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A stable isotopic examination of particulate organic matter during Karenia brevis blooms on the central west Florida shelf

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A stable isotopic examination of particulate organic matter during Karenia brevis blooms on the central west Florida shelf hints at nitrogen sources in oligotrophic waters
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English
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Havens, Julie Ann
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stable isotope
nitrogen
carbon
phytoplankton
Dissertations, Academic -- Marine Science -- Masters -- USF   ( lcsh )
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bibliography   ( marcgt )
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ABSTRACT: Blooms of the red tide dinoflagellate Karenia brevis occur annually on the west Florida shelf. In the late summer/early fall months, background concentrations increase from 10³ cells L⁻¹ to excesses of 10⁶ cels L⁻¹. Blooms are most common between Tampa Bay and Charlotte Harbor, and may be maintained for months. The region's hydrography may play a role in the initiation, maintenance and termination of blooms. The west Florida shelf is depauperate in inorganic nutrients. Inorganic nitrogen and phosphorus rarely exceed the limits of detection, whereas dissolved organic nitrogen is often present at concentrations of 15 to 20 &micro M. Because K. brevis exhibits ability to utilize both organic nitrogen and phosphorus, the organic pool may serve as an important nutrient source. The source of nutrients for K. brevis blooms is the focus of much scientific research. Nitrogen is considered to be the limiting nutrient in marine waters and may have several sources. Potential sources of inorganic and organic nitrogen are estuarine outflow, atmospheric deposition, upwelling, dissolved organic nitrogen released from N₂ fixing cyanobacteria, diatom blooms, decaying seagrasses, fish or other organic matter. The natural abundance stable isotopic signatures of particulate bloom material (&#948¹⁵N and &#948¹³C) associated with K. brevis blooms during 1998 to 2001 was analyzed and compared with known isotopic values of potential nutrient sources. Data was analyzed from blooms occurring from 1998 to 2001. Extensive analysis of the 2001 bloom showed that the &#948¹⁵N of bloom material ranged from 2% to 5%. &#948¹³C bloom material ranged from -22% and -17%. Non-bloom material was considerably more variable in both &#948¹⁵N and &#948¹³C. &#948¹³C values were higher near shore than offshore during the 2001 bloom, suggesting lower disolved inorganic carbon levels due to high temperature and/or high biomass. &#948¹⁵N of bloom material fell within the range of the &#948¹⁵N values of potential nitrogen sources. It appears that K. brevis utilizes the available nitrogen sources opportunistically, and that isotopically more depleted sources are more important. More enriched sources such as upwelled nitrate or sewage nitrogen can be excluded as significant sources based on the isotopic data.
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Thesis (M.S.)--University of South Florida, 2004.
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Includes bibliographical references.
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by Julie Ann Havens.
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A Stable Isotopic Examination of Particulate Organic Matter During Karenia brevis Blooms on the Central West Florida Shelf: Hints at Nitrogen Sources in Oligotrophic Waters by Julie Ann Havens A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science Department of Marine Science College of Marine Science University of South Florida Major Professor: Gabriel A. Vargo, Ph.D. Cynthia A. Heil, Ph.D. David J. Hollander, Ph.D. Date of Approval: May 10, 2004 Keywords: stable isotope, nitrogen, carbon, phytoplankton 2004, Julie A. Havens

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I would like to acknowledge my committ ee members, Dr. Gabriel Vargo, Dr. Cynthia Heil and Dr. David Hollander for thei r continual support thr oughout this project. I would like to extend special thanks to Dany lle Spence, Susan Murasko and Merrie Beth Neely for help with sampling, data processing and moral support. In addition, thanks to Dr. Deborah Bronk, Dr. Judith O’Neill, Dr. Marjorie Mullholland and Marta Sanderson for help with sampling. Last but not least; thanks to the crews of the R/V Suncoaster, R/V Bellows, R/V Pelican and R/V Walton Smith.

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i Table of Contents List of Tables iii List of Figures iv Abstract vii Chapter One: Introduction 1 Nitrogen Utilization by Phytoplankton 7 Stable Isotopes: Inferring Nutrient Sources 9 Stable Nitrogen Isotopes at Natural Abundance 11 Nitrate (NO3 -) 14 Ammonium (NH4 +) 15 Dissolved Organic Nitrogen (DON) 16 Stable Carbon Isotopes at Natural Abundance 18 Dissolved Inorganic Carbon (DIC) 21 Dissolved Organic Carbon (DOC) 22 Chapter Two: Objectives and Methodology 24 Research Objectives 24 Sampling 25 Laboratory Processing 30 Statistical Methodology 31 Chapter Three: Results 32 2001 Bloom: Cell Abundance and Biomass 32 Nutrient Distributions 34 Stable Isotopes 35 Statistical Analysis 37 Chapter Four: Discussion 38 Stable Isotopes and Other Parameters 43 References 75

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ii Appendices Appendix A: K. brevis counts from 2001 86 Appendix B: Chlorophyll a concentrations from 2001 90 Appendix C: C:N of particulate organic matter from 2001 93 Appendix D: Dissolved inorganic ni trogen concentrations from 2001 96 Appendix E: Dissolved inorganic phos phorus concentrations from 2001 104 Appendix F: Dissolved organic phos phorus concentrations from 2001 108 Appendix G: Dissolved silica c oncentrations from 2001 111 Appendix H: 15N of particulate organic matter from 2001 113 Appendix I: 13C of particulate organic matter from 2001 117 Appendix J: 15N of particulate organic matter from 121 ECOHAB: Florida 1998-2000

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iii List of Tables Table 1 Spatial 15N during the 2001 K. brevis bloom 71 Table 2 Spatial 13C during the 2001 K. brevis bloom 72 Table 3 15N and 13C of phytoplankton and associat ed particulate organic material from various U. S. coastal regions 73 Table 4 15N and 13C of miscellaneous primary producers on the west Florida shelf 74

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iv List of Figures Figure 1. 15N in a coastal shelf environment. 17 Figure 2. 13C in a coastal shelf environment. 23 Figure 3. Station maps from ECOHAB:Florida (a) 28 and DotGOM2 (b) cruises 29 Figure 4. Surface contour of Karenia brevis concentrations (cells L-1) in the 0 meter Niskin bottle sample for Sept. (a), Oct. (b), Nov. (c) and Dec. (d) of 2001. 51 Figure 5. Surface contour of chlorophyll a concentrations ( g L-1) in the 0 meter Niskin bottle sample for Sept. (a), Oct. (b) and Nov. (c) of 2001. 52 Figure 6. Relationship between surface Karenia brevis concentration (cells L-1) and surface chlorophyll a concentration ( g L-1) during the 2001 bloom. 53 Figure 7. Surface contour of carbon: nitrogen elemental ratios ( M) of particulate organic matter in the 0 meter Niskin bottle sample for Sept. (a), Oct. (b), Nov. (d) and Dec. (d) of 2001. 54 Figure 8. Surface contour of dissolved inorganic nitrogen concentrations ( M) in the 0 meter Niskin bottle sa mple for Sept. (a), Oct. (b), Nov. (c) and Dec. (d) of 2001. 55 Figure 9. Surface contour of dissolved organic nitrogen concentrations ( M) in the 0 meter Niskin bottle sa mple for Sept. (a), Oct. (b), Nov. (c) and Dec. (d) of 2001. 56

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v Figure 10. Surface contour of dissolved silica concentrations ( M) in the 0 meter Niskin bottle sample for Sept. (a), Oct. (b), Nov. (c) and Dec. (d) of 2001. 57 Figure 11. Surface contour of dissolved inorganic phosphorus concentrations ( M) in the 0 meter Niskin bottle sample for Sept. (a), Oct. (b), Nov. (c) and Dec. (d) of 2001. 58 Figure 12. Atmospheric deposition of inorganic nitrogen on the west Florida shelf: 1996 – 2003. 59 Figure 13. Surface contour of 15N values (0/00) of particulate organic material in the 0 meter Niskin bottle sample for Sept. (a), Oct. (b), Nov. (c) and Dec. (d) of 2001. 60 Figure 14. Surface contour of 13C values (0/00) of particulate organic material in the 0 meter Niskin bottle sample for Sept. (a), Oct. (b), Nov. (c) and Dec. (d) of 2001. 61 Figure 15. Monthly averaged 15N (0/00) of particulate organic material from ECOHAB: Florida cr uises: 1998-2000. 62 Figure 16. Relationship between the carbon:nitrogen elemental ratios ( M) of particulate organic material with Karenia brevis concentration (cells L-1) (a) and chlorophyll a concentration ( g L-1) (b) over the course of the 2001 bloom. 63 Figure 17. Relationship between th e dissolved inorganic nitrogen concentration ( M) with Karenia brevis concentration (cells L-1) (a) and chlorophyll a concentration ( g L-1) (b) over the course of the 2001 bl oom. 64 Figure 18. Relationship between th e dissolved organic nitrogen concentration ( M) with Karenia brevis concentration (cells L-1) (a) and chlorophyll a concentration ( g L-1) (b) over the course of the 2001 bloom. 65 Figure 19. Relationship between Karenia brevis concentration (cells L-1) with 15N (a) and 13C (b) of particulate organic material over the course of the 2001 bloom. 66

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vi Figure 20. Relationship between dissol ved inorganic nitrogen concentration ( M) and the 15N (a) and 13C (b) of particulate organic material over the course of the 2001 bloom. 67 Figure 21. Relationship between dissol ved organic nitrogen concentration ( M) and the 15N (a) and 13C (b) of particulate organic material over the course of the 2001 bloom. 68 Figure 22. Relationship between the el emental carbon: nitrogen ratios ( M) of particulate organic material and the 15N (a) and 13C (b) over the course of the 2001 bloom. 69 Figure 23. Relationship between the dissolved sili ca concentration ( M) and the 15N (a) and 13C (b) of particulate organic material over the course of the 2001 bloom. 70

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vii A Stable Isotopic Examination of Particul ate Organic Matter Du ring Karenia brevis Blooms on the West Florida Sh elf: Hints at Nitrogen Sour ces in Oligotrophic Waters Julie Ann Havens ABSTRACT Blooms of the red tide dinoflagellate Karenia brevis occur annually on the west Florida shelf. In the late summer/early fa ll months, background concentrations increase from 103 cells L-1 to excesses of 106 cells L-1. Blooms are most common between Tampa Bay and Charlotte Harbor, and may be main tained for months. The region’s hydrography may play a role in the initiation, main tenance and termination of blooms. The west Florida shelf is depauperate in inorganic nutrients. Inorganic nitrogen and phosphorus rarely exceed the limits of dete ction, whereas dissolved organic nitrogen is often present at concentrations of 15 to 20 M. Because K. brevis exhibits the ability to utilize both organic nitrogen and phos phorus, the organic pool may serve as an important nutrient source. The source of nutrients for K. brevis blooms is the focus of much scientific research. Nitrogen is considered to be the limiti ng nutrient in marine waters and may have several sources. Potential sources of i norganic and organic n itrogen are estuarine outflow, atmospheric deposition, upwelling, disso lved organic nitrogen released from N2 fixing cyanobacteria, diatom blooms, decaying seagrasses, fish or other organic matter. The natural abundance stable isotopic si gnatures of particul ate bloom material ( 15N and 13C) associated with K. brevis blooms during 1998 to 2001 was analyzed and

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viii compared with known isotopic values of poten tial nutrient sources. Data was analyzed from blooms occurring from 1998 to 2001. Extensive analysis of the 2001 bloom showed that the 15N of bloom material ranged from 2 0/00 to 5 0/00. 13C of bloom material ranged from -22 0/00 and -17 0/00. Non-bloom material was considerably more variable in both 15N and 13C. 13C values were higher near shore than offshore during the 2001 bloom, suggesting lower dissolve d inorganic carbon levels due to high temperature and/or high biomass. 15N of bloom material fell within the range of the 15N values of potential nitrogen sources. It appears that K. brevis utilizes the available nitrogen sources opportunistically, and that isot opically more depleted sources are more important. More enriched sources such as upwelled nitrate or sewage nitrogen can be excluded as significant sources based on the isotopic data.

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1 Chapter One Introduction Blooms of the toxic dinoflagellate Karenia brevis are a common seasonal phenomenon off of Florida’s west coast. In the past century, these blooms have received much attention from the scientific communit y, in an effort to understand both the ecology and physiology of the organism responsible, an d the characteristics of the West Florida Shelf (WFS) that make it such a suitab le environment for toxic algal blooms. Bloom events, commonly known as “red tides, ” have been observed in this region since the 16th century, when people noticed the asso ciated discolored water and fish mortalities. It was not until 1947 that the causative organism was discovered, and named Gymnodinium brevis (Davis 1948). Since then, ow ing to new structural and physiological information (Steidinger et al 1998), the organism has undergone several taxonomic changes. Today, it is known as Karenia brevis (Daugbjerg et al. 2000). A resident population of K. brevis exists in the Gulf of Mexico (Geesey and Tester 1993), and it is transported throughout it’s range by the Gulf Loop Current, the Florida Current and the Gulf Stream. It has been recorded throughout the U.S. South Atlantic Bight (Tester et al. 1993), but rarely occurs in shelf waters north of Cape Hatteras, North Carolina. While K. brevis blooms have been re ported by all states surrounding the Gulf of Mexico, they are mo st common off the west coast of central Florida (Tester and Steidinger, 1997). The impact s of these blooms can be extensive. For

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2 example, in the 1970’s, 2 bloom events lasting from 3 to 5 months cost local communities somewhere between $15 and $20 million (Habas and Gilbert 1974, 1975). It is reasonable to assume that there is something unique about this region of the west Florida shelf that allows K. brevis to outcompete other phytoplankton and persistently achieve bloom concentrations. The hydrography of the region may play a role in the initiation, maintenance and termin ation of these blooms (Vargo et al. 2001). Florida’s western continental shelf is sh allow and broad, and is characterized by oligotrophic waters and representative hydrographic features. Surface heating and subsequent water column stratification in the summer months gives way to thorough vertical mixing in the fall when thermal a nd salinity fronts pass through the region (Yang et al. 1999). Upwelling and downwelling events that occur near the coast as a result of the region’s wind patterns may influence th e onshore/offshore movement of blooms (Weisberg et al. 2000). Rainfall is highest in the late summer months, and may stimulate increased nutrient discharge into the estuar ies (Heil et. al 1999), but inorganic nitrogen and phosphorous levels are often at the limits of detection in coastal waters. Background concentrations of K. brevis of < 1,000 cells L-1 are present in the eastern Gulf year round (Geesey and Tester, 199 3). Almost annually, in the late summer and early fall, K. brevis cell concentrations increase and a “bloom” ensues. It takes about 2 to 8 weeks for bloom conditions to r each fish killing intensity (1 – 2.5 x 105 cells L-1), (Tester and Steidinger, 1997). Wh en concentrations reach 5 x 103 cells L-1, shellfish bed closures may become necessary. At levels of 105 cells L-1, fish and manatee mortalities may occur, and at 106 cells L-1, water discoloration becomes apparent to the human eye, and may cause respiratory irrita tion (Tester et. al, in press).

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3 In the past 50 years, considerable progr ess has been made in understanding what conditions allow these blooms to initiate and be maintained, often for months, at concentrations that cause considerable economic and human health impacts. One hypothesis is that blooms are initiated between 18 and 74 km offshore, and may be transported to near-shore waters give n appropriate current and wind conditions (Steidinger, 1975). Additionally, intrusions from the Loop Curre nt and associated thermal and salinity fronts may help to push blooms inshore and concentrate them (Haddad and Carder, 1979; Steidinger and Haddad, 1981). Once blooms are transported to nearshore waters, coastal nutrient inputs may serve to ma intain them, but are not likely to play a large role in bloom initiation. Furthermore, although Tampa Bay estuaries are typically enriched in dissolved inorganic phosphorus (D IP), dissolved inorga nic nitrogen (DIN) is often present at the lim it of detection suggesting that es tuarine N sources are insufficient to support bloom biomass (Vargo et. al, in pre ss). Past records of nutrient data indicate that there is rarely sufficient inorganic nitrog en in the Southwest Florida coastal waters to support observed K. brevis bloom biomass (Finucane and Dragovich, 1959; Dragovich et al., 1961; Dragovich et al., 1963). The main sources of DIN to this re gion are river outflow and atmospheric deposition during the rainy season and upwelling from deeper waters off the shelf break (Heil et. al, 1999). Despite the fact that W FS waters are often depl eted in both DIN and DIP, large K. brevis blooms with concentrations exceeding 10 6 cells L-1 have been maintained for months. N:P ratios are near Redfield when bloom concentrations are < 105 cells L-1, suggesting that cells have access to suffi cient N and P sources to grow at their maximum rate (Heil et. al, 2001). When cell concentrations exceed 105 cells L-1, N:P

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4 ratios are higher suggesting P-limitation (Vargo et. al, 2002). Other, as yet unidentified nutrient sources must exist to support these blooms. One possible source is dissolved organic nitrogen (DON). While DIN is often at or below the limits of detection in oli gotrophic waters, DON is found at much higher concentrations. In the open ocean, DON ranges from 3 to 7 M (Capone 2000), and values are even higher in coastal waters (Sharp 1983). On the WFS, DON has been found to range from 5 to 10 M when DIN is at nearly undet ectable levels (Heil et al., 2001). The DON pool consists of a wide variet y of compounds, varying greatly in size, complexity and lability (Zehr and Ward 2002) The more refractor y forms make up the dominant portion of the ambient pool, but the labile forms are far more important as potential nitrogen sources. The compounds that have been iden tified include urea, dissolved combined amino acids (DCAAs), dissolved free amino acids (DFAAs), humic and fulvic substances and nucleic acids (B ronk 2002). The remainder of the pool is a heterogeneous mixture of unidentified compounds. Much of the recent DON research has focu sed on the potential of this pool as a nutrient source for HABs. While diatom abunda nce tends to correlate with high nitrate concentrations, addition of DON tends to correlate with microflagellate abundance (Bronk 2002). Like other dinoflagellates, K. brevis can take up a variety of organic compounds (e.g. vitamins, amino acids ) as nitrog en sources (Steidinge r et al., 1998). In culture, K. brevis cell yields increased dramatically upon additions of glycine, leucine and aspartic acid (Shimizu et al., 1995).

