Distance offshore (km)P (M) N (M) 0 200 400 600 800 1000 050100150200 0 1000 2000 3000 4000 5000 050100150200 0 50 100 150 200 250 300050100150200C:N N:P C:PAAB C D E F 0 50 100 150 200 250 300050100150200C (M) 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 050100150200 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 050100150200 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 050100150200Distance offshore (km)P (M) N (M) 0 200 400 600 800 1000 050100150200 0 200 400 600 800 1000 050100150200 0 1000 2000 3000 4000 5000 050100150200 0 1000 2000 3000 4000 5000 050100150200 0 50 100 150 200 250 300050100150200C:N N:P C:PAAB C D E F 0 50 100 150 200 250 300050100150200C (M) Figure 7. Influence of distance from s hore on surface particulate C, N, P concentrations (Figures A, B,C) and p articulate nutrient ratios C:N, N:P, C:P ( Fi g ures D, E, F ) sam p led from June 1998 throu g h December 2001.

PAGE 72

56 scatter across the shelf, perhaps related to the diminishing inorganic supply of both nutrients with increasing dist ance from coastal inputs. To compliment other similar studies of the ECOHAB data set (Havens 2004; Lester 2005; Ault 2006) and to resolve particulate nutrient distributions, the data was partitioned into subsets by isobath (Table 6). The 10m isobath are those stations sampled closest to t he coast and are directly impacted by estuarine and riverine fluxes. The 30m is obath, located in the middle of the inner shelf region, seems to represent a transit ion zone from coastally influenced water to more oligotrophic waters, where parti culate nutrient concentrations remain constant. The 50m isobath is a transitiona l location from the inner shelf to the mid shelf and the 200m isobath located at the shelf break is associated with the transition between the shelf and the deep wate r processes (Weisberg et al. 2005, 2009). From the coastal stations out to t he 200m isobath, there is a decrease in the average particulate C (M) of 67% and a decrease in particulate N (M) and P (M) of 76% and 90% respectively (Table 6). This trend reflects the influence of estuarine sources of i norganic nutrients and detrital mate rial on the particulate nutrient pool, while the particulate nutri ent pool further offshore reflect the oligotrophic conditions asso ciated with this region. This decreasing trend is reflected in a similar decrease in Chl a concentration from the coastal region out to the 200m isobath (Figure 8). Average surface particulate (C:N:P) nutrient stoichiometries are well above the Redfield Ratio at the 10m, 30m, 50m and 200m isobaths (Table 7).

PAGE 73

57 Table 6. Central tendency and ranges fo r the surface particulate nutrient concentrations and particulate nutrient ratios sampled from June 1998 through December 2001 at the 10m, 30m, 50m and 200m isobaths. ________________________ _____________________ ___________________ Geometric Location N Mean Mean Minimum Maximum Median ________________________ _____________________ ___________________ C (M) 10m isobath 106 46.38 36.27 3.31 485.72 33.65 30m isobath 103 21.19 17. 76 1.71 80.77 16.10 50m isobath 102 20.16 16. 39 1.94 71.42 15.35 200m isobath 30 14.95 13.13 3.48 53.62 12.64 N (M) 10m isobath 106 10.91 5.89 1.20 97.69 4.97 30m isobath 104 3.52 2. 33 0.05 22.19 2.19 50m isobath 102 2.80 1. 90 0.16 23.06 2.05 200m isobath 30 2.66 1.52 0.17 20.09 1.59 P (M) 10m isobath 107 0.20 0. 17 0.04 0.52 0.18 30m isobath 104 0.04 0. 04 0.02 0.23 0.04 50m isobath 102 0.03 0. 03 0.01 0.21 0.03 200m isobath 30 0.02 0.02 0.004 0.06 0.02 C:N 10m isobath 106 8.63 6. 55 0.11 48.40 7.82 30m isobath 102 10.25 7.75 0.30 38.03 8.48 50m isobath 101 14.10 9.13 0.66 98.82 9.16 100m isobath 35 16.90 9.67 0.89 125.54 9.01 200m isobath 30 13.81 9.32 1.03 53.17 9.37 N:P 10m isobath 106 52.86 34.36 5.33 401.18 27.69 30m isobath 103 97.49 59.21 0.60 554.77 51.27 50m isobath 101 103.46 71.58 3.41 421.03 72.21 123m isobath 29 148.22 71.63 4.70 789.08 57.61 200m isobath 30 126.63 76.61 11.41 616.35 71.18 C:P 10m isobath 106 260.07 211. 47 20.82 1477.56 210.55 30m isobath 103 592.27 463. 82 37.19 3094.02 443.03 50m isobath 101 810.51 606. 97 41.60 3278.04 587.22 125m isobath 29 880.59 617.80 52.56 3773. 94 536.96 200m isobath 30 773.72 662.91 273. 58 3574.67 636.82 ________________________ __________________ _____________________

PAGE 74

58 y = 0.8649e-0.0147xR2 = 0.3947 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 050100150200Distance offshore (km)Chl a (g/L) y = 0.8649e-0.0147xR2 = 0.3947 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 050100150200Distance offshore (km)Chl a (g/L) Figure 8. Relationshi p between surface Chl a concentration and distance from shore. The curve includes data sampled from June 1998 through December 2001.

PAGE 75

59 Table 7. Particulate nutrient stoichiome try of surface waters at the 10m, 30m, 50m and 200m isobaths based on the m ean and geometric mean of surface particulate nutrient concentrations. ________________________ _____________________ ___________________ Location N C:N: P Geometric C:N:P ________________________ _____________________ ___________________ 10m isobath 106 232:55:1 212:34:1 30m isobath 103 493:92:1 462:61:1 50m isobath 102 738:102:1 600:68:1 Shelf break 30 773:134:1 662:76:1 ________________________ _____________________ ___________________ The most balanced nutrient conditi ons are found at t he 10m isobath where average C:N:P=232:55:1. The ratios steadi ly increased with distance offshore to an average C:N:P ratio of 773:134:1 at the 200m isobath. Particulate C increases dramatically from the near shore to the off s hore stations relative to particulate P and supports the hypothesis that either the phytoplankton could be storing C in excess to P or there is incr easing detrital contributions with a greater portion of refractory C relative to P wit h increasing distance from the coast. The abundance of picocyanobacteria ( Synecococcu s and Prochlorococcus ) increases with distance offshore and t hese populations can have very high C:P ratios when P-limited (Table 4). Therefore, it is possi ble that the stoichio metry of a potentially P-limited picocyanobacteria asse mblage could also be a fact or contributing to the increasing C:P ratio with distance from the coast. Although particulate N increases from the 10m isobath to the 200m isobath relative to P, the increase is not as great when compared to particulate C (Table 7). This further supports the

PAGE 76

60 hypothesis that N2 fixation can be a very important process occurring on the WFS and also that nutrients have the potential to be recycled at different rates. All the particulate nutrient ratios in crease with distance fr om shore but the C:N ratio displays a fairly constrained range across the isobaths (8.63-16.90) in comparison to N:P (52.86-148.22) and C: P (260.07-880.59) (Tab le 6). The mean particulate C:N ratio increased by 49% from the near-shore stations along the10m isobath to the100m isobath (Table 6). This may be related to the slightly greater decrease of particulate nitrogen re lative to carbon with distance offshore as inorganic N sources most likely decr ease relative to inorganic C out on the shelf. The average ratio of particulate N:P increases by 64% from the 10m isobath out to the 100m isobat h (Table 6) and could be related to sources of “new” N contributed to shelf waters by N2 fixers and the relative lack of coincident new” P with increasing distance from the coast. The largest increase from the coastal stations to the 100m isobath is exhibited by the mean particulate C:P ratios which increase by 70% (Table 6). The average particulate nutrient ratios all show a decrease in values after t he 100m isobath out to the 200m isobath, where C:N shows an 18% decrease, N:P decreases by 14% and P declines by 12%. This decrease could be in respons e to surface fronts at shelf break supplying regenerated nutrients to the pr imary producers, pot entially reducing conditions of nutrient limitation. Scatter plots suggest that particula te N:P and C:P ratios at the 10m isobath are distinct from those found at the 30m, 50m and 200m isobaths (Figure 9) and particulate C:N ratios are not distinct at any of the sampled isobaths. It is

PAGE 77

61 0.01 0.10 1.00 10.00 100.00 0.0010.0100.1001.000P (M)N (M) 1.00 10.00 100.00 1000.00 0.0010.0100.1001.000P (M)C (M)A B C 1.00 10.00 100.00 1000.00 0.010.101.0010.00100.00N (M)C (M) Figure 9. Scatter plots of su rface particulate C, N and P concentrations at the 10m is obath (blue), 30m isobath (red), 50m isobath (green) and 200m isobath (turquoise) sampled from June 1998 through December 2001.

PAGE 78

62 interesting to note that most of the va riance within the C:N ratio is related to changes in particulate N rather than particulate C. Although the mean C concentrations decrease seaward of the c oast (Table 6, Figure 7), it appears that particulate C concentrations are not as re lated to isobath spatial distributions as particulate N and P concentrations. Spearman Rank Order Correlation coeffi cients suggest that particulate C, N and P are most related at the 10m isobath with rs values of C and N= 0.643, N and P= 0.567 and C paired with P= 0.574 fo llowed by the 200m isobath where C and N have an rs= 0.392, N and P= 0.338 and C pai red with P= 0.521 (Table 8). Nutrient inputs from the estuaries at the 10m isobath and upw elled regenerated nutrients from deep waters at the 200m is obath could potentially be responsible for the correlation between particulate C, N and P. Phytoplankton populations might be less nutrient limited at the 10 and 200m isobaths, where nutrient uptake could be based more on cellular requi rements rather than adapting nutrient uptake kinetics to nutrient availability, wh ich tends to de-couple particulate C, N and P relationships. In contrast, the rs values for particulate C, N and P at the 30m and 50m isobaths suggest that ther e is no relationship between these constituents. As these regi ons are primarily driven by regenerated nutrients, it is possible that particulate C, N, P relati onships become decoupled in response to greater nutrient limitation Spearman Ranking Order Correlation coefficients suggest that at all isobaths, the C:N and especially N:P ratios are most re lated to particulate N concentrations when compared to the rs of C:N with C and N:P with P (Table 8).

PAGE 79

63 This suggests that the potential for particu late N to vary in concentration across the shelf is greater than either particulate C or P. It is intere sting to note that the rs of the paired variables C, C:N and P, N:P suggest that these variables are not related at the 10m isobath or the 200m isobath but are somewhat related at the 30m and 50m isobaths. The results are si milar when considering C, C:P, but there is a weak correlation at the 10m and 200m isobath and a relatively strong relationship at the 30m and 50m isobath. It appears that the influence of particulate C on the C:N and especially t he C:P ratio, are strongest in regions that are less productive, where detrital contributions could comprise a larger portion of the particulate pool. The strong correlation of C with C:P relative to the C:N at the 30m and 50m is obaths could be related to the lack of inorganic P inputs resulting in less cellular P and t herefore particulate C would be expected to dominate this ratio. In contras t, the C:N ratio at the 30m and 50m isobath should be related to both additional particulate N inputs due to N2 fixation and particulate C. The correlation between t he paired variables of N with C:N, N with N:P and P with C:P does not change with distance from s hore, and implies that the influence of N on the C:N and N:P rati os and the influence of particulate P on the C:P ratios remains similar across the shelf. At each isobath, the frequency of surface particulate nutrient ratios were binned into categories of near Redfield, nutrient lim ited and severe limitation (Figures 10-12 see figure captions for ex planations of individual categories for each ratio). The frequency distribution of the C: N ratio at the 0, 30, 50 and 200m isobaths remain constant in each category across the shelf, with

PAGE 80

64 approximately 50% of t he data near to the Redfield Rati o (Figure 10, Table 9). In contrast, the N: P ratio decreased from 26% of the data near to Redfield at the 10m isobath to 3% near Redfield at the 200m isobath, (Fi gure 11, Table 9) Table 8. Summary of Spearman Rank Order Correlation coefficients (rs) for surface particulate C (M), N (M), P (M) concentrations and particulate nutrient ratios at the 10m (N=106), 30m (N=103), 50m (N=101) and 200m (N=32) isobaths sampled from June 1998 through December 2001. ________________________ _____________________ ___________________ Isobath Paired Vari ables 10m 30m 50m 200m ________________________ _____________________ ___________________ C, N 0.643 0.369 0.237 0.392 N, P 0.567 0.012 0.105 0.338 C, P 0.574 0.103 0.121 0.521 C, C:N -0.076 0.340 0.401 0.095 C, C:P 0.331 0.721 0.732 0.339 N, C:N -0.746 -0.681 -0.706 -0.709 N, N:P 0.748 0.836 0.837 0.853 P, N:P -0.065 -0.449 -0.390 -0.142 P, C:P -0.494 -0.554 -0.515 -0.498 C:N, N:P -0.702 -0.626 -0.624 -0.709 C:N, C:P 0.170 0.237 0.407 0.238 N:P, C:P 0.485 0.506 0.348 0.287 ________________________ __________________ ______________________ and the C:P decreased from 8% near Redfie ld at the 10m isob ath to 0% at the 30, 50 and 200m isobaths (Figure 12, Tabl e 9). At the 10m isobath 23% of the N:P data was indicative of severe P-limit ation; this percentage increased to 65% at the 200m isobath. The sa me trend is found in the C: P ratio, where 50% of the data at the 10m isobath coul d be considered severely P-limited, which increased to 92% at the 30m isobath and 100% out at the 200m isobath. These results

PAGE 81

65 A) 10m isobath 0 20 40 60 80 B) 30m isobath0 20 40 C) 50m isobath0 20 40 E) 200m isobath0 5 10 0-44-1010-2020+C:NFrequency Distribution D) 100m isobath 0 10 20 0 10 20Figure 10. Histograms of su rface particulate C:N binned according to nutrient limitation as indicated by Redfield proportions (106C:16N) for the A) 10m isobat h, B) 30m isobath, C) 50m isobath, D) 100m isobat h and E) 200m isobath. C-limitation is indicated by 0-4, near Redfield proportions by 4-10, N-limitation by 10-20 and severe N-limitation by 20+. The data include samples collected from June 1998 through December 2001. Note that the frequency distribution scale for the 200m isobath has been changed to a maximum of 15 due to a decrease in the number of samples at this site.

PAGE 82

66 Frequency DistributionN:P C) 50m isobath0 40 A) 10m isobath0 40 80 B) 30m isobath0 40 E) 200m isobath0 10 20 0 0-1010-2020-5050+ D) 129km offshore10 20Frequency DistributionN:P C) 50m isobath0 40 A) 10m isobath0 40 80 B) 30m isobath0 40 E) 200m isobath0 10 20 0 0-1010-2020-5050+ D) 129km offshore10 20 Figure 11.) Histograms of surface particulate N:P binned according to nutrient limitation as indicated by Redfield proportions (16N:1P) for the A) 10m isobath, B) 30m isobath, C) 50m isobath, D) 100m isobath andE) 200m isobath. N-limitation is indicated by 0-10, near Redfield proportions by 10-20, P-limitation by 20-50 and severe P-limitation by 50+. The data include samples collected from June 1998 through 2001. Note that the frequency distribution scale for the 200m isobath has been changed to a maximum of 30 due to a decrease in the number of samples at that site.

PAGE 83

67 A) 10m isobath0 50 100 150 B) 30m isobath0 50 100 C) 50m isobath0 50 100 D) 129km offshore0 20 E) 200m isobath0 20 0-9090-122122-212212+C:P A) 10m isobath0 50 100 150 B) 30m isobath0 50 100 C) 50m isobath0 50 100 D) 129km offshore0 20 E) 200m isobath0 20 0-9090-122122-212212+C:PFrequency Distribution Figure 12.) Histograms of surface particulate C:P binned according to nutrient limitation as indicated by Redfield proportions (106C:1P) for the A) 10m isobath, B) 30m isobath, C) 50m is obath, D) 100m isobath andE) 200m isobath. C-limitation is indicated by 0-90, near Redfield proportions by 90122, P-limitation by 122-212 and severe P-limitation by 212+. The data include samples collected from June 1998 through December 2001. Note that the frequency distribution scale fo r the 100 km and 200m isobaths have been changed to a maximum of 30 due to a decrease in the number of samples at these sites.

PAGE 84

68 support the hypothesis that P limitation in creases with distance offshore, but do not support the idea of a decrease in P lim iting conditions at the 200m isobath (Table 7) that is suggested by mean N: P and C:P values. These data also strongly suggests that N-limitation does not increase with distance off shore, Table 9. Frequency percentage (%) of surfac e particulate nutrient ratio values to total sample number within different isobaths with considerations to the Redfield Ratio and nutrient limitation. ________________________ _____________________ ___________________ Isobath 10m 30m 50m 100m 200m ________________________ _____________________ ___________________ C:N* C-limited 19% 16% 15% 6% 16% Near Redfield 55% 42% 44% 57% 42% N-limited 21% 36% 25% 23% 23% Severe N-limitation 6% 8% 17% 14% 19% N:P** N-limited 2% 2% 2% 7% 0% Near Redfield 26% 8% 7% 0% 3% P-limited 49% 39% 24% 34% 32% Severe P-limitation 23% 51% 67% 59% 65% C:P*** C-limited 4% 2% 3% 3% 0% Near Redfield 8% 0% 0% 0% 0% P-limited 38% 6% 2% 0% 0% Severe P-limitation 50% 92% 95% 97% 100% ________________________ _____________________ ___________________ *for C:N values, C-limited was 0-4, Near Redfield was 4-10, N-limited was 10-20, Severe N-limitation was greater than 20; **for N:P values, C-limited was 0-10, Near Redfield was 10-20, P-limited was 20-50, Severe P-limitation was greater than 50; ***for C:P values, C-limited wa s 0-90, Near Redfield was 90-122, Plimited was 122-212, Severe P-li mitation was greater than 212

PAGE 85

69 consistent with the idea that pelagic nitr ogen fixation is a very important process in the oligotrophic wa ters of the WFS. The trend for increasing particulate N:P ratios across the shelf, could result from a decreasing supply of inor ganic P or an increasing supply of new N relative to P due to nitrogen fixation. Eit her explanation or a combination of both are plausible, as new sources of P away from coastal sources are restricted to inputs from deeper waters and nitrogen fixa tion is known to occur in offshore oligotrophic waters. The process of ni trogen fixation can contribute to a draw down in PO4 concentration, as this proc ess itself requires P.

PAGE 86

70 Latitudinal Trends Heil et al (2007) demonstrated a re lationship between particulate N:P ratios and latitude in the coastal area bet ween Tampa Bay to Florida Bay, which they hypothesized was related to the di fferent nutrient inputs from various riverine sources along this gradient. T he current study included three onshoreoffshore sampling transects which originat ed from Tampa Bay, Sarasota Bay and Fort Meyers. Each transect was sampl ed out to the 50m is obath, which allows for analysis of latitudinal trends. In this section the particulate nutrient data were partitioned into north (Tampa Bay) to s outh (Fort Meyers) transect subsets to examine potential trends. Central tendency measures of the parti culate nutrient data, organized by latitude (Table 10), suggest that surface particulate nutrient concentrations and ratios were very similar along the Ta mpa Bay, Sarasota and Fort Meyers transects. The geometric mean of N: P and C:P ratios dec reased from the northern Tampa Bay to the southern Fort Meyers by 19% and 9% respectively, suggesting a weak trend of decreasing P-li mitation along this gradient. The geometric mean of the C:N ratio increased by 10%, suggesting a weak trend of increasing N limitation towards the south. Stoichiometry calculations using the geometric mean support this as Tampa Bay has a C:N:P of 527:71:1, Sarasota 383:49:1 and Fort Meyers 383:44:1 (Tabl e 11). All particulate C:N:P stoichiometries are above the classic R edfield Ratio which suggests P-limiting conditions along all three transects however.

PAGE 87

71 Table 10. Central tendency measures and ranges of surface particulate nutrient concentrations and particulate nutrient ra tios for the Tampa Bay, Sarasota and Fort Meyers transects. The data include all stations sampled out to the 50m isobath for each transect from June 1998 through December 2001. ________________________ _____________________ ___________________ Geometric N Mean Mean Minimum Maximum Median ________________________ _____________________ ___________________ C (M) Tampa Bay 214 27.97 21.33 1.16 135.63 21.61 Sarasota 169 25.05 20.92 3.35 167.88 20.13 Fort Meyers 179 29.46 22.53 4.39 485.72 21.68 N (M) Tampa Bay 214 6.52 3.08 0.05 97.69 2.93 Sarasota 169 4.17 2.73 0.44 35.99 2.58 Fort Meyers 179 4.57 2.85 0.35 71.12 2.49 P (M) Tampa Bay 216 0.08 0.05 0.002 0.51 0.04 Sarasota 169 0.08 0.06 0.01 0.71 0.05 Fort Meyers 174 0.09 0.06 0.002 0.52 0.06 C:N Tampa Bay 212 11.85 7.38 0.11 86.00 8.29 Sarasota 169 11.36 8.09 0.66 76.46 8.18 Fort Meyers 176 10.11 8.16 0.68 66.25 8.97 N:P Tampa Bay 212 94.53 57.87 0.60 609.92 52.05 Sarasota 168 79.90 50.24 6.77 585.32 41.85 Fort Meyers 171 73. 05 46.62 4.63 554.77 40.95 C:P Tampa Bay 213 568.88 405. 15 15.13 4431.17 415.21 Sarasota 168 504.24 380. 72 26.23 3278.04 372.31 Fort Meyers 171 524.21 368.22 47.93 4105. 85 338.73 ________________________ _____________________ ___________________

PAGE 88

72 when the particulate ratios are consi dered and binned according to nutrient deficiency or sufficiency, the dist ribution percentages do not support a Table 11. Surface particulate nutri ent stoichiometry based on the geometric mean and median of the Tampa Bay, Sarasota and Fort Meyers transects. The data include all stations sampled out to the 50m isobath and at the 10m isobath for each transect. ________________________ _____________________ ___________________ Geometric m ean Median Transect C:N:P C:N:P ________________________ _____________________ ___________________ Entire Transect Tampa Bay 414:60:1 527:71:1 Sarasota 379:49:1 383:49:1 Fort Meyers 367:47:1 383:44:1 10m Isobath Tampa Bay 180:40:1 168:35:1 Sarasota 223:29:1 230:26:1 Fort Meyers 222:33:1 178:26:1 ________________________ _____________________ ___________________ trend of decreasing P limitation nor incr easing N-limitation fr om Tampa Bay to Fort Meyers (Figure 13, Table 12). Fort Meyers has the highest percentage of data distributed within the near Redfield bin for all particulate ratios with 53% of C:N, 13% of N:P and 3%of C:P in this category (Tabl e 12). The Fort Meyers station is influenced by nutrient i nputs from Charlotte Harbor and the Calossahatchee River which have greater flux es of TN and TP compared to both Tampa Bay and Sarasota Bay (Vargo et al. 2008)and could potentially explain this observation. The lack of strong tr ends is not surprising, as the factors

PAGE 89

73 0 50 100 150 200 0-9090-122122-212212+N-limited Near Redfield Ratio P-limited Severely P-limited 0 50 100 150 200 0-9090-122122-212212+N-limited Near Redfield Ratio P-limited Severely P-limited 0 20 40 60 80 100 120 0-1010-2020-5050+N-limited Near Redfield Ratio P-limited Severely P-limited 0 20 40 60 80 100 120 0-1010-2020-5050+N-limited Near Redfield Ratio P-limited Severely P-limited 0 20 40 60 80 100 0-44-1010-2020+C-limited Near Redfield Ratio N-limited Severely N-limitedC:N N:P C:PA B CFrequency Distribution Figure 13. Histogram of surface particulate A) C:N, B) N:P and C) C:N ratios sampled from June 1998 through December 2001 binned according to potential nutrient limit ation as indicated by Redfield proportions of 106C:16N:1P. Tampa Bay (blue), Sarasota (red) and Fort Meyers (green) transects.

PAGE 90

74 influencing the particulate C:N:P ratios ac ross the distances of the entire transect are most likely to be similar regardle ss of the small changes in latitude. However, each transect point of origin is influenced by a different riverine system and drainage basin, so the particulate nutri ent data at the 10m could potentially reflect these different influences. In times of high river flow the 30m isobath Table 12. Frequency percentage (%) of surf ace particulate nutrient ratio values to total sample number within different transects with considerations to the Redfield Ratio and nutrient lim itation. Each transect includes all station data from the 10m isobath to the 50m isobath. ________________________ _____________________ ___________________ Transect Tampa Bay Sarasota Fort Meyers ________________________ _____________________ ___________________ C:N* C-limited 24% 17% 10% Near Redfield 40% 43% 53% N-limited 24% 30% 31% Severe N-limitation 12% 10% 6% N:P* N-limited 4% 1% 0.6% Near Redfield 8% 10% 13% P-limited 35% 49% 47% Severe P-limitation 52% 39% 39% C:P* C-limited 4% 2% 2% Near Redfield 3% 2% 3% P-limited 11% 11% 15% Severe P-limitation 83% 85% 80% ________________________ _____________________ ___________________ *for C:N values, C-limited was 0-4, Near Redfield was 4-10, N-limited was 10-20, Severe N-limitation was greater than 20; **for N:P values, C-limited was 0-10, Near Redfield was 10-20, P-limited was 20-50, Severe P-limitation was greater than 50; ***for C:P values, C-limited wa s 0-90, Near Redfield was 90-122, Plimited was 122-212, Severe P-li mitation was greater than 212

PAGE 91

75 could be potentially influenced by coastal processes but will not be considered at this time (Vargo et al. 2008). At the 10m isobath, Sarasota has the lowest concentration of average particulate nutrients and Chl a concentrations (Ault 2006) compared to Tampa Bay (Table 13) and Fort Meyers. Saraso ta Bay does not have the large river systems influencing its adjacent coasta l stations, as does the Tampa Bay transect (Manatee River) and the Fort Meye rs transect (Charlotte Harbor and Caloosahatchee River), but instead is fed by small creeks. T herefore, it seems likely that dissolved nutrient or detrital inputs to the coastal stations of Tampa Bay and Fort Meyers would be larger resulting in greater particulate C, N and P concentrations relative to Sarasota Bay. Tampa Bay has the highest concentration of average particulate C (Gmean=40.71M) and P (Gmean=0.23M). The tributaries which enter Tampa Bay and Charlotte Harbor drain the Hawthorn phosphat ic deposits yet; inorganic P concentrations at the mouth of Tampa Bay are gr eater than at the mouth of the Caloosahatchee River (Vargo et al. 2008). This could potentially be a contributing factor to the high particulate P concentration at the 10m is obath of the Tampa Bay transect. Fort Meyers has the greatest average concentration of particulate N (Gmean=41.09M) (Table 13) at the 10m isobath and is 74% greater than the Tampa Bay station and 89% greater than the Sarasota station at the 10m isobath. The Caloosahatchee River has a higher total nitrogen flux compared to Tampa Bay and supports this obs ervation (Vargo et al. 2008).

PAGE 92

76 Table 13. Central tendency measures and ranges of surface particulate nutrient concentrations and nutrient ratios of Tampa Bay, Sarasota and Fort Meyers transects. The data include all stations sampled at the 10m isobath for each transect from June 1998 through December 2001. ________________________ _____________________ ___________________ Geometric N Mean Mean Minimum Maximum Median ________________________ _____________________ ___________________ C (M) Tampa Bay 37 49.01 40.73 3.31 135.63 40.14 Sarasota 35 36.04 29.89 7.68 167.88 31.35 Fort Meyers 33 41.09 36.16 10.72 125.67 32.28 N (M) Tampa Bay 37 16.84 9.22 1.27 97.69 8.45 Sarasota 35 5.22 3.96 1.20 20.26 3.62 Fort Meyers 33 41.09 36.16 10.72 125.67 32.28 P (M) Tampa Bay 37 0.25 0.23 0.07 0.51 0.24 Sarasota 35 0.15 0.13 0.06 0.38 0.14 Fort Meyers 35 0.19 0.16 0.04 0.52 0.18 C:N Tampa Bay 37 6.81 4.97 0.11 22.11 6.40 Sarasota 35 10.42 7.80 0.96 48.40 8.14 Fort Meyers 34 8. 75 7.39 0.68 17.69 9.02 N:P Tampa Bay 37 66.62 40.19 5.33 286.27 32.42 Sarasota 35 37.03 29.59 10.47 189.81 26.89 Fort Meyers 34 54.17 33.16 10.09 401.18 23.84 C:P Tampa Bay 37 206.20 180.66 20.82 525.29 179.69 Sarasota 35 283.60 223. 60 26.23 1477.56 215.79 Fort Meyers 34 294.25 236.98 96.84 1408.51 231.17 ________________________ _____________________ _________________

PAGE 93

77 The Gmean C:N ratio for Sarasota (7.8 ) and Fort Meyers (7.39) are very similar while Tampa Bay (4.97) is below the Redfield Ratio (Table 13). This implies that at the 10m isobath of the Tampa Bay tr ansect, phytoplankton cells are not limited by N (Figure 14). This is unexpected as it is well known that phytoplankton biomass is limited by N in side the Tampa Bay estuary (Walsh et al. 2006; Vargo et al. 2008). However, a DIN/PO4 ratio of 5.7 at the mouth of the estuary (Walsh et al. 2006) suggests that N-limiting conditi ons could potentially be restricted to the inside of Tampa Bay. Further confounding this study, are the Gmean particulate N:P ratios at the 10m isobath whic h are: 40.19 for Tampa Bay, 29.59 for Sarasota and 33.16 for Fort Meyers. This implies that all three coastal stations are potentia lly limited by P (Table 11, Table 13, Figure 14). The Gmean of the particulate C:P ratios also imply P-limitation at these stations (Table 11, Table 13). However, the DIN:PO4 at these stations are all below the Redfield ratio (Walsh 2006) and do not s upport the hypothesis drawn from the particulate nutrient data. There must eit her be a significant pool of particulate P that was not accounted for while sampling (i .e. zooplankton), a significant sink of inorganic P other than phytopl ankton uptake (abiotic or bi otic processes) or the method for particulate P determination underestimated P concentrations. Spearman Ranking Correlation coefficient s indicate that there is better correlation between the Particulate C, N and P concentrations at the 10m isobath of Tampa Bay and Fort Meyers stations then at the Sarasota station (Table 14). This supports the hypothesis that the hydrology of the region (i.e. the larger riverine systems influence on the Tampa Bay and Fort Meyers regions and the

PAGE 94

78 Frequency Distribution 0 5 10 15 20 25 0-44-1010-2020+C-limitedN-limited Near Redfield Ratio Severely N-limited 0 5 10 15 20 25 0-44-1010-2020+C-limitedN-limited Near Redfield Ratio Severely N-limited 0 5 10 15 20 25 0-1010-2020-5050+N-limited P-limited Near Redfield Ratio Severely P-limited 0 5 10 15 20 25 0-1010-2020-5050+N-limited P-limited Near Redfield Ratio Severely P-limited 0 5 10 15 20 0-9090-122122-212212+C-limited P-limited Near Redfield Ratio Severely P-limited 0 5 10 15 20 0-9090-122122-212212+C-limited P-limited Near Redfield Ratio Severely P-limitedC:N N:P C:P Figure 14. Histogram surface particu late A) C:N, B) N:P and C) C:N ratios sampled at the 10m isobath from June 1998 through December 2001 binned according to potential nut rient limitation as indicated by Redfield proportions of 106C:16N:1 P. Tampa Bay (blue), Sarasota (red) and Fort Meyers (green) transects.

PAGE 95

79 Table 14. Summary of Spearman Rank Order Correlation coefficients (rs) for surface particulate C (M), N (M), P (M) concentrations and particulate nutrient molar ratios at Tampa Bay (N=37) Sarasota (N=35), Fo rt Meyers (N=33) at the 10m isobath sampled from June 1998 through December 2001. ________________________ _____________________ ___________________ Transect Paired Variables Tampa Bay Sarasota Fort Meyers ________________________ _____________________ ___________________ C, N 0.613 0.386 0.735 N, P 0.584 0.450 0.528 C, P 0.654 0.349 0.656 C, C:N 0.356 0.236 0.007 C, C:P 0.402 0.401 0.235 N, C: N -0.851 -0.737 -0.574 N, N:P 0.885 0.787 0.556 P, N: P -0.001 -0.140 -0.330 P, C: P -0.360 -0.525 -0.464 C:N, N: P -0.773 -0.659 -0.598 C:N, C: P 0.023 0.392 0.007 N:P, C:P 0.463 0.309 0.738 ________________________ _____________________ ___________________ smaller freshwater systems influencing t he Sarasota regions) could potentially influence the particulate nutrient conc entrations and the relationships between the particulate constituents. However, the correlation coefficients indicate that correlation decreases between particulate C and N and the ratios C:N, N:P, C:P from Tampa Bay south to Fort Meyers at the 10m isobath. The decoupling of N to the C:N and N:P ratio could potentially be related to the decrease of inorganic N concentrations from Tampa Bay to Fort Meyers (Walsh 2006). In response to lower inorganic N concentrations, adjust ed phytoplankton uptake ratios could be responsible for this trend. The particu late C:N ratio does support increasing Nlimited growth from Tampa Bay to Fort Meyers (Figure 14).

PAGE 96

80 Temporal Considerations Seasonal Trends Particulate nutrient concentrations and nutrient ratios should be influenced by the seasonal patterns of climatol ogy, ocean circulation, sea surface temperature and stratification as the va rying influences of these parameters ultimately control the nutrient regime available to phytoplankton. The rainy season in southern Florida typically la sts from June to September and the dry season from October to May (Figure 15) The rainy season coincides with the along shore current flowing from the s outh to north and increased sea surface temperature which in deeper waters can resu lt in the thermal stratification of the 0 2 4 6 8 10 12 14Jan Feb Mar A pr May June July Aug Sep Oct Nov DecRainfall (Inches) 1998 1999 2000 2001 Month 0 2 4 6 8 10 12 14Jan Feb Mar A pr May June July Aug Sep Oct Nov DecRainfall (Inches) 1998 1999 2000 2001 0 2 4 6 8 10 12 14Jan Feb Mar A pr May June July Aug Sep Oct Nov DecRainfall (Inches) 1998 1999 2000 2001 MonthFigure 15. The monthly average rainfall at Tampa Bay, Sarasota and Fort Meyers for each month from 1998-2001. Data are from Florida State University. http://www.coaps.fsu.edu/climate_center/prcpdat.

PAGE 97

81 water column. During the dry season, the along shore currents flow from the north to the south and sea surf ace temperature decreases. Scatter plots of all (the entire data set) the particulate C, N and P from the wet season and the dry season do not show any notable differences between the two data sets (Figure 16). The Gm ean of the particulate C, N and P concentrations support this observation, as there is little difference in the concentrations between the two seasons (Table 15). However, the range of particulate C and N concentrations are gr eater during the dry season than during the wet season. This result seems count erintuitive; logic suggests that there would be greater flux of particulate detrita l material during time s of high river flow giving rise to a larger range of conc entrations within the particulate pool. Despite the similar range of the partic ulate constituents during the wet and dry period, the Gmean of the molar ratios sugges t that there might be a difference in how these constituents ar e incorporated into phytoplankton cells potentially based on nutrient availability. The Gmean of the C:N ratio during the wet season is 6.77 and implies balanced growth while the C:N ratio during the dry season is 8.44 which suggests that N could potentially become limiting during that time. In contrast the Gmeans of both N:P and C:P suggest conditions of greater P-limitation during t he wet season. This is again counterintuitive as dissolved P inputs would be expected to be greater during times when river flow is highest. When considering specifically the influence of rainfall on the particulate nutrients and ratios, it is reasonabl e to assume that t he stations that

PAGE 98

82 1.00 10.00 100.00 1000.00 0.010.101.0010.00100.001000.00 0.01 0.10 1.00 10.00 100.00 1000.00 0.0010.0100.1001.000 1.00 10.00 100.00 1000.00 0.0010.0100.1001.000A B CC (M) C (M) N (M)N (M) P (M) P (M) Figure 16. Scatter plots of surf ace particulate A) carbon, B) nitrogen and C) phosphorus concentra tions during the wet season (pink) and dry season (blue) sampled from June 1998 through December 2001.

PAGE 99

83 Table 15. Central tendency measures and ranges of surface particulate nutrient concentrations and nutrient ratios of t he wet season (June to September) and the dry season (October to May). The data in clude all stations sampled from June 1998 through December 2001. ________________________ _____________________ ___________________ Geometric N Mean Mean Minimum Maximum Median ________________________ _____________________ ___________________ C (M) Wet 337 26.88 20. 94 1.16 167.88 21.48 Dry 501 26.67 20. 73 1.94 485.72 20.32 N (M) Wet 337 6.31 3.31 0.35 144.79 2.95 Dry 501 6.00 2.59 0.05 266.24 2.48 P (M) Wet 338 0.07 0. 05 0.002 0.71 0.04 Dry 490 0.08 0. 05 0.002 0.60 0.04 C:N Wet 335 10.89 6.77 0.11 98.82 8.10 Dry 497 12.12 8.44 0.10 92.65 9.05 N:P Wet 331 108.37 67. 51 4.63 789.08 56.54 Dry 481 77.48 47.18 0.60 609.92 41.16 C:P Wet 334 623.54 437.45 15.13 4431.17 434.51 Dry 483 531.89 385.47 15. 22 4240.92 373.85 ________________________ _____________________ ___________________ are directly influenced by estuaries should reflect the changes in dissolved nutrient concentrations and availability and detrital materials associated with changes in river flow. When only the aver age particulate nutrient data from the Tampa Bay, Sarasota and Fort Meyers stations at the 10m isobath are considered, the particulate C,N and P conc entrations are still similar during both

PAGE 100

84 the wet and the dry period and the widest range of particulate concentrations remain during the dry period (Figure 17, Table 16). The dry period still has C:N values above the Redfield ratio but the N: P and C:P ratios are very similar during the wet and dry season where values in both cases are suggestive of Plimitation. Spearman Ranking Correlation C oefficients indicate that there is no correlation between any possible paired par ticulate variables and rainfall. Analyzing the data binned as the wet or dry season may have been too broad a classification and subtle trends we re not recognized. To analyze the data on a finer scale of temporal re solution, the particulate nutrient concentrations and nutrient ratios were plotted against month Plots of all particulate C, N, P and of the particulate nutrient ratios, indicate that there is a wide range of values for each month, most notic eably from June to October (Figure 18, 19). However, av erage particulate nutrient concentrations for each month suggest that there may be seasonal trends within the wet and dry seasons that are not only associated with rainfall, but with other process as well (Figure 20). The particulate nutrient concent rations seem to indicate that similar processes are influencing C and P and t hese processes could potentially be different during the wet and dry periods (Figure 20). The particulate N curve displays a similar curve to particulate C and P during the dry season, suggesting these concentrations might be linked to pr ocesses potentially dr iving particulate C and P concentrations. However, dur ing the wet season, particulate N concentrations increase linearly from June to October appearing independent from the curve of t he C and P concentrations. Thus, a different set of processes

PAGE 101

85 1.00 10.00 100.00 0.010.101.00 1.00 10.00 100.00 1000.00 1.0010.00100.00 1.00 10.00 100.00 1000.00 0.010.101.00C (M) N (M) C (M)N (M) P (M) P (M)A B C Figure 17. Scatter plots of surface particulate A) carbon, B) nitrogen and C) phosphorus concentrations at the 10m isobath of the Tampa Bay, Sarasota and Fort Meyers stat ions during the wet season (pink) and dry season (blue) sampled from June 1998 through December 2001.

PAGE 102

86 1.00 10.00 100.00 1000.00 0.01 0.10 1.00 10.00 100.00 0.001 0.010 0.100JanMarMayJulSepNovC (M) N (M) P (M)Month A B C Figure 18. Relationship between m onth and surface particulate A) carbon, B) nitrogen an d C) phosphorus concentrations sampled from June 1998 through December 2001.

PAGE 103

87 0.01 0.10 1.00 10.00 100.00 0.10 1.00 10.00 100.00 1.00 10.00 100.00 1000.00JanMarMayJulSepNovA B CC:N N:P C:PMonth Figure 19. Relationship between month and surface particulate ratios A) C:N, B) N:P and C) C:P sampled from June 1998 through December 2001.

PAGE 104

88 Table 16. Central tendency measures and ranges of surface particulate nutrient concentrations and nutrient ratios of t he wet season (June to September) and the dry season (October to May). The data include the averaged data of the Tampa Bay, Sarasota and Fort Meyers stations at the 10m isobath sampled from June 1998 through December 2001. ________________________ _____________________ ___________________ Geometric N Mean Mean Minimu m Maximum Median ________________________ _____________________ ___________________ C (M) Wet 42 41.58 35.15 3.31 167.88 34.07 Dry 63 49.66 37.06 7.68 485.72 33.26 N (M) Wet 43 10.81 6.60 1.46 68.61 4.89 Dry 63 10.98 5.46 1.20 97.69 5.17 P (M) Wet 43 0.19 0.17 0.06 0.41 0.18 Dry 64 0.21 0.17 0.04 0.52 0.18 C:N Wet 43 8.08 5.72 0.11 48.40 7.15 Dry 63 9.00 7.19 0.68 30.88 8.73 N:P Wet 43 58.43 38.92 12.94 286.27 31.76 Dry 63 49.06 31.56 5.33 401.18 25.98 C:P Wet 43 244.94 207.19 20.82 926.42 212.59 Dry 63 270.40 214.44 26.23 1477.56 208.51 ________________________ _____________________ ___________________ may be acting on particulate N during t he wet period. Average C:N and N:P ratios do not exhibit the strong seasonal patterns of the particulate C, N, P concentrations and C:P ratios (Figure 21) The monthly average C:N ratios

PAGE 105

89 suggest decreasing N-limitation from February to October and the monthly average N:P ratios suggest increasing P-limi tation during this time period. This could potentially be related to increasing N2 fixation during these months which would alleviate N-limitation and compound Plimiting conditions. It is interesting that the C:P curve is practically identical to the curves of particulate C and P concentrations. In contrast, the C:N and N:P curves are somewhat different in comparison with particulate C and N c oncentrations. This suggests that phytoplankton C:P uptake ratios might be mo re straightforward and more related to the physical processes controlling nutri ent availability while C and N and N and P uptake ratios seems more comple x and potentially more related to phytoplankton adaptation strategies concer ning nutrient uptake. The processes which influence the average monthly rati os should potentially be different across the shelf (e.g. coastal processes versus offshore processes). Therefore, to 0.00 10.00 20.00 30.00 40.00 50.00 JanFebMarAprMayJunJulAugSepOctNovDec 0.00 0.04 0.08 0.12 0.16MonthC, N (M) P (M) Figure 20. Monthly average surface particulate C (blue), N (pink) and P (green) concentrations sampled from June 1998 through December 2001

PAGE 106

90 C:N N:P C:P 0.00 5.00 10.00 15.00 20.00 25.00 0.00 40.00 80.00 120.00 0.00 200.00 400.00 600.00JanMarMayJulySeptNovMonth Figure 21. Relationship betw een month and average surface particulate ratio A) C:N, B) N: P and C) C:P sampled from June 1998 through December 2001.

PAGE 107

91 assess the seasonal influence on the particu late nutrients and ratios across the WFS, it is necessary to combine spatial and temporal perspectives. The monthly averaged particulate C, N and P curves at the 10m isobath (Figure 22A) are surprisingly similar to the average curves (Figure 20). The particulate C, N and P concentrations track very well at the 10m and 30m and to some degree, at the 50m and 200m isobaths as well. This suggests that there may be a fundamental process or set of proc esses driving the particulate nutrient pool across the shelf. Alt hough the basic patterns are retained, the curves of particulate C, N and P begin to shift with each seaward isobath and suggest that with distance offshore the relations hip between particulate C, N and P decreases. The curves of the particulate C, N and P concentration all exhibit increases in concentrations during the spring, early summer and fall at all isobaths presented (Figure 22, 23). Ther e does seem to be a seasonal influence on the particulate nutrient constituents that is not simply due to rainfall, but may be related to the seasonal change in flow regime on the WFS and probably other processes not revealed in this study. During the spring, increased day length could potent ially increase phytoplankton productivity, resulting in the increase of particulate C, N and P (Figure 23) during this time of the year. The peaks in the curves of particulate C, N and P (Figure 23) during the summer at the 10m and 30m isobaths could potentially be related to the “f irst flush” of runoff asso ciated with the start of the rainy season, when detrital material degradation products and anthropogenic

PAGE 108

92 0.000 20.000 40.000 60.000 0.000 0.100 0.200 0.300 0.000 10.000 20.000 30.000 0.000 0.020 0.040 0.060 0.000 10.000 20.000 30.000 0.000 0.010 0.020 0.030 0.040 0.050 0.000 10.000 20.000 JanMarMayJulySeptNov 0.000 0.010 0.020 0.030C, N (M) P (M)Month A B C D Figure 22. Monthly average su rface particulate C, N and P concentrations at the A) 10m, B) 30m, C) 50m and D) 200m isobaths sampled from June 1998 through December 2001. Particulate C (blue), particulate N (pink) and particulate P (green).

PAGE 109

93 0.00 10.00 20.00 30.00 40.00 50.00 60.00 0.00 10.00 20.00 30.00 40.00 0.000 0.050 0.100 0.150 0.200 0.250JanMarMayJulySeptNovC (M) N (M) P (M)A B C Month Figure 23. Monthly average surface par ticulate A) carbon, B) nitrogen and C) phosphorus concentrations along different isobaths sampled from June 1998 through December 2001. 10m isobath (blue), 30m isobath (red), 50m isobath (green) and the 200m isobath (turquoise).

PAGE 110

94 nutrient sources built up during the dry period are discharged into the marine environment at higher concentrations during t he rest of the rainy season. At the 50m and 200m isobaths it should be expected that this trend is more related to ocean circulation patterns as increased (o r decreased) riverine nutrient inputs should not influence this region of the shel f. In situ regeneration within the photic zone of regions that become thermally st ratified could also be responsible for increased particulate nutrient concentrati ons. The peaks in the curves of particulate C, N and P (Figure 23) during t he fall could potentially be related to the fall water column turnover event wher e cooler temperatures result in the break down of thermal stratification in t he water column, resulting in the upward diffusion of nutrients increasing phyt oplankton production and the observed increase in particulate nutrient concentrati ons. In the fall, along shore currents revert back to the north to south fl ow pattern and could potentially influence particulate C, N and P concentrations at this time of the year. The dips that often follow the peaks might be a re sult of the draw down of nutrients after periods of increased growth and would result in a decrease of nutrients in the particulate pool. During the dry season, the particulate C: N ratio at all isobaths have similar curves with peak values occurring in February, followed by another peak in May and the lowest values occurring in October (Figure 24A). Th is suggests that similar processes may be acting on the par ticulate C:N ratio across the shelf during that period. Ocean circulation pa tterns are known to reverse during May and October and might be a contributing factor to the more N limiting conditions

PAGE 111

95 0.00 5.00 10.00 15.00 20.00 25.00 30.00 0.00 50.00 100.00 150.00 200.00 250.00 0.00 400.00 800.00 1200.00C:N N:P C:PJanMarMay July SeptNovA B C Month Figure 24. Monthly average surface ratios A) C:N, B) N:P and C) C:P along different isobaths sa mpled from June 1998 through December 2001. 10m isobath (b lue), 30m isobath (red), 50m isobath (green) and the 200m isobath (turquoise).

PAGE 112

96 during the spring and less N-lim iting conditions during t he fall. At the 10m and 30m isobaths this pattern could possibly be related to rainfall where the spring peak may be related to the first flush of nut rients at the start of the rainy season and the low concentrations in October result s as a lack of rive r flow. The first heavy rainfall would be expected to bri ng large loads of detrital C into the estuaries and coastal zones thereby elev ating the C:N rati o. The high C:N values that occur in February could be related to carbon over-consumption (Fuhs 1972) as inorganic nutrient concentrations are known to decrease during the winter months. For all hypotheses presented, it is difficult to determine if the C:N ratios are more influenced by particulate N or particulate P as both of these concentrations decrease in February and May (Figure 23A, 23B) and increase in October. During the rainy season the par ticulate C:N curves at all isobaths exhibit a different trend compared to t he dry season. This suggests that processes contributing to the C:N ratio across the shelf may be different during wet and dry seasons. More over, the curves at the10m and 30m isobath are similar and the curves at the 50m and 200m isobaths ar e somewhat similar to each other (Figure 24A) and implies that from June to September the processes contributing to the particulate C:N val ues found within the i nner shelf could be different than processes contributing to offshore particulate C:N values. The particulate C:N ratios at the 10m and 30m isobaths steadily declines throughout the wet season and could be related to the po tential increase in concentrations of inorganic N due to increased river flow during the summer months or perhaps N2 fixers are responding to an increase in iron availability deposited as Saharan

PAGE 113

97 dust. It is also possible that detrital C materials become less important after the “first flush” of the rainy season contributing to this trend by reducing particulate C concentrations (Figure 23A). Explanations for the rise in the average particulate C:N ratios at the 50m and 200m isobaths during July and September are not as readily available and may be related to summer circulation patterns within the offshore region. The particulate N:P ratio exhibits a general trend of increasing P-limitation from February to July across the WFS as particulate N:P values steadily increase from the lowest values in February to hi gher values in July (Figure 24B). From August to November the curve of the 10m isobath exhibits a different trend when compared to the surprisingly similar curves at 30m, 50m and 200m isobaths exhibited throughout all months (Figure 24B). Particulate N:P values at the 10m isobath increase throughout the wet season indicating conditions of continually increasing P-limitation into September. In contrast, t he particulate N:P ratios farther offshore decrease in value dur ing August and September, indicating decreasing P-limitation during the late su mmer. This implies that during the summer and fall, processes driving the coas tal particulate N:P ratios are different from those processes infl uencing particulate N:P ratios farther offshore. However, which processes contributing to the trend of increas ing P-limitation at the 10m isobath and decreasin g P-limitation at the 30 m, 50m and 200m isobaths during the late summer are di fficult to explain. Duri ng the wet season, inorganic P concentrations along the coast increas e as the flow of rivers draining Hawthorne phosphatic deposit incr ease. This should result in a decrease of the

PAGE 114

98 particulate N:P ratio during the rainy s eason as coastal phytoplankton should not, in theory, be limited by P. It is possibl e that a large portion of the inorganic P is taken up within the estuar ies and therefore not availa ble to coastal populations, but does not explain why the N:P ratio in creases from May to September. It is unclear why the offshore stations appear to become less P-limited during the late summer months than during July. N2 fixation rates offshore should increase during the late summer, increasing particu late N concentrations relative to particulate P at the 30m, 50m, and 200m isobath. However, this trend is observed during the month of October. It is interesting to note that average C:N and N:P values generally exhibit opposite tr ends at all isobaths in all months, which implies that particulate N may be driving both ratios on the WFS during the wet and dry periods. These ratios displa y seasonal trends which are potentially related to changing circulation patterns, thermal regimes, biological processes (i.e. of N2 fixation by Trichodesmium populations in late summer), and rainfall (10m and 30m isobaths). Desp ite the relatively constant values of the average particulate N concentrations (Figure 20, 23B), it seems likely that seasonal processes affect the mechanisms by wh ich particulate N is partitioned into cellular material to a greater degree than particulate C. The particulate C:P ratio lacks some of the structure seen in both the C:N and N:P curves, most notable at the 10m isobath (Figure 24C), which implies that this ratios may be less seasonally dependent than ratios which include particulate N. However, throughout the we t season the particulate C:P ratios at both the 10 and 30m isobath decline and could potentially be related to increased