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5 Several potential sources of DON are available to K. brevis blooms. Among these are atmospheric inputs (Paerl et. al, 2002; Seitzinger and Sanders, 1999; Mopper and Zika, 1987), terrigenous and estuarine input s (Seitzinger and Sanders, 1997), DON from nutrient rich waters upwelled at the sh elf break, atmospheric nitrogen fixed by cyanobacteria and subsequently released as DON (Glibert and Bronk, 1994), and that released from diatom blooms, floating seagra sses, dead fish or other decaying organic materials (Vargo et al. 2001). All of these sources may contribute to the regenerated nitrogen pool in WFS waters. The ammonium released in the z ooplankton grazing and microbially mediated regeneration processes are readily available for phytoplankton utilization, especially after bloom initiation (Bronk et al., 2003). It has r ecently been proposed that the fish kills associated with K. brevis blooms may also supply regenerated N in sufficient amounts to sustain blooms during their maintenance phase (Walsh, submitted) and laboratory experiments have demonstrated the ability of K. brevis to use fish extracts as a nutrient source (Wilson and Collier, 1955). Atmospheric deposition processes are highl y variable in terms of the magnitude of DIN and DON delivered. In general, contin entally derived storm events deliver higher DIN loads than oceanic fronts (Fogel and P aerl, 1993). While no comprehensive studies to date have been done to describe and quan tify the process in the WFS region, studies of other coastal areas may be comparable (Paer l et. al, 2002). Citing the first recorded K. brevis bloom off the coast of North Carolina in 1988, (Paerl et al. 1994 ) suggest that the recent geographic expansion of these blooms ma y indicate increasing N loading along the eastern seaboard, much of wh ich comes from atmospheric sources. Estimates suggest

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6 that from 20% to 50% of annual “new” nitr ogen may come from atmospheric deposition in geographically diverse regi ons (Fisher et al., 1988). The WFS receives the majority of it’s annual rainfall from July to October. While no studies have been conducted to quantify the amount of DON deposition in this region, estimates of DIN deposition range from 0 to 18 kg/ha, with elevated values occurring during the rainy season.

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7 Nitrogen Utilization by Phytoplankton Phytoplankton nitrogen metabolism is comple x, largely because of the number of different forms of nitrogen available for phytoplankton uptake and assimilation. Phytoplankton are able to assimilate dissolved DIN in the form of nitrate, nitrite and ammonium. It is generally agreed that they prefer NH4 + to NO3 because of the need to reduce NO3 before assimilation, but this is not a universal preference (Zehr and Ward, 2002). In oligotrophic regions, low con centrations of DIN often limit primary productivity in the surface layer (Zehr and Ward, 2002). The major source of NO3 in such areas is upwelling of NO3 rich deep waters, while the major source of NH4 + is via regeneration, resulting from the degradation of organic matter by bacterial processes or animal excretion (McCarthy, 1980), although atmospheric deposition of DIN may be important sporadically (Fogel and Paerl, 1993). It has been shown that a large fraction of the DI N assimilated by phytoplankton can be released as DON (Bronk and Ward 1999; Ward and Bronk 2001), and it is known that phytoplankton and cyanobacteria can assimi late components of this pool, such as some amino acids and urea (Antia et al., 1991). Recent work shows that many phytoplankton have cell-surface enzymes that allow them to take up DON in larger amounts than previously thought (Palenik and Morel, 1990). This suggests that phytoplankton may be a sink for, as well as a source of DON (Palenik and Morel 1990).

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8 Seitzinger and Sanders (1997) reported that diatoms and dinoflagellates accounted for > 90% of the phytoplankton biomass in tr eatments receiving DON from rainwater. Karenia brevis is much like other dinoflagellates in that it exhibits the ability to utilize both inorganic and organic forms of nitrogen. It has been shown to have a relatively high affinity for NO3 -, NH4 +, urea and glutamate in kinetic experiments (Bronk et al., 2003). Growth of K. brevis in a seawater medium containing no detectable NO3 or NO2 has been reported (Wilson, 1967). It has been shown to assimilate organic forms of both N (Baden and Mende, 1979; Shimizu and Wrensford, 1993; Shimizu et al. 1995; Steidinger et. al 1998) and P (Vargo and Shanley, 1985) in culture studies.

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9 Stable Isotopes: Inferring Nutrient Sources Natural abundance stable isotopic ratios ar e often used in ecological studies as a means of understanding trophic st ructure. Such studies utiliz e stable isotope ratios of elements common in organic material; most commonly nitrogen (15N/14N), carbon (13C/12C), hydrogen (D/H) and sulfur (34S/32S). An advantage of the natural abundance stable isotopic approach is that it is a relatively quick an alysis, and does not involve time intensive uptake/kinetics, or the use of radioactivity. Diffe rences in isotopic ratios of various materials are expressed relative to a universal standard ma terial, in terms of “delta” notation as follows: = [(Rsample/Rstandard) – 1] X 1000 where Rsample and Rstandard are the isotopic ratios of the sample and standard materials. The notation is 0/00, or “per mil.” The underlying premise of such stable is otopic analyses is that the isotopic compositions of organisms should reflect thos e of their diets to some difference in 0/00, with the consumer being enriched in the h eavier isotope relative to it’s current food source (Peterson and Fry 1987). Such studi es are aided by some knowledge of the isotopic signatures of the primary producer s in the environment, which may vary spatially and temporally with the nutrient pool sources and concentr ations (O’Reilly and Hecky, 2002).

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10 Another approach is analysis of the is otopic signatures of the primary producers themselves to gain information about the nut rient sources supporting them. This may be useful for placing constraints about th e potential nitrogen sources sustaining K. brevis blooms on the WFS. This technique is base d on the isotopic fract ionation that occurs during enzyme mediated biological reactions. The lighter isotope of a given element will enter into such a reaction at a higher rate than the heavier on e, so that the product of the reaction is depleted in the heav ier isotope relative to the reac tant. If something is known about the amount of fractionation that occurs in a given reaction type, such as that which occurs during the uptake and assimilation of a nutrient by phytoplankton, then a nutrient source can be inferred. The difference in the isotopic signatures of the dissolved species and the particulate matter it becomes assimilate d into is the “fractionation factor”. The 15N signature of the particulate organic matter associated with a monospecific K. brevis bloom should reflect the 15N signature of the nitroge n source supporting the bloom, which should differ substantially between potential sources.

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11 Stable nitrogen isotopes at natural abundance There are a few complications involved with using isotopic ratios of POM as a tool for tracking potential nitrogen sources. First, 15N values of nitrogen sources vary among nitrogen species, (NO3 vs. NH4 vs. dissolved organic nitrogen) and among sources of these species. Both N species and source ar e often variable temporally and spatially. In addition, in situ nitrogen transformation processes such as atmospheric nitrogen (N2) fixation (Hoering and Ford 1960, Macko et al. 1982), bacterial nitrification and denitrification (Miyake and Wada 1971, Ch eckley and Miller 1989) can modify the 15N of the nitrogen source pools. Furtherm ore, the isotopic composition of a primary producer at one time may reflect a combinati on of sources utilized over it’s lifetime, creating an issue of “time av eraging” (O’Reilly and Hecky 2002). In coastal or offshore systems where mixing of nitrogen from two or more isotopically di stinct sources is important, the 15N signature will reflect a combin ation of these (Fry, 1988). A second complication is the variabi lity associated w ith the amount of fractionation involved in nutri ent uptake and assimilation. The isotopic fractionation associated with nitrogen utilization by phyt oplankton is a very si gnificant fractionation process in the biogeochemical cycle of N in the ocean, but the amount of fractionation is not always known, and the mechanisms c ontrolling it are not we ll understood (Handley and Raven 1992; Goeriche et al. 1994). In general, phytoplankton di scriminate between 14N and 15N during uptake and assimilation, leavi ng biomass more depleted than the

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12 source. Variability in fractionation occurs in terms of nitrogen availability (and thus physiological state), N sources, and phytopla nkton species composition (Waser et al. 1998). In laboratory cultures reported fractionation duri ng the growth of marine microorganisms on both NO3 and NH4 varies greatly (Wada and Hattori 1976; Wada 1980; Montoya and McCarthy 1995; Pennock et al. 1996). It has also been shown to vary with light intensity, N substrate and growth rate (Wada and Hattori, 1978; Wada, 1980). Much information on isotopic fractionati on by phytoplankton has been gained with the use of laboratory cultures, whic h may not always be a good proxy for field conditions. Most past culture studies have empl oyed substrates at concentrations that are usually much higher than those found in oceanic environments and may overestimate fractionation occurring in the natural environment. Mont oya and McCarthy (1995) found evidence of variation among species, with lo wer fractionation factors for a flagellate compared with a diatom. An investigati on of the nitrogen isotope fractionation during uptake of 4 different nitrogen sources by a ma rine diatom showed fractionation values ranging from 0.8 to 20 0/00 (Waser et al. 1998), and demons trated the importance of urea and NO2 as nitrogen sources in addition to NO3 and NH4. The variability in 15N signatures of marine phyt oplankton and associated particulate organic matter (POM) has often b een explained by the geographical variation in nitrogen dynamics in oceanic surface waters (Nakatsuka, 1992). The low 15N of plankton in low latitudinal areas has been associated with N2 fixation (Wada and Hattori, 1987; Minagawa and Wada, 1986), while in high latitudes, it has been associated with large isotopic fractionati on during the uptake of NO3 (Wada and Hattori, 1978). Alternatively, Checkley and Miller (1989) s uggested that large isotopic fractionation

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13 during ammonium excretion by z ooplankton could explain the low 15N of plankton in low latitudes. Literature values for phytoplankton and POM 15N range from around -1 to 12 0/00. If some information were available about the 15N values of the potential forms and sources of DIN and DON on th e WFS, and this information could be related to the isotopic signature of K.brevis during a bloom, then it may be possible to infer which ones are most useful in sustaining such large blooms. Fig. 1 shows 15N values for potential sources and sinks of nitrogen in a coastal shelf environment.

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14 Nitrate (NO3 -) Potential sources of nitrate on the WFS include: fertilizer and /or sewage NO3 -introduced via terrigenous runoff, upwelled NO3 from beyond the shelf break, and NO3 -delivered via atmospheric deposition. Each of these source pools s hould have a distinct characteristic isotopic signature. For terr igenous inputs, fertiliz er DIN is typically isotopically depleted ( 15N: -2 to 2 0/00); while sewage NO3 is enriched, ranging from 5 to 11 0/00 (Paerl et al. 1993). Atmospherically deposited nitrate varies considerably, depending on the source of the combined nitr ogen to the atmosphere. Where the source is high temperature combustion from pollution, 15N should be close to 0 0/00; whereas if the source is soil nitrificati on, it may be more depleted (F ogel and Paerl, 1993). Values range from 15N ~ -5.5 to 10/00 (Paerl et al. 1994, Fogel and Paerl, 1993). Upwelled NO3 -varies geographically, but tends to be rela tively enriched. In deep, low oxygen regions where microbially mediated denitrification is occurring, 15N ~ 15 0/00 (Michener and Schell, 1994), and where this process is not as prominent, it is ~ 5 0/00 (Mahaffey et al., 2003). Wide variability in fractionation factors for NO3 have been reported, ranging from 0.7 to 23 0/00 (Wada and Hattori, 1978). As studies have begun to employ micromolar substrate concentrations, fractionation values of NO3 uptake have been reported that are much less than previously determined. Mo st recent values range from about 2-5 0/00 (Waser et al., 1999).

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15 Ammonium (NH4 +) Potential NH4 + sources on the WFS include: terrig enous runoff of sewage and/or fertilizer, atmospheric sources or that remineralized w ithin the water column and sediments. These source pools also diffe r isotopically. Terrigenous inputs of NH4 + from sewage are 15N ~ 8 0/00 (Paerl et al. 1993), while atmospherically deposited NH4 + is relatively depleted, at 15N ~ -3.1 0/00 (Paerl and Fogel, 1994). Isotopic values of remineralized NH4 + vary. In estuarine environments, th ey tend to be more enriched, at 15N ~ 13 0/00 (Paerl et al. 1993), while in oligotr ophic environments it is more depleted, at 15N ~ -3.5 0/00 (Miyake and Wada, 1971). For NH4 + many uncertainties remain, but fractionation may range from 6.5 9 0/00 in eutrophic systems (Cifuentes et al., 1989; Montoya et al., 1991) to as low as 0 0/00 in N-depleted environments (Waser et al. 1999).

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16 Dissolved Organic Nitrogen (DON) DON may be atmospherically deposited or produced by regeneration processes within the water column. It may be released from the primary producers ( K. brevis and other phytoplankton, Trichodesmium spp., decaying seagrass on the WFS), or from consumers (fish, benthic consumers). These different sources will likely vary isotopically, although there is very little in formation in the literature concerning 15N of DON due to methodological problems associated with its measurement. Values obtained from samples taken at various locations a nd depths spanning the Atlantic and Pacific Oceans and the Gulf of Mexico range from 6.6 to 10.2 0/00, the most depleted value coming from a surface sample from the Sarga sso Sea, suggesting a contribution from N2 fixation (Benner et al. 1997). As is the case for 15N values for DON, there is very little information regarding isotopic fractionation factors for DON. As is olation and characteriz ation of this pool becomes more routine, this may prove to be valuable information, as DON has been shown to be an important N source to estu arine ecosystems (Sietzinger and Sanders 1997,1999). It has also been shown that the release of DON by Trichodesmium spp. is, on average, 50% of the N2 fixation rate (Glibert and Bronk, 1994), and that K. brevis has the ability to exploit this pool (Bronk et al., 2003).

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17 Fig. 1: 15N in a coastal shelf environment.

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18 Stable carbon isotopes at natural abundance To overcome some of the issues involved in isotopic analysis of ecosystem processes, natural abundance studies often examine ratios of 2 or more compounds simultaneously. Ecological studies using 15N are often done in conjunction with 13C, because the different fractionation factors and processes associated with these 2 elements often compliment one another in interpretation of the data. Isotopic enrichment of both carbon and n itrogen has been shown to occur as one moves up the trophic ladder, but 13C is more variable at the base of the food chain, and tends to better conserve it’s primary s ource signature with in creasing trophic level (Zanden and Rasmussen, 1999). 13C enrichment has been estimated at about 10/00 per trophic level, and 15N enrichment at 3-4 0/00 (Fry and Sherr, 19 84). Continuous flow isotope ratio mass spectrometry (IRMS) provides a rapid way to analyze both at the same time. Differences in 13C values of organic matter re flect different photosynthetic pathways; (C3 vs. C4) (Boutton, 1991). In the marine environment, photosynthesis occurs mainly via the C3 pathway, which fract ionates to a greater extent relative to the C4 pathway utilized by some terrestrial plants. However, 13C values of marine primary producers often differ from those of C3 photosynthesizing terrestrial ones due to a combination of factors associated with is otopic fractionation dur ing photosynthesis. Fractionation has been shown to vary with aqueous CO2 concentration and algal growth rate (Fry and Wainright, 1991). As a result it can be a function of temperature and

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19 salinity (Boutton, 1991). It may also be dependent on the growth-rate limiting resource (Burkhardt et al., 1999b). Raven et al. (1993) suggested that variat ions in carbon isotop ic fractionation may be linked to bicarbonate (HCO3 -) utilization, or a non-passi ve inorganic carbon uptake mechanism during periods of CO2 limitation. Differences in cell size (Fry and Wainright, 1991) and cell membrane permeability (Fra ncois et al., 1993) can also modify fractionation. Depending on temperature and pH, the concentration of HCO3 in seawater is much greater than that of free CO2, (about 2.5 mM and 10-12 M, respectively), (Falkowski, 1991). It is generally agreed that phytoplankton primarily utilize CO2 for photosynthesis (Raven et al 1993). Utilization of HCO3 would require the C4 photosynthesis pathway. The presence of this pathway in marine phytoplankton is still under debate. Results by Falkowski (1991) show a wide range (24.2 0/00) in 13C values for 13 species of phytoplankton grown in culture This range along w ith the lack of a clear dichotomy in these values suggests va riability in the capacity to assimilate HCO3 -, with diatoms having a greater ability than di noflagellates or cyanobacteria. However, it has been suggested that C3 vs C4 photosynt hesis pathways cannot be determined on the basis of 13C values (Wong, 1976). Despite the uncertainty associated w ith carbon isotopic fractionation and DIC utilization in marine phytoplankton, 13C values are typically more enriched than those of terrestrial C3 plants. Sackett et al. (1986) s howed that the sedimentary organic carbon in Tampa Bay and adjacent riverine sy stems becomes more depleted in 13C with increasing distance upriver; ranging from -20 0/00 in the middle of Tampa Bay to -28 0/00 up the

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20 rivers. This same study found relatively enriched 13C values, (~10 0/00), in several small bays along the Gulf of Mexico coastline. Thes e enriched values are thought to reflect a contribution of organic ma terial from seagrasses ( 13C -5 to -10 0/00), and/or decreased isotopic fractionation in warm waters, as seen in an earlier study (Sack ett et al. 1965). 13C values of marine phytopl ankton range from –30 to –18 0/00, but are typically around –22 0/00, while terrestrial plant material a nd soil organic matter averages around 27 0/00 (Boutton, 1991). Fig. 2 shows 13C values of potential sources and sinks of carbon in a coastal shelf environment.

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21 Dissolved Inorganic Carbon (DIC) Dissolved carbon dioxide (CO2) and bicarbonate (HCO3 -) are the most abundant forms of DIC in the oceans, with HCO3 comprising > 99% of DIC (Smit, 2001). Variation in the chemical equilibrium of DIC can alter the 13C of this pool. In the ocean, both DIC and CaCO3 have mean 13C values ~ 0 0/00, reflecting the small amount of fractionation between the carbonate ion (CO3 2-) and CaCO3 (Boutton, 1991). In estuarine waters, the 13C of DIC may be modified depending on the source of CO2. The classical weathering reaction (CaCO3 + CO2 + H20 = 2HCO3 + Ca2+) can be used to explain variations in 13C. If CaCO3 has a 13C~0 0/00 and organically derived CO2 has a 13C~ 26 0/00, then weathering should produce HCO3 with a 13C~ -13 0/00 (Sackett et al., 1997). The HCO3 can undergo further exchange with atmospheric CO2 or additional organically derived CO2 to shift it’s isotopic compositi on further in either direction. As photosynthesis discriminates against 13C, residual DIC in surface waters tends to be slightly enriched, ranging from about 1 to 3 0/00 (Smit, 2001).

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22 Dissolved Organic Carbon (DOC) Dissolved organic carbon is the largest pool of organic carbon in marine waters, and globally has a reservoir si ze similar to atmospheric CO2 (Fry et al., 1998). In contrast to DIC, DOC is relatively depleted due to th e enzymatic fractionation of the DIC pool associated with photosynthesis. DOC in marine waters consists largely of soluble products of plankton decomposition, and has an average isotopic signature of 13C ~ -23 0/00, similar to that for phy toplankton (Boutton, 1991). Riverine DOC is more depleted, reflect ing the contribution to this pool of more depleted freshwater riverine plankton ( 13C ~-30 to –25 0/00) and surrounding terrestrial vegetation ( 13C ~ -27 0/00), (Boutton, 1991). This variation in 13C values between marine and freshwater DOC is often used to tr ace the source of dissolved organic carbon (Simenstad and Wissmar, 1985) to coastal mari ne ecosystems, which can be important in understanding the contribution of terr estrial nutrient sources.

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23 Fig. 2: 13C in a coastal shelf environment.

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24 Objectives and Methodology Research Objectives The overall objective of this research is to measure the stable isotopic signatures of POM associated with K brevis blooms and to use these signatures to constrain the potential sources of nitrogen that suppor t them. Specific objectives were to: 1. Examine spatial and temporal stable isotopic behavior of particulate organic matter (POM) associated with the 2001 K. brevis bloom 2. Utilize this analysis in conjunction with previous bloom isotopic behavior and measured chemical and biological parameters to infer possible nutrient sources sustaining blooms 3. Assess the feasibility of using dual stable isotopic analysis of POM as a means of constraining nutrient sources supporting harmful algal blooms

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25 Sampling Sampling for this research occurred on the monthly ECOHAB cruises from 1998 to 2001. ECOHAB cruises consisted of 4 da y quasi-synoptic sampling of approximately 75 stations located along 3 transects extendi ng from Tampa Bay and Ft. Myers out to the 50 meter isobath and from Sarasota out to th e 200 meter isobath. Th e area within these transects comprised the ECOHAB control volume (Fig. 3a). Additionally, more extensive sampling was done monthly from September through December 2001. During this time, a large bloom of K. brevis was present throughout the ECOHAB control volume. Continuous underway measurements of surface temperature, salinity and fluorescence were taken on all cruises with a Falmouth Scientific underway CTD system. The CTD was placed in a large, darkened c ooler and seawater was continuously pumped through it. Vertical water column measuremen ts of these parameters were also taken on station with a Seabird CTD coupled with a rosette sampler consisting of 12 8L Niskin bottles. During the October (DotGOM; Fig. 3b)) 2001 cruise, additional samples were taken of the surface layer (0 to 10 cm) by filling a plastic bucket over the side of the ship. Particulate samples for 15N and 13C analysis were obtained via rosette sampling during CTD casts. For September and October 2001, ~1.25 L of water was immediately taken from the Niskin bottle and filtered through precombusted (2 hr, 450oC) 25 mm Whatman GF/F filters under mild (10 – 15 psi) vacuum pressure. For

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26 November and December sampling, 4L of water was transferred direct ly from the Niskin bottles into 20L metal canisters and f iltered through precombusted 47 mm Whatman GF/F filters using pressurized (10 to 15 psi) N2 gas. All samples were taken in duplicate, folded, placed in precombusted (2 hr, 450oC) foil packets and immediately frozen for later analysis. Total dissolved phosphorus (TDP), total dissolved nitrogen (TDN), chlorophyll a (chl), particulate carbon nitrogen and phosphorus and K. brevis cell concentration were also sampled. Duplicate samples for chl c oncentration were obtained by filtering 285 ml of water drawn directly from Niskin bo ttles through 25 mm Whatman GF/F filters. Samples were either immediately placed in 10 ml of methanol and extracted for ~ 48 to 76 hr., or were folded and placed in foil pack ets and immediately frozen in darkness. Samples stored in foil were placed in 10 ml. of methanol within 24 hrs. of the end of each cruise. All samples were analyzed fluorometrically for chl a according to Holm-Hansen et al. (1978). Duplicate samp les for particulate C and N analysis were obtained by filtering 50 to 200 ml water through 13 mm precombusted ( 2 hr, 450oC) Whatman GF/F filters and were rinsed with 1 ml of 10% HCL to remove inorganic carbonate, followed by a filtered sea water rinse to remove the acid, folded and placed in fired foil packets and immediately frozen for later analysis Total dissolved and particulate phosphorus samples were analyzed according Solorza no and Sharp (1980a, b). For particulate phosphorus, 585 ml of water was taken direc tly from the Niskin bottle and filtered through 25 mm precombusted ( 2 hr, 450oC) Whatman GF/F filters, briefly washed with 4 ml of 0.17M Na2SO4, placed into precombusted ( 2 hr, 450oC) 20 ml scintillation vials containing 2 ml of 0.017M MgSO4 and frozen until analyzed. For total dissolved

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27 phosphorus, 10 ml of water was taken directly from the Niskin bottle and filtered through precombusted (2 hr, 450oC) 25 mm Whatman GF/F filters and the filtrate placed into precombusted (2 hr, 450oC) scintillation vials. 0.2 ml of 0.17M MgSO4 was added to each vial and all vials were immediately frozen for later analysis. Duplicate samples for total dissolved nitrogen were obtained by filtering 50 ml samples through precombusted (2 hr, 450oC) 25mm Whatman GF/F filters into 60 ml polypropylene bottles for analysis. Samples for inorganic nutrient (NO3, NO2, NH4, PO4 and SiO4) analysis were collected directly from the Niskin bottle into 20 ml polypropylene bottles and immediately frozen for later analysis. Inorganic nutrient samp les taken on the September, November and December ECOHAB cruises were not filtered prior to freezing while inorganic nutrient samples taken on the 2001 October cruise were filtered through precombusted (2 hr, 450oC) 25 mm Whatman GF/F filters. Chl a samples and all particulate and nutrient samples were stored at between –20oC and 4oC on board for later analysis. In most cases, K. brevis was counted live shortly after sample collection (according to Heil et al. 1999), but some samples were preserved in Lugol’s Iodine and transported back to the lab. Karenia brevis concentrations were determined by five replicate counts of 0.2 ml water at 100X using a dissection microscope. Locations for sampling were selected to represent a wide range of K. brevis cell concentrations within the bloom. In additi on to surface water samples taken within the bloom, samples were occasionally taken at 5m intervals throughout the water column (when the depth was <50m) or at 10m inte rvals (when the depth was >200m). Depths were chosen to sample the deep chlo rophyll maximum (DCM) for comparison of 2 distinct phytoplankton popul ations. Samples of Trichodesmium spp. were also obtained

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28 when blooms of this cyanobacterium were encountered during a K. brevis bloom. Individual Trichodesmium spp. colonies were picked from samples with inoculating loops and placed onto precombusted (2 hr, 450oC) 25mm Whatman GF/F filters, placed in precombusted (2 hr, 450oC) foil packets and immediat ely frozen. Zooplankton samples were obtained from zooplankton net tows and frozen in the same manner. In addition, samples of floating seagrass and Sargassum spp. were obtained when encountered by placing them into plas tic bags and freezing immediately. Fig. 3a: Station map from ECOHAB: Florida cruises.

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29 Fig. 3b: Station map from DotGOM2 (Oct. 2001) cruise.

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30 Laboratory Processing Isotopic analysis of particulate bloo m samples was conducted on a continuous flow dual analysis Isotope Ratio Mass Spectrometer. The frozen particulate filters were rinsed with 1 ml of 10% HCL to remove any carbonate material, lyophilized, and the filters cut into pieces from which subsamples were taken to establish material homogeneity on the filter. Filters were introduced into the mass spectrometer via combustion with a Carlo-Erba Elemental Analyzer. Particulate carbon and nitrogen concentra tions were determined using a CarloErba Model 1106 Elemental Analyzer. TDN (total dissolved nitr ogen) concentrations were determined using the persulfate oxida tion method of Solorzano and Sharp (1980). Inorganic nutrients (NO2, NO3, PO4) were determined on a Alpkem RFA II segmentedflow nutrient analyzer according to Gordon et al. (1993). NO3, NO2 or PO4 were subtracted from total N or P, respectively, to give concentrations of dissolved organic nitrogen and phosphorus.

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31 Statistical Methodology Statistical analysis was perf ormed with STATISTICA software. Stable isotopic data (both 15N and 13C) was subdivided into temporal and spatial categories. The Shapiro-Wilks W test for normality was performed on each data set to determine distribution. All data sets were determ ined to have a non-normal distribution. Nonparametric methods were us ed to test for statistica lly significant spatial and temporal differences. The Mann-Whitney U test was employed to test for differences in stable isotopic signature between surface buc ket samples and 0 meter Niskin samples, between 0 meter and depth samples, and between samples taken within and outside of the 2001 K. brevis bloom. The Kruskal-Wallis ANOVA test was employed to test for temporal differences between the 4 months of the 2001 K. brevis bloom.

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32 Results The 2001 K. brevis Bloom Cell Abundance and Biomass The 2001 K. brevis bloom was first encountered in September outside the mouth of Charlotte Harbor. Maximum cell c oncentrations at this time were 3.76 x 105 cells L-1 (fig. 4a). The bloom intensified and mo ved north to the mouth of Tampa Bay in October when cell concentrations in the 0 meter Niskin bottle sample reached 106 cells L-1 (fig. 4b), and 9.00 x 106 cells L-1 in the surface layer (1 to 10 cm). The bloom remained in this area in November at the same intensity (fig. 4c). In December, cell concentrations decreased to a maximum of 2.24 x 105 cells L-1, and the bloom became “patchier,” spreading along the coast between Tampa Bay and Charlotte Harbor (fig. 4d). Surface (0 meter) chlorophy ll concentrations follow the same pattern, except in November where there was an additional phyt oplankton population lo cated south of the K. brevis bloom (Fig. 5a-c). Due to sampling/ processing error, no data was obtained for the month of December. Chlorophyll a concentrations increased steadily with increasing bloom biomass in September 2001, and continued to increase as 0 meter K. brevis populations reach maximum at around 106 cells L-1 in October and November. Chlorophyll a was higher in the surface (0 to 10 cm) layer; reaching 24 M at one station. Concentrati ons decreased as K. brevis populations decreased in December (Fig. 6).

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33 Surface contours of C:N showed a larger variation in regions outside of the bloom when compared to bloom regions (Fig. 7a-d ). During September and October, C:N of bloom POM were near Redfield (6), but in creased during November and December to > 9 as cell populations and chlo rophyll concentrations stabiliz ed and then decreased (Fig. 7a -d).

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34 Nutrient Distributions Surface maps of monthly nutrient concentr ations show small patches of DIN (0.25 M) off the mouths of both Tampa Bay and Char lotte Harbor in September (fig. 8a). As the bloom moved north to Tampa Bay in Octobe r, DIN decreased to the limit of detection (0.03 M) in the 0 meter samples (fig. 8b), and remained depleted in November and December (fig. 8c & 8d). Yearly average values of atmospheric DIN deposition show an annual maximum of ~ 10 kg/ha/yr (fi g. 12) being delivered to the WFS. Surface concentrations of DON varied spatially during al l months of the 2001 bloom, ranging from ~5 to ~ 20 M over the sampling volume (Fig. 9a-d). DON concentration is much higher than DIN ove r the entire sampling volume; ranging from ~ 5 to ~25 M (Fig. 9a-d). Dissolved silica concentrations in the surface layer exhibited clear on/offshore gradients during all 4 months, with maximum concentrations of ~ 26 M in December (Fig. 10a-d). Highest concentr ations are found near the mout h of Charlotte Harbor in September (Fig. 10a), November (Fig. 10c) and December (Fig. 10d). Surface layer concentrations of DIP were highest (1.25 M) in September (Fig. 11a) in a patch off the coast of Charlotte Ha rbor. This level decreased within bloom areas over the next 3 months (Fig. 11b-d).

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35 Stable Isotopes Surface maps (using 0 meter Niskin samples) of 15N of POM showed a wide range of values over the sampling area, includ ing samples taken from within and outside of the bloom (Fig. 13a-d). During September, 15N ranged from -2.10 0/00 to 9.18 0/00, showing no discernible pattern of distribution (Fig. 13a). In October, values ranged from -0.58 0/00 to 4.52 0/00, exhibiting a gradient with 15N decreasing with distance from shore (Fig. 13b). In November, this gradient di sappears, (Fig. 13c) e xhibiting a patchier distribution, with one patch along th e 50m isobath having an elevated 15N signature. In December, the range narrows to between 2.24 0/00 and 5.43 0/00 (Fig. 13d). 15N values of samples taken within the bloom are between ~ 2 and 5 0/00 during all 4 months (Table 1). Surface maps (0 meter Niskin samples) of 13C of POM show a gradient with 13C decreasing with distance offshore in all 4 months (Fig. 14a-d). 13C values are within a range between –17 and –22 0/00 within the bloom and are more variable outside the bloom during all 4 months (Table 2). Isotopic signatures of both nitrogen and carbon are comparable to those of phytoplankton and associated POM in va rious U.S. coastal regions, while 15N of POM associated with this K. brevis bloom on the West Florida shelf is slightly more depleted (Table 3). Stable isotopic signatures of floating seagrass, Sargassum spp., Trichodesmium spp. and zooplankton on the WFS increase in the increment between primary producers and consumers (Table 4). The 15N of these samples is comparable to that of bloom associated POM on the WFS, while the 13C is more isotopically enriched.

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36 Monthly averages of POM 15N from August 1998 to October 2000 show more variation between months than spatially within the same m onth (Fig. 15). Values from months when a bloom occurred are less variab le and fall within a range of 2 to ~6.5 0/00. Isotopic variability does not appear to be related to distance from shore during these months, although monthly averages are comprised of samples taken over the entire ECOHAB:Florida control volume. 15N of POM is depleted during April 1999 and May 2000, when Trichodesmium spp. were abundant (Fig. 15).

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37 Statistical Analysis A significant difference was found between 13C (POM) of surface bucket samples and 0 meter Niskin samples ( >99% c onfidence, p = .00). Significant differences were also observed between surface samples taken inside and outside of the bloom in both 15N (91% confidence, p = .09) and 13C (100% confidence, p = .0). Variance in either 15N or 13C with time over the 4 month period wa s not statistically significant.