PAGE 115

99 inorganic P concentrations associated wit h increased river flow. Based on the hypothesis when discussing trends of the N:P ratio, this trend seems more likely to be related to a decrease in particu late C after the “first flush”. Inter-annual Trends The primary controls on the particulate nutrients and ratios would be expected to be the same throughout t he study period, however, inter-annual differences in the inorganic nutrient regimes that would be reflected in phytoplankton C:N:P stoichiometry. Wind events of various direction, strength and duration which result in upwelling/do wnwelling conditions would be expected to alter inorganic nutrient concentrations throughout the years, as would the variability in rainfall (Figure 15). Geometric means of part iculate P concentrations across the shelf are relatively constrained throughout the study period, while average particulate C and N concentrations have lower average co ncentrations during 1998 and 2001 and greater average concentration during 1999 and 2000 (Table 17 ). This could potentially be related to different envir onmental conditions on the WFS during 1998/2001 and 1999/2000. The geometric means of particulate C:N (14.01) and N:P (32.38) during 1998 suggest that this year was the mo st N-limited and the least P-limited compared to 1999-2001 (Table 17, 18). This seems to be related to the very low concentrations of particulate N (1.93 uM) from June to December of that year rather than an increase in particulate P or C (Table 17). This could be related to

PAGE 116

100 Table 17. Central tendency measures and ranges of surface particulate nutrient concentrations and nutrient ratios from sampled from June 1998 through December 2001. The data only include t he months of June to December for each year in order to direct ly compare the study years. ________________________ _____________________ ___________________ Geometric N Mean Mean Mi nimum Maximum Median ________________________ _____________________ ___________________ C (M) 1998 126 21.98 19.08 1.94 62.19 21.07 1999 186 29.02 22.68 1.16 114.39 24.27 2000 139 34.16 25.79 7.42 231.79 22.50 2001 120 20.75 16.84 3.72 89.87 15.47 N (M) 1998 126 1.93 1.45 0.16 9. 87 1.45 1999 186 7.63 4.19 0.58 144.79 3.79 2000 139 13.75 5.79 0.77 266.24 5.16 2001 120 4.29 2.74 0.53 27.28 2.41 P (M) 1998 129 0.06 0.05 0.002 0.35 0.04 1999 177 0.11 0.07 0.02 0. 60 0.07 2000 137 0.07 0.05 0.01 0. 50 0.04 2001 121 0.09 0.05 0,01 0. 71 0.03 C:N 1998 123 16.89 14.01 3.17 92.64 13.29 1999 186 10.16 5.70 0.10 98.82 7.16 2000 139 8.39 4.98 0.21 54.20 5.24 2001 120 7.94 6.50 0.89 20.30 7.60 N:P 1998 125 50.62 32.38 3.41 520.90 29.38 1999 174 86.93 56.28 4.70 789.08 47.95 2000 133 177.16 119.22 19.14 616.35 129.20 2001 119 85.52 58.92 4.63 685.96 50.06 C:P 1998 125 581.85 430. 05 41.60 4105.85 421.30 1999 175 509.57 309. 63 15.13 3367.11 298.45 2000 137 763.24 563.36 117.99 4431.17 545.86 2001 119 421.81 358. 69 38.36 1333.86 391.65 ________________________ _____________________ ___________________

PAGE 117

101 Table 18. Surface particulate nutrient stoichiometry based on the mean and geometric mean. The data only include t he months of June to December for each year in order to direct ly compare the study years. ________________________ _____________________ ___________________ Geometric N C:N:P C:N:P ________________________ _____________________ ___________________ 1998 126 351:31:1 423:32:1 1999 186 270:71:1 313:58:1 2000 139 477:191:1 567:127:1 2001 120 242:50:1 356:58:1 ________________________ __________________ ______________________ a deep water upwelling event which occurred during the spring and into the fall of 1998 (Vargo et al. 2008). Weisberg et al. 2005 observed that during this period, “Complimentary deep ocean and local forcing led to anomalous stratification and circulation where the thermocline stay ed strong into July even up to the beach and cold water outcrops were observed in satellite images” The upwelled nutrient rich water could have the effe ct of preferentiall y sustaining non-N2 fixing organisms which have lower half saturation constants allowing them to outcompete N2-fixers for the available nutrients. N2 fixing organisms typically have cellular concentrations enriched in N relative to P compared to non-Nitrogen fixers, which might explain why the aver age particulate N values and N:P ratio are lower, but the C:P ratio are higher in 1998 compared to other years within this study (Table 17, 18). In contrast, 2000 has an average C:N:P stoichiometry indicative of the greatest P-limitation relative to the other sample years (Table 18). The average N:P and the C:P molar ratios of 177 and 763 are values which suggest conditions

PAGE 118

102 of severe P limitation (Table 17). These extremely high values seem to be more related to larger detrital contributions of refractory C and P during this year. It seems unlikely that N:P ratio values would reach 177 as a result of N2 fixation processes alone. Hurricane Gordon, whic h affected the WFS during September, could certainly have contributed to an incr ease in detrital contributions to the particulate pools via both to heavier rive r flows due to increased rainfall and resuspension of particulates from the s ediments as a result of increased wind activity. This hypothesis is supported in the curves of the particulate constituent concentrations (Figure 25) and particulate ratio values (Figure 26). During 2000, particulate C concentrations and the C:P ratio both increased dramatically in October and during November particulate N concentrations and the particulate N:P values also radically increased. Pa rticulate P concentrations were only slightly elevated during those months and the C:N ratio does not increase in October or November. This is most likely due to the fact that detrital components are primarily composed of re fractory particulate C and N and very little particulate P. The June–Decem ber periods of 1999 and 2001 have more similar particulate stoichiometries when compared to those of 1998 and 2000, especially the average particulate N:P rati os which are almost identical (Table 17, 18). Neither of these years had anom alous weather conditions, which might be responsible for the similarity of the particulate ratios. Average values of particulate nutrient concentrations and nutrient ratios for all stations sampled each month of eac h year show pulsed increases/decreases

PAGE 119

103 0.00 20.00 40.00 60.00 0.00 10.00 20.00 30.00 0.00 0.05 0.10 0.15 0.20 JanMarMayJulySeptNov C (M) N (M) P (M)Month A B C Figure 25. Monthly averages of surface particulate A) carbon, B) nitrogen and C) phosphorus concentrations sampled from June through December of 1998 (blue), 1999 (red), 2000 (green) and 2001 (turquoise)..

PAGE 120

104 0.00 10.00 20.00 30.00 0.00 100.00 200.00 300.00 0.00 400.00 800.00 1200.00JanMarMayJulSepNov A B CC:N N:P C:PMonth Figure 26. Monthly averages of surf ace particulate nutrient A) C:N, B) N:P and C) C:P ratios for all stations sampled from June through December of 1998 (blue), 1999 (red), 2000 (green) and 2001 (turquoise).

PAGE 121

105 during different months and the structure of the curves ar e very different for each year (Figure 25, 26). This supports the hypothesis t hat interannual physical and biological process are different for each year and result in a variety of particulate C, N, P concentrations and particulate ratio values within each year. Particulate N and P concentrations as related to distance offshore all share very similar trends seaward of t he 30m isobath (Figure 27). This implies that offshore processes influencing particu late N and P concentrations are similar from year to year on the WFS. The va riability at the 10m is obath is most likely due to the variety of coastal processes which would be expected to vary with year. In contrast, the parti culate C concentration curves tend to vary from year to year seaward of the 30m isobath, indicating that processes influencing particulate C concentration may not be as constrained as those acting on particulate N and P and could potentially be related to detrital contributions, C over-consumption or phytoplankton asse mblage (i.e. picocyanobacteria) Although the particulate N and P c oncentrations are constrained, and potentially limited by physical proce sses seaward of th e 30m isobath, the particulate ratios are much more variable with distance o ffshore from year to year (Figure 28). This is most likely relat ed to the complexity of the processes involving phytoplankton uptake mechanisms, adaptive strategies and competition between species based on nutrient regime s that would be expected to change from June through December during each year of the study period.

PAGE 122

106 0.00 20.00 40.00 60.00 0.00 4.00 8.00 12.00 16.00 0.000 0.100 0.200 103050200C (M) N (M) P (M)Isobath (m) A B C 0.00 20.00 40.00 60.00 0.00 20.00 40.00 60.00 0.00 4.00 8.00 12.00 16.00 0.00 4.00 8.00 12.00 16.00 0.000 0.100 0.200 103050200C (M) N (M) P (M)Isobath (m) A B C Figure 27. Average surface parti culate A) carbon, B) nitrogen and C) phosphorus concentrations at each isobath sampled from June through December of 1998 (b lue), 1999 (red), 2000 (green) and 2001 (turquoise).

PAGE 123

107 1600.00 0.00 1.00 2.00 3.00 0.00 100.00 200.00 300.00 0.00 400.00 800.00 1200.00103050200Isobath (m) A B CC:N N:P C:P Figure 28. Average surface particulate ratios A) C:N, B) N:P and C) C:P at each isobath for all stat ions sampled from June through December of 1998 (blue), 1999 (red), 2000 (green) and 2001 ( tur q uoise )

PAGE 124

108 Karenia brevis Karenia brevis is the toxic dinoflagellate responsible for the large red tide blooms that occur with almost inter-annual regularity on the WFS. Because of the high cell biomass associated with thes e blooms, it would be expected that K. brevis blooms have a relationship with parti culate nutrient st oichiometry on the SW Florida shelf. When K. brevis concentration ranges are binned in ranges (i.e. <1,000 cells/L, 1,000-10, 000 cells/L, >10,000-100, 000 cells/L and >100,000 cells/L) there is a difference in the r anges of the particulate nutrient ratios associated with each binned cell concentrati on. The ranges when there are no K. brevis cells present or in low concentrati ons are much larger for particulate C:N, N:P and C:P than when K. brevis is present in concentrations greater than 10,000 cells/L (Table 19). Mean C:N, N:P, C:P and C:N:P ratios decrease as K. brevis cell concentration increase from 0 to >100,000 cells/L (Table 19, 20). This indicates that the particulate nutrient concentra tions of high biomass populations are approaching the Redfield ratio and per haps are not as nutrient limited as K. brevis populations of lower biomass and populations which do not include K. brevis This trend may also potentially be rela ted to a higher portion of live cells relative to detrital materials contributing to the particulate pool in blooms, which would result in lower C:N:P stoichiometr y values. It should be mentioned that during the November 2000, particulate N va lues at five coastal stations where K. brevis cell concentrations were 1,000 cells/L, were anomalously high, larger than

PAGE 125

109 Table 19. Central tendency measures and ranges of surface particulate nutrient ratios of K. brevis concentration, cells/L (0 includes sample with no K. brevis detected, 1,000-10,000 includes regulatory limits for commercial shellfish bed closure, >10,000-10,0000 includes low bloom concentrations and >100,000 includes high bloom concentrations) sampled from June 1998 through December 2001. The stations with less than 1000 K. brevis are only those stations that had a record of K. brevis present at some point during the study period. ________________________ _____________________ ___________________ K. brevis* N Mean Mini mum Maximum Median ________________________ _____________________ ___________________ C:N <1,000 166 9.46 0.11 76.24 8.73 1,000-10,000 47 10.24 0.21 46.77 8.47 >10,000-100,000 18 9.47 1.13 35.46 8.37 >100,000 24 7.86 0.09 24.93 8.07 N:P <1,000 166 90.23 0.68 949.28 47.37 1,000-10,000 44 124.08 10.95 959.61 39.40 >10,000-100,000 18 63.43 19.14 465.05 33.64 >100,000 24 46.19 11.28 236.30 35.82 C:P <1,000 166 445.92 14.83 3415.72 330.64 1,000-10,000 44 536.74 99.75 3124.96 328.51 >10,000-100,000 18 344.61 134. 77 1391.34 282.54 >100,000 24 248.73 17.72 1142.58 196.30 ________________________ __________________ ______________________ *cells /L Table 20. Average surface particu late C:N:P stoichiometry within K. brevis blooms from June 1998 through December 2001. ________________________ _____________________ ___________________ K brevis cell concentration C:N:P ________________________ _____________________ ___________________ <1,000 292:95:1 1,000-10,000 292:194:1 >10,000100,000 265:61:1 >100, 000 174:38:1 ________________________ _____________________ ___________________

PAGE 126

110 particulate C values for the same stati ons. These values could be related to a localized event at these coastal stat ions, (e.g. Hurrica ne Gordon) or the contamination of that particular set of samples. The nutrient sources which fuel these high biomass blooms are hypothesized to include at least six different sources (Havens et al. 2004; Heil et al. 2007: Vargo et al. 2008). The capability of K. brevis to potentially adjust to a variety of nutrient conditions is supported by the variety of particulate ratio values wit hin four different blooms examined on the WFS during 1998-2001 (Table 21). In most cases, all 4 blooms had particulate Table 21. Summary of average surface particulate nutrient ratios for each K brevis bloom that occurred from June 1998 through December 2001. ________________________ _____________________ ___________________ Particulate Ratio No Bloom* 1998-1999 19992000 2000 2001 ________________________ _____________________ ___________________ C:N 15.22 14.57 7.52 4. 60 9.03 N:P 90.22 24.15 61. 15 321.98 38.43 C:P 445.92 292.13 441.80 529.58 293.67 ________________________ __________________ ______________________ *Includes only those stations which had K. brevis cells present at some point during the sampling period. ratio values closer to Redfield values than the average particulate ratios of samples where K. brevis was not present. The blooms which occurred during 1998-1999 and 2001 seem to be less nutrient limited than the blooms which occurred during 1999-2000 and 2000. The longev ity and the lower C:N, N:P and

PAGE 127

111 Table 22. Particulate C, N and P content (SE) of K. brevis within blooms sampled from June 1998 through December 2001. ________________________ _____________________ ___________________ (nmol/cell) Sample # C N P* C:N:P ________________________ _____________________ ___________________ Bloom Samples 1998-1999 Bloom All data 8.52 (2. 70) 0.59 (0.18) 319 ( 122) 267:18:1 <100,000 11 15.36 (3.85) 1. 06 (0.26) 573 (193) 267:18:1 >100,000 9 0.17 (0.03) 0.02 (0.00) 8 (1) 210:22:1 1999-2001 Bloom All data 6.99 (2.86) 0.77 (0.27) 158 (61) 447:50:1 <100,000 15 10.25 (3.95) 1.12 (0.36) 230 (84) 457:50:1 >100,000 7 0.03 (0.04) 0. 01 (0.01) 2 ( 1) 138:78:1 2000 Bloom All data 15.08 (3.38) 17.07 (6.86) 413 (95) 364:413:1 <100,000 17 15.96 (3.46 18.07 (7.19) 437 (97) 364:413:1 >100,000 1 0. 11 (0.00) 0.01 (0.00) 1 (0.) 905:62:1 2001 Bloom All data 2.77 (1. 33) 0.43 (0.22) 170 (124) 162:25:1 <100,000 14 4.05 (1.93) 0.63 (0.32) 251 (184) 161:25:1 >100,000 7 0.20 (0.05 ) 0.03 (0.01) 8 (2) 248:32:1 Literature Culture Values Shanley ** Low Light 0.06 (0.40 ) 0.0055 (0.30) Medium Light 0.04 (0.30 ) 0.004 (0.30) High Light 0.05 (1.00 ) 0.0065 (1.20) Heil# Exponential growth 0.04 ( 0.00) 0.0063( 0.34) 3 (0.02) 120:21:1 ________________________ _____________________ __________________ 104, data not reported, ** Wilson clone,low li ght is 24, medium light is 90 and high light is 160 E m-2 sec-1, # Wilson clone at exponential growth..

PAGE 128

112 C:P ratios of the 1998-1999 K. brevis bloom could be related to the anomalous upwelling event that occurred during the spring and summer of that year. The comparison of particulate C, N and P content of K. brevis cells during the different blooms supports the hypothesis that the r anges of particulate C, N and P concentrations decrease with incr easing cell concentration and that K. brevis populations with concentrations > 100,000 are growing more near to the Redfield ratio (Table 22). This could possibly be related to an increasing supply of regenerated nutrients wit hin the bloom supplied by organisms which have succumbed to the effe cts of the brevetoxin The values of in situ particulate C and N concentrations within K. brevis blooms are greater t han those reported for K brevis culture at a range of light levels (Shanley 1985) and during exp onential growth (Heil 1985). These differences could potentially be related to detrital contributions to the particulate values in the marine environment. In c ontrast, particulate P concentrations are greater during the 1998-1999 and 2001 bl ooms but less during the 1999-2001 and 2000 blooms compared to cultured values of cells growing exponentially. Detrital contributions of particulate P would be expected to be less in the marine environment due to the rapid tu rnover times of P.

PAGE 129

113 Summary In situ particulate nutrient ratios are diffi cult to interpret for a variety of reasons. The method of sample collecti on is such that it was often unknown exactly what comprised the particulate fraction that were measured (i.e. live phytoplankton cells versus detrital material ) as all material in the size range of 0.7m to 153m was analyzed. The diffe rent methods employed to determine particulate C, N and particulate P concent ration could potentially skew resultant ratio values underestimating particulate P concentrations and resulting in the very high N:P and C:P values observed th roughout the course of this study. Furthermore, the interpretation of in situ particulate ratios requires that the physical processes of nutrient delivery, microbial nutrient regeneration and the different uptake strategies employed by different groups of phytoplankton (i.e. N2 fixers and non-N2 fixers) must all be considered. Particulate C, N, P concentrations and the particulate ratios of C:N, N:P and C:P of the entire data set display a wide range of values across the shelf, most likely related to the wide variety of physical and biological processes that occur both spatially and temporally on the WFS. The frequency distribution histogram of the data and Spearman Ranking Correlation coefficients indicate that particulate C concentrations are more conservative relative to particulate N and P concentrations, which probably hav e a greater potential to vary in response to changing nutrient regime s across the shelf. The frequency distributions of particulate C and particu late P are similar, but differ from distributions of particulate N concentrations This suggests that processes acting

PAGE 130

114 on particulate C and P concentrations may be different than those acting on particulate N concentrations, is most likely due to N inputs from N2 fixation. Correlation coefficients suggest that parti culate N concentrations drive the C:N and N:P ratios. The WFS from June 1998 through December 2001 had a geometric mean particulate C:N:P stoich iometry of 332:77:1 which is very different from the classic Redfield Ratio or values reported for natural phytoplankton in the literature, but similar to reported literary values for P-limited cultures. This implies that phytopl ankton growth on the WFS seems to be predominately P-limited, which is driven by particulate N concentrations. In theory, P-limitation on the WFS could be due to: 1) populations of N2 fixing Trichodesmium and picocyanobacteria provid ing new sources of N while concurrently drawing down inorgani c P concentrations, 2) populations of picocyanobacteria substituting non-P memb rane lipids for phospholipids resulting in non-Redfieldian ratios 3) inorganic P adsorption to deposits of Saharan dust during summer months, 4) underestimation of particulate P concentrations due to problems with the molybdenum blue method and 5) inability to correct for detrital C and N contributions to the particulate nutrient samples. The relationship between average parti culate C, N, P concentrations and distance offshore are well described by a polynomial functions and the similarity of the curves for the different nutrients suggest that there ar e similar regulating mechanisms acting on all three variables are related. There is an initial decline in average particulate C, N and P concentra tions from the 10m isobath out to the 30m isobath where concentrations then becom e level out to the shelf break. The

PAGE 131

115 30m isobath potentially repres ents a transition zone from a coastally influenced environment to a more oligotrophic env ironment. The relationship between average particulate ratios and distance can also be described by polynomial functions where values increase out to the 100m isobath than slightly decrease out to the 200m isobath. The greatest ranges in the particulate C:N and C:P ratios occur at distances greater than 50km offshore and implies a decoupling of processes regulating particulate C from both N and P with distance offshore as related to biological activi ty. This could be related to phytoplankton storing C in excess relative to N and P as nutrient availability decreases with distance offshore, or may be indicative of a change in the contribution of detrital materials as a result of decrease biomass in this region. The comparison of the geometric mean particulate nutrient stoichiometry (C:N:P) indicates that P-limitation increases with distance from the coast and is supported by frequency distribution histograms binned according to nutrient limitation. The geometric means of the particulate C, N and P concentrations at the Tampa Bay, Sarasota and Fort Meyers alon g the entire transect (10m isobath to the 50m isobath are very similar but s uggest a very weak trend of decreasing Plimitation and increasing Nlimitation from the north to the south. When only considering these stations at the 10m isobath, Sarasota has the lowest concentrations of particulate C, N and P compared to the Tampa Bay and Fort Meyers stations. The C:P and N:P particu late ratios at the 10m isobath suggest that all three coastal stations are predom inantly P-limited. Given the N-limited

PAGE 132

116 environment of adjacent estuaries, th is observation presents a bit of a conundrum. Particulate C, N, P concentrations and particulate ratios are similar during the wet season (June-September) and the dr y season (October-May). However, average particulate nutrient ratios indi cate that phytoplankton growth could potentially be more N limit ed during the dry period and more P limited during the wet season in response to an increase of N2 fixing populations during the summer and early fall. There do appear to be monthly trends within the wet and dry periods as well, where peaks in the particulate concentrations and ratios occur during the spring, summer and fall as phytoplankton populations adapt (i.e. N2 fixers vs nonN2 fixers) to the seasonal mechanis ms of nutrient delivery (i.e. day length, circulation patterns, storms river flow, therma l stratification/non stratification). The particulate C, N, P concentrations and the particulate ratios differ on inter-annual scales. Though the basic ph ysical processes throughout the years would not be expected to change, the str ength and duration of these processes vary from 1998 through 2001 and could potentially be responsible for the fluctuations of the particulate C, N, P concentrations and ratios throughout the study period. Particulate C:N:P stoichiometry within K. brevis blooms has a narrower range and appears to be growing closer to the Redfield ratio than particulate ratios where K. brevis is not present. This relationship strengthens with increasing cell concentration. Particulat e C:N, N:P and C:P ra tios do vary within

PAGE 133

117 different blooms are most likely relat ed to the different nutrient regimes associated within each bloom. The values of the particulate nutrient ratios within natural blooms are greater than that of cultured K. brevis cells. This difference is most likely related to detrital contributi ons within the marine environment and the nutrient replete conditions in culture experiments. The particulate C, N and P concentrations and ratios vary both spatially and temporally and are often above the classi c Redfield ratios as related to the flexibility in phytoplankton respons es to varying nutrient regimes.

PAGE 134

118 REFERENCES Aksnes, D.L., Egge, J.K., 1991. A theor etical model for nutrient uptake in phytoplankton. Marine Ecology Progress Series 70, 65-72. Anonymous, 1994-1995. Phosphorus cycl es and transfers in the global environment. Scientific Committee on Problems of t he Environment (SCOPE), Newsletter 47, 1-4. Antia, N.J., Harrison, P. J., Olveira, L., 1991. The role of dissolved organic nitrogen in phytoplankton nutrition, ce ll biology and ecology. Phycologia 30(1), 1-89. Ammerman, J.W., Hood, R.R., Case, D. A., Cotner, J.B., 2003. Phosphorus deficiency in the Atlantic: An em erging paradigm in oceanography. EOS, Transactions, American Geophysi cal Union 84(18), 165-170. Atkins, M.J., Smith, S.V ., 1983. C:N:P ratios of benthic marine plants. Limnology and Oceanography, 28(3), 568-574. Ault, D., 2006. Temporal and spatial di stibutions of chlorophyll on the West Florida Shelf. Masters Thesis, Universi ty of South Florida, St. Petersburg. Banse, B., 1974. On the interpretation of data for the carbon-to-nitrogen ratio of phytoplankton. Limnology and Oceanography 19(4), 695-699. Bathman U.V., Scharik R., Klaas C., Dubi schar C.D.,Smetacek V., 1996. Spring development of phytoplankton bioma ss and composition in major water masses of the Atlantic sector of th e Southern Ocean. Deep-Sea Research II 44, 51-67. Benitez-Nelson, C.R., Buesse ler, K.N., 1999. Variability of inorganic and organic phosphorus turnover rates in the c oastal ocean. Nature 398, 502-505. Berland, B.R., Bonin, D.J., Maestrin i, S.Y., 1980. Azote ou phophore? Cendiderations sul le “paradoxe nu trerionnel” de la mer Medirerranee. Oceanology Octa 3, 135-142.

PAGE 135

119 Bertilsson, S., Berglund, O., Karl, D. M., Chisholm, S.W., 2003. Elemental composition of marine Prochlorococcus and Synechococcus : Implications for the ecological stoichiome try of the sea. Limnology and Oceanography 48(5), 1721-1731. Biddanda, B., Benner, R., 1997. Carbon, nitrogen, and carbohydrate fluxes during the production of particulate and dissolved organic matter by marine phytoplankton. Limnology and Oceanography 42(3), 506-518. Bissett W.P., et al., 2 005. Predicting the optical prop erties of the west Florida shelf: resolving the potential impact of a terrestrial boundary condition on the distribution of colored dissolved and par ticulate matter. Marine Chemistry 95, 199-233. Bronk, D.A., Glibert, P. M., 1994. Nitrogen uptake, di ssolved nitrogen release, and new production. Science 265(5180), 1843-1846. Bronk, D.A., Ward, B.B., 1999. Gro ss and net nitrogen uptake and DON release in the euphotic zone of Monteray Bay, California. Limnology and Oeanography 44, 573-585. Bronk, D.A., Sanderson, M.P ., Mullholland, M.R., Heil, C.A., O’Neil, J.M., 2004. Organic and inorganic nitrogen uptake kinet ics in field populations dominated by Karenia brevis In: Steidinger, K.A., Landsberg, J.H., Tomas, C.R., Vargo, G.A. (Eds), Harmful Algae 2002. Flor ida Fish and Wildlife Conservation Commission, Florida Institute of Oceanography, and Intergovernmental Oceanographic Commission of UNESCO, pp. 80-82. Brzezinski, M.A., Dickson, M.L., Nelson, D.V ., Sambrotto, R., 2003 Ratios of Si, C and N uptake by microplankton in the Southern Ocean. Deep-Sea Research II 50, 619-633. Carlson, C.A., Hansell, D.A., Peltze r, E.T., Smith W.O., 2000. Stocks and dynamics of dissolved and particulate organic matter in the southern Ross Sea, Antarctica. Deep-Sea Research II 47, 3201-3225. Caperon, J., Meyer j., 1972. Nitrogen limited growth of marine phytoplankton II. Uptake kinetics and their role in nutri ent limited growth of phytoplankton. Deep Sea Research 19(9), 619-632. Capone, D.G., 2001. Marine ni trogen fixation: what’s the fuss? Current Opinion in Microbiology 4, 341-348. Cappellen, P.V., Ingell, E.D., 1996. R edox stabilization of the atmosphere and oceans by phosphorus-limited marine produ ctivity. Science 271, 493-496.

PAGE 136

120 Carlsson, P., Graneli, E., 1999. Effects of N:P:Si ratios and zooplankton grazing on phytoplankton communities in the north ern Adriatic Sea. II. Phytoplankton species composition. Aquatic Microbial Ecology 18, 55-65. Chempedia.com Chen, C.A., Lin, C.L., Huang, B.T., Chang, L., 1996. Stoichio metry of carbon, hydrogen, nitrogen, sulfur and oxygen in the particulate matter of the western North Pacific marginal seas. Marine Chemistry 54 179-190. Christian, J.M., Lewis, M., Ka rl, D., 1997. Vertical fluxes of carbon, nitrogen, and phosphorus in the North Pacific Subtropi cal gryre near Hawa ii. Journal of Geophysical Research 102(C7), 15667-15677. Cochlan W.P., Bronk D.A., 2001. Nitr ogen uptake kinetics in the Ross Sea, Antarctica. Deep-Sea Research II 48, 4127-4153. Copin-Montegut, C., Copin-Montegut, G. 1983. Stoichiometry of carbon, nitrogen, and phosphorus in marine particu late matter. De ep-Sea Research 30(1), 31-46. Diehl, S., Berger, S., Wohrl, R., 2005. Flexible nutrien t stoichiometry mediates environmental influences on phytoplank ton and its resources. Ecology 86(11), 2931-2945. Dixon, L.K., Steidinger, K. A., 2004. Correlation of Karenia brevis presence in the eastern Gulf of Mexico with rainfall and riverine flow. In: Steidinger, K.A., Landsberg, J.H., Tomas, C.R., Vargo G.A. (Eds.). Harmful Algae 2002. Florida Fish and Wildlife Conservati on Commission, Florida Institute of Oceanography, and Intergovernment al Oceanographic Commission of UNESCO, pp. 29-31. Donaghay, P.L., Demanche, J.M., Sm all, L.F., 1978. On predicting phytoplankton growth rates from ca rbon:nitrogen ratios. Limnology and oceanography 23(4), 359-362. Downing, J.A., 1997. Mari ne nitrogen: phosphorus stoich iometry and the global N:P cycle. Biogeoche mistry 37, 237-252. Droop, M.R., 1974. The nutrient status of algal cells in continuous culture. Journal of the marine biological associ ation of the Unit ed Kingdom 54, 825855.

PAGE 137

121 Droop, M.R., 1975. The nutrient status of algal cells in bat ch culture. Journal of the marine biological a ssociation of the Unit ed Kingdom 55, 541-555. Duarte C.M., 1992. Nutrient concentra tion of aquatic plants: patterns across species. Limnology and Oceanography 37(4), 882-889. Dugdale, R.C., 1967. Nutrient limitation in the sea: Dynam ics, Identification, and significance. Limnology and Oceanography 12(4) 685-695. Dugdale, R.C., Goering, J. J., 1967. Uptake of new and regenerated forms of nitrogen in primary productivity. Limnology and Oceanography 12(2), 196206. Elser, J.J., Urabe, J., 1999. The stoi chiometry of consumer-driven nutrient recycling: theory, observations, and c onsequences. Ecology 80, 735-751. Eppley, R.W., Renger, E.H., Venrick, E.L., Mullin M.M., 1973. A study of plankton dynamics and nutrient cycling in the central gyre of the north Pacific Ocean. Limnology and Oceanography 18(4) 534-551. Eppley, R.W., Peterson, B.J., 1979. The particulate organic matter flux and planktonic new production in the deep ocean. Nature 282, 677-680. Eppley, R. W., 1981. Rela tions between nutrient assimilation and growth in phytoplankton with a brief review of esti mates of growth ra te in the ocean. Canada Bulletin of Fish Aquatic Science 210, 251-263. Falkowski, P., 2000. Rationalizing elemental ratios in unicellular algae. Journal of Phycology 36, 3-6. Finkel, Z.V., Quigg, A., Raven, J.A., Re infelder, J.R., Schofield, O.E., Falkowski, P.G., 2006. Irradiance and the elem ental stoichiometry of marine phytoplankton. Limnology and Oceanography 51(6), 2690-2701. Fleming, R., 1940. The compositi on of plankton and units for reporting populations and productions. Pacific Science Congress of California Procession 6th, 1939, 3, pp. 535-540. Fuhs, G.W., Demmerle, S.D., Canelli, E ., Chen, M., 1972. Characterization of phosphorus-limited algae. In: Nutri ents and eutrophication: The limiting nutrient controversy, pp. 113-133. American Society of Limnology and Oceanography Special Symposia Vol I, Allen Press, Lawrence, Kansas.

PAGE 138

122 Ganeshram, R.S., Pedersen, T.F., Calver t, S.E., Francois, R., 2002. Reduced nitrogen fixation in the glacial oce an inferred from changes in marine nitrogen and phosphorus inventorie s. Nature 415, 156-158. Geider R.J., La Roche, J., 2002. Redfield revisited: vari ability of C:N:P in marine microalgae and its biochemical basis. European Journal of Phycology 37, 117. Glibert P.M., Bronk, D.A., 1994. Release of dissolved organic nitrogen by marine diazotrophic cyanobacteria, Trichodesmium ssp. Applied and Environmental Microbiology 60(11), 3996-4000. Glibert, P.M., Heil, C.A., Hollander, D., Revilla, M., Hoare, A., Alexander, J., Murasko, S., 2004. Evidence for dissolved organic nitrogen and phosphorus uptake during a cyanobacterial bloom in Florida Bay. Marine Ecology Progress Series 280, 73-83. Gobler, J.C., Sanudo-Wilhelmy, S.A., 2003. Cycling of colloidal carbon and nitrogen during an estuarine phytopl ankton bloom. Limnology and Oceanography 48(6), 2314-2320. Goldman, J.C., McCarthy, J.J., Peavey, D.G., 1979. Growth rate influence on the chemical composition of phytopl ankton in oceanic waters. Nature 279(5710), 210-215. Goldman, J.C., 1986. On phytoplankton growth rates and particulate: C:N:P ratios at low light. Limnol ogy and Oceanography 31(6), 1358-1363. Graneli, E., Carlsson, P., Legrand, C., 1999. The role of C, N and P in dissolved and particulate organic matter as a nutri ent source for phytoplankton growth, including toxic species. Aquatic Ecology 33, 17-27. Hall, S.R., Smith, V.H., Lytle, D.A., Lei bold, M.A., 2005. Constraints on primary producer N:P stoichiometry along N:P s upply ratio gradients. Ecology 86(7), 1894-1904. Harris, G.P., 1986. Phytoplankton Ecology: Structure, Function and Fluctuation. Chapman and Hall, New York, NY, pp. 1-386. Harrison, H.G., 1983. Uptake and recycli ng of soluble reactive phosphorus by marine microplankton. Marine Ecology Progress Series 10, 127-135.

PAGE 139

123 Havens, J.A., 2004. A stable isotopic exam ination of particulate organic matter during Karnia Brevis blooms on the C entral West Florida Shelf: Hints at Nitrogen sources in oligotrophic waters Masters Thesis, University of Florida, St. Petersburg. He, R., Weisberg, R.H., 2002. West Flor ida shelf circulation and temperature budget for the 1999 spring transition. C ontinental Shelf Research 22(5), 719-748. He, R., Weisberg, R.H., 2003. A loop curr ent intrusion case study on the West Florida Shelf. Journal of Ph ysical Oceanography 33(2), 465-477. Healy F.P., Hendzel, L.L., 1980. Physiological indicators of nutrient deficiency in lake phytoplankton. Canadian Journal of Fisheries and Aquatic Sciences 37(3), 442-453. Hecky, R.E., Kilham, P., 1988. Nutrient lim itation of phytoplankton in freshwater and marine environments: A review of recent evidence on the effects of enrichment. Limnology and Oceanography 33 (4, part 2), 796-822. Hecky, R.E., Campbell, P., Hendzel, L.L. 1993. The stoichiometry of carbon, nitrogen, and phosphorus in particulate matter of lakes and oceans. Limnology and Oceanography 38(4), 709-724. Heil, C.A., 1985. P hotoadaptation in the r ed tide dinoflagellate Ptychodiscus brevis Masters Thesis, University of South Florida, St. Petersburg. Heil, C.A., Vargo, G.A., Spence, D.N., Neely M.B., Merkt, R., Lester, K.M., Walsh, J.J., 2001. Nutri ent stoichiometry of a Gymnodinium breve bloom: What limits blooms in oligotrophic environments? In: Hallegraeff, G.M., Blavckburn, S.I., Bolch, C.J., Lewis, R.J. (Eds.), Harmful Algal blooms 2000. UNESCO, Paris, pp. 165-168. Heil, C.A., Mullholland, M.R., Bronk, D. A., Bernhardt,P., O’Neil, J.M., 2004. Bacterial and size fractionated primar y production within a large Karenia brevis bloom on the west Florida shelf. In: Steidinger, K.A., Landsberg, J.H., Tomas, C.R., Vargo, G.A (Eds), Harmful Algae 2002. Florida Fish and Wildlife Conservation Commission, Fl orida Institute of Oceanography, and Intergovernmental Oceanographic Co mmission of UNESCO, pp. 38-40. Heil,C.A., Revilla, M., Gliber t, P.M., Murasko, S., 2007. Nutrient quality drives differential phytoplankton community co mposition on the southwest Florida shelf. Limnology and Oc eanography 52(3), 1-12.

PAGE 140

124 Herbland A., Delmas D., Laborde P ., Sautour B., Artigas F., 1998. Phytoplankton spring bloom of the Gi ronde plume waters in the Bay of Biscay: Early phosphorus limitat ion and food-web consequences. Oceanologica Acta 21, 279-291. Hetland, R.D., Hsueh, Y., Leben, R.R., Niile r, P.P., 1999. A loop current-induced jet along the edge of the west Florida shelf 26(15), 2239-2242. Hillebrand, H., Sommer, U. 1999. The nutrient stoichiometry of benthic microalgal growth: Redfield proporti ons are optimal. Limnology and Oceanography 44(2), 440-446. Hobson, L.A., 1967. The seasonal and vertical distribution of suspended particulate matter in an area of the nor thwest Pacific Ocean. Limnology and Oceanography 12(4), 642-649. Hobson, L.A., Menzel, D.W., 1969. The di stribution and chemic al composition of organic particulate matter in the sea and sediments off the east coast of South America. Limnology and Oceanography 14(1), 159-163. Holm-Hansen O., Strickland J.D.H., Williams P.M., 1966. A detailed analysis of biologically important substances in a profile off Southern California. Limnology and and Oceanography 11, 548-561. Hopkins, C.S., Fry, B., Nolin, A. L., 1997. Stoichiometry of dissolved organic matter dynamics on the continental s helf of the northeastern USA. Continental Shelf Research 17(5), 473-489.. Hu, C., Muller-Karger, F.E ., Swarzenski, P.W., 2006. Hurricanes, submarine groundwater discharge, and Florida’s red tides. Geophysical Research Letters 33, L11601. Hudson, J.J., Taylor, W.D., Schindler, D.W., 2000. Phosphate concentration in lakes. Nature 406, 54-56. Hung, J.J., Chen, C.H., Gong, G.C., Sheu, D.D., Shiah, F.K., 2003. Distributions, stoichiometric patterns and cross-shelf exports of dissolved organic matter in the East China Sea. DeepSea Research II 50, 1127-1145. Huppert, A., Blasius, B., Stone, L., 2002. A model of phytoplankton blooms. The American Naturalist 159(2), 156-171. Ingle, R.M., Martin, D.F., 1971. Prediction of the Flor ida Red Tide by means of the iron index. Environment al Letters 1(1), 69-74.

PAGE 141

125 Jackson, G.A., Williams, P.M., 1985. Im portance of dissolved organic nitrogen and phosphorus to biological nutrient cycling. Deep Sea Research 32(2) 223-235. Jarvinen, M., Salonen, K., Sarvala, J ., Vuorio, K., Virtanen, A., 1999. The stoichiometry of particulate nutri ent limitation of phytoplankton. Hydrobiologia 407, 81-88. Johansson, N., Graneli, E., 1998. Toxicity of Chrysochromulina polylepis cells growing in different N:P ratios. In: Reguera, B., Blanco, J., Fernandez, M.L., Wyatt, T. (Eds.), Harmful Algae 1998. Xunta de Galicia and Intergovernmental Oceanographic Co mmision of UNESCO, pp. 329-330. Joint, I., Rees, A.P., Woodward, M.S., 2001. Primary produc tion and nutrient assimilation in the Iberian upwe lling in August 1998. Progress in Oceanography 51, 303-320. Jonge, V.N., 1980. Flucuations in the or ganic carbon to chlorophyll a ratios for estuarine benthic diatom populations. Marine Ecology 2, 345-353. Kahler, P., Koeve, W., 2001. Marine dissolved organic ma tter: Can its C:N ratio explain carbon overconsumption? Deep-Sea Research I 48, 49-62. Karl, D.M., 2000. Phosphorus, the st aff of life. Nature 406, 31-33. Karl, D.M., Bjorkman, K.M., Dore, J.E., Fujieki, L., Hebel, D.V., Houlihan, T., Letelier, R.M., Tupas., 2001. Ec ological nitrogen-to-phosphorus stoichometry at station ALOHA. Deep-Sea Research II 48, 1529-1566. Klausmeier, C.A., Litchman, E., Daufresne, T., Levin, S.A., 2004. Optimal nitrogen-to-phosphorus stoichiometry of phytoplankton. Nature 429, 171174. Klausmeier, C.A., Litchamn, E., Daufresne, T., Levin, S. A., 2008. Phytoplankton stoichiometry. Ecologica l Research 23, 479-485. Kortzinger, A., Koeve, W., K ahler, P., Mintrop. L., 2001. C:N ratios in the mixed layer during the productive season in the northeast Atlantic Ocean. DeepSea Research I 48, 661-688. Krauk, J.M., Villareal, T.A ., Sohm, J.A., Montoya, J. P., Capone, D.G., 2006. Plasticity of N:P ratios in laboratory and field populations of Trichodesmium spp. Aquatic Microbial Ecology 42, 243-253.

PAGE 142

126 Kroeger, K.D., Swarzenski, P. W., Greenwood, W.J. Reich, C., 2006. Submarine groundwater discharge to Tampa Bay: Nu trient fluxes and biogeochemistry of the coastal aquifer. Mari ne Chemistry 104(1-2), 85-97. Krom, M.D., Kress, N., Brenner S., Gordon, L.I., 1991. Phosphorus limitation of primary productivity in the eastern Mediterranean Sea. Limnology and Ocenaography 36(3), 424-432. Laws, E.A., Bannister, T. T., 1980. Nutrientand light-limited growth of Thalassiosira fluviatilis in continuous culture, with implications for phytoplankton growth in the ocean. Limnology and Oceanography 25, 457473. Lenes, J.M., Darrow, B.A., Ca ttrall, C., Heil, C.A., Callahan, M., Vargo, G.A., Byrne, R.H., 2001. Iron fertilization and the Trichodesmium response on the west Florida shelf. Limnology and Oceanography 46(6), 1261-1277. Lenes, J.M., Darrow, B.A., Wa lsh, J.J., Prospero, J.M. He, R., Weisberg, R.H., Vargo, G.,A., Heil, C.A., 2008. S aharan dust and phosphatic fidelity: A three-dimensional bio geochemical model of Trichodesmium as a nutrient source for red tides on the west Flori da shelf. Continental Shelf Research 28, 1091-1115. Lester, K., 2005. Zooplankton of the West Florida Shelf. Relationships with Karenia brevis blooms. Ph.D. Dissertation, Un iversity of South Florida, St. Petersburg. Lester et al., 2008. Zooplankton and Karenia brevis in the Gulf of Mexico. Continental Shelf Research 28, 99-111. Menzel, D.W., Ryther J.H., 1964. The composition of particulate organic matter in the western north Atlantic. Limnology and Oceanography 9(2), 179-186. McCarthy, J.J., 1980. Nit rogen. pp. 191-223. In: Mo rris, I. (Ed.), The Physiological Ecology of Phytoplankton. University of California Press, Berkley. Michaels, A.F., Karl, D.M., Capone, D.G. 2001. Element stoichiometry, new production and nitrogen fixation. Oceanography 14(4), 68-77. Mitchum, G.T., Sturges, W ., 1982. Wind-driven current s on the west Florida shelf. Journal of Physical Oceanography 12, 1310-1317.

PAGE 143

127 Moal, M.L., Biegala, I.C., 2009. Diazotr ophic unicellular cyanobacteria in the northwestern Mediterranean Sea: A seasonal cycle. Limnology and Oceanography 54(3), 845-855. Mongin, M., Nelson, D.M., Pondavan, P., Brzezinski, P.T., 2003. Simulation of upper-ocean biogeochemistry with a fl exible-composition phytoplankton model: C, N and Si cycling in the western Sargasso Sea. Deep Sea Research I 50, 1445-1480. Montoya J.P., et al., 2004. High rates of N2 fixation by unice llular diazotrophs in the oligotrophic Pacific Oc ean. Nature 430, 1027-1031. Mullholland, M.R., Capone, D.G., 2000. The nitrogen physiology of the marine N2 fixing cyanobacteria Trichodesmium spp. Trends in Plant Science 5(4), 148-153. Mullholland, M.R., Capone, D.G., 2001. St oichiometry of nitrogen and carbon utilization in cult ured populations of Trichodesmium IMS101: Implications for growth. Limnology and Oceanography 46(2), 436-443. Mullholland. M.R., Heil, C.A. Bronk, D.A., O’Neil, J. M., Bernhardt, P., 2004. Does nitrogen regener ation from the N2 fixing cyanobacteria Trichodesmium spp. fuel Karenia brevis blooms in the Gulf of Mexi co. In: Steidinger, K.A., Landsberg, J.H., Tomas, C.R., Vargo, G.A. (Eds.), Harmful Algae 2002. Proceedings of the Xth Inte rnational Conference on Harmful Algae. Florida Fish and Wildlife Conservation Co mmission, Florida Institute of Oceanography and Intergovernment al Oceanographic Commission of UNESCO, Paris, pp. 47-49. Nalewajko C., Lean D.R.S., 1980. Phosphor us. In: Morris, I. (Ed.), The Physiological Ecology of Phytoplankton. University of California Press, Berkley, pp. 235-259. Neely, M.B et al., 2004. Florida’s bl ack water event. In: Steidenger, K.A., Landsberg, J.H., Tomas, C.R., Vargo, G.A. (Eds.), Harmful Algea 2002. Florida Fish and Wildlife Conservati on Commission, Florida Institute of Oceanography and Intergovernment al Oceanographic Commission of UNESCO, pp. 377-379. Pahlow, M., 2005. Linking chlorophyll-nutri ent dynamics to the Redfield N:C ratio with a model of optimal phytoplankt on growth. Marine Ecology Progress Series 287, 33-43.

PAGE 144

128 Paerl, H.W., 1997. Coastal eutrophicati on and harmful algal blooms: Importance of atmospheric and groundwater as “new” nitrogen and other nutrient sources. Limnology a nd Oceanography 42(5) 1154-1165. Parsons, T.R., Stephens, K., Strickland, J.D.H., 1961. On the chemical composition of eleven species of mari ne phytoplankters. Journal of the Fisheries Research Board of Canada 18, 1001-1016. Perry, M.J., 1976. Phosphate utilizati on by an oceanic diatom in phosphoruslimited chemostat culture and in the olig otrophic waters of the central North Pacific. Limnology and Oceanography 21(1), 88-107. Poor, N., Pribble, R., Greening, H., 2001. Direct wet and dry deposition of ammonia, nitric acid, ammonium and ni trate to the Tampa Bay estuary, FL, USA. Atmospheric En vironment 35, 3947-3955. Redfield, A.C., 1934. On t he proportions of organic derivitives in sea water and their relation to the composition of plank ton. In: Daniel, R.J. (ed.), James Johnstone Memorial Volume. University Press of Liverpool, pp. 177-192. Redfield, A.C., 1958. The biological control of c hemical factors in the environment. American Sc ientist 46, 205-221. Redfield, A.C., Ketchum, B.H., Richards F.A., 1963. The influence of organisms on the composition of seawater. In: Hill, M.N. (Ed.), The Seas, Ideas and Observations on Progress in the study of the Seas, Vol. 2. Interscience, New York, pp. 26-77. Rees, A.P., Joint, I., Donald, K.M., 1999. Early spring bloom phytoplanktonnutrient dynamics at the Celtic Sea shelf edge. Deep-Sea Research I 46, 483-510. Rhee G-Y., 1974. Phosphate uptak e under nitrate limitation by Scenedesmus Sp and its ecological implications. Journal of Phycology 10, 470-475. Rhee, G.Y., 1978. Effects of N:P atomic ratios and nitrate limitation on algal growth, cell composition, and nitrat e uptake. Limnology and Oceanography 23, 10-25. Rivkin, R., Swift, E., 1980. Characterization of alkaline phosphatase and organic phosphorous utilization in the oceanic dynoflagellates Pyrocystis noctiluca Marine Biology 61, 1-8.

PAGE 145

129 Ruardij, P., Haren, H.V., Ridderink hof, H., 1997. The impact of thermal stratification on phytoplankton and nutrient dynamics in shelf seas: A model study. Journal of Sea Research 38, 311-331. Rubin, S.I., Takahashi, T., Chipman, D.W., Goddard, J .G., 1998. Primary productivity and nutrient utilization ratios in the Pacific sector of the Southern Ocean based on seasonal changes in seawater chemistry. Deep-Sea Research I 45, 1211-1234. Sakshaug, E., Andresen, K., Myklestad, S., Olsen, Y., Nit rient status of phytoplankton communities in Norwegi an waters (marine, brackish, and fresh) as revealed by their chemical composition. Journal of Plankton Research 5(2), 175-196. Sanudo-Wilhelmy, S.A., Kustka, A.B., G obler, C.J., Hutchins, D.A., Yang, M., Lwiza, K., Burns, J., Capone, D.G., Raven, J.A., Carpenter, E.J., 2001. Phosphorus limitation of nitrogen fixati on by Trichodesmium in the central Atlantic Ocean. Nature 411, 66-69. Sanudo-Wilhelmy, S.A., Tovar-Sanches, A., Fu, F., Capone, D.A., Carpenter, E.J., Hutchins, D.A., 2004. The im pact of surface-adsorbed phosphorus on phytoplankton Redfield stoichio metry. Nature 432(7019), 897-901. Shanley, E., 1985. Photoadaptation in the red tide dinoflagellate Ptychodiscus brevis. Masters Thesis, University of South Florida, Saint Petersburg. Sharp, J.H., Perry, M.J., Renger, E.H., E ppley, R.w., 1980. Phytoplankton rate processes in the oligotrophic waters of the central Nort h Pacific Ocean. Journal of Plankton Research 2(4), 335-353. Shuter, B., 1979. A model of physiolog ical adaptation in unicellular algae. Journal of Theoretical Biology 78(4), 519-552. Smith W.O., Marra J., Hiscock M.R., Bar ber R.T., 2000. The seasonal cycle of phytoplankton biomass and primary productivity in the Ross Sea, Antarctica. Deep-Sea Research II 47, 3119-3140. Smith, S.V., 1984. Phosphorus vers us nitrogen limitation in the marine environment. Limnology and Oceanography, 29(6), 1149-1160. Solorzano, L., Sharp, J. H., 1980. Determination of total dissolved phosphorus and particular phosphorus in natural waters. Limnology and Oceanograpphy 25(4), 754-758.

PAGE 146

130 Sommer, U., 1985. Comparison betw een steady state and non-steady state competition: Experiments with natur al phytoplankton. Limnology and Oceanography 30(2), 335-346. Steele, J.H., Baird, I.E., 1961. Relati ons between primary production, chlorophyll and particulate carbon. Lim nology and Oceanography 6(1), 68-78. Stelzer, R.S., Lamberti, G.A., 2001. E ffects of N:P ratio and total nutrient concentraion on stream periphyton co mmunity structure, biomass, and elemental composition. Limnol ogy and Oceanography 46(2), 356-367. Sterner, R.W., Elser j.j., 2002. Ecological Stoichiometry: The Biology of elements from Molecules to Biosphere. Prince ton University Press, pp. 1-439. Sterner, R.W., Anderson, T. Elser, J.J., Hesson, D .O., Hood, J.M., McCauley, E., Urabe, J., 2008. Scale-dependent carbon:nitrogen:phosphorus seston stoichiometry. Limnology and Oceanography 53(3), 1169-1180. Sundareshwar, P.V., Morris, J.T., Koepfler, E.K., Fornwalt, B ., 2003. Phosphorus limitation of coastal ecosystem processes. Science 299, 563-565. Sylvan, J.B., Quigg, A., Tozzi, S., A mmerman, J.W., 2007. Eutrophicationinduced phosphorus limitation in the Mi ssissippi River plume: Evidence from fast repetition rate fluorometry. Limnology and Oceanography 52(6), 26792685. Tanoue, E., Handa, N., 1979. Distribut ion of particulate organic carbon and nitrogen in the Bering Sea and Nort h Pacific Ocean. Journal of Oceanography 35(1), 47-62. Terry K.L., Laws E.A., Burns D.J., 1985. Growth rate variation in the N:P requirement ratio of phytoplankton. Journal of Phycology 21, 323-329. Tett., P., Hydes, D., Sanders, R., 2003. In fluence of nutrient biochemistry on the ecology of northwest European shelf seas In: Black, K.D ., Shimmield, G.B. (Eds.), Biogeochemistry of marine systems, CRC Press, pp. 293-301. Thingstad, T.F., Zweifel, U.L., Rass aulzadegan, F., 1998. P limitation of heterotrophic bacteria and phytoplankton in the northwest Mediterranean. Limnology and Oceanography 43(1), 88-94. Thomas, H., Osterroht, C., Schneider, B ., 1999. Preferential recycling of nutrientsthe ocean’s way to increas e new production and to pass nutrient limitation? Limnology and Oceanography 44(8), 1999-2004.