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38 Discussion Several sources of nitrogen and car bon are available for utilization by Karenia brevis on the WFS. Fig. 1 & 2 show these potential sources and their corresponding 15N and 13C values (0/00). Because the intense K. brevis bloom of 2001 was first encountered in September (Fig. 4a) off the mouth of Ch arlotte Harbor, it seems obvious to consider estuarine sources of nitrogen first. Indee d, sampling revealed small patches of DIN (0.1 M) and DIP (0.5 M) in this region at this time (Fig. 8a & Fig. 11a). The relationship between K. brevis and DIN concentration during the 4 months of the 2001 bloom shows a wide range of cell concentrations in the presence of low DIN (fig. 17a). When chlorophyll concentrations are maximum, DIN c oncentration is at and below the limits of detection; ~ 0.03 M (Fig. 17b). 15N values of POM collected from areas with detectable DIN (~ 2 M) ranged from 3 to 5 0/00 (Fig. 13a); a range of va lues that overlaps thos e of both atmospheric and estuarine (fertilizer) DIN (fig. 1). This suggest s that either of thes e are possible nitrogen sources to support growth in this bloom. However, reviews of historical cr uise track data suggested that K. brevis blooms originate on the mid WFS, between 18 and 74 km offshore. This was verified by subsequent offshore cruise tr ack data showing increased cel l concentrations appearing offshore and then onshore several weeks late r (Tester and Steidinger 1997). Estuarine outflow on the WFS does not reach this far; moreover, estuarine outwelling has been

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39 found to provide phosphorus enriched waters with NO3: PO4 of <2 (Vargo et al., 2003). Even in the summer and fall when increased rainfall may contribute to higher nutrient outflow, this same process can se rve to create salinity fronts that concentrate the nutrients inshore (Vargo et al. 2001). In addition to an estuarine source, upwe lling is a potential source of inorganic nitrogen. Haddad and Carder (1979) note that wind speeds are rarely sufficient to drive upwelling at the edge of the WFS except in wi nter. One exception occurred in the spring of 1998, when strong west winds caused an upwelling event causing the near bottom isopleth of 1 mol NO3 kg-1 to penetrate to the 20m isoba th in the Panhandle, Big Bend and Southeast regions of the WFS by May (Wals h, in review). In a ddition, intrusions of the Gulf Loop Current have been documented prior to K. brevis blooms (Haddad and Carder 1979), and may be a source of deeper waters containing elevated DIN concentrations. Theoretically, these events could supply DIN, as K. brevis has been found down to depths of 50 meters (Steidinger 1998) However, natural populations tend to concentrate at the surface (Steidi nger 1998). At one stat ion in this study, cell concentrations were 8 times as high in the thin 0 to 10 cm surface layer as in the 0 to 1 m layer. Another problem is that NO3 supplies from either upwelling or the Loop Current yield both pelagic and bent hic diatoms (Khromov, 1969; Saunders and Glenn, 1969) instead of dinoflagellates. Heil et al. (1999) found that upwelled NO3 on the WFS fueled near bottom diatom blooms. This is hardly surprising considering th at diatoms grow ~ 10 times faster than K. brevis, and that dinoflagellates have a half-saturation constant for

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40 NO3 that is ~ 7 times that for diatoms (Smayda 1997). This leads to the question of the importance of any source of NO3 to blooms of K. brevis Atmospheric deposition (AD) is another pot ential source of DIN. It is estimated that the nitrogen deposition to the global o cean from the atmosphere is equal to that from riverine sources (Fogel and Paerl, 1993). Co mplex chemical reactions result in a wide range of 15N values of nitrogen-bearing gases in the atmosphere (Kendall, 1998). Seasonal and meteorological variations, t ypes of anthropogenic inputs, proximity to pollution sources and distance from the ocean are all factors contributing to this range. In general, NO3 in rain has a more enriched 15N value than the co-existing NH4 (Fig. 1). There are no studies to date examining the 15N signature of the atmospheric nitrogen source pools on the WFS. In the A tlantic coastal waters of North Carolina, however, AD is a major source (35 to 80%) of new nitrogen (Fogel and Paerl, 1993). In this region, combined DIN (NO3 + NH4) has a range of 15N values from -13 to 2 0/00 (fig. 1) (Fogel and Paerl 1994). A medium sized K. brevis bloom amounting to 50 – 100 mg chl m-2 and having a PON:chl ( mol/ g) of 0.4 and a C:chl of 30 requires that at least 20 – 40 mmol N m-2 of new nitrogen be delivered to the WFS (Walsh & Steidinger 2001). NO3 stocks on the WFS above the 40 m isobath are generally < 0.25 mol NO3 kg-1, or < 10 mmol NO3 m-2 (Walsh and Steidinger, 2001). High-sensitiv ity fluorometric methods have provided an even lower estimate for background NO3 stocks of < 0.01 mol NO3 kg-1 (Masserini and Fanning, 2000). It seems that there must be an additional source of nitrogen. Because K. brevis is known to have the ability to use organic nitrogen, it seems that this is a potential source pool. During all four months or the 2001 bloom, DON was

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41 present at high concentrations in al l regions of the sampling area reaching 20 M in some places (Fig. 9a-d). The relationship between K. brevis concentration and DON concentration shows elevated cell concentra tions where DON ranges from between 10 to 20 M (Fig. 18a). A similar pattern is seen with chlorophyll concentration (fig. 18b). There are several source pools of DON on the WFS. Nearshore sources include estuarine, atmospheric, resuspension from n ear-bottom diatom populations (Lester et al. 2001) and release from decaying floating seagrass es. It is thought that riverine inputs (Seitzinger & Sanders, 1997) and atmospheri c inputs (Seitzinger and Sanders 1999) of DON may contribute much more to estuar ine and shelf eutrophication than was previously expected. Offshore s ources include releases from N2 fixing Trichodesmium spp. (Walsh and Steidinger, 2001). Regenerated DON in the global ocean at va rious depths displays a range from 6.6 to 10.2 0/00 (Benner et al. 1997). In the Gulf of Mexico, this range narrows to 9.5 10.2 0/00 (fig. 1) (Benner et al. 1997). Because of methodological difficulties associated with the isolation of DON, the literature is lacking in 15N values for this pool. The lack of sufficient nitrate to sustai n red tides on the WFS led to an early hypothesis that K. brevis could fix atmospheric nitrogen (Lasker and Smith, 1954). It now appears that the N2 fixing diazotroph Trichodesmium spp may play an important role in the nitrogen economy of large K. brevis blooms in coastal waters of the southeastern U.S. This is the dominant species of colonial N2 fixer on the west coast of Florida (Walsh and Steidinger, 2001). Blooms of Trichodesmium on the WFS have been related to annual summertime wind-induced deliveries of iron from the Saha ra Desert (Lenes et al. 2001; Walsh and

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42 Steidinger, 2001). Iron is necessary for the enzymatic reaction controlling nitrogen fixation. When iron limitation is alleviated and phosphorus needs are met by the surface P stocks reaching 0.4 mol P kg-1 at times (Lenes et al., 2001), conditions are prime for Trichodesmium blooms. It has been demonstrated that Trich odesmium releases DON at 50% the rate of nitrogen fixation (Glibert and Bronk, 1994). During a 1999 ECOHAB cruise, increments of DON elevation were observed following population increases of Trichodesmium (Lenes et al, 2001). Further inves tigation has shown the capability of K. brevis to utilize 15N labeled DON released from Trichodesmium as a result of N2 fixation (Bronk et al., 2003).

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43 Stable Isotopes and Other Parameters The isotopic signatures of POM both within and outside of the K. brevis bloom were plotted against other parameters to ex amine the relationships between them. The relationship between the isotopic values of POM and surface DIN concentration shows a wide range of isotopic values for bot h carbon and nitrogen with the low DIN concentrations seen over the 4 month period (F ig. 20 a & b). A sample taken within the bloom in September where DIN was ~ 2.5 M had a 15N value of 5.1 0/00 and a 13C value of –20.5 0/00 (Fig. 20b). 15N and 13C of surface POM exhibit wide variability over the large range of DON con centration (Fig. 21a & b). There is no clear relations hip between the elemental C:N and the isotopic signatures of POM. While C:N incr eases with bloom progression, both 15N and 13C vary in a different manner. 15N becomes more constrained in December, and 13C becomes more depleted (Fig. 22 a & b). Ranges of 15N and 13C POM values become restrict ed with increasing dissolved silica concentration during all 4 months (Fig. 23a & b). Ranges narrow to between 3 and 5 0/00 for 15N and –20 to –16 0/00 for 13C. 15N values of the POM within the K. brevis bloom in September of 2001 ranged from 4.93 to 5.10 0/00 (Table 1). This isotopic value in combination with the nearshore proximity of the bloom during this time suggests a combination of estuarine sources (fertilizer and sewage DIN) and atmospheri c DIN were potentially supporting the bloom

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44 (Fig. 1). However, the uncertainties asso ciated with the isotopic fractionation of phytoplankton during nitrogen assimilation (Han dley and Raven 1992; Goeriche et al. 1994) complicate this interpretation. Nonetheless, this value is at the top of the range of 15N values observed during this bloom, and is low when compared to 15N values of POM from other coastal regions (Table 3) suggesting that so me of the nitrogen utilized by this bloom came from a 15N depleted source pool. 13C values of POM within the bloom in this region ranged from -24.1 to -18.7 0/00 (Table 2). This wide range in carbon isotopic signatures re flects both typical values seen for POM in coastal regions (Table 3), and the more enriched values found in nearshore waters in th is study (Fig. 14 a-d). K. brevis cell concentrations within the bloom during September averaged ~ 75 x 103 cells L-1. Elemental C:N from samples within the bloom were close to Redfield, suggesting that the n itrogen required for maximum cell growth was present (Fig. 7a). The bloom was found north of the mouth of Tampa Bay the following month with cell concentrations reaching 9 x 106 cells L-1 in the surface (0 to 10 cm) layer. Both DIN and DIP were at detectable, but very low leve ls in this region (Fig. 8b & 11b). During this month, both 15N and 13C values of POM (Table 1 & 2) from within the bloom fall within ranges of 2 to 6 0/00 and -22 to -17 0/00, respectively (Fig. 19a & b). The range of 15N is similar to that seen in September, and suggests that K. brevis is relying on similar source pools or source pool combinations th roughout the course of the bloom. Fig. 1 shows a depleted isotopi c signature for regenerated NH4 in oligotrophic environments, and an enriched signature for DON. It is important to note that these values were not obtained fo rm WFS samples, and are de pendent upon the sources of

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45 nitrogen supplied for the regeneration process. For NH4, this depleted signature is not unrealistic in an environment where a significant source of DON is from Trichodesmium spp., as this isotopically deplet ed pool is likely to become even more depleted with regeneration (Walsh and Steidinger 2001). The enrichment in 13C seen at maximum bloom concentrations could suggest a depletion of DIC as a result of high cell density and/or elevated temperature. Elemental C:N within the bloom during October were clos e to Redfield, sugges ting that cells were growing at maximum growth rates in a nitr ogen replete environm ent (Fig. 7a). In November of 2001, cell concentrations be gan to decrease, but still remained in the 106 cells L-1 range (Fig. 4c). Inorganic nutrient concentrations were at the limit of detection, but DON concentrations were sti ll elevated in some regions (Fig. 9c), suggesting that this source pool may be regenerated within the bloom. Isotopic signatures of both carbon and nitrogen (Table 1 & 2) remained within the ranges characteristic of those seen in high (> ~ 5 x 103 cells L-1) cell populations, further suggesting the occurrence of n itrogen regeneration processes within the bloom (Fig. 19a & b). C:N ratios during this month began to increase above Redfield. This is the first suggestion that cells were depleting their nut rient sources. Alternatively, it may suggest elevating amounts of detritus as sociated with the bloom. During December, maximum cell concentrations decreased to around 3 x 105 cells L-1 (Fig. 4d). Inorganic nutrient concentrati ons remained at the limits of detection (Fig. 8d & 11d), but there remained a surplus of DON (Fig. 9d). 15N and 13C of POM

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46 within the bloom remained constrained (Fi g. 19a & b). C:N remained above Redfield, suggesting further nutrient depletion or detrital contribution (Fig. 7d). 13C of POM becomes more enriched as s ilica concentration increases in all 4 months (Fig. 23b), suggesting an inflow of freshwater into the bloom region. Some diatoms were found to occur in bloom regions, but at much lower concentrations than K. brevis so it is likely that the elevated silica is coming from a riverine source. At high silica concentrations, 15N ranges from ~2 to 5 0/00, suggesting that if nitrogen is being provided by freshwater inflow, it is not comi ng from sewage, as this would be more isotopically enriched (Fig. 1). Estuarine out flow of inorganic fer tilizer is one source possibility, with isotopic va lues ranging from 0 to 3 0/00 (Fig. 1). The relationship between K. brevis concentration and chlorophyll concentration (Fig. 6) indicates that K. brevis is responsible for most of the surface biomass in the sampling area. This means that samples that were taken within the bloom reflect bloom characteristics, and not those of other phytoplankton. Indeed, C:N, (Fig. 16a & b), 15N (Fig. 19a) and 13C (Fig. 19b) are much more variable in areas of low K. brevis concentration. Samples from past ECOHAB cruises have provided 15N data similar to that seen in 2001. The monthly averages shown in Fig. 15 show that during bloom months, 15N falls between a range of ~ 2 – 5 0/00. During months when there was no bloom the isotopic signatures are much more variable. This suggests that K. brevis opportunistically

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47 uses whatever nitrogen source it can “find”, and regenerate s this nitrogen within the bloom as it progresses, to give such a constrained isotopic si gnature range. Table 4 presents some 15N and 13C values for samples of biological material found in close proximity to the bloom in 2001. One nitrogen source possibility is decaying seagrass that is often floating in bloom regions. The 15N of this seagrass averages 2.30 0/00, similar to that found in seagrasses sampled in the Florida Keys (Anderson 2003). The previously cited study demonstrates that is otopic signatures of seagrasses can be used to monitor nitroge n source pools in a region. The relatively depleted signatures seen in Florida waters li kely reflect the isotopi cally depleted source pools. The relatively enriched 13C of seagrasses could be one source of detritus present within the bloom which could contribut e to an enrichment of bloom POM 13C, if the observed enrichment is to be explained by de tritus and not depleted DIC concentration. Trichodesmium spp. sampled from around the K. brevis bloom gave a characteristic 15N value of -0.6 0/00. DON released from this diazotroph would be isotopically depleted as well. Recent studies (Bronk et al. submitted) have shown that K. brevis has the ability to utilize 15N-labelled DON which was released by Trichodesmium after fixing 15N-labelled N2. Since this organism is common in the oligotrophic WFS waters and is found to co-occur in and around K. brevis blooms, it seems that this may be one source of nitrogen contribu ting to the lower end of the 15N range seen in bloom POM.

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48 Figures 1 and 2 give a schematic represen tation of the isotopic values of possible nitrogen source pools and various types of biomass found in co astal areas. All of the sources represented are potentially av ailable to supply nitrogen for use by K. brevis although based on data from past studies and th e isotopic values of bloom POM from this study, some seem more likely than others. Given the relatively narrow and isotopically depleted range of 15N found within blooms on the WFS, it seems that terrigenous input of sewage material can be excluded as a si gnificant source. In addition, upwelled nitrate is probably not significant, give n the isotopic discrepancy and th e rarity of this process on the WFS. It is likely that a combination of th e other source pools ar e responsible, and are probably exploited by K. brevis opportunistically. If K. brevis blooms are initiated in offshore waters, then offshore sources of nitrogen must support the initiation process. Walsh and Steidinger (2001) concluded that the likelihood of a large K. brevis bloom at the shoreline incr eases with the co-occurrence of seasonal Saharan dust events (and dissolution of iron deliv ered); sufficient rainfall; seed stocks of both Trichodesmium spp. and K. brevis ; release of DON to all dinoflagellate competitors; selective grazing st ress on diatoms and other dinoflagellates; and onshore flow to facilitate congregation in shore. They note that smaller red tide events are more enigmatic, given that there are multiple sources of nitrogen inshore that may serve to initiate and maintain smaller K. brevis stocks. Indeed, POM associated with a small event (105 cells L-1) in December 1998 had an isotopic signature of 4.80/00. This value is intermediate between values for Trichodesmium spp., (0.3 0/00, Walsh and Steidinger 2001; -0.62 0/00, this study), and 7.3 0/00 for diatoms above the 30-40 m isobath

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49 (Walsh and Steidinger 2001). This value falls in the middle of the range seen in the present study, and may reflect a 15N enriched DON substrate modified by bacterial processing. Alternatively, it ma y reflect the isotopic composition of DON from another source, such as estuarine (Seitzinger and Sanders 1997) or atmospheric (Seitzinger and Sanders 1999). The similarities in the isotopic data from this and past studies indicates that there is a source or combination of sources of n itrogen being utilized that is unchanging over time. The greater incidence of blooms in the late summer early fall adds a seasonal component that, in combination with offshore bloom initiation, seems to suggest a relationship with release of DON by Trichodesmium spp. The more depleted isotopic signatures for bloom associated POM corroborate this, and together the data suggest that release of DON by cyanophytes may se rve to initiate large blooms. Once blooms are transported to nears hore waters, other nitrogen sources may serve to maintain them, and bacterial proces sing may serve to regenerate the nitrogen pool, thereby modifying it’s isot opic signature. It appears that over the course of a typical K. brevis bloom, various sources are utilized opportunistically. Th e isotopic data in this study suggest that sources exhibiti ng relatively depleted is otopic signatures (< 5 0/00) are more important than those that are more isotopically enriched. Given the affinity K. brevis has for organic nitrogen and the large supply of it on the WFS (in contrast to the lack of inorga nic nitrogen), it is likely that the DON pool is the most important substrate se rving to initiate and maintain blooms. This pool contains a diverse array of compounds coming from se veral different potential sources. Future

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50 research should focus on the relative cont ribution of each potential source to the WFS, and on the isotopic compositions of each source. Answers to these questions will help us to find out why Florida’s oligotrophic gulf coas tal waters are such a prime habitat for this red tide dinoflagellate.

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51 Fig 4: Surface contour of Karenia brevis concentrations (x 103 cells L-1) in the 0 meter Niskin bottle sample for Sept. (a), Oct. (b ), Nov. (c), and Dec. (d) of 2001. Stations sampled are indicated by the black dots.

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52 Fig. 5: Surface contour of chlorophyll a concentrations ( g L-1) in the 0 meter Niskin bottle sample for Sept. (a), Oct. (b), and N ov. (c) of 2001. Stations sampled are indicated by the black dots. *No data for Dec.

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53 Fig. 6: Relationship between surface Karenia brevis concentration (cells L-1) and surface chlorophyll a concentration ( g L-1) during the 2001 bloom. October samples are comprised of both 0 meter Niskin bottle sa mples and surface bucket samples while other months are 0 meter Niskin bottle samples only.

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54 Fig. 7: Surface contour of carbon: nitrogen elemental ratios ( M) of particulate organic matter in the 0 meter Niskin bottle sample for Se pt. (a), Oct. (b), N ov. (c) and Dec. (d) of 2001. Stations sampled are indicated by the black dots.

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55 Fig. 8: Surface contour of dissolved inorganic nitrogen concentrations ( M) in the 0 meter Niskin bottle sample for Sept. (a), Oct. (b), Nov. (c) and Dec. (d) of 2001. Stations sampled are indicated by the black dots.

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56 Fig. 9: Surface contour of dissolved organic nitrogen concentrations ( M) in the 0 meter Niskin bottle for Sept. (a), Oct. (b), Nov. (c) and Dec. (d) of 2001. Stations sampled are indicated by the black dots.