PAGE 147

131 Turner R.E., 2002. Element ratios and aquatic food webs. Estuaries 25(4B), 694-703. Tyrrell, T., 1999. The relative influences of nitrogen and phosphorus on oceanic primary production. Nature 400(6744), 525-531. Vaillancourt, R. D., Marra, J., Barber R.T., Smith, W.O., 2003. Primary productivity and in situ quantum yields in the Ross Sea and Pacific sector of the Antarctic Circumpolar Current. Deep Sea Research II 50, 559-578. Valiela, I., 1995. Marine Ecological Proc esses. Springer Verlag, New York, pp. 1-686. Van Dolah, F.M., Leighfield, T.A., Kamykow ski, D., Kirkpatrick, G.J., 2008. Cell cycle behavior of laboratory and field po pulations of the Florida red tide dinoflagellate, Karenia brevis. Continental Shelf Research 28, 11-23. Van Mooy, B.A.S., et al., 2006. Sulfol ipids dramatically decrease phosphorus demand by picocyanobacteria in oligotrophic marine environments. Proceedings of the Na tional Academy of Sciences 103, 8607-8612. Van Mooy, B.A.S., et al., 2009. Phytopl ankton in the ocean use non-phosphorus lipids in response to phosphorus scarcity. Nature 458, 69-72. Vargo et al., 2001. The hydrographic regime, nutrient requirements, and transport of a Gymnodinium breve Davis red tide on the west Florida Shelf. In: Hallegraeff, G.M., Bla vckburn, S.I., Bolch, C.J., Lewis, R.J. (Eds.), Harmful Algal blooms 2000. UNE SCO, Paris, pp. 157-160. Vargo, G.A., Heil, G.A., Ault, D., Neely, M.B., Murasko, S., Havens, J., Lester, K.M., Dixon, L.K., Merkt, R., Walsh, J. Weisberg, R., Steidenger, A., 2004. Four Karenia brevis blooms: A comparative analy sis. In: Steidinger, K.A., Landsberg, J.A., Tomas, C.J., Vargo G.A. (Eds.), Harmful Algae 2002. Proceedings of the Xth Inte rnational Conference on Harmful Algae. Florida Fish and Wildlife Conservation Co mmission, Florida Institute of Oceanography and Intergovernment al Oceanographic Commission of UNESCO, Paris, pp. 14-16. Vargo, G.A., Heil, C.A., Fanning, K.A., Dixon L.K., Neely, M.B., Lester, K., Ault, D., Murasko, S., Havens, J., Walsh, J., Be ll, S., 2008. Nutrient availability in support of Karenia brevis blooms on the central We st Florida Shelf: What keeps Karenia blooming? Continental S helf Research 28, 73-98.

PAGE 148

132 Vargo, G.A., 2009. A brief summary of the physiologica l and ecology of Karenia brevis Davis (G. Hansen and Moestrup comb Nov.) red tides on the West Florida Shelf and of hypotheses pos ed for their initiation, growth, maintenance, and termination. Harmful Algae 8, 573-584. Virmani, J.I., Weisberg, R.H., 2003. F eatures of the obs erved annual oceanatmosphere flux variability on the west Florida shelf. Journal of Climate 16(4), 734-745. Vitousek, P.M., Howarth, R. W., 1991. Nitrogen limitatio n on land and in the sea: How can it occur? Biogeochemistry 13, 87-115. Walsh J.J., Steidinger, K.A., 2001. Saharan dust and Florida red tides: The cyanophyte connection. Journal of G eophysical Research 106(C6), 11,59711,612. Walsh, J.J., Steidenger, K.A., 2004. EC OHAB: Florida-A catalyst for recent multi-agency studies of t he west Florida shelf. In: Steidinger, K.A., Landsberg, J.H., Tomas, C.R., Vargo G.A. (Eds.). Harmful Algae 2002. Florida Fish and Wildlife Conservati on Commission, Florida Institute of Oceanography, and Intergovernment al Oceanographic Commission of UNESCO, pp. 543-545. Walsh, J.J., et al., 2006. Red tides in t he Gulf of Mexico: Where, when and why? Journal of Geophysical Research, 111, C11003,doi:10.102 9/2004JC002813. Walsh, J.J., et al., Phytoplankton respons e to intrusions of slope water on the West Florida Shelf: Models and obser vations. Journal of Geophysical Research., 108(C6), 3190, doi :10.1029/2002JC001406, 2003. Wang, P.F., Martin, J., Morrison, G., 1999. Water quality and eutrophication in Tampa Bay, Florida. Estuarine, Coastal and Shelf Science 49, 1-20. Wawrik, B., Paul J.H., 2004. Phytoplankt on community structure and productivity along the axis of the Mississippi River pl ume in oligotrophic Gulf of Mexico waters. Aquatic Microbial Ecology 35, 185-196. Weisberg, R.H., Black, B.D., Yang, H., 1996. Seasonal modulat ion of the west Florida continental shelf circulation. Geophysical Research Letters 23(17), 2247-2250. Weisberg, R.H., Black, B.D., Li, Z., 2000. An upwelling case study on Florida’s west coast. Journal of Geophysical Research 105, 11459-11469.

PAGE 149

133 Weisberg, R.H., He, R., Liu, Y., Virmani, J. 2005. West Flori da shelf circulation on synoptic, seasonal, and inter-annual ti me scales. In: Sturges, W., LugoFernandez, A., (Eds.), New De velopments in the Circula tion of the Gulf of Mexico, Geophysical Monograph Series 161. American Geophysical Union, Washington D.C., pp. 325-347. Weisberg, R.H., Barth, A., Alvera-Azcara te, A., Zheng, L., A coordinated coastal ocean observing and modeling system for the west Florida continental shelf. Harmful Algae (2009), doi: 10.1016/j.hal.2008.11.003. Wu, J., Sunda, W., Boyle, E.A., Karl, D.M., 2000. P hosphate depletion in the western North Atlantic Oc ean. Science 289, 759-762. Yang, H., Weisberg, R.H., 1998. Response of west Florida shelf circulation to climatological wind stress forcing. Journal of Geophysical Research 104(C3), 5301-5320. Zehr, J.P. and Ward, B.B., 2002. Nitrogen cycling in the ocean: New perspectives on processes and paradigm s. Applied an d Environmental Microbiology 68, 1015-1024.

PAGE 150

134 APPENDICES

PAGE 151

135 Appendix A: Particulate Carbon, Nitrogen and Phosphorus Conc entrations and standard devia tion (S.D.) from 1998-2000 Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 6/8/1998 1 27.5417 -82.8000 1 31.490 8.776 2.657 2.369 0.095 0.003 6/8/1998 3 27.4655 -82.9664 1 33.421 3.121 3.131 0.301 0.113 0.024 6/8/1998 5 27.3895 -83.1338 1 36.086 16.944 3.245 0.688 0.064 0.004 6/9/1998 7 27.3135 -83.3010 1 23.101 4.415 1.163 0.374 0.099 0.091 6/9/1998 9 27.2380 -83.4683 1 32.158 6.031 0.425 0.132 0.068 0.004 6/9/1998 10 27.2000 -83.5517 1 22.065 2.481 2.794 1.690 0.095 0.005 6/9/1998 11 26.4715 -84.3920 1 53.620 22.155 2.182 1.319 0.015 0.004 6/9/1998 13 26.5490 -84.2264 1 39.477 8.633 5.284 1.678 0.026 0.015 6/9/1998 17 26.6918 -83.8891 1 35.514 1.408 1.886 0.505 0.018 0.003 6/11/1998 19 26.7694 -83.7239 1 23.202 2.603 2.748 0.272 0.077 0.038 6/11/1998 21 26.8500 -83.5604 1 26.324 13.098 1.286 0.827 0.095 0.048 6/11/1998 23 26.9310 -83.3969 1 31.311 9.866 0.042 0.000 6/11/1998 27 27.0932 -83.0693 1 25.986 1.947 1.056 0.180 0.039 0.004 6/10/1998 29 27.1744 -82.9052 1 25.259 8.225 1.141 0.708 0.053 0.011 6/10/1998 30 27.2151 -82.8231 1 29.480 2.466 1.891 0.167 0.069 0.036 6/10/1998 32 27.2960 -82.6592 1 48.420 0.488 2.365 1.505 0.103 0.017 6/11/1998 40 26.0667 -83.1317 1 35.424 16.372 6.334 4.049 0.031 0.013 6/11/1998 42 26.1296 -82.9594 1 16.149 2.976 1.105 0.191 0.040 0.003 6/11/1998 44 26.1919 -82.7875 1 25.673 1.713 2.968 0.034 0.061 0.013 6/11/1998 46 26.2545 -82.6157 1 14.118 0.822 1.870 1.362 0.066 0.022 6/11/1998 48 26.3169 -82.4435 1 18.757 3.563 1.905 0.352 0.025 0.003 6/11/1998 51 26.4108 -82.1850 1 24.906 6.262 2.490 0.384 0.041 0.001 7/6/1998 1 27.5417 -82.8000 1 41.259 0.095 5.046 0.050 0.123 0.025 7/6/1998 3 27.4655 -82.9664 1 31.436 7.031 3.256 0.331 0.093 0.012 7/6/1998 5 27.3895 -83.1338 1 36.000 2.236 2.600 0.302 0.049 0.005 7/6/1998 7 27.3135 -83.3010 1 62. 190 4.069 0.025 0.083 0.002 7/6/1998 9 27.2380 -83.4683 1 43. 226 9.151 5.085 0.038 0.014 7/6/1998 10 27.2000 -83.5517 1 20.830 6.994 0.671 0.468 0.039 0.005 7/7/1998 11 26.4715 -84.3920 1 16.585 2.564 1.751 0.118 0.025 0.010

PAGE 152

136 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 7/7/1998 17 26.6918 -83.8891 1 24.665 6.478 1.182 0.397 0.021 0.000 7/7/1998 19 26.7694 -83.7239 1 26.435 0.877 2.046 0.665 0.049 0.002 7/7/1998 21 26.8500 -83.5604 1 20.177 8.492 1.748 0.720 0.023 0.002 7/7/1998 23 26.9310 -83.3969 1 27.496 3.821 4.160 2.822 0.024 0.001 7/8/1998 27 27.0932 -83.0693 1 23.687 1.194 0.946 0.791 0.034 0.006 7/8/1998 29 27.1744 -82.9052 1 24. 547 3.657 0.483 0.049 0.010 7/8/1998 30 27.2151 -82.8231 1 32.303 3.735 1.767 0.632 0.261 0.277 7/8/1998 32 27.2960 -82.6592 1 33.550 13.106 1.456 0.179 0.113 0.012 7/8/1998 40 26.0667 -83.1317 1 35. 816 11.119 0.350 0.034 0.004 7/8/1998 42 26.1296 -82.9594 1 33.620 6.167 1.680 0.743 0.057 0.019 7/8/1998 44 26.1919 -82.7875 1 21.676 12.777 5.350 4.055 0.041 0.001 7/8/1998 46 26.2545 -82.6157 1 18.309 9.239 1.345 1.430 0.045 0.011 7/8/1998 48 26.3169 -82.4435 1 10.149 1.804 0.059 0.006 7/8/1998 51 26.4108 -82.1850 1 32.140 9.617 2.389 1.407 0.181 0.015 8/6/1998 1 27.5417 -82.8000 1 32.961 4.730 4.076 0.661 0.164 0.004 8/6/1998 3 27.4655 -82.9664 1 13.700 0.506 1.463 0.302 0.027 0.018 8/6/1998 5 27.3895 -83.1338 1 7.987 0.996 0.554 0.182 0.019 0.001 8/7/1998 7 27.3135 -83.3010 1 17. 678 0.319 1.026 0.189 0.018 8/7/1998 9 27.2380 -83.4683 1 12.930 0.932 1.143 0.229 0.036 0.005 8/7/1998 10 27.2000 -83.5517 1 14.813 5.233 1.086 0.160 0.009 0.005 8/8/1998 11 26.4715 -84.3920 1 11.865 1.434 1.269 0.538 0.013 0.000 8/8/1998 13 26.5490 -84.2264 1 8.749 3.022 3.357 8/6/1998 17 26.6918 -83.8891 1 12.459 0.745 1.145 0.006 0.018 0.004 8/6/1998 19 26.7694 -83.7239 1 7.186 0.852 0.502 0.209 0.024 0.013 8/8/1998 21 26.8500 -83.5604 1 21. 670 16.526 2.373 1.429 0.020 8/8/1998 23 26.9310 -83.3969 1 17.103 5.878 2.760 2.564 0.007 0.004 8/8/1998 27 27.0932 -83.0693 1 14.696 3.777 1.185 0.244 0.036 0.001 8/8/1998 29 27.1744 -82.9052 1 16.044 1.467 0.055 0.003 8/8/1998 30 27.2151 -82.8231 1 13.005 0.427 1.292 0.057 0.042 0.010

PAGE 153

137 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 8/8/1998 30 27.2151 -82.8231 1 13.005 0.427 1.292 0.057 0.042 0.010 8/9/1998 32 27.2960 -82.6592 1 21.160 0.387 2.336 0.183 0.103 0.026 8/9/1998 40 26.0667 -83.1317 1 6.248 0.719 0.944 0.056 0.016 0.018 8/9/1998 42 26.1296 -82.9594 1 7. 522 0.284 0.954 0.215 0.002 8/9/1998 44 26.1919 -82.7875 1 9.827 2.566 0.933 0.078 0.017 0.012 8/9/1998 46 26.2545 -82.6157 1 7.692 0.474 0.964 0.017 0.011 0.013 8/9/1998 48 26.3169 -82.4435 1 7.782 0.363 0.917 0.036 0.016 0.016 8/9/1998 51 26.4108 -82.1850 1 10.717 0.167 1.503 0.115 0.071 0.008 9/9/1998 1 27.5417 -82.8000 1 35.130 0.131 3.661 0.038 0.238 0.006 9/9/1998 3 27.4655 -82.9664 1 31. 751 4.214 4.030 0.081 0.003 9/9/1998 5 27.3895 -83.1338 1 21.952 0.200 1.037 0.183 0.049 0.003 9/9/1998 7 27.3135 -83.3010 1 23.667 1.006 1.511 0.244 0.020 0.020 9/9/1998 9 27.2380 -83.4683 1 20.975 1.352 1.639 0.318 0.037 0.006 9/9/1998 10 27.2000 -83.5517 1 19.799 5.869 3.368 3.783 0.021 0.014 9/10/1998 11 26.4715 -84.3920 1 32.551 12.100 0.928 0.030 0.025 0.003 9/10/1998 13 26.5490 -84.2264 1 15.095 3.207 1.350 0.512 0.025 0.002 9/10/1998 17 26.6918 -83.8891 1 24.835 0.116 1.446 0.437 0.034 0.003 9/10/1998 19 26.7694 -83.7239 1 0.037 0.014 9/10/1998 21 26.8500 -83.5604 1 30.026 4.596 1.207 0.106 0.029 0.010 9/10/1998 23 26.9310 -83.3969 1 29.589 3.191 0.930 0.033 0.033 0.011 9/10/1998 27 27.0932 -83.0693 1 28.766 3.884 1.617 0.280 0.051 0.037 9/10/1998 29 27.1744 -82.9052 1 18.030 1.947 1.241 0.043 0.042 0.001 9/10/1998 30 27.2151 -82.8231 1 25. 830 1.482 1.700 0.004 0.108 9/11/1998 32 27.2960 -82.6592 1 40. 431 3.093 0.072 0.195 0.006 9/11/1998 40 26.0667 -83.1317 1 23.041 0.027 1.007 0.120 0.053 0.001 9/11/1998 42 26.1295 -82.9594 1 16.165 0.012 1.772 0.991 0.063 0.005 9/11/1998 44 26.1919 -82.7875 1 2.385 0.899 0.057 0.001 9/11/1998 46 26.2545 -82.6157 1 18.921 0.674 1.157 0.043 0.048 0.027 9/11/1998 48 26.3169 -82.4435 1 23.231 1.166 1.307 0.231 0.067 0.000

PAGE 154

138 Appendix A (Continued) Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 9/11/1998 51 26.4108 -82.1850 1 46.424 1.030 4.104 0.555 0.252 11/9/1998 1 27.5417 -82.8000 1 17. 869 0.154 1.846 0.265 0.346 11/9/1998 3 27.4655 -82.9664 1 11. 307 0.399 0.988 0.077 0.107 11/9/1998 5 27.3895 -83.1338 1 0.036 11/9/1998 7 27.3135 -83.3010 1 7. 263 0.490 0.475 0.030 0.038 11/10/1998 9 27.2380 -83.4683 1 12.781 6.554 0.712 0.464 0.037 11/10/1998 10 27.2000 -83.5517 1 1.942 0.248 0.159 0.097 0.047 11/10/1998 11 26.4715 -84.3920 1 3.484 0.175 0.382 0.044 0.013 11/10/1998 23 26.9310 -83.3969 1 0.199 11/11/1998 27 27.0932 -83.0693 1 6.999 4.935 0.890 0.414 0.052 11/11/1998 29 27.1744 -82.9052 1 3.348 1.768 0.437 0.188 0.042 11/11/1998 30 27.2151 -82.8231 1 9.738 2.020 0.859 0.164 0.081 11/11/1998 32 27.2960 -82.6592 1 9.623 1.277 1.198 0.021 0.095 11/11/1998 40 26.0667 -83.1317 1 9.463 1.391 1.312 0.111 0.025 11/11/1998 42 26.1295 -82.9594 1 13.580 0.348 1.495 0.093 0.040 11/11/1998 44 26.1919 -82.7875 1 15.208 0.207 1.436 0.232 0.028 11/11/1998 46 26.2545 -82.6157 1 21.457 0.493 1.811 0.039 0.047 11/11/1998 48 26.3169 -82.4435 1 12.631 0.225 0.907 0.059 0.046 11/11/1998 50 26.3795 -82.2707 1 34.251 1.396 2.332 0.074 0.115 11/11/1998 51 26.4108 -82.1850 1 29.514 1.185 2.224 0.137 0.131 12/1/1998 1 27.5417 -82.8000 1 23. 574 3.189 2.360 0.480 0.202 12/1/1998 3 27.4655 -82.9664 1 17. 550 1.755 1.211 0.310 0.064 12/1/1998 5 27.3895 -83.1338 1 12. 408 1.559 0.357 0.278 0.042 12/1/1998 7 27.3135 -83.3010 1 13. 709 1.812 0.728 0.135 0.037 12/1/1998 9 27.2380 -83.4683 1 15. 331 0.302 0.522 0.252 0.024 12/1/1998 10 27.2000 -83.5517 1 12.005 1.886 0.436 0.057 0.029 12/1/1998 11 26.4715 -84.3920 1 15.628 1.442 0.307 0.038 0.015 12/2/1998 13 26.5490 -84.2264 1 12.813 1.170 0.346 0.385 0.017 12/2/1998 17 26.6918 -83.8891 1 12.198 2.974 0.285 0.241 0.018

PAGE 155

139 Appendix A (Continued) Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 12/2/1998 19 26.7694 -83.7239 1 15.189 0.872 0.176 0.156 0.022 0.005 12/2/1998 21 26.8500 -83.5604 1 11.475 0.529 0.641 0.088 0.018 0.002 12/2/1998 23 26.9310 -83.3969 1 13.976 2.609 0.811 0.037 0.015 0.003 12/2/1998 27 27.0932 -83.0693 1 13.048 1.142 1.234 0.008 0.037 0.005 12/2/1998 29 27.1744 -82.9052 1 15.852 0.467 1.239 0.051 0.044 0.002 12/2/1998 30 27.2151 -82.8231 1 32.023 2.385 1.609 0.004 0.057 0.006 12/2/1998 32 27.2960 -82.6592 1 25.733 6.013 1.798 0.326 0.123 0.006 12/3/1998 40 26.0667 -83.1317 1 21.372 1.256 1.485 0.114 0.026 0.001 12/3/1998 42 26.1295 -82.9594 1 20.348 2.454 1.575 0.247 0.055 0.020 12/3/1998 44 26.1919 -82.7875 1 16.374 1.418 1.085 0.094 0.032 0.003 12/3/1998 46 26.2545 -82.6157 1 19.169 1.594 1.317 0.072 0.062 0.008 12/3/1998 48 26.3169 -82.4435 1 22.167 0.933 2.006 0.086 0.087 0.003 12/3/1998 49 26.3481 -82.3574 1 36.847 1.589 6.351 0.091 0.201 0.030 12/3/1998 50 26.3795 -82.2707 1 25. 072 30.260 6.053 0.148 0.009 12/3/1998 51 26.4108 -82.1850 1 37.018 10.197 5.169 1.069 0.111 0.001 1/13/1999 1 27.5417 -82.8000 1 21.766 2.223 0.121 0.009 1/13/1999 3 27.4655 -82.9664 1 21.730 3.356 2.120 0.327 0.045 0.005 1/13/1999 5 27.3895 -83.1338 1 12.129 1.019 1.059 0.038 0.031 0.003 1/13/1999 7 27.3135 -83.3010 1 9.577 0.377 0.799 0.022 0.025 0.021 1/13/1999 9 27.2380 -83.4683 1 16.473 3.649 2.007 2.373 0.014 0.000 1/13/1999 10 27.2000 -83.5517 1 7.610 0.336 0.264 0.044 0.034 0.035 1/13/1999 11 26.4715 -84.3920 1 5. 081 0.420 0.280 0.004 0.004 1/13/1999 13 26.5490 -84.2264 1 5.214 0.912 0.994 0.667 0.007 0.007 1/13/1999 17 26.6918 -83.8891 1 5.504 3.255 0.560 0.154 0.018 0.000 1/13/1999 19 26.7694 -83.7239 1 8.294 4.733 1.061 0.585 0.008 0.002 1/13/1999 21 26.8500 -83.5604 1 19.440 22.396 0.480 0.132 0.014 0.002 1/12/1999 23 26.9310 -83.3969 1 4.071 1.092 0.521 0.358 0.010 0.006 1/12/1999 27 27.0932 -83.0693 1 15.474 1.746 1.530 0.154 0.040 0.010 1/12/1999 29 27.1744 -82.9052 1 8.392 0.183 0.666 0.069 0.023 0.003

PAGE 156

140 Appendix A (Continued) Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 1/12/1999 30 27.2151 -82.8231 1 16.822 11.856 2.000 1.730 0.045 0.004 1/12/1999 32 27.2960 -82.6592 1 16.753 1.219 1.603 0.163 0.078 0.004 1/12/1999 40 26.0667 -83.1317 1 4.389 1.633 0.526 0.035 0.023 0.007 1/12/1999 42 26.1296 -82.9594 1 16.279 6.007 2.178 0.040 0.030 0.002 1/12/1999 44 26.1919 -82.7875 1 12.043 1.568 2.130 0.711 0.038 0.004 1/12/1999 46 26.2545 -82.6157 1 13.183 1.400 1.894 0.345 0.052 0.000 1/11/1999 48 26.3169 -82.4435 1 24.394 10.740 2.630 0.864 0.094 0.008 1/11/1999 51 26.4108 -82.1850 1 29.585 0.509 2.989 0.249 0.220 0.021 1/11/1999 70 26.4870 -82.2260 1 43.447 0.930 4.506 0.082 0.260 0.013 1/11/1999 72 26.6350 -82.2689 1 28.255 2.889 2.035 0.476 0.188 0.056 1/11/1999 74 26.7870 -82.3890 1 32.312 0.826 3.084 1.199 0.151 0.002 1/11/1999 76 26.9380 -82.4680 1 23.012 0.096 2.321 0.084 0.138 0.009 1/11/1999 80 27.2400 -82.6260 1 30.856 1.717 3.290 0.246 0.163 0.061 1/11/1999 82 27.3930 -82.7130 1 31.063 0.960 3.241 0.026 0.209 0.013 2/8/1999 1 27.5417 -82.8000 1 27. 201 0.324 1.268 0.288 0.134 2/8/1999 3 27.4655 -82.9664 1 28. 646 5.805 0.430 0.041 0.008 2/8/1999 5 27.3895 -83.1338 1 15. 511 0.786 0.170 0.036 0.003 2/8/1999 7 27.3135 -83.3010 1 13.358 0.052 0.087 0.015 2/8/1999 9 27.2380 -83.4683 1 18.558 1.008 0.523 0.559 0.024 0.004 2/8/1999 10 27.2000 -83.5517 1 13.357 0.150 0.374 0.196 0.023 0.017 2/8/1999 11 26.4715 -84.3920 1 12.572 1.849 0.500 0.244 0.017 0.001 2/8/1999 13 26.5490 -84.2264 1 15. 881 0.462 0.278 0.025 0.020 2/8/1999 17 26.6918 -83.8891 1 12. 201 2.405 0.565 0.198 0.019 2/8/1999 19 26.7694 -83.7239 1 13.803 0.558 0.377 0.097 0.014 0.002 2/8/1999 21 26.8500 -83.5604 1 13.561 0.600 0.419 0.346 0.009 0.009 2/8/1999 23 26.9310 -83.3969 1 15.304 0.633 0.451 0.083 0.024 0.003 2/8/1999 27 27.0932 -83.0693 1 14.666 0.140 0.749 0.013 0.022 0.004 2/8/1999 29 27.1744 -82.9052 1 15.446 0.039 0.586 0.289 0.047 0.010 2/8/1999 30 27.2151 -82.8231 1 20.321 0.340 2.592 1.188 0.043 0.010