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57 Fig. 10: Surface contour of disso lved silica concentrations ( M) in the 0 meter Niskin bottle sample for Sept. (a), Oct. (b), Nov. (c ) and Dec. (d) of 2001. Stations sampled are indicated by the black dots.

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58 Fig. 11: Surface contour of dissolved i norganic phosphorus concentrations ( M) in the 0 meter Niskin bottle sample for Sept. (a), Oct. (b), Nov. (c) and Dec. (d) of 2001. Stations sampled are indicated by the black dots.

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59 Fig. 12: Atmospheric deposition of inorganic nitrogen on the west Florida shelf: 1996 – 2003.

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60 Fig. 13: Surface contour of 15N values (0/00) of particulate organic material in the 0 meter Niskin bottle sample for Sept. (a), Oct. (b), Nov. (c) and Dec. (d) of 2001. Stations sampled are indicated by the black dots.

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61 Fig. 14: Surface contour of 13C values (0/00) of particulate organic material in the 0 meter Niskin bottle sample for Sept. (a), Oct. (b), Nov. (c) and Dec. (d) of 2001. Stations sampled are indicated by the black dots.

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62 Fig. 15: Monthly averaged 15N (0/00) of particulate organic material from ECOHAB: Florida cruises: 1998-2000. Averages ar e from Aug. 1998 to Nov. 2000 along the 10, 30 and 50 meter isobaths and offshore at ~200 mete rs. The arrow indicates the month where high Trichodesmium spp. concentrations were observed.

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63 Fig. 16: Relationship between the ca rbon: nitrogen elemental ratios ( M) of particulate organic material with Karenia brevis concentration (cells L-1) (a) and chlorophyll a concentration ( g L-1) (b) over the course of the 2001 bloom. Samples were taken from the 0 meter Niskin bottle.

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64 Fig. 17: Relationship between the dissolved inorganic nitrogen concentration ( M) with Karenia brevis concentration (cells L-1) (a) and chlorophyll a concentration ( g L-1) (b) over the course of the 2001 bloom. October samples are comprised of 0 meter Niskin bottle samples and surface bucket samples while other months are 0 meter Niskin samples only.

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65 Fig. 18: Relationship between the dissolv ed organic nitrogen concentration ( M) with Karenia brevis concentration (cells L-1) (a) and chlorophyll a concentration ( g L-1) (b) over the course of the 2001 bloom. Samples are from the 0 meter Niskin bottle.

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66 Fig. 19: Relationship between Karenia brevis concentration (cells L-1) and the 15N (0/00) (a) and 13C (0/00)(b) of particulate organic material over the course of the 2001 bloom. Data is from all stations and all depths sampled.

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67 Fig. 20: Relationship between dissolved inorganic nitrogen concentration ( M) and the 15N (0/00) (a) and 13C (0/00) (b) of particulate organic ma terial over the course of the 2001 bloom. October data is comprised of 0 meter Niskin bottle samples as well as surface bucket samples while other mont hs are 0 meter Niskin samples only.

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68 Fig. 21: Relationship between dissolved organic nitrogen concentration ( M) and the 15N (0/00) (a) and 13C (0/00) (b) of particulate organic ma terial over the course of the 2001 bloom. October data are comprised of 0 meter Niskin bottle samples as well as surface bucket samples while other mont hs are 0 meter Niskin samples only.

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69 Fig. 22: Relationship between the elemental carbon:nitrogen ratio ( M) of particulate organic material with the 15N (0/00) (a) and 13C (0/00) (b) over the course of the 2001 bloom. Data are from all stations and depths sampled.

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70 Fig. 23: Relationship between dissolved silica ( M) and the 15N (0/00) (a) and 13C (0/00) (b) of particulate material ove r the course of the 2001 bloom. Da ta is from all stations and depths sampled.

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71 Table 1: Spatial N during the 2001 K. brevis bloom. Values are the means with ranges given in parenthesis where N>1. “Bloom” signifies the presence of K. brevis in the sample at concentrations > 5000 cells L-1. 2001 Sept. Oct. Nov. Dec. Nearshore: Non-bloom Tampa Bay (inside) 9.17 N=1 * Tampa Bay (mouth) 3.77 N=1 * Longshore 3.03 N=1 * Nearshore: Bloom Tampa Bay (mouth) 4.51 N=1 5.43 N=1 4.11 N=3 (3.21 to 5.43) Charlotte Harbor (mouth) 5.04 N=3 4.80 N=1 4.90 N=1 (4.93 to 5.10) Longshore 3.27 N=1 2.51 N=5 3.30 N=2 4.21 N=1 (0.46 to 4.52) (1.91 to 4.68) Offshore Non-bloom Outside Tampa Bay * 4.26 N=3 (4.06 to 4.60) Outside Charlotte Harbor * 7.69 N=2 (5.42 to 9.96) 50m isobath 3.66 N=1 0.54 N=1 5.77 N=5 3.10 N=1 (3.88 to 11.92) 200m isobath * 10.43 N=1

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72 Table 2: Spatial 13C during the 2001 K. brevis bloom. Values are the means with ranges given in parenthesis where N>1. “Bloom” signifies the presence of K. brevis in the sample at concentrations > 5000 cells L-1. 2001 Sept. Oct. Nov. Dec. Nearshore: Non-bloom Tampa Bay (inside) -19.4 N=1 * Tampa Bay (mouth) -20.5 N=1 * Longshore -20.6 N=1 * Nearshore: Bloom Tampa Bay (mouth) -17.49 N=1 -20.9 N=1 -20.2 N=3 (-20.41 to – -19.33) Charlotte Harbor (mouth) -21.7 N=3 -19.5 N=1 -19.2 N=1 (-24.1 to -18.7) Longshore -22.1 N=1 -18.97 N=4 -20.2 N=2 -20.8 N=1 (-20.1 to -17.3)(-20.9 to -19.4) Offshore Non-bloom Outside Tampa Bay * -23.8 N=3 (-24.7 to -22.93) Outside Charlotte Harbor * -22.4 N=2 (-24.2 to -20.8) 50m isobath -23.8 N=1 -24.3 N=1 -23.8 N=5 -23.6 N=1 (-24.2 to -23.1) 200m isobath * -25.2 N=1

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73 Table 3: 15N and 13C of phytoplankton and associated pa rticulate organic material from various U. S. coastal regions. Region Material 15N 13C Source George’s Bank POM 5.1 +/1.8 -21.3 +/1.6 Fry, 1988 Wood’s Hole Harbor POM (mostly 7.5 to 12 -19 to -25 Wainright Diatoms) and Fry, 1994 Mississippi salt marsh Edaphic Algae 6.0 -20 Sullivan, 1990 Salt marsh estuary, POM 8.6 +/1 -23 +/1.1 Peterson, 1987 Sapelo Island, Georgia San Fransisco Bay phytoplankton 5 to 11 -27 to -17 Cloern et al. 2002 N.W. Gulf of Mexico POM 7.5 +/0.8 -21 +/1.4 Macko et al. 1984 South Florida POM ( Tricho -0.9 +/1.4 -19.4 +/1.2 Macko et al. present) 1984 Delaware Estuary POM 8 to 11 no data Fogel and Paerl, 1993 North Carolina POM 3 to 6 no data Fogel and Estuary Paerl, 1993 West Florida shelf POM (2001 2 to 5 -22 to -17 *this study K. brevis bloom material) *typical estuarine phytoplankton 6 to 20 no data Paerl et al. phytoplankton 1994

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74 Table 4: 15N and 13C of miscellaneous primary produ cers on the west Florida shelf. Samples include floating seagrass and Sargassum spp., zooplankton samples from tows and hand-picked Trichodesmium spp. collected during the 2001 K. brevis bloom. Values are means with ranges given where N>1. Average 15N (0/00) Average 13C (0/00) Floating Seagrass 2.307 N=7 -11.843 N=7 (-.204 to 3.616) (-13.108 to -9.483) Floating Sargassum spp. 3.201 N=1 -18.698 N=1 Zooplankton 10 m tow 5.673 N=4 -20.287 N=5 (5.387 to 6.441) (-23.664 to -14.976) 64 m tow 5.948 N=3 -15.056 N=3 (4.826 to 6.757) (-15.826 to -13.927) 153 m tow 6.126 N=9 -17.323 N=9 (4.952 to 7.974) (-18.992 to -13.681) Trichodesmium spp. -.619 N=1 -13.146 N=1

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75 References Anderson, W. T. and J. W. Fourqurean. 2003. Intraand interannual variability in seagrass carbon and nitrogen stable isotope s from south Florida, a preliminary study. Organic Geochemistry 34: 185-194. Antia, N. J., P. J. Harrison, and L. Oliveira 1991. The role of dissolv ed organic nitrogen in phytoplankton nutrition, cell biolo gy, and ecology. Phycologia 30: 1-89. Baden, D. G., AND T.J. Mende. 1979. Amino acid utilization by Gymnodinium breve. Phytochemistry 18: 247-251. Benner, R., B. Biddanda, B. Black, and M. McCarthy. 1997. Abundance, size distribution, and stable carbon and nitr ogen isotopic compositions of marine organic matter isolated by tangential -flow ultrafiltration. Mar. Chem. 57: 243263. Boutton, T. W. 1991. Stable carbon isotope rati os of natural materials: Atmospheric, terrestrial, marine, and fr eshwater environments, p. 173-186. In D. C. Coleman and B. Fry [eds.], Carbon Isotope Techniques. Bronk, D. A. 2002. Dynamics of DON, p.153-231. In D.A. Hansell and C.A Carlson [eds.], Biogeochemistry of Marine Dissolved Organic Matter. Bronk, D. A. and B. B. Ward. 1999. Gross and net nitrogen uptake and DON release in the euphotic zone of Monterey Bay, Ca lifornia. Limnol. Oceanogr. 44: 573-585. Bronk, D. A., M. P. Sanderson, M. R. Mulho lland, C. A. Heil, and J. M. O’Neil. 2003. Organic and Inorganic Nitrogen Uptake Ki netics in Field Populations Dominated by Karenia brevis In review. Burkhardt, S. U., U. Riebesell, a nd I. Zondervan. 1999b. Stable carbon isotope fractionation by marine phytopl ankton in response to daylength, growth rate, and CO2 availability. Mar. Ecol Prog. Ser. 184: 31-41. Capone, D. G. and M. R. Mullholland. 2000. Th e nitrogen physiology of the marine N2 fixing cyanobacteria Trichodesmium spp. Trends Plant Sci. 5: 148-153. Checkley, D. M., Jr. and C. A. Miller. 1989. Nitrogen isotope fractionation by oceanic zooplankton. Deep-Sea Res. 36: 1449-1456.

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76 Cifuentes, L. A., J. H. Sharp, M.L. Foge l. 1988. Stable carbon and nitrogen isotope biogeochemistry in the Delaware estuary. Limnol. Oceanogr. 33: 1102-1115. Cloern, J. E., E. A. Canuel, D. Harris. 2002. Stable carbon and nitrogen isotope composition of aquatic and terrestrial plan ts of the San Francisco Bay estuarine system. Limnol. Oceanogr. 47: 713-729. Coleman, D.C and B. Fry. 1991. Ca rbon Isotope Techniques. Acad emic Press, Inc. 274 p. Daugbjerg, N. J. Hansen, J. Larsen, and O. Moestrup. 2000. Phylogeny of some of the major genera of dinoflagellates based on ultrastructure and partial LSU rDNA sequence data, including the erection of three new genera of unarmoured dinoflagellates. Phyc ologia 39: 302-317. Davis. 1948. Gymnodinium brevis sp. nov., a cause of discol ored water and animal mortality in the Gulf of Mexico. Botan. Gaz., 109: 358-360. Dragovich, A., J. H. Finucane, J. A. Ke lly. 1963. Counts of red-tide organisms, Gymnodinium breve, and associated oceanogr aphic data from Florida west coast, 1960-61. Spec. Sci. Fish. U.S. Fish Wildl. Serv. 455. Falkowski, P. G. 1991. Species vari ability in the fractionation of C and 12C by marine phytoplankton. J. Plankton Res. 13: 21-28. Finucane, J. H. and A. Dragovich. 1959. Counts of red tide organisms, Gymnodinium breve and associated oceanographic data from Florida west coast, 1957-59. Spec. Sci. Rep. Fish. U.S. Fish Wildl. Serv.1. 369. Fisher, T. R., L. W. Harding, D.W. Stan ley, L.G. Ward. 1988. Phytoplankton, nutrients, and turbidity in the Chesapeake, Delaware and Hudson estuaries. Estuar. Coast. Shelf Sci. 27: 61-93. Fogel, M. L. and H.W. Paerl. 1993. Isotopi c tracers of nitrogen from atmospheric deposition to coastal waters Chemical Geology 107: 233-236. Francois, R., M. A. Altabet, R. Goeriche, D.C. McCorkle, C. Brunet and A. Poisson. 1993. Changes in the 13C of surface water particulat e organic matter across the subtropical convergence in the S.W. Indi an Ocean. Global Biogeochem. Cycles. 7: 627-644. Fry, B. 1988. Food web structure on Georges Bank from stable., C, N and and S isotopic compositions. Limnol. Oceanogr. 33: 1182-1190.. Fry, B. and E. B. Sherr. 1984. 13C measurements as indicators of carbon flow in marine and freshwater ecosystems. Cont. in Mar. Sci. 27: 13-47.

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77 Fry, B. and S. C. Wainright. 1991. Diatom sources of 13C-rich carbon in marine food webs. Mar. Ecol. Prog. Ser. 78: 149-157. Fry, B., C.S. Hopkinson, A. Nolin, S. C. Wainright. 1998. 13C/12C composition of marine dissolved organic carbon. Chemical Geology 152: 113-118. Geesey, M. E. and P. A. Tester. 1993. Gymnodinium breve : ubiquitous in Gulf of Mexico waters. Dev. Mar. Biol. 3: 251-256 Glibert, P. M. and D. A. Bronk. 1994. Release of dissolved organic nitrogen by marine diazotrophic cyanobacteria, Trichodesmium spp. App. and Environ. Micro. 39964000. Goeriche, R., J. P. Montoya, and B. Fr y. 1994. Physiology of isotopic fractionation in algae and cyanobacteria, p. 187-221. In K. Lajtha and R. H. Michener [eds.], Stable isotopes in ecology and environmental science. Gordon, L. I., J. C. Jennings Jr., A. A. Ross, and J. M. Krest. 1993. WHP Office Report 90-1, WOCE Report 77, 68: 1-52. Habas, E. J. and C. Gilbert.1974. The economic effects of the 1971 Florida red tide and the damage it presages for future occurrences. Environ. Lett. 6: 139-147. Habas, E. J. and C. Gilbert. 1975. A prelimin ary investigation of the economic effects of the 1973-1974 red tide. Proceedings of th e Florida Red Tide Conference, 10-12 October 1974, Sarasota, Florida. Fla. Mar. Res. Publ. no.8. Haddad, K. and K. Carder. 1979. p. 268-274. In D.L. Taylor & H.H. Selinger [eds.] Toxic Dinoflagellate Blooms. Handley, L. L. and J. A. Raven. 1992. The use of natural abundance of nitrogen isotopes in plant physiology and ecology. Plant Cell Environ. 15: 965-985. Heil, C. A., G. A. Vargo, D. N. Spence, M. B. Neely, R. Merkt, K. M. Lester, and J. J. Walsh. 1999. Nutrient stoichiometry of a Gymnodinium breve bloom: what limits blooms in oligotrophic environments? p. 165-168. In G.M. Hallegraeff, S.I. Blackburn, C.J. Bolch and R.J. Lewis [e ds.], Proc. IX Intern. Symp. Harmful Algal Blooms, Hobart, Australia. Hoering, T. C. and H. T. Ford. 1960. The isotop ic effect in the fixation of nitrogen by Azobacter J. Am. Chem. Soc. 82: 376-378. Holm-Hansen, O. and B. Reimann. 1978. Chlo rophyll a determinations: Improvements in methodology. Oikos. 30: 438-447.

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78 Kendall, C. 1998. Tracing nitrogen sources and cycling in catchments. p. 519-576. In Kendall, C. and J.J. McDonnell [eds.], Isotope Tracers in Catchment Hydrology. Elsevier Science B.V., Amsterdam. Khromov, N. S. 1969. Distribu tion of plankton in the Gulf of Mexico and some aspects of its seasonal dynamics. p. 36-56. In A.S. Bogdanov [ed.], Soviet-Cuban Fishery Research. Isr. Prog. Sci. Trans., Jerusalem. Lasker, R. and F.G. Smith. 1954. Red tide. Gulf of Mexico: it’s Origin Waters, and Marine Life. Fish. Bull. 89: 173-176. Laws, E. A. and R. R. Bidigare. 1997. Effect of gr owth rate and CO2 concentration on carbon isotopic fractionati on by the marine diatom Phaeodactylum tricornutum Limnol. Oceanogr. 42: 1552-1560. Laws, E. A., P. A. Thompson, B. N. Popp, and R. R. Bidigare. 1998. Sources of inorganic carbon for marine microalg al photosynthesis: A reassessment of 13C data from batch culture studies of Thalassiosira pseudonana and Emiliania huxleyi Limnol. Oceanogr. 43: 136-142. Lenes, J. M., B. P. Darrow, C. Cattrall, C. A. Heil, M. Callahan, G. A. Vargo and R. H. Byrne. 2001. Iron fertilization and the Trichodesmium response on the West Florida shelf. Lim nol. Oceanogr. 46: 1261-1277. Lester, K. M, R. Merkt, C. A. Heil, G. A. Vargo, M. B. Neely, D. N. Spence, L. Melahn and J.J. Walsh. 1999. Evolution of a Gymnodinium breve red tide bloom on the west Florida shelf: relationship with organic nitrogen and phosphorus. p. 161-164. In G.M. Hallegraeff, S.I. Blackburn, C.J. Bolch and R.J. Lewis [eds.], Proc. IX Intern. Symp. Harmful Algal Blooms, Hobart, Australia. Macko, S. A., L. Entzeroth and P. L. Parker 1984. Regional differences in nitrogen and carbon isotopes on the continental shelf of the Gulf of Mexico. Naturwissenschaften 71: 374-375. Macko, S. A., Marilyn L. Fogel, P. E. Hare and T. C. Hoering. 1987. Isotopic fractionation of nitrogen and carbon in the synthesis of amino acids by microorganisms. Chemical Geology. 65: 79-92. Mahaffey, C., R. G. Williams, George A. Wolf f, Natalie Mahowald, W. Anderson and M. Woodward. 2003. Biogeochemical signatures of nitrogen fixation in the eastern North Atlantic. Geo. Res. Let. 30: 33(1)-33(4). Masserini, R. T. and K. A. Fanning. 2000. A sensor package for the simultaneous determination of nanomolar concentrations of nitrite, nitrat e, and ammonia in seawater by fluorescence detec tion. Mar. Chem.. 68: 323-333.

PAGE 89

79 McCarthy, J. J. 1980. Nitrogen. p. 191-223 In I. Morris [ed.], The Physiological Ecology of Phytoplankton. McCarthy, J. J. and M. A. Altabet. 1984. Patc hiness in nutrient supply: Implications for phytoplankton ecology. p. 29-48. In Meyers, D.G. and J.R. Strickler [eds.], Trophic Interactions Within Aquatic Ec osystems. AAS SEL. SYMP. SER. vol. 185. McMillan, C., P. L. Parker, and B. Fry. 1980. (13C/ 12)C ratios in seagrasses. Aquatic Botany. 9: 237-249. Michener R. H. and Schell D. M. 1994. Stable isotope ratios as trac ers in marine aquatic food webs. In K. Lajtha and R.H. Michener [eds.], Stable Isotopes in Ecology and Environmental Science. Blackwell Scientific Publications: Oxford. Minigawa, M. and E. Wada. 1986. Nitrogen isot ope ratios of red tide organisms in the East China Sea: a characterization of bi ological nitrogen fixation. Mar. Chem. 19: 245-259. Miyake, Y. and E. Wada. 1971. The isotope effect on the nitrogen in biochemical oxidation-reduction reactions. Rec. Oceanogr. Wks Japan 11: 1-6. Mopper, K. and R. G. Zika. 1987. Free amino acids in marine rains: Evidence for oxidation and potential role in n itrogen cycling. Nature 325: 246-249. Nakatsuka, T., N. Handa, E. Wada and C. Shing Wong. 1992. The dynamic changes of stable isotopic ratios of carbon and nitrogen in suspended and sedimented particulate organic matter during a phytoplan kton bloom. J. Mar. Res.of Marine Research 50: 267-296. O’Reilly, C. M. and R. E. Hecky. 2002. Interpreting stable isotopes in food webs: Recognizing the role of time averagi ng at different trophic levels. Limnol. Oceanogr. 47: 306-309. Paerl, H. W., M. L. Fogel, P.W. Bates, and P. M. O’Donnell. 1994. Is there a link between atmospheric deposition and eutrophi cation in coastal wa ters? Changes in Fluxes in Estuaries: Implications from Science to Management, Olsen & Olsen, Fredensborg, Denmark. 197-202.

PAGE 90

80 Paerl, H. W., R. L. Dennis, D. R. Whita ll. 2002. Atmospheric deposition of nitrogen: Implications for nutrient over-enrichment of coastal waters. Estuaries. 25: 677693. Palenik, B. and F.M. Morel. 1990. Amino acid utilization by marine phytoplankton: A novel mechanism. Limnol. Oceanogr. 35: 260-269. Peterson, B. J. & B. Fry. 1987. Stable isot opes in ecosystem studies. Ann. Rev. Ecol. Syst. 18: 293-320. Pennock, J. R., D. J. Velinsky, J. M. Ludlam, J. H. Sharp and M. L. Fogel. 1996. Isotopic fractionation of ammonium and nitrate during uptake by Skeletonema costatum : implications for 15N dynamics under bloom conditions. Limnol. Oceanogr. 41: 451-459. Raven, J. A., A. M. Johnston and D.H. Turpin. 1993. Influence of changes in CO2 concentration and temperature on marine phytoplankton 13C/12C ratios: an analysis of possible mechanisms. Global and Planetary Change. 8: 1-12. Sackett, W. M., W. R. Ecklemann, M. L. Bender and A.W.H. Be’. 1965. Temperature dependence of carbon isotope composition in marine plankton and sediments. Science 148: 235-237. Sackett, W., G. Brooks, M. Conkright, L. Doyle and L. Yarbro. 1986. Stable isotope compositions of sedimentary organic carbon in Tampa Bay, Florida, U.S.A: implications for evaluating oil contam ination. Applied Geochemistry. 1: 131-137. Sackett, W. M., T. Netratanawong and M. E. Holmes. 1997. Carbon-13 variations in the dissolved inorganic carbon in estuarine waters. Geo. Res.Let.. 24: 21-24. Saunders, R. P. and D. A. Glenn. 1969. Diatoms: Memoirs of the hourglass cruises. Tech. Ser. Fla. Dep. Nat. Resour. Mar. Res. Lab. 1: 1-119. Seitzinger, S. P. and R.W. Sanders. 1997. Contribution of dissolved organic nitrogen from rivers to estuarine eutrophi cation. Mar. Ecol. Prog. Ser. 159:1-12. Seitzinger, S. P. and R. W. Sanders. 1999. Atmospheric inputs of dissolved organic nitrogen stimulate estuarine bacteria and phytoplankton. Limnol. Oceanogr. 44: 721-730. Sharp 1983. The distribution of inorganic nitroge n and dissolved and particulate organic nitrogen in the sea., p. 1-35. In E.J. Carpenter and D.G. Capone [eds.], Nitrogen in the Marine Environment. Acad emic Press, Inc., New York.

PAGE 91

81 Shimizu and Wrensford. 1993. p. 919-924. In T.J. Smayda and Y.Shimizu [eds.] Toxic phytoplankton blooms in the sea, Elsevier, Amsterdam. Shimizu, Y., N. Watanabe, and G. Wrensf ord. 1995. Biosynthesis of brevetoxins and heterotrophic metabolism in Gymnodinium breve In P. Lassus, G. Arzul, E. Erard, P. Gentien, and C. Marcaillou [e ds], Harmful Marine Algal Blooms. Lavoisier, Intercept, Ltd. Shimizu, Y., N. Watanabe, and G. Wrensford. 1995. p. 351-357. In P. Lassus, G. Arzul, E. Erard-Le Denn, P. Genten, & C. Ma rcaillon-LeBaut [eds] Harmful Marine Algal Blooms: Proceedings of the Sixth International Conference on Toxic Marine Phytoplankton. Simenstad, C.A. and R.C. Wissmar. 1985. 13C evidence of the origins and fates of organic carbon in estuarine and nears hore food webs. Mar. Ecol. Prog. Ser. 22:141-152. Smayda, T. S. 1997. Harmful algal blooms: Th eir ecophysiology and ge neral relevance to phytoplankton blooms in the sea. Limnol. Oceanogr. 42: 1137-1153. Smit, A. J. 2001. Source identification in marine ecosystem: food web study in 13C and 15N. p.219-246. In M. Unkovich, J. S. Pate, A. Mc Neil and D. J. Gibbs [eds.], Stable isotope techniques in the study of biological processes and functioning of ecosystems. Kluwer-Academic. Solorzano, L. and J.H. Sharp. 1980. Determinati on of total dissolved nitrogen in natural waters. Limnol. Oceanogr. 25: 751-754. Solorzano, L. and J.H. Sharp. 1980. Determination of total dissolved phosphorus and particulate phosphorus in natural waters. Limnol. Oceanogr. 25: 751-754. Steidinger, K.A. 1975. Implicat ions of dinoflagellate life cycles on initiation of Gymnodinium breve red tides. Environ. Lett. 9(2): 129-139. Steidinger, K. A. and K. Haddad. 1981. Biologic and hydrologic aspects of red tides. Bioscience 31: 814-819. Steidinger, K. A. Vargo, G. A., Tester, P. A. and C. R. Tomas. 1998. Bloom dynamics and physiology of Gymnodinium breve with emphasis on the Gulf of Mexico. In D.M. Anderson, A.D. Cembella, and G.M. Hallegraeff [eds.], Physiological Ecology of Harmful Algal Blooms. Springer-Verlag, Berlin.

PAGE 92

82 Sullivan, M. J. and C. A. Moncreiff. 1990. Ed aphic algae are an important component of salt marsh food-webs: evidence from multiple stable isotope analyses. Mar. Eco. Prog. Ser. 62: 149-159. Tester, Patricia A. and Karen A. Steidinger. 1997. Gymnodinium breve red tide blooms: Initiation, transport, and consequences of surface circulation. Limnol. Oceanogr. 42: 1039-1051. Tester, P.A., M.E. Geesey, and F.M. Vukovich. 1993. Gymnodinium breve and global warming: What are the possibilities? p. 76-72. In Toxic phytoplankton blooms in the sea. Proc. 5th Int. Conf. on Toxic Marine Phytoplankton. Elsevier. Vargo, G.A. and E. Shanley. 1985. Alkaline phosphatase activity in the red-tide dinoflagellate, Ptycodiscus brevis P.S.Z.N.I: MAR.ECOL. 6: 251-264. Vargo, Gabriel A., C.A. Heil, D.N. Spence, M.B. Neely, Rachel Merkt, K.M. Lester, R.H. Weisberg, J.J. Walsh, and Kent Fanning. 1999. The hydrographic regime, nutrient requirements, and transport of a Gymnodinium breve Davis red tide on the west Florida shelf. In G.M. Hallegraeff,. S.I. Blackburn, C.J. Bolch and R.J. Lewis [eds], Proc. IX Inte rn. Symp. Harmful Algal Blooms. Hobart, Australia. Vargo, Gabriel A., C.A. Heil, D.N. Spence, M.B. Neely, Rachel Merkt, K.M. Lester, R.H. Weisberg, J.J. Walsh, and Kent Fanning. 2001. The hydrographic regime, nutrient requirements, and transport of a Gymnodinium breve Davis red tide on the west Florida shelf. Pp.157 – 160, In G.M. Hallegraeff,. S.I. Blackburn, C.J. Bolch and R.J. Lewis [eds], Proc. IX Intern. Symp. Harmful Algal Blooms. Hobart, Australia. Vargo, G.A., C.A. Heil, D. Ault, M.B. Neely, S. Murasko, J. Havens, K.M. Lester, L.K. Dixon, R. Merkt, J.J. Walsh, R. Weisberg and K.A. Steidinger. In press. Four Karenia brevis blooms: A comparative analysis. Proceedings of the Xth Harmful Algal Bloom Conference, St. Pete Beach, FL. October 2002. Wada, E. 1980. Nitrogen isotope fractionati on and its significance in biogeochemical processes occurring in mari ne environments. p. 375-398. In E.D. Goldberg, S. Horibe and K. Saruhashi [eds.], Isot ope Marine Chemistry. Uchida Rokakuho Co., Tokyo. Wada, E. and A. Hattori. 1976. Natural abundance of 15N in particulate organic matter in the North Pacific Ocean. Geochim. Cosmochim. Acta. 40: 249-256. Wada, E., and A. Hattori. 1978. Nitrogen isotope e ffects in the assimilation of inorganic nitrogenous compounds. Geomicrobiol. J. 1: 85-101.

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83 Walsh, J. J., G. J. Kirkpatrick, B. P. Darrow, G. A. Vargo, K. A. Fanning, K. M. Lester, S. P. Milroy, E. B. Peebles, J. M. Lene s, C. A. Heil and K. A. Steidinger. Fish farming by Karenia brevis ; a positive feedback for form ation of large red tides. In review. Walsh, J.J. and K.A. Steidinger. 2001. Sa haran dust and Florida red tides: The cyanophyte connection. J. of Geophys. Res. 106: 11597-11612. Ward, B.B. and D.A. Bronk. 2001. Net nitr ogen uptake and DON release in surface waters: importance of tr ophic interactions implied from size fractionation experiments. Mar. Ecol. Prog. Ser. 219:11-24. Waser, N.A., K. Yin, Z, YU, K. Tada, P.J. Harrison, D.H. Turpin, and S.E. Calvert. 1998. Nitrogen isotope fractionation during n itrate, ammonium and urea uptake by marine diatoms and coccolithophores under va rious conditions of N availability. Mar.Ecol. Prog. Ser. 109: 29-41. Waser, N.A.D., P.J. Harrison, B. Nielsen, S. E. Calvert, and D.H. Turpin. 1998. Nitrogen isotope fractionation during the uptake a nd assimilation of nitrate, nitrite, ammonium and urea by a marine di atom. Limnol. Oceanogr. 43: 215-224. Waser, N. A. Z. Yu, K. Yin, B. Nielsen, P. J. Harrison, D.H. Turpin, and S.E. Calvert. 1999. N isotopic fractionation furing a simulated diatom spring bloom: importance of N-starvation in controlli ng fractionation. Mar. Ecol. Prog. Ser. 179: 291-296. Weisberg, R.H., B. Black and Z. Li. 2000. An upwelling case study on Florida’s west coast. Geophys. Res., (in press). Wilson, W.B. 1967. The suitability of seawat er for the survival and growth of Gymnodinium breve Davis; and some effects of phosphorus and nitrogen on its growth. Fla. Board Cons.Prof. Pap. Ser.7: 1-42. Wilson, W. B. and A. Collier. 1955. Pr eliminary notes on the culturing of Gymnodinium brevis Davis. Science 121: 394-395. Wong, W.W. 1976. Carbon isotope fractionation by marine phyt oplankton. PhD thesis. Texas A&M University, College Station. 116 pp. Yang, H. and R.H. Weisberg. 1999. Response of the West Florida shelf circulation to climatological wind stress forci ng. J. Geophys. Res.:104: 1221-1245. Zanden, M. Jake Vander, and Joseph B. Rasmussen. 1999. Primary consumer 13C and 15N and the trophic position of aqua tic consumers. Ecology. 80: 1395-1404.

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84 Zehr, Jonathon P. and Bess B. Ward. 2002. Nitrogen cycling in the ocean: new perspectives on processes and paradi gms. App. and Environ. Micro. 68: 10151024.

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85 Appendices

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86 Appendix A: K. brevis counts from 2001 Date Station lat. (oN) long. (oW) Depth K. brevis (cells L-1) Sep-01 1 27.5417 -82.8000 0 1000 Sep-01 3 27.4655 -82.9664 0 0 Sep-01 5 27.3895 -83.1338 0 0 Sep-01 5 27.3895 -83.1338 25 0 Sep-01 7 27.3135 -83.3010 0 0 Sep-01 7 27.3135 -83.3010 30 0 Sep-01 9 27.2380 -83.4683 0 0 Sep-01 10 27.2000 -83.5517 0 0 Sep-01 10 27.2000 -83.5517 40 0 Sep-01 13 26.5490 -84.2264 0 0 Sep-01 13 26.5490 -84.2264 30 0 Sep-01 15 26.6264 -84.0615 0 0 Sep-01 17 26.6918 -83.8891 80 0 Sep-01 19 26.7694 -83.7239 0 0 Sep-01 19 26.7694 -83.7239 65 0 Sep-01 21 26.8500 -83.5604 0 0 Sep-01 21 26.8500 -83.5604 40 0 Sep-01 23 26.9310 -83.3969 0 0 Sep-01 23 26.9310 -83.3969 45 0 Sep-01 25 27.0122 -83.2333 0 0 Sep-01 25 27.0122 -83.2333 40 0 Sep-01 29 27.1744 -82.9052 0 0 Sep-01 30 27.2151 -82.8231 0 0 Sep-01 30 27.2151 -82.8231 15 0 Sep-01 32 27.2960 -82.6592 0 0 Sep-01 33 27.1450 -82.6833 0 0 Sep-01 33 27.1450 -82.6833 13 0 Sep-01 34 26.3795 -82.2707 0 0 Sep-01 34 26.3795 -82.2707 20 0 Sep-01 35 26.3481 -82.3574 0 0 Sep-01 35 26.3481 -82.3574 25 0 Sep-01 37 26.2856 -82.4435 0 0 Sep-01 37 26.2856 -82.4435 30 0 Sep-01 38 26.2545 -82.6157 0 0 Sep-01 38 26.2545 -82.6157 35 0 Sep-01 39 26.2233 -82.7014 0 0 Sep-01 40 26.0667 -83.1317 0 0 Sep-01 40 26.0667 -83.1317 45 0 Sep-01 42 26.1296 -82.9594 0 0 Sep-01 42 26.1296 -82.9594 35 0 Sep-01 44 26.1919 -82.7875 0 0 Sep-01 44 26.1919 -82.7875 30 0