PAGE 157

141 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 2/8/1999 32 27.2960 -82.6592 1 15.241 0.284 2.867 0.444 0.085 0.001 2/8/1999 40 26.0667 -83.1317 1 12.913 1.429 1.596 0.439 0.030 0.012 2/8/1999 42 26.1296 -82.9594 1 15.035 2.116 1.020 0.265 0.035 0.003 2/8/1999 44 26.1919 -82.7875 1 10.592 0.766 1.441 0.130 0.037 0.003 2/8/1999 46 26.2545 -82.6157 1 16.243 0.571 1.652 0.022 0.043 0.008 2/8/1999 48 26.3169 -82.4435 1 17.566 1.023 1.610 0.248 0.045 0.012 2/8/1999 51 26.4108 -82.1850 1 20.664 1.391 2.052 0.826 0.087 0.001 2/8/1999 72 26.6350 -82.2683 1 37.762 0.650 2.708 0.043 0.177 0.005 2/8/1999 76 26.9380 -82.4680 1 28.760 4.338 0.860 0.697 0.064 0.003 2/8/1999 80 27.2400 -82.6260 1 17.707 0.714 1.706 0.681 0.154 0.012 2/8/1999 81 27.3187 -82.6691 1 50.219 7.225 3.772 0.011 0.128 0.016 2/8/1999 82 27.3930 -82.7130 1 53.523 10.057 2.517 1.178 0.214 0.005 2/8/1999 83 27.4679 -82.7559 1 34.363 2.126 5.369 0.955 0.165 0.010 3/1/1999 1 27.5417 -82.8000 1 72.207 7.748 0.511 0.045 3/1/1999 3 27.4655 -82.9664 1 26. 107 0.480 2.596 0.335 0.082 3/1/1999 5 27.3895 -83.1338 1 16.272 1.310 1.237 0.244 0.056 0.011 3/1/1999 7 27.3135 -83.3010 1 15.215 2.341 1.931 0.850 0.047 0.018 3/1/1999 9 27.2380 -83.4683 1 17.713 0.616 5.431 0.629 0.063 0.031 3/1/1999 10 27.2000 -83.5517 1 15.922 1.571 3.913 3.985 0.035 0.001 3/1/1999 11 26.4715 -84.3920 1 15.575 3.888 4.370 4.552 0.019 0.005 3/1/1999 13 26.5490 -84.2264 1 11.572 0.719 1.704 0.317 0.031 0.002 3/1/1999 17 26.6918 -83.8891 1 13.291 1.331 0.676 0.146 0.027 0.008 3/1/1999 19 26.7694 -83.7239 1 14.450 1.063 0.037 0.015 3/1/1999 21 26.8500 -83.5604 1 16.180 2.639 0.698 0.135 0.023 0.002 3/1/1999 23 26.9310 -83.3969 1 18.650 5.218 0.800 0.546 0.022 0.003 3/1/1999 27 27.0932 -83.0693 1 15.233 0.259 1.034 0.087 0.060 0.024 3/1/1999 29 27.1744 -82.9052 1 15.756 1.363 1.274 0.037 0.053 0.004 3/1/1999 30 27.2151 -82.8231 1 15.674 1.843 1.601 0.050 0.057 0.007 3/1/1999 32 27.2960 -82.6592 1 31.349 2.789 2.753 0.288 0.161 0.010

PAGE 158

142 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 3/1/1999 40 26.0667 -83.1317 1 12.355 0.530 1.198 0.039 0.047 0.014 3/1/1999 42 26.1296 -82.9594 1 14.689 2.881 1.247 0.087 0.034 0.003 3/1/1999 44 26.1919 -82.7875 1 13.250 0.915 1.107 0.160 0.036 0.005 3/1/1999 46 26.2545 -82.6157 1 9.182 0.840 1.118 0.187 0.050 0.006 3/1/1999 48 26.3169 -82.4435 1 11.496 1.127 1.233 0.057 0.053 0.003 3/1/1999 51 26.4108 -82.1850 1 27.926 0.309 2.716 0.030 0.192 0.003 3/1/1999 70 26.4870 -82.2260 1 41.846 1.511 4.339 0.663 0.262 0.020 3/1/1999 72 26.6360 -82.3100 1 39.569 0.534 4.241 0.284 0.262 0.020 3/1/1999 74 26.7870 -82.3890 1 36.036 5.819 5.080 1.953 0.149 0.002 3/1/1999 76 26.9380 -82.4680 1 22.838 3.226 3.999 1.885 0.143 0.007 3/1/1999 78 27.0890 -82.5460 1 29.749 0.938 3.452 0.297 0.269 0.016 3/1/1999 80 27.2400 -82.6260 1 41.956 5.430 4.848 0.104 0.420 0.024 3/1/1999 82 27.3930 -82.7130 1 53.831 0.430 5.584 0.152 0.479 0.018 4/5/1999 1 27.5417 -82.8000 1 15.082 2.017 1.719 0.020 0.066 0.008 4/5/1999 3 27.4655 -82.9664 1 10.060 1.604 1.292 0.121 0.044 0.008 4/5/1999 5 27.3895 -83.1338 1 10.538 2.482 0.983 0.192 0.031 0.004 4/5/1999 7 27.3135 -83.3010 1 6.055 0.171 0.708 0.046 0.020 0.001 4/5/1999 9 27.2380 -83.4683 1 12.492 0.842 1.469 0.102 0.048 0.036 4/5/1999 10 27.2000 -83.5517 1 11.572 2.703 3.189 0.375 0.023 0.001 4/6/1999 11 26.4715 -84.3920 1 9.182 0.017 0.465 0.103 0.020 0.008 4/6/1999 13 26.5490 -84.2264 1 9.234 0.295 0.444 0.116 0.016 0.006 4/6/1999 17 26.6918 -83.8891 1 15.977 1.594 1.132 0.023 0.021 0.003 4/6/1999 19 26.7694 -83.7239 1 10.908 1.699 0.606 0.254 0.015 0.004 4/6/1999 21 26.8500 -83.5604 1 18.310 0.662 0.959 0.035 0.016 0.006 4/6/1999 23 26.9310 -83.3969 1 12.040 1.795 0.950 0.500 0.014 0.000 4/6/1999 27 27.0932 -83.0693 1 20.030 2.221 1.412 0.572 0.033 0.004 4/6/1999 29 27.1744 -82.9052 1 22.700 0.634 1.171 0.137 0.039 0.004 4/6/1999 30 27.2151 -82.8231 1 19.783 4.837 1.237 0.107 0.041 0.001 4/6/1999 32 27.2960 -82.6592 1 19.181 0.597 1.616 0.063 0.074 0.002

PAGE 159

143 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 4/7/1999 40 26.0667 -83.1317 1 11.812 0.183 0.883 0.056 0.018 0.003 4/7/1999 42 26.1296 -82.9594 1 21.723 2.127 2.189 1.027 0.030 0.001 4/7/1999 44 26.1919 -82.7875 1 30.274 1.940 0.037 0.006 4/7/1999 46 26.2545 -82.6157 1 22.384 1.335 0.038 0.005 4/7/1999 48 26.3169 -82.4435 1 11.037 1.192 0.036 0.018 4/7/1999 51 26.4108 -82.1850 1 26.147 0.439 1.988 0.072 0.091 0.004 4/7/1999 70 26.4870 -82.2260 1 41.266 2.106 0.098 0.006 4/7/1999 72 26.6360 -82.3100 1 23.301 2.219 5.337 4.709 0.094 0.000 4/7/1999 74 26.7870 -82.3890 1 22.622 4.074 1.577 0.842 0.063 0.001 4/7/1999 76 26.9380 -82.4680 1 25.152 0.792 2.120 0.090 0.048 0.003 4/7/1999 78 27.0890 -82.5460 1 23.304 2.389 3.011 1.762 0.062 0.011 4/8/1999 80 27.2400 -82.6260 1 27.666 10.124 4.079 2.383 0.053 0.004 4/8/1999 82 27.3930 -82.7130 1 27.703 12.104 8.303 8.041 0.080 0.007 5/2/1999 1 27.5417 -82.8000 1 30.040 3.629 2.980 0.126 0.193 0.004 5/2/1999 3 27.4655 -82.9664 1 20.351 3.517 12.517 0.344 0.081 0.013 5/2/1999 5 27.3895 -83.1338 1 10.162 2.638 6.166 2.003 0.042 0.000 5/2/1999 7 27.3135 -83.3010 1 15.114 0.799 4.052 1.372 0.040 0.002 5/2/1999 9 27.2380 -83.4683 1 12.410 1.726 2.216 0.624 0.028 0.002 5/2/1999 10 27.2000 -83.5517 1 10.157 4.977 2.933 0.769 0.024 0.001 5/3/1999 11 26.4715 -84.3920 1 10.522 0.814 1.899 1.134 0.018 0.002 5/3/1999 13 26.5490 -84.2264 1 9.425 4.225 2.933 1.662 0.018 0.005 5/3/1999 17 26.6918 -83.8891 1 5.868 1.248 0.017 0.001 5/3/1999 19 26.7694 -83.7239 1 5.632 0.362 2.057 1.045 0.018 0.001 5/3/1999 21 26.8500 -83.5604 1 6.224 1.714 2.679 1.765 0.020 0.001 5/3/1999 23 26.9310 -83.3969 1 6.748 1.027 2.501 0.450 0.021 0.001 5/3/1999 27 27.0932 -83.0693 1 9.142 1.291 4.289 0.789 0.038 0.002 5/3/1999 29 27.1744 -82.9052 1 14.812 0.842 2.585 0.544 0.059 0.002 5/3/1999 30 27.2151 -82.8231 1 21.095 0.520 11.683 11.400 0.066 0.008 5/4/1999 32 27.2960 -82.6592 1 12.898 0.792 1.800 0.946 0.172 0.020

PAGE 160

144 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 5/4/1999 40 26.0667 -83.1317 1 10.863 1.021 2.881 1.218 0.023 0.001 5/4/1999 42 26.1296 -82.9594 1 6.616 0.117 1.656 0.345 0.034 0.001 5/4/1999 44 26.1919 -82.7875 1 11.827 0.511 2.802 0.301 0.034 0.000 5/4/1999 46 26.2545 -82.6157 1 14.391 4.189 3.509 1.549 0.039 0.005 5/4/1999 48 26.3169 -82.4435 1 11.881 2.189 5.287 1.736 0.115 0.076 5/4/1999 50 26.3795 -82.2707 1 17.609 2.059 5.426 1.381 0.083 0.016 5/4/1999 51 26.4108 -82.1850 1 32.280 3.569 5.625 1.457 0.191 0.001 5/4/1999 70 26.4870 -82.2260 1 24.433 0.374 5.458 2.470 0.149 0.005 5/5/1999 72 26.6360 -82.3100 1 24.698 1.853 6.660 2.320 0.142 0.000 5/5/1999 74 26.7870 -82.3890 1 27.445 1.881 7.220 3.876 0.089 0.021 5/5/1999 76 26.9380 -82.4680 1 19.581 1.767 5.356 2.959 0.060 0.007 5/5/1999 78 27.0890 -82.5460 1 14.057 0.297 2.117 0.102 0.067 0.011 5/5/1999 80 27.2400 -82.6260 1 23.088 1.779 2.496 0.559 0.096 0.023 5/5/1999 82 27.3930 -82.7130 1 23.088 0.290 3.581 0.049 6/5/1999 1 27.5417 -82.8000 1 25.918 0.457 2.976 0.170 0.094 0.008 6/5/1999 3 27.4655 -82.9664 1 21.875 11.210 4.301 0.669 0.120 0.000 6/5/1999 5 27.3895 -83.1338 1 15.188 0.356 1.985 0.785 0.043 0.011 6/5/1999 7 27.3135 -83.3010 1 23.177 3.289 0.023 6/5/1999 9 27.2380 -83.4683 1 11. 775 1.219 1.299 0.245 0.032 6/6/1999 10 27.2000 -83.5517 1 8.252 1.800 0.908 0.050 0.030 0.003 6/6/1999 11 26.4715 -84.3920 1 11. 108 0.771 1.001 0.023 0.038 6/6/1999 13 26.5490 -84.2264 1 10.878 2.050 1.329 0.149 0.026 0.000 6/6/1999 17 26.6918 -83.8891 1 21.177 1.332 2.566 0.210 0.082 0.012 6/6/1999 19 26.7694 -83.7239 1 29.999 2.929 2.847 1.905 0.073 0.002 6/6/1999 21 26.8500 -83.5604 1 11.422 2.251 1.069 0.039 0.029 0.005 6/6/1999 23 26.9310 -83.3969 1 16.056 0.333 3.896 0.621 0.034 0.001 6/7/1999 27 27.0932 -83.0693 1 31.782 2.823 3.591 0.426 0.085 0.000 6/7/1999 29 27.1744 -82.9052 1 19.818 6.617 2.543 0.462 0.084 0.008 6/7/1999 30 27.2151 -82.8231 1 23.070 2.030 2.936 0.295 0.079 0.000

PAGE 161

145 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 6/7/1999 32 27.2960 -82.6592 1 35.586 6.039 4.351 0.213 0.162 0.022 6/7/1999 40 26.0667 -83.1317 1 30.769 2.244 3.504 1.242 0.077 0.007 6/7/1999 42 26.1296 -82.9594 1 24.732 1.694 2.887 0.788 0.051 0.003 6/7/1999 44 26.1919 -82.7875 1 17.513 2.370 0.103 0.011 6/7/1999 46 26.2545 -82.6157 1 21.488 0.835 3.046 0.704 0.137 0.023 6/8/1999 48 26.3169 -82.4435 1 9.456 6.025 2.018 0.901 0.136 0.012 6/8/1999 50 26.3795 -82.2707 1 21.687 4.823 2.669 0.000 0.250 0.016 6/8/1999 51 26.4108 -82.1850 1 26.147 4.227 3.680 1.251 0.186 0.013 6/8/1999 70 26.4870 -82.2260 1 42.961 6.509 5.261 0.642 0.168 0.022 6/8/1999 72 26.6360 -82.3100 1 41.235 3.520 3.794 0.032 0.255 0.015 6/8/1999 74 26.7870 -82.3890 1 23.742 0.234 3.652 0.700 0.163 0.010 6/8/1999 76 26.9380 -82.4680 1 35.007 0.044 4.443 0.571 0.134 0.010 6/8/1999 78 27.0890 -82.5460 1 30.869 0.117 4.392 0.162 0.172 0.013 6/8/1999 80 27.2400 -82.6260 1 36.441 2.746 5.896 0.561 0.130 0.015 6/8/1999 82 27.3930 -82.7130 1 35.395 0.622 5.415 0.435 0.180 0.009 7/5/1999 1 27.5417 -82.8000 1 32.390 7.580 5.958 3.514 0.192 0.006 7/5/1999 3 27.4655 -82.9664 1 90.277 18.774 8.227 3.023 0.091 0.001 7/5/1999 5 27.3895 -83.1338 1 52. 826 19.567 3.715 2.471 0.074 7/5/1999 7 27.3135 -83.3010 1 47.341 1.373 0.044 0.002 7/5/1999 9 27.2380 -83.4683 1 53.178 1.215 0.038 0.003 7/5/1999 10 27.2000 -83.5517 1 71.225 1.194 1.184 0.592 0.026 0.004 7/6/1999 11 26.4715 -84.3920 1 18. 238 1.006 2.066 0.396 0.055 7/6/1999 13 26.5490 -84.2264 1 12.457 0.275 1.503 0.044 0.017 0.003 7/6/1999 17 26.6918 -83.8891 1 55.181 0.582 0.026 0.003 7/6/1999 19 26.7694 -83.7239 1 36.263 15.579 1.323 0.368 0.017 0.002 7/6/1999 21 26.8500 -83.5604 1 61.407 1.054 0.019 0.002 7/6/1999 23 26.9310 -83.3969 1 51.355 6.360 0.749 0.384 0.016 0.002 7/6/1999 27 27.0932 -83.0693 1 24.238 3.988 3.307 1.235 0.021 0.000 7/6/1999 29 27.1744 -82.9052 1 17.324 0.832 2.242 0.035 0.066 0.013

PAGE 162

146 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 7/7/1999 30 27.2151 -82.8231 1 34.928 5.371 3.918 0.924 0.086 0.016 7/7/1999 32 27.2960 -82.6592 1 19.358 5.091 4.210 1.147 0.063 0.008 7/7/1999 36 26.6767 -82.8750 1 12.865 0.672 1.145 0.007 0.021 0.001 7/7/1999 40 26.0667 -83.1317 1 71.421 1.078 0.023 0.001 7/7/1999 42 26.1296 -82.9594 1 66.695 8.322 3.591 1.150 0.020 0.005 7/7/1999 44 26.1919 -82.7875 1 62.784 26.805 3.893 3.132 0.023 0.001 7/7/1999 46 26.2545 -82.6157 1 42.614 16.208 2.017 0.405 0.027 0.000 7/7/1999 51 26.4108 -82.1850 1 96.826 13.738 6.002 1.645 0.168 0.017 7/7/1999 70 26.4870 -82.2260 1 114.39 0 42.998 11.848 6.112 0.170 0.009 7/7/1999 72 26.6360 -82.3100 1 98.836 11.440 12.810 1.307 0.286 0.026 7/8/1999 74 26.7870 -82.3890 1 50.788 6.324 8.295 3.705 0.196 0.009 7/8/1999 76 26.9380 -82.4680 1 56.348 8.565 8.430 5.861 0.152 0.025 7/8/1999 78 27.0890 -82.5460 1 51.949 26.421 5.481 2.993 0.170 0.048 7/8/1999 80 27.2400 -82.6260 1 24.103 4.092 3.416 0.721 0.117 0.012 7/8/1999 82 27.3930 -82.7130 1 23.041 2.358 2.986 0.240 0.094 0.000 8/6/1999 1 27.5417 -82.8000 1 94.105 90.057 18.564 14.251 0.379 0.009 8/6/1999 3 27.4655 -82.9664 1 34.460 8.252 3.019 0.145 0.117 0.002 8/7/1999 5 27.3895 -83.1338 1 32.628 1.189 2.450 0.220 0.051 0.003 8/7/1999 7 27.3135 -83.3010 1 34.077 2.090 1.204 0.135 0.029 0.002 8/7/1999 9 27.2380 -83.4683 1 20.771 3.778 2.068 0.617 0.025 0.002 8/8/1999 10 27.2000 -83.5517 1 25.309 10.686 2.218 0.812 0.019 0.003 8/8/1999 11 26.4715 -84.3920 1 18.343 0.393 1.887 0.039 0.029 0.006 8/8/1999 13 26.5490 -84.2264 1 25. 253 3.423 1.639 0.096 0.032 8/8/1999 17 26.6918 -83.8891 1 45.213 16.936 1.577 0.369 0.020 0.000 8/8/1999 19 26.7694 -83.7239 1 14.686 2.888 1.219 0.016 0.035 0.006 8/8/1999 21 26.8500 -83.5604 1 15.667 0.288 1.250 0.059 0.019 0.002 8/8/1999 23 26.9310 -83.3969 1 38.961 5.922 1.113 0.061 0.024 0.003 8/8/1999 27 27.0932 -83.0693 1 16.359 3.080 1.271 0.219 0.036 0.004 8/9/1999 29 27.1744 -82.9052 1 21.651 8.049 2.004 0.821 0.086 0.007

PAGE 163

147 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 8/9/1999 30 27.2151 -82.8231 1 40.276 25.194 2.874 0.089 0.110 0.023 8/9/1999 32 27.2960 -82.6592 1 62.357 12.396 8.485 2.722 0.106 0.017 8/9/1999 40 26.0667 -83.1317 1 55.670 44.560 0.683 0.238 0.033 0.022 8/9/1999 42 26.1296 -82.9594 1 15.978 0.776 2.297 0.181 0.034 0.014 8/9/1999 44 26.1919 -82.7875 1 17.111 5.645 2.131 1.053 0.026 0.005 8/9/1999 46 26.2545 -82.6157 1 93.691 28.732 2.502 1.470 0.065 0.003 8/9/1999 48 26.3169 -82.4435 1 28.750 12.503 3.352 1.222 0.084 0.009 8/9/1999 51 26.4108 -82.1850 1 69.294 12.797 0.260 0.013 8/9/1999 70 26.4870 -82.2260 1 83.903 56.118 56.202 24.856 0.231 0.013 8/9/1999 72 26.6360 -82.3100 1 44.315 5.610 144.787 2.507 0.203 0.014 8/9/1999 74 26.7870 -82.3890 1 40.339 2.815 10.381 4.925 0.115 0.025 8/10/1999 76 26.9380 -82.4680 1 37.237 3.049 5.187 1.309 0.110 0.009 8/10/1999 78 27.0890 -82.5460 1 23.422 1.390 9.057 10.172 0.096 0.013 8/10/1999 80 27.2400 -82.6260 1 41.709 4.541 4.994 0.631 0.090 0.006 8/10/1999 82 27.3930 -82.7130 1 30.604 3.760 3.853 0.234 0.137 0.009 9/7/1999 1 27.5417 -82.8000 1 3.313 0.214 34.482 18.926 0.159 0.030 9/7/1999 3 27.4655 -82.9664 1 1.471 0.589 3.795 1.812 0.097 0.017 9/7/1999 5 27.3895 -83.1338 1 1.160 0.130 3.359 0.577 0.026 0.000 9/7/1999 7 27.3135 -83.3010 1 1.706 0.245 5.983 1.340 0.046 0.015 9/7/1999 9 27.2380 -83.4683 1 1.694 0.224 5.224 1.544 0.020 0.000 9/7/1999 10 27.2000 -83.5517 1 7.526 8.749 2.218 0.537 0.030 0.003 9/8/1999 11 26.4715 -84.3920 1 9.036 3.278 4.584 2.204 0.023 0.001 9/8/1999 13 26.5490 -84.2264 1 11.778 3.015 2.394 0.010 0.022 0.001 9/8/1999 17 26.6918 -83.8891 1 16.221 4.949 18.344 3.688 0.037 0.020 9/8/1999 19 26.7694 -83.7239 1 10.382 0.757 17.769 0.087 0.023 0.008 9/8/1999 21 26.8500 -83.5604 1 16.554 5.730 28.100 16.846 0.019 0.001 9/8/1999 23 26.9310 -83.3969 1 13.927 4.510 23.059 13.312 0.088 0.089 9/8/1999 27 27.0932 -83.0693 1 14.832 2.196 22.190 1.827 0.048 0.007 9/8/1999 29 27.1744 -82.9052 1 30.288 6.780 35.991 7.349 0.061 0.002

PAGE 164

148 Appendix A (Continued) Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 9/8/1999 30 27.2151 -82.8231 1 26.499 10.748 9.201 0.593 0.093 0.011 9/8/1999 32 27.2960 -82.6592 1 25.995 6.287 9.780 0.688 0.181 0.040 9/9/1999 40 26.0667 -83.1317 1 15.793 4.557 2.338 0.839 0.020 0.001 9/9/1999 44 26.1919 -82.7875 1 13.803 0.878 4.015 1.869 0.060 0.004 9/9/1999 48 26.3169 -82.4435 1 21.485 0.635 5.087 1.697 0.068 0.037 9/9/1999 51 26.4108 -82.1850 1 30.481 6.085 9.052 1.657 0.125 0.008 9/9/1999 70 26.4870 -82.2260 1 31.603 11.653 8.598 1.474 0.048 0.033 9/10/1999 72 26.6360 -82.3100 1 57.885 11.527 12.024 0.547 0.167 0.008 9/10/1999 74 26.7870 -82.3890 1 24.306 6.015 21.094 16.485 0.092 0.082 9/10/1999 76 26.9380 -82.4680 1 30.272 5.762 33.964 4.614 0.147 0.006 9/10/1999 78 27.0890 -82.5460 1 21. 834 1.296 44.808 17.268 0.244 9/10/1999 80 27.2400 -82.6260 1 18.922 6.607 42.875 27.100 0.115 0.022 9/10/1999 82 27.3930 -82.7130 1 27.646 0.045 104.183 59.620 0.159 0.006 10/7/1999 1 27.5417 -82.8000 1 61.945 1.608 11.327 0.386 0.460 0.015 10/7/1999 3 27.4655 -82.9664 1 13.583 0.084 4.863 0.369 0.126 0.032 10/7/1999 5 27.3895 -83.1338 1 7.695 1.047 3.265 0.676 0.045 0.003 10/7/1999 7 27.3135 -83.3010 1 8.221 2.751 1.989 0.671 0.045 0.020 10/7/1999 9 27.2380 -83.4683 1 6.066 1.675 2.988 2.026 0.045 0.032 10/7/1999 10 27.2000 -83.5517 1 2. 415 1.247 1.586 0.843 0.028 10/7/1999 19 26.7694 -83.7239 1 31.531 2.820 0.600 0.011 10/7/1999 21 26.8500 -83.5604 1 47.936 0.090 5.066 0.092 0.601 0.032 10/7/1999 23 26.9310 -83.3969 1 8.574 2.500 3.175 1.293 0.025 0.004 10/7/1999 27 27.0932 -83.0693 1 12.156 5.336 2.727 0.496 0.047 0.004 10/7/1999 29 27.1744 -82.9052 1 15.223 3.543 2.486 0.370 0.100 0.005 10/7/1999 30 27.2151 -82.8231 1 24.856 6.525 3.529 0.574 0.089 0.009 10/5/1999 32 27.2960 -82.6592 1 7.678 0.045 7.997 0.292 0.293 0.015 10/7/1999 35 26.8333 -82.8167 1 22.089 0.007 4.284 0.758 0.200 0.026 10/6/1999 37 26.5233 -82.9433 1 24.746 1.152 4.091 0.580 0.215 0.002 10/6/1999 39 26.2083 -83.0733 1 32.626 1.647 5.441 0.616 0.232 0.178

PAGE 165

149 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 10/6/1999 40 26.0667 -83.1317 1 31.144 4.058 4.068 0.185 0.087 0.000 10/6/1999 42 26.1296 -82.9594 1 41.799 7.863 7.087 2.047 0.216 0.016 10/6/1999 48 26.3169 -82.4435 1 18.122 0.513 3.970 0.574 0.098 0.017 10/6/1999 51 26.4108 -82.1850 1 0.097 0.012 10/5/1999 70 26.4870 -82.2260 1 24.104 0.644 4.391 0.689 0.143 0.004 10/5/1999 72 26.6360 -82.3100 1 32.120 2.999 6.196 0.193 0.178 0.007 10/5/1999 74 26.7870 -82.3890 1 6.793 0.224 16.111 2.975 0.283 0.006 10/5/1999 76 26.9380 -82.4680 1 13.736 0.116 19.384 0.271 0.452 0.013 10/5/1999 78 27.0890 -82.5460 1 11.311 0.124 15.394 0.340 0.389 0.030 10/5/1999 80 27.2400 -82.6260 1 16.902 0.531 22.143 3.047 0.519 0.007 10/5/1999 82 27.3930 -82.7130 1 2. 512 0.584 28.446 14.907 0.165 11/6/1999 1 27.5417 -82.8000 1 48.840 7.683 8.281 1.474 0.255 0.007 11/6/1999 3 27.4655 -82.9664 1 33.964 4.134 5.923 1.729 0.071 0.002 11/6/1999 5 27.3895 -83.1338 1 34.431 4.081 4.852 0.806 0.070 0.007 11/6/1999 7 27.3135 -83.3010 1 20.014 1.202 2.823 0.751 0.049 0.014 11/7/1999 27 27.0932 -83.0693 1 17.958 1.102 2.437 0.583 0.046 0.001 11/7/1999 29 27.1744 -82.9052 1 16.891 1.865 2.639 0.345 0.067 0.012 11/7/1999 30 27.2151 -82.8231 1 26. 201 1.044 3.881 1.663 0.121 11/7/1999 32 27.2960 -82.6592 1 25.735 0.086 6.023 1.993 0.171 0.011 11/8/1999 40 26.0667 -83.1317 1 12.468 1.940 1.747 0.290 0.058 0.002 11/7/1999 44 26.1919 -82.7875 1 12. 387 0.562 2.024 0.113 0.056 11/7/1999 46 26.2545 -82.6157 1 12.908 0.517 1.802 0.230 11/7/1999 48 26.3169 -82.4435 1 22.043 4.501 2.453 0.025 0.098 0.009 11/7/1999 50 26.3795 -82.2707 1 25.355 4.971 3.310 0.252 11/7/1999 51 26.4108 -82.1850 1 29.779 0.744 4.527 0.326 0.269 0.007 12/7/1999 1 27.5417 -82.8000 1 65. 812 9.399 11.287 4.420 0.435 12/7/1999 3 27.4655 -82.9664 1 28.780 7.576 3.262 0.616 0.063 0.003 12/7/1999 5 27.3895 -83.1338 1 24.579 6.154 1.671 0.703 0.033 0.000 12/7/1999 7 27.3135 -83.3010 1 28.708 2.836 2.327 0.078 0.045 0.001

PAGE 166

150 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 12/7/1999 9 27.2380 -83.4683 1 19.463 0.114 3.828 2.301 0.039 0.002 12/7/1999 10 27.2000 -83.5517 1 10.784 1.021 3.754 1.788 0.049 0.014 12/8/1999 11 26.4715 -84.3920 1 10.846 0.557 1.428 0.545 0.017 0.001 12/8/1999 13 26.5490 -84.2264 1 6.860 0.465 4.546 0.395 0.021 0.004 12/8/1999 17 26.6918 -83.8891 1 37.302 11.185 1.092 0.346 0.051 0.018 12/8/1999 19 26.7694 -83.7239 1 20.390 3.848 1.947 1.296 0.029 0.005 12/8/1999 21 26.8500 -83.5604 1 21.311 3.824 1.629 0.503 0.045 0.002 12/8/1999 23 26.9310 -83.3969 1 20.189 0.151 4.387 2.800 0.047 0.002 12/8/1999 27 27.0932 -83.0693 1 39.671 5.721 10.703 4.251 0.028 0.002 12/9/1999 29 27.1744 -82.9052 1 13.989 0.788 3.014 0.391 0.055 0.001 12/9/1999 30 27.2151 -82.8231 1 14.412 0.381 3.940 0.631 0.056 0.000 12/9/1999 32 27.2960 -82.6592 1 27.626 1.359 10.173 4.103 0.126 0.020 12/9/1999 40 26.0667 -83.1317 1 12.646 2.706 3.082 0.008 0.042 0.004 12/9/1999 44 26.1919 -82.7875 1 24.164 0.505 3.020 0.062 0.071 0.002 12/9/1999 48 26.3169 -82.4435 1 16.820 1.153 4.144 0.418 0.086 0.002 12/9/1999 50 26.3795 -82.2707 1 20.916 1.572 6.598 1.158 12/9/1999 51 26.4108 -82.1850 1 22.642 0.503 5.451 0.704 0.126 0.011 12/8/1999 70 26.4870 -82.2260 1 29.732 0.361 4.232 1.143 12/8/1999 72 26.6360 -82.3100 1 36.329 5.989 4.970 0.011 12/8/1999 74 26.7870 -82.3890 1 36.856 3.927 6.872 0.654 12/8/1999 76 26.9380 -82.4680 1 27.947 0.954 4.243 0.501 12/8/1999 78 27.0890 -82.5460 1 34.750 9.251 5.082 1.522 12/8/1999 80 27.2400 -82.6260 1 27.127 6.034 5.896 1.993 12/8/1999 82 27.3930 -82.7130 1 38.548 16.329 4.853 0.596 12/9/1999 88 26.4625 -83.2782 1 17.981 5.536 3.421 2.710 0.034 0.001 12/9/1999 90 26.6208 -83.3368 1 10.982 2.518 4.204 1.770 12/10/1999 92 26.7791 -83.3953 1 0.029 0.004 12/10/1999 96 27.0956 -83.5130 1 11. 229 1.406 2.960 2.145 0.031 0.003 1/11/2000 1 27.5417 -82.8000 1 128.6 98 12.890 43.150 15.723 0.245 0.012

PAGE 167

151 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 1/11/2000 3 27.4655 -82.9664 1 55.319 31.348 9.089 9.177 0.040 0.001 1/11/2000 5 27.3895 -83.1338 1 83.628 38.412 6.342 2.347 0.025 0.001 1/11/2000 7 27.3135 -83.3010 1 54. 467 21.409 1.527 0.324 0.024 1/11/2000 9 27.2380 -83.4683 1 0.027 0.004 1/11/2000 10 27.2000 -83.5517 1 19.082 0.544 2.782 0.768 0.036 0.003 1/12/2000 11 26.4715 -84.3920 1 14.841 4.287 2.194 0.886 0.023 0.002 1/12/2000 13 26.5490 -84.2264 1 18.578 1.843 2.853 1.509 0.019 0.005 1/12/2000 17 26.6918 -83.8891 1 76.843 4.197 0.015 0.006 1/12/2000 19 26.7694 -83.7239 1 88.702 2.562 3.804 2.280 0.024 0.001 1/12/2000 21 26.8500 -83.5604 1 74.438 6.041 4.171 1.473 0.031 0.002 1/12/2000 23 26.9310 -83.3969 1 44.218 23.505 2.645 0.609 0.014 0.004 1/12/2000 27 27.0932 -83.0693 1 15.083 3.334 3.524 0.649 0.033 0.005 1/12/2000 29 27.1744 -82.9052 1 24.441 4.302 2.218 0.540 0.033 0.006 1/12/2000 30 27.2151 -82.8231 1 72.796 11.152 5.560 2.676 0.053 0.004 1/13/2000 32 27.2960 -82.6592 1 92.794 3.005 0.063 0.050 1/13/2000 40 26.0667 -83.1317 1 60.897 54.207 2.100 1.183 0.038 0.004 1/13/2000 44 26.1919 -82.7875 1 50.146 37.632 2.809 2.006 0.042 0.002 1/13/2000 48 26.3169 -82.4435 1 31.981 14.833 4.797 2.853 0.063 0.002 1/13/2000 51 26.4108 -82.1850 1 47. 216 4.930 5.310 1.264 0.044 1/13/2000 88 26.4625 -83.2782 1 7.625 4.006 1.148 0.438 0.028 0.003 1/13/2000 92 26.7791 -83.3953 1 4.780 2.332 0.061 0.052 1/13/2000 96 27.0956 -83.5130 1 53.083 7.421 54.981 8.686 0.023 0.002 3/1/2000 1 27.5417 -82.8000 1 67.110 2.369 13.718 11.953 0.155 0.006 3/1/2000 3 27.4655 -82.9664 1 15.548 4.926 1.085 0.665 0.048 0.001 3/1/2000 5 27.3895 -83.1338 1 30.655 7.962 7.959 8.757 0.039 0.001 3/1/2000 7 27.3135 -83.3010 1 13.182 1.777 1.418 0.456 0.035 0.000 3/1/2000 9 27.2380 -83.4683 1 19.190 8.147 2.484 1.465 0.035 0.002 3/1/2000 10 27.2000 -83.5517 1 27.178 2.275 3.499 0.645 0.029 0.001 3/2/2000 11 26.4715 -84.3920 1 17.317 6.955 1.413 0.960 0.020 0.006

PAGE 168

152 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 3/2/2000 13 26.5490 -84.2264 1 10.449 1.361 0.789 0.074 0.020 0.003 3/2/2000 17 26.6918 -83.8891 1 10.146 2.674 0.888 0.148 0.026 0.003 3/2/2000 19 26.7694 -83.7239 1 23.030 2.448 1.666 0.502 0.029 0.004 3/2/2000 21 26.8500 -83.5604 1 32.313 34.746 0.924 0.546 0.023 0.001 3/2/2000 23 26.9310 -83.3969 1 11.063 1.900 0.919 0.320 0.028 0.003 3/2/2000 27 27.0932 -83.0693 1 21.003 0.904 1.822 0.359 0.039 0.006 3/3/2000 29 27.1744 -82.9052 1 16.791 3.751 1.271 0.065 0.034 0.000 3/3/2000 30 27.2151 -82.8231 1 17.087 8.240 2.645 1.069 0.044 0.009 3/3/2000 32 27.2960 -82.6592 1 16.942 9.983 2.906 0.568 0.063 0.002 3/3/2000 40 26.0667 -83.1317 1 8.266 2.909 0.833 0.091 0.038 0.010 3/3/2000 44 26.1919 -82.7875 1 15. 147 0.951 2.209 0.490 0.045 3/3/2000 48 26.3169 -82.4435 1 77.234 11.239 2.184 0.072 0.056 0.001 3/3/2000 51 26.4108 -82.1850 1 24.320 0.729 2.326 0.928 0.110 0.013 3/3/2000 88 26.4625 -83.2782 1 29.455 10.759 0.739 0.103 0.023 0.002 3/4/2000 92 26.7791 -83.3953 1 24.800 9.913 1.743 0.002 0.048 0.001 3/4/2000 96 27.0956 -83.5130 1 11.915 0.379 1.163 0.282 0.029 0.001 4/4/2000 1 27.5417 -82.8000 1 55.867 10.806 39.527 14.066 0.220 0.007 4/7/2000 1 27.5417 -82.8000 1 77.376 1.999 27.995 10.778 0.472 0.002 4/4/2000 3 27.4655 -82.9664 1 27.368 11.565 8.636 1.337 0.079 0.003 4/4/2000 5 27.3895 -83.1338 1 32.212 6.719 10.449 1.805 0.038 0.004 4/7/2000 5 27.3895 -83.1338 1 8.790 0.428 3.640 0.207 0.029 0.001 4/7/2000 7 27.3135 -83.3010 1 41.515 4.730 14.849 5.738 0.028 0.003 4/7/2000 9 27.2380 -83.4683 1 50.331 5.558 10.081 3.246 0.022 0.002 4/7/2000 10 27.2000 -83.5517 1 22.160 6.981 2.315 0.050 0.018 0.004 4/6/2000 40 26.0667 -83.1317 1 45.125 6.687 4.910 1.210 0.027 0.004 4/5/2000 44 26.1919 -82.7875 1 76.055 4.309 10.789 11.943 0.042 0.001 4/5/2000 48 26.3169 -82.4435 1 26.022 4.314 5.552 0.426 0.114 0.018 4/5/2000 51 26.4108 -82.1850 1 125.66 8 11.626 11.546 9.807 0.524 0.043 4/6/2000 88 26.4625 -83.2782 1 18.765 0.555 3.217 2.283 0.034 0.012

PAGE 169

153 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 4/6/2000 92 26.7791 -83.3953 1 4.268 1.526 1.537 0.717 0.015 0.001 4/7/2000 96 27.0956 -83.5130 1 12.101 5.902 2.634 0.481 0.028 0.012 5/1/2000 1 27.5417 -82.8000 1 25.273 1.312 2.353 0.071 0.190 0.007 5/1/2000 3 27.4655 -82.9664 1 18.615 7.555 2.530 1.217 0.077 0.002 5/1/2000 5 27.3895 -83.1338 1 53.043 1.084 0.039 0.003 5/1/2000 7 27.3135 -83.3010 1 14.940 4.415 0.933 0.548 0.019 0.002 5/1/2000 9 27.2380 -83.4683 1 62.296 21.622 0.708 0.490 0.025 0.001 5/1/2000 10 27.2000 -83.5517 1 17.937 2.412 0.475 0.338 0.027 0.007 5/2/2000 11 26.4715 -84.3920 1 9.248 1.307 0.174 0.023 0.015 0.001 5/2/2000 13 26.5490 -84.2264 1 7. 214 0.044 0.294 0.016 0.000 5/2/2000 17 26.6918 -83.8891 1 18.323 0.704 0.017 0.002 5/2/2000 19 26.7694 -83.7239 1 24.364 24.381 0.401 0.359 0.016 0.002 5/2/2000 21 26.8500 -83.5604 1 25. 630 21.881 1.067 0.017 0.004 5/2/2000 23 26.9310 -83.3969 1 38.624 35.273 0.678 0.277 5/2/2000 27 27.0932 -83.0693 1 14.910 1.180 0.036 0.010 5/2/2000 29 27.1744 -82.9052 1 12.744 1.295 0.055 0.003 5/2/2000 30 27.2151 -82.8231 1 34.520 2.356 0.072 0.001 5/3/2000 32 27.2960 -82.6592 1 21.699 5.912 1.354 0.093 0.113 0.010 5/3/2000 40 26.0667 -83.1317 1 20.580 1.660 0.025 0.010 5/3/2000 44 26.1919 -82.7875 1 17.846 2.587 1.138 0.029 0.058 0.005 5/3/2000 48 26.3169 -82.4435 1 16.622 4.817 0.785 0.329 0.074 0.010 5/3/2000 50 26.3795 -82.2707 1 24.099 31.275 0.966 5/3/2000 51 26.4108 -82.1850 1 33.740 4.486 2.071 0.002 0.205 0.022 5/3/2000 88 26.4625 -83.2782 1 24.129 2.862 0.017 0.002 5/3/2000 92 26.7791 -83.3953 1 13.642 0.684 0.274 0.191 0.018 0.003 5/4/2000 96 27.0956 -83.5130 1 26.718 3.269 0.072 0.032 0.019 0.001 6/6/2000 1 27.5417 -82.8000 1 51.556 21.475 68.610 78.148 0.240 0.005 6/6/2000 3 27.4655 -82.9664 1 20.288 5.196 5.893 3.957 0.074 0.002 6/6/2000 5 27.3895 -83.1338 1 21.492 5.344 2.831 1.458 0.041 0.003

PAGE 170

154 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 6/6/2000 7 27.3135 -83.3010 1 80.767 2.400 8.283 7.141 0.026 0.003 6/6/2000 9 27.2380 -83.4683 1 88.850 5.121 2.228 1.433 0.020 0.003 6/7/2000 10 27.2000 -83.5517 1 11.988 1.445 1.567 0.028 0.025 0.003 6/7/2000 11 26.4715 -84.3920 1 15.852 1.731 3.923 1.328 0.014 0.001 6/7/2000 13 26.5490 -84.2264 1 10.784 2.883 1.662 0.713 0.013 0.005 6/7/2000 17 26.6918 -83.8891 1 63.670 7.432 14.262 17.989 0.025 0.004 6/7/2000 19 26.7694 -83.7239 1 59.511 38.298 2.285 0.441 0.017 0.016 6/7/2000 21 26.8500 -83.5604 1 48.110 7.785 1.374 0.064 0.019 0.002 6/7/2000 23 26.9310 -83.3969 1 20.477 3.016 2.688 0.235 0.016 0.000 6/7/2000 27 27.0932 -83.0693 1 16.999 2.288 3.445 0.865 0.035 0.001 6/7/2000 29 27.1744 -82.9052 1 155.8 77 11.309 6.244 6.590 0.053 0.010 6/7/2000 30 27.2151 -82.8231 1 92.069 28.033 2.495 0.292 0.078 0.014 6/8/2000 32 27.2960 -82.6592 1 167.8 82 14.710 3.468 0.299 0.181 0.019 6/8/2000 40 26.0667 -83.1317 1 36.003 27.138 3.908 4.078 0.017 0.014 6/8/2000 44 26.1919 -82.7875 1 46.899 0.553 6.406 4.600 0.031 0.003 6/8/2000 48 26.3169 -82.4435 1 45.678 5.370 5.950 3.621 0.056 0.002 6/8/2000 51 26.4108 -82.1850 1 23.847 7.203 4.534 0.656 0.058 0.002 6/8/2000 88 26.4625 -83.2782 1 27.674 8.042 2.462 0.680 0.017 0.002 6/8/2000 92 26.7791 -83.3953 1 16.570 1.016 1.987 0.462 0.016 0.001 6/9/2000 96 27.0956 -83.5130 1 16.418 0.580 1.599 0.649 0.029 0.016 6/27/2000 1 27.5417 -82.8000 1 34.820 5.717 14.134 1.758 0.102 0.003 6/27/2000 3 27.4655 -82.9664 1 22.310 0.869 11.586 5.406 0.049 0.003 6/27/2000 5 27.3895 -83.1338 1 27.072 4.502 21.180 13.284 0.041 0.001 6/27/2000 7 27.3135 -83.3010 1 16.501 1.306 18.911 1.488 0.022 0.002 6/27/2000 9 27.2380 -83.4683 1 13.037 1.609 11.951 1.521 0.022 0.003 6/27/2000 10 27.2000 -83.5517 1 11.346 0.656 7.935 0.496 0.019 0.002 6/28/2000 11 26.4715 -84.3920 1 10.278 0.104 8.626 0.912 0.014 0.001 6/27/2000 13 26.5490 -84.2264 1 10.813 0.060 5.458 0.711 0.014 0.001 6/28/2000 17 26.6918 -83.8891 1 14.973 0.442 4.131 0.508 0.027 0.005

PAGE 171

155 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 6/28/2000 19 26.7694 -83.7239 1 9.686 1.205 3.709 0.799 0.024 0.004 6/28/2000 21 26.8500 -83.5604 1 9.928 0.967 3.217 0.328 0.017 0.000 6/28/2000 23 26.9310 -83.3969 1 12.945 0.244 7.653 0.068 0.018 0.001 6/28/2000 27 27.0932 -83.0693 1 10.384 1.123 8.320 0.172 0.028 0.007 6/29/2000 29 27.1744 -82.9052 1 29.799 2.012 15.323 1.935 0.084 0.002 6/29/2000 30 27.2151 -82.8231 1 28.133 1.436 10.230 8.770 0.073 0.002 6/29/2000 32 27.2960 -82.6592 1 33.117 0.476 20.259 5.167 0.107 0.025 6/29/2000 40 26.0667 -83.1317 1 7. 686 0.005 5.988 0.571 0.021 6/29/2000 44 26.1919 -82.7875 1 15.702 3.375 9.164 0.082 0.024 0.005 6/29/2000 48 26.3169 -82.4435 1 25.239 1.767 13.663 2.048 0.069 0.000 6/29/2000 51 26.4108 -82.1850 1 78.851 4.622 67.268 24.495 0.258 0.015 6/29/2000 88 26.4625 -83.2782 1 10.883 1.011 20.747 2.972 0.019 0.001 6/29/2000 92 26.7791 -83.3953 1 8.996 0.291 5.807 0.105 0.019 0.002 6/30/2000 96 27.0956 -83.5130 1 11.449 4.053 6.118 0.602 0.021 0.002 8/2/2000 1 27.5417 -82.8000 1 22.174 1.322 28.738 7.060 0.188 0.005 8/2/2000 3 27.4655 -82.9664 1 36.103 2.054 15.321 2.153 0.104 0.003 8/2/2000 5 27.3895 -83.1338 1 18.282 2.603 2.295 0.298 0.063 0.001 8/2/2000 7 27.3135 -83.3010 1 16.099 1.548 2.793 0.537 0.028 0.007 8/2/2000 9 27.2380 -83.4683 1 23.595 3.409 0.902 0.429 0.022 0.002 8/2/2000 10 27.2000 -83.5517 1 19.632 2.207 1.182 0.425 0.022 0.002 8/3/2000 11 26.4715 -84.3920 1 10.740 0.141 3.552 0.353 0.016 0.001 8/3/2000 13 26.5490 -84.2264 1 11.722 0.446 5.161 3.826 0.021 0.000 8/3/2000 17 26.6918 -83.8891 1 16.495 2.128 1.458 0.018 0.024 0.001 8/3/2000 19 26.7694 -83.7239 1 15.323 4.298 2.071 0.689 0.033 0.005 8/3/2000 21 26.8500 -83.5604 1 14.657 5.628 0.877 0.002 0.019 0.001 8/3/2000 23 26.9310 -83.3969 1 12.965 0.067 1.307 0.235 0.018 0.001 8/3/2000 27 27.0932 -83.0693 1 12.297 0.023 2.401 0.517 0.028 0.001 8/3/2000 29 27.1744 -82.9052 1 18.907 0.085 2.737 1.395 0.067 0.001 8/3/2000 30 27.2151 -82.8231 1 22.288 0.973 2.514 0.142 0.082 0.002

PAGE 172

156 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 8/3/2000 32 27.2960 -82.6592 1 28.886 2.897 2.922 0.572 0.136 0.001 8/4/2000 40 26.0667 -83.1317 1 42.098 11.784 2.155 0.136 0.051 0.005 8/4/2000 44 26.1919 -82.7875 1 45.272 3.175 3.381 0.195 0.091 0.005 8/4/2000 48 26.3169 -82.4435 1 40.748 0.618 4.081 0.225 0.144 0.010 8/4/2000 50 26.3795 -82.2707 1 55.012 5.672 4.587 0.814 8/4/2000 51 26.4108 -82.1850 1 31.025 0.207 2.982 0.134 0.111 0.007 8/4/2000 88 26.4625 -83.2782 1 18.903 3.031 1.391 0.190 0.039 0.004 8/4/2000 92 26.7791 -83.3953 1 12.982 0.184 1.170 0.666 0.031 0.002 8/5/2000 96 27.0956 -83.5130 1 18.440 4.474 1.355 0.152 0.037 0.001 9/7/2000 1 27.5417 -82.8000 1 36.429 4.132 6.336 0.127 0.259 0.009 9/7/2000 3 27.4655 -82.9664 1 28.002 3.463 2.647 0.025 0.064 0.008 9/7/2000 5 27.3895 -83.1338 1 18.403 0.981 2.696 0.689 0.057 0.001 9/7/2000 7 27.3135 -83.3010 1 26.405 1.511 3.528 0.217 0.054 0.000 9/8/2000 9 27.2380 -83.4683 1 9.267 0.332 0.861 0.016 0.022 0.002 9/8/2000 10 27.2000 -83.5517 1 10.358 0.898 1.060 0.213 0.019 0.000 9/8/2000 23 26.9310 -83.3969 1 24.342 8.514 1.951 0.650 0.027 0.001 9/8/2000 27 27.0932 -83.0693 1 12.609 1.344 1.213 0.233 0.044 0.005 9/8/2000 29 27.1744 -82.9052 1 11.558 0.877 1.490 0.049 0.070 0.002 9/8/2000 30 27.2151 -82.8231 1 19.264 5.386 2.403 0.214 0.064 0.000 9/8/2000 32 27.2960 -82.6592 1 33.101 3.821 3.616 0.431 0.080 0.035 9/12/2000 40 26.0667 -83.1317 1 10.358 1.034 1.645 0.503 0.024 0.008 9/12/2000 44 26.1919 -82.7875 1 10.805 1.253 2.286 1.645 0.038 0.005 9/12/2000 48 26.3169 -82.4435 1 23.458 2.688 2.655 0.824 0.072 0.006 9/12/2000 51 26.4108 -82.1850 1 48.102 0.147 4.888 0.513 0.202 0.067 9/8/2000 96 27.0956 -83.5130 1 11.405 2.492 0.775 0.016 0.020 0.001 10/4/2000 1 27.5417 -82.8000 1 135.6 34 18.967 97.693 13.479 0.496 0.003 10/4/2000 3 27.4655 -82.9664 1 66.300 2.715 63.830 24.777 0.140 0.010 10/4/2000 5 27.3895 -83.1338 1 87.326 30.318 37.235 22.915 0.076 0.008 10/4/2000 7 27.3135 -83.3010 1 41.983 22.722 6.093 2.641 0.043 0.002