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87 Appendix A: (Continued) Date Station lat. (oN) long. (oW) Depth K. brevis (cells L-1) Sep-01 46 26.2545 -82.6157 0 0 Sep-01 46 26.2545 -82.6157 25 0 Sep-01 48 26.3169 -82.4435 0 16000 Sep-01 50 26.3795 -82.2707 0 13000 Sep-01 51 26.4108 -82.1850 0 4000 Oct-01 3 27.3927 -82.7131 surface 10000000 Oct-01 3 27.3927 -82.7131 0 1000000 Oct-01 4 27.2394 -82.6267 0 302000 Oct-01 6 27.7519 -82.9054 surface 1000000 Oct-01 6 27.7519 -82.9054 0 1000000 Oct-01 7 27.8802 -82.9045 surface 760000 Oct-01 7 27.8802 -82.9045 0 568000 Oct-01 8 28.0001 -82.9049 surface 120000 Oct-01 9 28.1289 -82.9046 surface 24000 Oct-01 9 28.1289 -82.9046 0 18000 Oct-01 10 27.9999 -83.0035 surface 924000 Oct-01 10 27.9999 -83.0035 0 742000 Oct-01 11 28.0011 -83.1395 surface 694000 Oct-01 11 28.0011 -83.1395 0 846000 Oct-01 16 27.8763 -83.1862 surface 9000000 Oct-01 16 27.8763 -83.1862 0 1000000 Oct-01 21 27.7501 -83.0184 0 1000000 Oct-01 21 27.7501 -83.0184 surface 666000 Oct-01 23 27.7504 -83.2602 0 4000 Oct-01 26 27.7554 -83.6189 surface 0 Oct-01 26 27.7554 -83.6189 0 0 Oct-01 29 27.2022 -83.5513 0 0 Oct-01 30 27.3131 -83.3005 0 0 Oct-01 31 27.3336 -83.0077 surface 1000000 Oct-01 31 27.3336 -83.0077 0 596000 Oct-01 32 27.5417 -82.7989 surface 514000 Oct-01 32 27.5417 -82.7989 0 272000 Oct-01 2a 27.5374 -82.8014 surface 680000 Oct-01 2a 27.5374 -82.8014 0 1000000 Nov-01 1 27.5417 -82.8000 0 1560000 Nov-01 3 27.4655 -82.9664 0 284000 Nov-01 5 27.3895 -83.1338 0 24000 Nov-01 7 27.3135 -83.3010 0 0 Nov-01 9 27.2380 -83.4683 0 0 Nov-01 10 27.2000 -83.5517 0 0 Nov-01 11 26.4715 -84.3920 0 0 Nov-01 15 26.6264 -84.0615 0 0

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88 Appendix A: (Continued) Date Station lat. (oN) long. (oW) Depth K. brevis (cells L-1) Nov-01 17 26.6918 -83.8891 0 0 Nov-01 21 26.8500 -83.5604 0 0 Nov-01 23 26.9310 -83.3969 0 0 Nov-01 25 27.0122 -83.2333 0 0 Nov-01 27 27.0932 -83.0693 0 0 Nov-01 29 27.1744 -82.9052 0 10000 Nov-01 30 27.2151 -82.8231 0 1755000 Nov-01 32 27.2960 -82.6592 0 194000 Nov-01 40 26.1919 -82.7875 0 0 Nov-01 42 26.1295 -82.9594 0 0 Nov-01 44 26.0667 -83.1317 0 114000 Nov-01 46 26.9900 -82.7467 0 10000 Nov-01 48 26.6767 -82.8750 0 34000 Nov-01 50 26.3650 -83.0083 0 34000 Nov-01 51 26.2083 -83.0733 0 92000 Nov-01 72 26.6350 -82.2683 0 66000 Nov-01 76 26.9292 -82.3849 0 254000 Nov-01 78 27.0901 -82.5464 0 342000 Nov-01 84 26.1462 -83.1610 0 0 Nov-01 86 26.3042 -83.2200 0 0 Nov-01 88 26.4625 -83.2780 0 0 Nov-01 90 26.6208 -83.3370 0 0 Nov-01 92 26.7791 -83.3950 0 0 Nov-01 94 26.9372 -83.4540 0 0 Nov-01 96 27.0956 -83.5130 0 0 Dec-01 1 27.5417 -82.8000 0 16000 Dec-01 3 27.4655 -82.9664 0 144000 Dec-01 5 27.3895 -83.1338 0 2000 Dec-01 7 27.3135 -83.3010 0 0 Dec-01 9 27.2380 -83.4683 0 0 Dec-01 10 27.2000 -83.5517 0 0 Dec-01 11 26.4715 -84.3920 0 0 Dec-01 13 26.5490 -84.2264 0 0 Dec-01 15 26.6264 -84.0615 0 0 Dec-01 17 26.6918 -83.8891 0 0 Dec-01 19 26.7694 -83.7239 0 0 Dec-01 21 26.8500 -83.5604 0 0 Dec-01 23 26.9310 -83.3969 0 0 Dec-01 25 27.0122 -83.2333 0 0 Dec-01 27 27.0932 -83.0693 0 10000 Dec-01 29 27.1744 -82.9052 0 4000 Dec-01 30 27.2151 -82.8231 0 56000

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89 Appendix A: (Continued) Date Station lat. (oN) long. (oW) Depth K. brevis (cells L-1) Dec-01 32 27.2960 -82.6592 0 68000 Dec-01 33 27.1450 -82.6833 0 224000 Dec-01 34 26.3795 -82.2707 0 54000 Dec-01 35 26.3481 -82.3574 0 108000 Dec-01 36 26.3169 -82.4435 0 0 Dec-01 37 26.2856 -82.5296 0 0 Dec-01 38 26.2545 -82.6157 0 0 Dec-01 39 26.2233 -82.7014 0 0 Dec-01 40 26.1919 -82.7875 0 0 Dec-01 44 26.0667 -83.1317 0 0 Dec-01 46 26.9900 -82.7467 0 0 Dec-01 48 26.6767 -82.8750 0 88000 Dec-01 50 26.3650 -83.0830 0 36000 Dec-01 51 26.2083 -83.0733 0 190000 Dec-01 70 26.4870 -82.2260 0 176000 Dec-01 72 26.6360 -82.3100 0 16000 Dec-01 74 26.7870 -82.3890 0 44000 Dec-01 76 26.9380 -82.4680 0 68000 Dec-01 78 27.0890 -82.5460 0 58000 Dec-01 80 27.2400 -82.6260 0 22000 Dec-01 82 27.3930 -82.7130 0 4000 Dec-01 98 27.3351 -83.0231 0 206000

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90 Appendix B: Chlorophyll a concentrations from 2001 Date Station lat. (oN) long. (oW) Depth chl a average ( g L-1) Sep-01 1 27.5417 -82.8000 0 2.73 Sep-01 3 27.4655 -82.9664 0 0.57 Sep-01 5 27.3895 -83.1338 0 0.44 Sep-01 7 27.3135 -83.3010 0 0.10 Sep-01 9 27.2380 -83.4683 0 0.12 Sep-01 10 27.2000 -83.5517 0 0.11 Sep-01 13 26.4715 -84.3920 0 0.08 Sep-01 15 26.6264 -84.0615 0 0.10 Sep-01 17 26.6918 -83.8891 0 0.10 Sep-01 19 26.7694 -83.7239 0 0.10 Sep-01 21 26.8500 -83.5604 0 0.11 Sep-01 23 26.9310 -83.3969 0 0.10 Sep-01 25 27.0122 -83.2333 0 0.11 Sep-01 27 27.0932 -83.0693 0 0.21 Sep-01 29 27.1744 -82.9052 0 0.24 Sep-01 30 27.2151 -82.8231 0 0.29 Sep-01 32 27.2960 -82.6592 0 1.21 Sep-01 33 27.1450 -82.6833 0 0.43 Sep-01 34 26.9900 -82.7467 0 0.22 Sep-01 35 26.8333 -82.8167 0 0.17 Sep-01 36 26.6767 -82.8750 0 0.12 Sep-01 37 26.5233 -82.9433 0 0.13 Sep-01 38 26.3650 -83.0083 0 0.11 Sep-01 39 26.2083 -83.0733 0 0.10 Sep-01 40 26.0667 -83.1317 0 0.08 Sep-01 42 26.1296 -82.9594 0 0.13 Sep-01 44 26.1919 -82.7875 0 0.11 Sep-01 46 26.2545 -82.6157 0 0.20 Sep-01 48 26.3169 -82.4435 0 2.07 Sep-01 50 26.3795 -82.2707 0 1.64 Sep-01 51 26.4108 -82.1850 0 1.50 Sep-01 70 26.4870 -82.2260 0 2.72 Sep-01 71 26.5620 -82.2680 0 2.92 Sep-01 72 26.6360 -82.3100 0 4.42 Sep-01 73 26.7110 -82.3340 0 9.49 Sep-01 74 26.7870 -82.3890 0 1.99 Sep-01 75 26.8627 -82.4290 0 1.00 Oct-01 3 27.3927 -82.7131 surface 11.62 Oct-01 3 27.3927 -82.7131 0 11.51 Oct-01 4 27.2394 -82.6267 surface 5.64 Oct-01 4 27.2394 -82.6267 0 4.88 Oct-01 6 27.7529 -82.9054 surface 9.17

PAGE 101

91 Appendix B: (Continued) Date Station lat. (oN) long. (oW) Depth chl a average ( g L-1) Oct-01 6 27.7529 -82.9054 0 6.28 Oct-01 7 27.8802 -82.9045 surface 8.06 Oct-01 7 27.8802 -82.9045 0 8.33 Oct-01 8 28.0001 -82.9049 surface 2.95 Oct-01 8 28.0001 -82.9049 0 2.84 Oct-01 9 28.1289 -82.9046 surface 1.47 Oct-01 9 28.1289 -82.9046 0 1.32 Oct-01 10 27.9998 -83.0035 surface 11.66 Oct-01 10 27.9998 -83.0035 0 10.68 Oct-01 11 28.0011 -83.1395 surface 8.61 Oct-01 11 28.0011 -83.1395 0 7.98 Oct-01 16 27.8763 -83.1862 surface 24.26 Oct-01 16 27.8763 -83.1862 0 5.71 Oct-01 21 27.7501 -83.0184 0 12.29 Oct-01 21 27.7501 -83.0184 surface 9.72 Oct-01 23 27.7504 -83.2602 0 0.82 Oct-01 26 27.7554 -83.6189 surface 0.22 Oct-01 26 27.7554 -83.6189 0 0.23 Oct-01 29 27.2022 -83.5513 0 0.11 Oct-01 30 27.3131 -83.3005 0 0.3 Oct-01 31 27.4446 -83.0077 surface 15.65 Oct-01 31 27.4446 -83.0077 0 16.09 Oct-01 32 27.5417 -82.7989 surface 6.02 Oct-01 32 27.5417 -82.7989 0 4.35 Oct-01 2a 27.5374 -82.8014 surface 10.91 Oct-01 2a 27.5374 -82.8014 0 8.79 Nov-01 1 27.5417 -82.8000 0 1.96 Nov-01 3 27.4655 -82.9664 0 2.55 Nov-01 5 27.3895 -83.1338 0 0.43 Nov-01 7 27.3135 -83.3010 0 0.3 Nov-01 9 27.2380 -83.4683 0 0.38 Nov-01 10 27.2000 -83.5517 0 0.36 Nov-01 11 26.4715 -84.3920 0 0.17 Nov-01 15 26.6264 -84.0615 0 0.19 Nov-01 17 26.6918 -83.8891 0 0.2 Nov-01 21 26.8500 -83.5604 0 0.2 Nov-01 23 26.9310 -83.3969 0 0.27 Nov-01 25 27.0122 -83.2333 0 0.35 Nov-01 27 27.0932 -83.0693 0 0.32 Nov-01 29 27.1744 -82.9052 0 0.6 Nov-01 30 27.2151 -82.8231 0 5.22 Nov-01 32 27.2960 -82.6592 0 1.36

PAGE 102

92 Appendix B: (Continued) Date Station lat. (oN) long. (oW) Depth chl a average ( g L-1) Nov-01 40 26.1919 -82.7875 0 0.3 Nov-01 42 26.1295 -82.9594 0 0.44 Nov-01 44 26.0667 -83.1317 0 1.17 Nov-01 46 26.9900 -82.7647 0 1.37 Nov-01 48 26.6767 -82.8750 0 2.76 Nov-01 50 26.3650 -83.0083 0 2.63 Nov-01 51 26.3083 -83.0733 0 3.28 Nov-01 72 26.6350 -82.2683 0 2.13 Nov-01 76 26.9292 -82.3849 0 1.84 Nov-01 78 27.0901 -82.5464 0 2.05 Nov-01 84 26.1462 -83.1613 0 0.3 Nov-01 86 26.3042 -83.2197 0 0.82 Nov-01 88 26.4625 -83.2782 0 0.38 Nov-01 90 26.6208 -83.3368 0 0.39 Nov-01 92 26.7791 -83.3953 0 0.33 Nov-01 94 26.9372 -83.4543 0 0.27 Nov-01 96 27.0956 -83.5130 0 0.36 Dec-01 33 27.1450 -82.6833 0 1.36 Dec-01 34 26.3795 -82.2707 0 0.52 Dec-01 35 26.3481 -82.3574 0 1.24 Dec-01 36 26.3169 -82.4435 0 0.46 Dec-01 37 26.2856 -82.5296 0 0.42 Dec-01 38 26.2545 -82.6157 0 0.2 Dec-01 39 26.2233 -82.7014 0 0.16 Dec-01 40 26.1919 -82.7875 0 0.19 Dec-01 44 26.0667 -83.1317 0 0.2 Dec-01 46 26.9900 -82.7467 0 0.43 Dec-01 48 26.6767 -82.8750 0 1.3 Dec-01 50 26.3650 -83.0083 0 2.81 Dec-01 51 26.2083 -83.0733 0 4.59 Dec-01 70 26.4870 -82.2260 0 3.27 Dec-01 72 26.6360 -82.3100 0 2 Dec-01 74 26.7870 -82.3890 0 2.4 Dec-01 76 26.9380 -82.4680 0 3.34 Dec-01 78 27.0890 -82.5460 0 1.88 Dec-01 80 27.2400 -82.6260 0 1.69 Dec-01 82 27.3930 -82.7130 0 1.9

PAGE 103

93 Appendix C: C:N of particulate organic matter from 2001 Date station lat. (oN) long. (oW) depth C:N ( M) Sep-01 1 27.5417 -82.8000 0 6.4 Sep-01 3 27.4655 -82.9664 0 2.73 Sep-01 5 27.3895 -83.1338 0 1.89 Sep-01 7 27.3135 -83.3010 0 2.96 Sep-01 9 27.2380 -83.4683 0 5.72 Sep-01 10 27.2000 -83.5517 0 13.36 Sep-01 13 26.5490 -84.2264 0 2.68 Sep-01 19 26.7694 -83.7239 0 4.21 Sep-01 21 26.8500 -83.5604 0 1.5 Sep-01 23 26.9310 -83.3969 0 7.34 Sep-01 29 27.1744 -82.9052 0 2.41 Sep-01 30 27.2151 -82.8231 0 7.3 Sep-01 32 27.2960 -82.6592 0 7.73 Sep-01 38 26.2545 -82.6157 0 3.19 Sep-01 40 26.1919 -82.7875 0 4.83 Sep-01 44 26.0667 -83.1317 0 5.96 Sep-01 48 26.6767 -82.8750 0 6.84 Sep-01 51 26.2083 -83.0733 0 4.69 Sep-01 70 26.4848 -82.2249 0 5.84 Sep-01 72 26.6350 -82.2683 0 6.48 Sep-01 73 26.7124 -82.3348 0 8.12 Sep-01 74 26.7861 -82.3347 0 4.41 Sep-01 75 26.8633 -82.4294 0 5.66 Oct-01 3 27.3927 -82.7131 0 8.43 Oct-01 4 27.2394 -82.6267 0 4.65 Oct-01 8 28.0001 -82.9049 surface 8.96 Oct-01 9 28.1289 -82.9046 0 3.93 Oct-01 11 28.0011 -83.1395 0 5.92 Oct-01 13 27.9927 -83.3684 0 2.01 Oct-01 16 27.8763 -83.1862 0 3.47 Oct-01 23 27.7504 -83.2602 0 6.01 Oct-01 26 27.7554 -83.6189 0 5.69 Oct-01 30 27.3131 -83.3005 0 0.69 Oct-01 32 27.5417 -82.7989 0 7.1 Oct-01 32 27.5417 -82.7989 surface 4.98 Oct-01 2a 27.5374 -82.8014 0 5.88 Nov-01 1 27.5417 -82.8000 0 5.14 Nov-01 3 27.4655 -82.9664 0 8.09 Nov-01 5 27.3895 -83.1338 0 9.21 Nov-01 7 27.3135 -83.3010 0 17.5 Nov-01 9 27.2380 -83.4683 0 11.08 Nov-01 10 27.2000 -83.5517 0 10.39

PAGE 104

94 Appendix C: (Continued) Date station lat. (oN) long. (oW) depth C:N ( M) Nov-01 11 26.4715 -84.3920 0 11.15 Nov-01 15 26.6264 -84.0615 0 15.4 Nov-01 17 26.6918 -83.8891 0 20.9 Nov-01 21 26.8500 -83.5604 0 6.55 Nov-01 23 26.9310 -83.3969 0 11.83 Nov-01 27 27.0932 -83.0693 0 9.03 Nov-01 29 27.1744 -82.9052 0 11.28 Nov-01 30 27.2151 -82.8231 0 10.3 Nov-01 32 27.2960 -82.6592 0 11.66 Nov-01 40 26.1919 -82.7875 0 8.75 Nov-01 44 26.0667 -83.1317 0 11.97 Nov-01 46 26.9900 -82.7467 0 10.87 Nov-01 48 26.6767 -82.8750 0 8.83 Nov-01 51 26.2083 -83.0733 0 8.72 Nov-01 72 26.6350 -82.2683 0 12.55 Nov-01 76 26.9292 -82.3849 0 12.99 Nov-01 78 27.0901 -82.5464 0 12.3 Nov-01 84 26.1462 -83.1613 0 9.7 Nov-01 88 26.4625 -83.2782 0 16.19 Nov-01 92 26.7791 -83.3953 0 12.02 Nov-01 96 27.0956 -83.5130 0 11.47 Dec-01 1 27.5417 -82.8000 0 2.17 Dec-01 3 27.4655 -82.9664 0 5.17 Dec-01 5 27.3895 -83.1338 0 13.89 Dec-01 7 27.3135 -83.3010 0 12.73 Dec-01 9 27.2380 -83.4683 0 16.46 Dec-01 10 27.2000 -83.5517 0 12.56 Dec-01 11 26.4715 -84.3920 0 17.14 Dec-01 13 26.5490 -84.2264 0 10.14 Dec-01 19 26.7694 -83.7239 0 16.98 Dec-01 21 26.8500 -83.5604 0 15.75 Dec-01 23 26.9310 -83.3969 0 10.76 Dec-01 27 27.0932 -83.0693 0 12.26 Dec-01 29 27.1744 -82.9052 0 11.84 Dec-01 30 27.2151 -82.8231 0 12.87 Dec-01 32 27.2960 -82.6592 0 9.86 Dec-01 34 26.3795 -82.2707 0 9.07 Dec-01 36 26.3169 -82.4435 0 8.85 Dec-01 38 26.2545 -82.6157 0 12.28 Dec-01 40 26.1919 -82.7875 0 10.36 Dec-01 44 26.0667 -83.1317 0 4.97 Dec-01 48 26.6767 -82.8750 0 10.18