PAGE 173

157 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 10/4/2000 9 27.2380 -83.4683 1 22.085 7.069 2.379 0.104 0.020 0.002 10/4/2000 10 27.2000 -83.5517 1 26.098 0.816 3.538 0.189 0.016 0.000 10/5/2000 11 26.4715 -84.3920 1 14.528 2.002 5.649 3.233 0.020 0.001 10/5/2000 13 26.5490 -84.2264 1 15.305 3.645 3.718 1.861 0.020 0.006 10/5/2000 17 26.6918 -83.8891 1 15.482 4.383 3.764 0.311 0.019 0.003 10/5/2000 19 26.7694 -83.7239 1 41.704 17.630 13.730 3.850 0.024 0.009 10/5/2000 21 26.8500 -83.5604 1 66.424 38.371 28.601 9.131 0.016 0.001 10/5/2000 23 26.9310 -83.3969 1 46.117 34.890 4.306 1.045 0.027 0.002 10/5/2000 27 27.0932 -83.0693 1 41.865 7.663 12.215 6.702 0.036 0.002 10/5/2000 29 27.1744 -82.9052 1 20.773 1.315 5.639 3.425 0.050 0.003 10/5/2000 30 27.2151 -82.8231 1 21.402 0.149 3.081 0.856 0.072 0.001 10/5/2000 32 27.2960 -82.6592 1 23.444 3.119 5.594 3.310 0.124 0.003 10/6/2000 40 26.0667 -83.1317 1 58.942 4.644 8.896 6.737 0.021 0.001 10/6/2000 44 26.1919 -82.7875 1 16.016 3.084 4.509 0.740 0.054 0.002 10/6/2000 48 26.3169 -82.4435 1 20.889 4.144 2.130 0.220 0.068 0.010 10/6/2000 50 26.3795 -82.2707 1 29.394 3.331 5.980 3.070 10/6/2000 51 26.4108 -82.1850 1 42.693 7.672 6.729 0.983 0.175 0.018 10/5/2000 74 26.7870 -82.3890 1 165.3 48 5.953 11.364 3.209 0.183 0.007 10/6/2000 88 26.4625 -83.2782 1 43.616 6.221 1.815 1.357 0.021 0.001 10/6/2000 94 26.9372 -83.4543 1 82.806 2.991 1.732 0.844 0.041 0.023 10/5/2000 999 26.4947 -82.2451 1 231.7 89 41.562 11.687 1.242 0.385 0.034 11/7/2000 1 27.5417 -82.8000 1 62.387 5.788 19.089 12.431 0.407 0.009 11/7/2000 3 27.4655 -82.9664 1 31.838 4.498 9.832 2.320 0.088 0.006 11/8/2000 5 27.3895 -83.1338 1 27.426 4.633 4.667 0.884 0.034 0.003 11/8/2000 7 27.3135 -83.3010 1 26.616 4.334 5.967 1.732 0.038 0.010 11/8/2000 9 27.2380 -83.4683 1 21.458 7.556 10.902 2.962 0.033 0.002 11/8/2000 10 27.2000 -83.5517 1 19.440 6.348 6.214 3.154 0.035 0.015 11/8/2000 11 26.4715 -84.3920 1 19.758 7.595 20.092 10.842 0.033 0.021 11/8/2000 17 26.6918 -83.8891 1 23.218 0.623 18.320 19.375 0.039 0.018

PAGE 174

158 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 11/9/2000 19 26.7694 -83.7239 1 22.498 4.730 15.949 14.778 0.037 0.006 11/9/2000 21 26.8500 -83.5604 1 23.367 7.959 5.435 2.583 0.022 0.001 11/9/2000 23 26.9310 -83.3969 1 20.475 1.168 5.099 3.173 0.040 0.019 11/9/2000 27 27.0932 -83.0693 1 31.512 9.779 7.703 3.683 0.037 0.008 11/9/2000 29 27.1744 -82.9052 1 21.529 2.388 11.386 5.474 0.050 0.010 11/9/2000 30 27.2151 -82.8231 1 23. 242 11.353 7.711 2.100 0.068 11/9/2000 32 27.2960 -82.6592 1 54.539 5.587 13.009 7.584 0.319 0.009 11/10/2000 40 26.0667 -83.1317 1 17. 398 3.324 7.152 6.516 0.023 0.001 11/10/2000 44 26.1919 -82.7875 1 22. 495 6.383 12.120 6.617 0.029 0.003 11/10/2000 48 26.3169 -82.4435 1 18. 233 1.445 9.119 0.026 0.062 0.016 11/10/2000 51 26.4108 -82.1850 1 48.205 71.117 0.177 0.075 11/9/2000 70 26.4870 -82.2260 1 47.163 4.791 97.885 54.123 0.234 0.152 11/9/2000 72 26.6360 -82.3100 1 38.152 0.804 116.191 66.859 0.221 0.011 11/9/2000 74 26.7870 -82.3890 1 52. 989 17.930 28.965 0.119 0.010 11/9/2000 76 26.9380 -82.4680 1 50. 570 3.354 65.801 0.200 0.006 11/9/2000 78 27.0890 -82.5460 1 53.794 2.182 266.242 91.418 0.225 0.015 11/9/2000 80 27.2400 -82.6260 1 63.450 3.623 114.316 13.542 0.326 0.033 11/10/2000 86 26.3042 -83.2197 1 7. 416 8.784 6.914 4.758 0.026 0.000 11/10/2000 90 26.6208 -83.3368 1 16. 664 2.565 3.016 1.558 0.025 0.003 11/10/2000 92 26.7791 -83.3953 1 12. 775 0.606 2.539 0.043 0.023 0.005 4/3/2001 1 27.5417 -82.8000 1 59.906 9.073 43.979 1.573 0.336 0.017 4/3/2001 3 27.4655 -82.9664 1 34.740 3.995 29.440 14.971 0.048 0.004 4/3/2001 5 27.3895 -83.1338 1 21.862 2.946 29.560 32.292 0.076 0.023 4/3/2001 7 27.3135 -83.3010 1 12. 824 0.681 2.598 1.094 0.088 4/3/2001 9 27.2380 -83.4683 1 19. 193 1.720 2.304 0.053 0.002 4/3/2001 10 27.2000 -83.5517 1 15.073 0.384 4.222 2.133 0.040 0.006 4/4/2001 11 26.4715 -84.3920 1 14.307 3.911 2.255 0.383 0.026 0.006 4/4/2001 13 26.5490 -84.2264 1 12.988 2.775 1.703 0.186 0.048 0.035 4/4/2001 17 26.6918 -83.8891 1 32.731 3.952 4.976 3.047 0.106 0.042

PAGE 175

159 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 4/4/2001 19 26.7694 -83.7239 1 27.291 3.271 4.353 2.083 0.077 0.027 4/4/2001 21 26.8500 -83.5604 1 17.352 0.226 2.654 0.793 0.098 0.014 4/4/2001 23 26.9310 -83.3969 1 11.569 1.029 1.237 0.084 0.044 0.006 4/4/2001 27 27.0932 -83.0693 1 16.597 0.716 2.171 0.447 0.049 0.004 4/5/2001 29 27.1744 -82.9052 1 17.787 0.661 2.380 0.337 0.058 0.002 4/5/2001 30 27.2151 -82.8231 1 21.060 1.720 3.214 1.056 0.054 0.012 4/5/2001 32 27.2960 -82.6592 1 36.531 0.066 6.799 0.569 0.144 0.003 4/5/2001 40 26.0667 -83.1317 1 13.741 2.446 2.635 0.589 0.031 0.004 4/5/2001 44 26.1919 -82.7875 1 13.915 0.935 1.004 0.097 0.063 0.015 4/5/2001 48 26.3169 -82.4435 1 20.653 1.786 0.106 0.009 4/5/2001 51 26.4108 -82.1850 1 485. 722 24.715 54.208 2.027 0.345 5/3/2001 1 27.5417 -82.8000 1 56.236 7.512 8.453 1.662 0.185 0.015 5/3/2001 3 27.4655 -82.9664 1 46.098 7.355 6.472 1.089 0.086 0.020 5/3/2001 5 27.3895 -83.1338 1 22.119 1.651 3.276 1.316 0.041 0.007 5/3/2001 7 27.3135 -83.3010 1 11.073 0.717 1.566 0.810 0.032 0.008 5/3/2001 9 27.2380 -83.4683 1 16.975 5.124 4.313 0.147 0.021 0.004 5/3/2001 10 27.2000 -83.5517 1 30.554 3.528 4.229 0.615 0.023 0.000 5/4/2001 11 26.4715 -84.3920 1 24.570 1.019 2.520 0.146 0.060 0.009 5/4/2001 17 26.6918 -83.8891 1 20.279 2.215 2.066 0.714 0.019 0.003 5/4/2001 19 26.7694 -83.7239 1 21.456 2.273 4.910 1.856 0.021 0.001 5/4/2001 23 26.9310 -83.3969 1 8.903 2.590 1.135 0.073 0.014 0.002 5/4/2001 27 27.0932 -83.0693 1 16.233 3.058 12.230 0.156 0.026 0.003 5/5/2001 29 27.1744 -82.9052 1 23.349 13.958 4.518 1.151 0.051 0.002 5/5/2001 30 27.2151 -82.8231 1 15.663 1.388 2.520 0.564 0.055 0.004 5/5/2001 32 27.2960 -82.6592 1 39.535 4.095 5.189 0.545 0.150 0.001 5/5/2001 40 26.0667 -83.1317 1 16.349 12.845 2.152 1.199 0.028 0.007 5/5/2001 44 26.1919 -82.7875 1 27.702 11.574 4.672 1.850 0.066 0.001 5/5/2001 46 26.2545 -82.6157 1 29.380 0.829 2.977 0.185 5/5/2001 48 26.3169 -82.4435 1 32.603 1.079 3.597 0.325 0.111 0.002

PAGE 176

160 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 5/5/2001 51 26.4108 -82.1850 1 40.040 1.190 4.336 1.544 0.252 0.029 6/5/2001 1 27.5417 -82.8000 1 40.138 1.764 7.437 1.160 0.338 0.015 6/5/2001 3 27.4655 -82.9664 1 22.986 1.446 12.516 6.676 0.067 0.001 6/5/2001 5 27.3895 -83.1338 1 17.558 1.277 4.710 0.437 0.058 0.003 6/5/2001 7 27.3135 -83.3010 1 12.428 1.217 2.917 0.787 0.025 0.004 6/5/2001 9 27.2380 -83.4683 1 15.124 0.082 1.775 0.109 0.020 0.002 6/5/2001 10 27.2000 -83.5517 1 20.346 3.478 3.980 2.395 0.023 0.004 6/6/2001 11 26.4715 -84.3920 1 11.062 1.220 1.210 0.209 0.022 0.008 6/6/2001 13 26.5490 -84.2264 1 7.294 1.522 0.030 0.003 6/6/2001 17 26.6918 -83.8891 1 13. 036 1.994 1.400 0.337 0.023 6/6/2001 19 26.7694 -83.7239 1 8.131 3.064 11.951 7.113 0.017 0.001 6/6/2001 21 26.8500 -83.5604 1 6.182 1.084 4.399 1.396 0.022 0.000 6/6/2001 23 26.9310 -83.3969 1 10.024 0.985 2.010 0.189 0.016 0.004 6/6/2001 27 27.0932 -83.0693 1 12.571 2.431 1.825 0.753 0.031 0.001 6/7/2001 29 27.1744 -82.9052 1 17.176 1.253 2.589 0.946 0.035 0.002 6/7/2001 30 27.2151 -82.8231 1 19.282 0.028 7.683 3.616 0.057 0.006 6/7/2001 32 27.2960 -82.6592 1 34.074 1.936 4.187 0.017 0.260 0.017 6/7/2001 40 26.0667 -83.1317 1 11. 727 1.166 1.295 0.286 0.026 6/7/2001 42 26.1296 -82.9594 1 10.894 1.620 8.960 4.498 0.020 0.002 6/7/2001 44 26.1919 -82.7875 1 15.448 10.060 13.470 8.156 0.024 0.002 6/7/2001 48 26.3169 -82.4435 1 18.633 4.838 4.086 1.318 0.072 0.013 6/7/2001 51 26.4108 -82.1850 1 46.744 4.453 7.933 1.360 0.415 0.006 6/7/2001 84 26.1462 -83.1613 1 8.476 2.179 1.648 0.689 0.023 0.002 6/7/2001 88 26.4625 -83.2782 1 7.732 0.720 1.097 0.018 0.017 0.001 6/8/2001 92 26.7791 -83.3953 1 7.965 1.562 5.575 4.823 0.025 0.000 6/8/2001 96 27.0956 -83.5130 1 6.287 1.047 0.911 0.011 0.019 0.000 6/30/2001 1 27.5417 -82.8000 1 61.895 1.025 12.746 6.835 0.263 0.003 6/30/2001 3 27.4655 -82.9664 1 24.070 11.135 3.280 0.654 0.050 0.009 6/30/2001 5 27.3895 -83.1338 1 34.383 6.626 7.724 2.329 0.034 0.002

PAGE 177

161 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 6/30/2001 7 27.3135 -83.3010 1 13.805 2.904 1.437 0.271 0.024 0.002 6/30/2001 9 27.2380 -83.4683 1 26.483 0.085 2.954 0.907 0.020 0.004 6/30/2001 10 27.2000 -83.5517 1 10.568 0.681 1.023 0.080 0.024 0.010 7/1/2001 11 26.4715 -84.3920 1 8.696 0.359 1.052 0.297 0.025 0.006 7/1/2001 13 26.5490 -84.2264 1 13.117 3.758 1.501 0.078 0.022 0.003 7/1/2001 17 26.6918 -83.8891 1 13.157 0.399 1.248 0.128 0.027 0.000 7/1/2001 19 26.7694 -83.7239 1 19.644 6.656 4.968 2.446 0.028 0.015 7/1/2001 21 26.8500 -83.5604 1 11.420 4.891 3.666 3.012 0.025 0.012 7/1/2001 23 26.9310 -83.3969 1 11.502 2.278 4.435 1.276 0.015 0.002 7/2/2001 27 27.0932 -83.0693 1 10.671 1.909 3.157 1.027 0.023 0.005 7/2/2001 29 27.1744 -82.9052 1 24.026 2.311 14.813 1.360 0.041 0.004 7/2/2001 30 27.2151 -82.8231 1 27.208 1.691 25.961 19.591 0.709 0.000 7/2/2001 32 27.2960 -82.6592 1 46.862 0.352 18.935 6.408 0.384 0.001 7/2/2001 40 26.0667 -83.1317 1 13.658 4.130 16.132 7.930 0.211 0.007 7/2/2001 42 26.1296 -82.9594 1 0.249 0.028 7/2/2001 44 26.1919 -82.7875 1 10.827 1.697 1.046 0.023 0.226 0.003 7/2/2001 48 26.3169 -82.4435 1 28.351 0.905 7.412 0.724 0.258 0.006 7/2/2001 50 26.3795 -82.2707 1 58.970 6.179 8.708 1.137 7/2/2001 51 26.4108 -82.1850 1 39.182 3.877 14.822 1.052 0.405 0.008 8/1/2001 1 27.5417 -82.8000 1 39.569 2.201 11.096 0.708 0.287 0.009 8/1/2001 3 27.4655 -82.9664 1 46.854 5.606 4.997 1.614 0.080 0.003 8/1/2001 5 27.3895 -83.1338 1 22.690 0.312 5.662 0.582 0.026 0.004 8/1/2001 7 27.3135 -83.3010 1 17.085 5.558 0.992 0.701 0.032 0.017 8/1/2001 9 27.2380 -83.4683 1 19.956 0.237 1.897 0.516 0.039 0.004 8/1/2001 10 27.2000 -83.5517 1 20.253 0.058 2.534 0.018 0.027 0.001 8/28/2001 1 27.5417 -82.8000 1 28.270 0.800 4.418 0.119 0.263 0.009 8/28/2001 3 27.4655 -82.9664 1 23.812 0.148 8.722 4.615 0.078 0.001 8/28/2001 5 27.3895 -83.1338 1 15.254 3.377 8.063 3.064 0.055 0.003 8/28/2001 7 27.3135 -83.3010 1 4.829 0.951 1.631 0.022 0.016 0.001

PAGE 178

162 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 8/28/2001 9 27.2380 -83.4683 1 5.543 3.494 0.968 0.523 0.016 0.001 8/28/2001 10 27.2000 -83.5517 1 15. 395 1.612 2.304 0.019 0.001 8/29/2001 13 26.5490 -84.2264 1 5.327 0.974 1.991 0.030 0.015 0.001 8/29/2001 17 26.6918 -83.8891 1 7.118 4.018 1.697 0.976 0.013 0.001 8/29/2001 19 26.7694 -83.7239 1 3.715 0.496 0.882 0.031 0.016 0.002 8/29/2001 21 26.8500 -83.5604 1 5.704 0.087 3.805 1.374 0.019 0.007 8/29/2001 23 26.9310 -83.3969 1 15.262 5.152 2.736 1.632 0.018 0.001 8/29/2001 27 27.0932 -83.0693 1 17.540 3.494 4.245 2.062 0.027 0.001 8/29/2001 29 27.1744 -82.9052 1 10.347 1.786 4.297 0.118 0.044 0.001 8/29/2001 30 27.2151 -82.8231 1 18.747 4.791 2.569 0.328 0.044 0.002 8/29/2001 32 27.2960 -82.6592 1 28.264 9.218 3.654 0.416 0.159 0.002 8/31/2001 34 26.9900 -82.7467 1 6.738 0.588 3.938 1.411 0.047 0.002 8/30/2001 36 26.6767 -82.8750 1 0.074 0.069 8/30/2001 38 26.3650 -83.0083 1 8.684 2.675 2.725 1.025 0.022 0.001 8/30/2001 40 26.0667 -83.1317 1 8.958 5.741 1.856 0.857 0.017 0.001 8/30/2001 44 26.1919 -82.7875 1 8.680 9.887 1.457 1.060 0.040 0.008 8/30/2001 48 26.3169 -82.4435 1 26.148 1.121 3.822 1.028 0.156 0.003 8/30/2001 51 26.4108 -82.1850 1 17.539 2.727 3.737 0.293 0.066 0.055 11/17/2001 1 27.5417 -82.8000 1 89.866 5.773 17.841 6.108 0.407 0.019 11/17/2001 3 27.4655 -82.9664 1 51.954 0.168 6.418 1.902 0.178 0.003 11/17/2001 5 27.3895 -83.1338 1 17.693 2.467 1.921 0.548 0.046 0.005 11/17/2001 7 27.3135 -83.3010 1 12.444 0.711 0.041 0.012 11/18/2001 9 27.2380 -83.4683 1 15.505 1.579 1.399 0.015 0.037 0.002 11/18/2001 10 27.2000 -83.5517 1 11. 977 0.247 1.153 0.142 0.028 0.003 11/18/2001 11 26.4715 -84.3920 1 12. 698 1.843 1.139 0.166 0.013 0.001 11/18/2001 15 26.6264 -84.0615 1 11. 712 0.550 0.761 0.008 0.032 0.006 11/18/2001 17 26.6918 -83.8891 1 15. 523 0.905 0.773 0.074 0.044 0.002 11/18/2001 21 26.8500 -83.5604 1 12. 763 2.367 1.947 1.619 0.024 0.002 11/18/2001 23 26.9310 -83.3969 1 10. 675 0.014 0.903 0.202 0.027 0.002

PAGE 179

163 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 11/19/2001 27 27.0932 -83.0693 1 14. 793 3.374 1.639 0.639 0.044 0.016 11/19/2001 29 27.1744 -82.9052 1 22. 556 1.749 2.000 0.080 0.066 0.003 11/20/2001 30 27.2151 -82.8231 1 51. 592 1.690 5.008 0.361 0.348 0.024 11/20/2001 32 27.2960 -82.6592 1 48. 083 3.283 6.576 1.469 0.185 0.002 11/20/2001 32 27.2960 -82.6592 1 33. 258 0.238 2.853 0.627 0.137 0.021 11/20/2001 40 26.0667 -83.1317 1 18. 748 3.377 2.144 1.874 0.035 0.006 11/19/2001 44 26.1919 -82.7875 1 29. 656 1.843 2.478 0.104 0.093 0.008 11/19/2001 48 26.3169 -82.4435 1 33. 001 6.332 3.739 0.616 0.115 0.004 11/20/2001 51 26.4108 -82.1850 1 46. 497 2.616 5.333 0.173 0.279 0.005 11/19/2001 84 26.1462 -83.1613 1 15. 489 5.394 1.596 0.004 0.033 0.001 11/20/2001 88 26.4625 -83.2782 1 21. 756 8.833 1.344 0.152 0.030 0.001 11/20/2001 92 26.7791 -83.3953 1 13.374 1.871 1.113 0.053 0.030 11/20/2001 96 27.0956 -83.5130 1 9. 696 7.080 0.845 0.308 0.035 0.001 12/11/2001 1 27.5417 -82.8000 1 59.130 0.298 27.281 5.625 0.203 0.010 12/11/2001 3 27.4655 -82.9664 1 40.454 2.190 7.820 2.922 0.132 0.002 12/11/2001 5 27.3895 -83.1338 1 11.517 1.376 0.829 0.055 0.030 0.001 12/11/2001 7 27.3135 -83.3010 1 16.971 4.570 1.259 0.465 0.035 0.001 12/12/2001 9 27.2380 -83.4683 1 12.195 1.705 0.741 0.203 0.028 0.002 12/12/2001 10 27.2000 -83.5517 1 13. 057 1.390 1.040 0.215 0.020 0.000 12/12/2001 11 26.4715 -84.3920 1 10. 475 1.023 0.611 0.006 0.018 0.002 12/12/2001 13 26.5490 -84.2264 1 8. 122 0.984 0.801 0.590 0.019 0.000 12/12/2001 17 26.6918 -83.8891 1 12.363 0.660 0.016 0.003 12/12/2001 19 26.7694 -83.7239 1 8.930 0.526 0.018 0.006 12/12/2001 21 26.8500 -83.5604 1 15. 082 2.758 0.957 0.110 0.017 0.000 12/12/2001 23 26.9310 -83.3969 1 16. 941 5.150 1.574 1.167 0.020 0.001 12/12/2001 27 27.0932 -83.0693 1 19. 761 0.084 1.612 0.012 0.037 0.004 12/13/2001 29 27.1744 -82.9052 1 20. 132 3.501 1.700 0.442 0.044 0.002 12/13/2001 30 27.2151 -82.8231 1 27. 372 5.563 2.127 0.459 0.068 0.003 12/13/2001 32 27.2960 -82.6592 1 43. 658 0.078 4.426 0.270 0.177 0.004

PAGE 180

164 Appendix A (Continued). Date Station Latitude Longitude Depth C (M) C (S.D.) N (M) N (S.D .) P (M) P (S.D.) 12/14/2001 34 26.9900 -82.7467 1 20. 565 1.748 2.267 0.059 0.074 0.002 12/14/2001 36 26.6767 -82.8750 1 20. 728 0.735 2.342 0.537 0.059 0.001 12/13/2001 38 26.3650 -83.0083 1 12. 494 0.594 1.017 0.139 0.029 0.001 12/13/2001 40 26.0667 -83.1317 1 12. 978 2.373 1.253 0.081 0.029 0.002 12/13/2001 44 26.1919 -82.7875 1 11. 441 0.571 2.300 1.507 0.030 0.002 12/13/2001 48 26.3169 -82.4435 1 26. 716 3.841 2.624 0.034 0.115 0.002 12/13/2001 51 26.4108 -82.1850 1 69. 757 2.683 6.829 0.168 0.373 0.004


xml version 1.0 encoding UTF-8 standalone no
record xmlns http:www.loc.govMARC21slim xmlns:xsi http:www.w3.org2001XMLSchema-instance xsi:schemaLocation http:www.loc.govstandardsmarcxmlschemaMARC21slim.xsd
leader nam 2200385Ka 4500
controlfield tag 001 002063952
005 20100318125129.0
007 cr mnu|||uuuuu
008 100318s2009 flu s 000 0 eng d
datafield ind1 8 ind2 024
subfield code a E14-SFE0003036
035
(OCoLC)558730725
040
FHM
c FHM
049
FHMM
090
GC11.2 (Online)
1 100
Murasko, Susan Mary.
0 245
Particulate carbon, nitrogen and phosphorus stoichiometry of south west Florida waters
h [electronic resource] /
by Susan Mary Murasko.
260
[Tampa, Fla] :
b University of South Florida,
2009.
500
Title from PDF of title page.
Document formatted into pages; contains 164 pages.
502
Thesis (M.S.)--University of South Florida, 2009.
504
Includes bibliographical references.
516
Text (Electronic thesis) in PDF format.
520
ABSTRACT: The southwestern Florida shelf marine environment has often been characterized as oligotrophic, yet these waters can support large, high biomass, persistent phytoplankton blooms, including blooms of the toxin producing dinoflagellate Karenia brevis. Little is known regarding which major nutrient potentially limits primary production in these waters as both inorganic nitrogen and phosphorus concentrations are often near the limits of analytical detection and it is difficult to estimate what percentage of the dissolved organic pool is available for phytoplankton uptake. To assess the nutrient status of phytoplankton populations on the southwest Florida shelf, this project examines the particulate nutrient stoichiometry of ambient phytoplankton assemblages from 1998-2000 as part of the ECOHAB: Florida Program. Particulate C, N, P concentrations and particulate ratios display a large range of values across the West Florida Shelf (WFS).The average particulate stoichiometry is well above the classic Redfield ratio with a geometric mean of 410C:56N:1P. Frequency percentages of particulate ratio values to total sample number binned according to potential nutrient limitation indicate that 39% (C:N) of the data have values suggesting N limitation and that from 88% (N:P) to 95% (C:P) of the data have values which suggest P-limitation. It is difficult to discern whether phytoplankton biomass is truly P-limited as related to the nutrient regime on the WFS or whether detrital contributions, which can potentially be large on this shallow shelf, are skewing the N:P and C:P ratios towards higher values. Errors which could potentially be related to the different methodologies of determining C, N and P concentrations must also be considered when interpreting the particulate nutrient ratios. The data were also analyzed as subsets to determine near-shore to offshore, latitudinal, seasonal, inter-annual and K. brevis bloom versus non-bloom trends.The near-shore to offshore transect indicates decreasing concentrations of particulate C, N, P concentrations and increasing C:N, N:P, C:P ratios with increasing distance offshore. Particulate nutrient concentrations and particulate ratio values are very similar between the Tampa Bay, Sarasota and Fort Meyers transects indicating that these latitudes are not spatially distinct with regards to these variables. There does not appear to be any relationship between the particulate C, N, P concentrations or C:N, N:P, C:P ratios and rainfall as indicated by Spearman Ranking Correlation coefficients. However, there does appear to be monthly trends across the shelf where peak particulate nutrient concentrations and particulate ratio values occur during the spring, summer and fall. The average particulate nutrient concentrations and ratios differ for each year as well as each K. brevis bloom which occurred during the study period.In summary, the particulate C, N, P concentrations and particulate nutrient ratios vary both spatially and temporally on the WFS and are potentially related to the flexibility of phytoplankton uptake kinetics in response to the varying nutrient regimes of the WFS.
538
Mode of access: World Wide Web.
System requirements: World Wide Web browser and PDF reader.
590
Advisor: Gabriel A. Vargo, Ph.D.
653
West Florida shelf
Redfield ratio
Nutrient limitation
Phytoplankton
Karenia brevis
690
Dissertations, Academic
z USF
x Marine Science
Masters.
773
t USF Electronic Theses and Dissertations.
4 856
u http://digital.lib.usf.edu/?e14.3036