PAGE 105

95 Appendix C: (Continued) Date station lat. (oN) long. (oW) depth C:N ( M) Dec-01 51 26.2083 -83.0733 0 17.5 Dec-01 70 26.4870 -82.2260 0 9.32 Dec-01 72 26.6360 -82.3100 0 10.51 Dec-01 74 26.7870 -82.3890 0 10.69 Dec-01 76 26.9380 -82.4680 0 11.28 Dec-01 78 27.0901 -82.5464 0 11.51 Dec-01 80 27.2408 -82.6270 0 11.25 Dec-01 82 27.3930 -82.7130 0 10.15

PAGE 106

96 Appendix D: Dissolved inorganic nitrogen concentrations from 2001 Date station lat. (oN) long. (oW) depth DIN ( M) Sep-01 1 27.5417 -82.8000 0 0.02 Sep-01 3 27.4655 -82.9664 3 0.01 Sep-01 3 27.4655 -82.9664 0 0.00 Sep-01 3 27.4655 -82.9664 13 0.00 Sep-01 3 27.4655 -82.9664 5 0.01 Sep-01 3 27.4655 -82.9664 10 0.01 Sep-01 5 27.3895 -83.1338 0 0.00 Sep-01 5 27.3895 -83.1338 10 0.04 Sep-01 5 27.3895 -83.1338 20 0.00 Sep-01 5 27.3895 -83.1338 25 0.01 Sep-01 7 26.2918 -83.8891 0 0.00 Sep-01 7 26.2918 -83.8891 10 0.00 Sep-01 7 26.2918 -83.8891 20 0.00 Sep-01 7 26.2918 -83.8891 30 0.01 Sep-01 7 26.2918 -83.8891 35 0.01 Sep-01 9 27.2380 -83.4683 0 0.07 Sep-01 9 27.2380 -83.4683 10 0.00 Sep-01 9 27.2380 -83.4683 20 0.04 Sep-01 9 27.2380 -83.4683 30 0.05 Sep-01 9 27.2380 -83.4683 40 0.04 Sep-01 10 27.2000 -83.5517 0 0.03 Sep-01 10 27.2000 -83.5517 5 0.11 Sep-01 10 27.2000 -83.5517 10 0.13 Sep-01 10 27.2000 -83.5517 15 0.00 Sep-01 10 27.2000 -83.5517 20 0.00 Sep-01 10 27.2000 -83.5517 25 0.01 Sep-01 10 27.2000 -83.5517 30 0.03 Sep-01 10 27.2000 -83.5517 35 0.05 Sep-01 10 27.2000 -83.5517 40 0.00 Sep-01 10 27.2000 -83.5517 45 0.15 Sep-01 13 26.5490 -84.2264 0 0.00 Sep-01 13 26.5490 -84.2264 10 0.00 Sep-01 13 26.5490 -84.2264 20 0.00 Sep-01 13 26.5490 -84.2264 30 0.00 Sep-01 13 26.5490 -84.2264 50 0.01 Sep-01 13 26.5490 -84.2264 75 4.11 Sep-01 13 26.5490 -84.2264 100 7.93 Sep-01 13 26.5490 -84.2264 150 11.81 Sep-01 13 26.5490 -84.2264 155 12.14 Sep-01 15 26.6264 -84.0615 0 0.00 Sep-01 17 26.6918 -83.8891 10 0.00 Sep-01 17 26.6918 -83.8891 20 0.00

PAGE 107

97 Appendix D: (Continued) Date station lat. (oN) long. (oW) depth DIN ( M) Sep-01 17 26.6918 -83.8891 30 0.00 Sep-01 17 26.6918 -83.8891 40 0.00 Sep-01 17 26.6918 -83.8891 50 0.00 Sep-01 17 26.6918 -83.8891 60 0.04 Sep-01 17 26.6918 -83.8891 70 1.16 Sep-01 17 26.6918 -83.8891 80 1.80 Sep-01 19 26.7694 -83.7239 0 0.00 Sep-01 19 26.7694 -83.7239 10 0.00 Sep-01 19 26.7694 -83.7239 20 0.05 Sep-01 19 26.7694 -83.7239 30 0.11 Sep-01 19 26.7694 -83.7239 40 0.00 Sep-01 19 26.7694 -83.7239 50 0.00 Sep-01 19 26.7694 -83.7239 60 0.29 Sep-01 19 26.7694 -83.7239 65 0.97 Sep-01 21 26.8500 -83.5604 0 0.00 Sep-01 21 26.8500 -83.5604 10 0.00 Sep-01 21 26.8500 -83.5604 20 0.03 Sep-01 21 26.8500 -83.5604 30 0.00 Sep-01 21 26.8500 -83.5604 40 0.22 Sep-01 21 26.8500 -83.5604 50 3.28 Sep-01 23 26.9310 -83.3969 0 0.01 Sep-01 23 26.9310 -83.3969 5 0.11 Sep-01 23 26.9310 -83.3969 10 0.05 Sep-01 23 26.9310 -83.3969 15 0.06 Sep-01 23 26.9310 -83.3969 20 0.10 Sep-01 23 26.9310 -83.3969 25 0.01 Sep-01 23 26.9310 -83.3969 30 0.03 Sep-01 23 26.9310 -83.3969 35 0.00 Sep-01 23 26.9310 -83.3969 40 0.13 Sep-01 23 26.9310 -83.3969 45 1.26 Sep-01 25 27.0122 -83.2333 0 0.06 Sep-01 25 27.0122 -83.2333 5 0.03 Sep-01 25 27.0122 -83.2333 10 0.02 Sep-01 25 27.0122 -83.2333 15 0.16 Sep-01 25 27.0122 -83.2333 20 0.07 Sep-01 25 27.0122 -83.2333 25 0.13 Sep-01 25 27.0122 -83.2333 30 0.12 Sep-01 25 27.0122 -83.2333 35 0.33 Sep-01 25 27.0122 -83.2333 40 0.39 Sep-01 27 27.0932 -83.0693 0 0.04 Sep-01 27 27.0932 -83.0693 5 0.04 Sep-01 27 27.0932 -83.0693 10 0.11

PAGE 108

98 Appendix D: (Continued) Date station lat. (oN) long. (oW) depth DIN ( M) Sep-01 27 27.0932 -83.0693 15 0.06 Sep-01 27 27.0932 -83.0693 20 0.04 Sep-01 27 27.0932 -83.0693 25 0.17 Sep-01 27 27.0932 -83.0693 30 0.11 Sep-01 29 27.1744 -82.9052 0 0.05 Sep-01 29 27.1744 -82.9052 5 0.05 Sep-01 29 27.1744 -82.9052 10 0.03 Sep-01 29 27.1744 -82.9052 15 0.06 Sep-01 29 27.1744 -82.9052 20 0.15 Sep-01 30 27.2151 -82.8231 0 0.23 Sep-01 30 27.2151 -82.8231 5 0.00 Sep-01 30 27.2151 -82.8231 10 0.00 Sep-01 30 27.2151 -82.8231 15 0.00 Sep-01 32 27.2960 -82.6592 0 0.11 Sep-01 32 27.2960 -82.6592 5 0.01 Sep-01 32 27.2960 -82.6592 8 0.01 Sep-01 33 27.1450 -82.6833 0 0.01 Sep-01 33 27.1450 -82.6833 10 0.27 Sep-01 33 27.1450 -82.6833 13 0.00 Sep-01 34 26.3795 -82.2707 0 0.05 Sep-01 34 26.3795 -82.2707 10 0.05 Sep-01 34 26.3795 -82.2707 20 0.02 Sep-01 35 26.3481 -82.3574 0 0.03 Sep-01 35 26.3481 -82.3574 10 0.05 Sep-01 35 26.3481 -82.3574 20 0.03 Sep-01 35 26.3481 -82.3574 25 0.00 Sep-01 36 26.3169 -82.4435 0 -0.03 Sep-01 36 26.3169 -82.4435 10 0.00 Sep-01 36 26.3169 -82.4435 20 0.00 Sep-01 36 26.3169 -82.4435 25 0.00 Sep-01 37 26.2856 -82.5296 0 0.00 Sep-01 37 26.2856 -82.5296 10 0.00 Sep-01 37 26.2856 -82.5296 20 0.00 Sep-01 37 26.2856 -82.5296 30 0.00 Sep-01 38 26.2545 -82.6157 0 0.00 Sep-01 38 26.2545 -82.6157 10 0.00 Sep-01 38 26.2545 -82.6157 20 0.00 Sep-01 38 26.2545 -82.6157 30 0.00 Sep-01 38 26.2545 -82.6157 35 0.01 Sep-01 39 26.2233 -82.7014 0 0.00 Sep-01 39 26.2233 -82.7014 10 0.01 Sep-01 39 26.2233 -82.7014 20 0.00

PAGE 109

99 Appendix D: (Continued) Date station lat. (oN) long. (oW) depth DIN ( M) Sep-01 39 26.2233 -82.7014 30 0.00 Sep-01 39 26.2233 -82.7014 40 0.04 Sep-01 40 26.0667 -83.1317 0 0.02 Sep-01 40 26.0667 -83.1317 5 0.00 Sep-01 40 26.0667 -83.1317 10 0.00 Sep-01 40 26.0667 -83.1317 15 0.00 Sep-01 40 26.0667 -83.1317 20 0.00 Sep-01 40 26.0667 -83.1317 25 0.00 Sep-01 40 26.0667 -83.1317 30 0.00 Sep-01 40 26.0667 -83.1317 35 0.00 Sep-01 40 26.0667 -83.1317 40 0.01 Sep-01 40 26.0667 -83.1317 45 0.11 Sep-01 42 26.1296 -82.9594 0 0.00 Sep-01 42 26.1296 -82.9594 10 0.00 Sep-01 42 26.1296 -82.9594 20 0.00 Sep-01 42 26.1296 -82.9594 30 0.00 Sep-01 42 26.1296 -82.9594 35 0.01 Sep-01 44 26.1919 -82.7875 0 0.00 Sep-01 44 26.1919 -82.7875 10 0.00 Sep-01 44 26.1919 -82.7875 20 0.01 Sep-01 44 26.1919 -82.7875 30 0.00 Sep-01 46 26.2545 -81.6157 0 0.00 Sep-01 46 26.2545 -81.6157 10 0.00 Sep-01 46 26.2545 -81.6157 20 0.13 Sep-01 46 26.2545 -81.6157 25 0.11 Sep-01 48 26.3169 -82.4435 0 0.01 Sep-01 48 26.3169 -82.4435 10 0.00 Sep-01 48 26.3169 -82.4435 15 0.02 Sep-01 50 26.3795 -82.2707 0 0.24 Sep-01 50 26.3795 -82.2707 5 0.01 Sep-01 50 26.3795 -82.2707 10 0.03 Sep-01 51 26.4108 -82.1850 0 0.03 Sep-01 51 26.4108 -82.1850 5 0.01 Oct-01 3 27.3927 -82.7131 surface 0.00 Oct-01 3 27.3927 -82.7131 0 0.00 Oct-01 3 27.3927 -82.7131 5 0.00 Oct-01 4 27.2394 -82.6267 surface 0.00 Oct-01 4 27.2394 -82.6267 0 0.00 Oct-01 4 27.2394 -82.6267 5 0.00 Oct-01 6 27.7519 -82.9054 surface 0.00 Oct-01 6 27.7519 -82.9054 0 0.00 Oct-01 6 27.7519 -82.9054 5 0.00

PAGE 110

100 Appendix D: (Continued) Date station lat. (oN) long. (oW) depth DIN ( M) Oct-01 7 27.8802 -82.9045 surface 0.03 Oct-01 7 27.8802 -82.9045 0 0.00 Oct-01 7 27.8802 -82.9045 5 0.00 Oct-01 8 28.0001 -82.9049 surface 0.12 Oct-01 8 28.0001 -82.9049 0 0.02 Oct-01 8 28.0001 -82.9049 5 0.23 Oct-01 9 28.1289 -82.9046 surface 0.02 Oct-01 9 28.1289 -82.9046 0 0.01 Oct-01 9 28.1289 -82.9046 5 0.09 Oct-01 10 27.9998 -83.0035 surface 0.01 Oct-01 10 27.9998 -83.0035 0 0.00 Oct-01 10 27.9998 -83.0035 5 0.00 Oct-01 10 27.9998 -83.0035 10 0.00 Oct-01 11 28.0011 -83.1395 surface 0.03 Oct-01 11 28.0011 -83.1395 0 0.00 Oct-01 11 28.0011 -83.1395 5 0.03 Oct-01 11 28.0011 -83.1395 15 0.01 Oct-01 16 27.8763 -83.1862 surface 0.01 Oct-01 16 27.8763 -83.1862 0 0.00 Oct-01 16 27.8763 -83.1862 10 0.00 Oct-01 16 27.8763 -83.1862 20 0.00 Oct-01 21 27.7501 -83.0184 0 0.03 Oct-01 21 27.7501 -83.0184 surface 0.03 Oct-01 21 27.7501 -83.0184 5 0.01 Oct-01 23 27.7504 -83.0184 0 0.00 Oct-01 23 27.7504 -83.0184 10 0.00 Oct-01 23 27.7504 -83.0184 20 0.00 Oct-01 26 27.7554 -83.6189 surface 0.00 Oct-01 26 27.7554 -83.6189 0 0.00 Oct-01 26 27.7554 -83.6189 10 0.00 Oct-01 26 27.7554 -83.6189 35 0.89 Oct-01 29 27.2022 -83.5513 0 0.00 Oct-01 29 27.2022 -83.5513 5 0.00 Oct-01 29 27.2022 -83.5513 10 0.00 Oct-01 29 27.2022 -83.5513 15 0.00 Oct-01 29 27.2022 -83.5513 20 0.00 Oct-01 29 27.2022 -83.5513 25 0.01 Oct-01 29 27.2022 -83.5513 30 0.00 Oct-01 29 27.2022 -83.5513 35 0.00 Oct-01 29 27.2022 -83.5513 40 0.21 Oct-01 29 27.2022 -83.5513 45 0.14 Oct-01 30 27.3131 -83.3005 0 0.00

PAGE 111

101 Appendix D: (Continued) Date station lat. (oN) long. (oW) depth DIN ( M) Oct-01 30 27.3131 -83.3005 10 0.00 Oct-01 30 27.3131 -83.3005 20 0.00 Oct-01 30 27.3131 -83.3005 30 0.44 Oct-01 30 27.3131 -83.3005 35 1.79 Oct-01 31 27.4446 -83.0077 surface 0.01 Oct-01 31 27.4446 -83.0077 0 0.02 Oct-01 31 27.4446 -83.0077 7 0.07 Oct-01 31 27.4446 -83.0077 15 0.05 Oct-01 32 27.5417 -82.7989 surface 0.00 Oct-01 32 27.5417 -82.7989 0 0.01 Oct-01 32 27.5417 -82.7989 5 0.03 Oct-01 2a 27.5374 -82.8014 surface 0.00 Oct-01 2a 27.5374 -82.8014 0 0.00 Oct-01 2a 27.5374 -82.8014 5 0.00 Nov-01 1 27.5417 -82.8000 0 0.03 Nov-01 3 27.4655 -82.9664 0 0.03 Nov-01 5 27.3895 -83.1338 0 0.01 Nov-01 7 27.3135 -83.3010 0 0.01 Nov-01 9 27.2380 -83.4683 0 0.08 Nov-01 10 27.2000 -83.5517 0 0.05 Nov-01 11 26.4715 -84.3920 0 0.02 Nov-01 15 26.6264 -84.0615 0 0.05 Nov-01 17 26.6918 -83.8891 0 0.02 Nov-01 21 26.8500 -83.5604 0 0.01 Nov-01 23 26.9310 -83.3969 0 0.01 Nov-01 25 27.0122 -83.2333 0 0.00 Nov-01 27 27.0932 -83.0693 0 0.09 Nov-01 29 27.1744 -82.9052 0 0.01 Nov-01 30 27.2151 -82.8231 0 0.02 Nov-01 32 27.2960 -82.6592 0 0.02 Nov-01 40 26.1919 -82.7875 0 0.00 Nov-01 42 26.1295 -82.9594 0 0.01 Nov-01 44 26.0667 -83.1317 0 0.01 Nov-01 46 26.9900 -82.7467 0 0.00 Nov-01 48 26.6767 -82.8750 0 0.02 Nov-01 50 26.3650 -83.0083 0 0.02 Nov-01 51 26.2083 -83.0733 0 0.02 Nov-01 72 26.6350 -82.2683 0 0.02 Nov-01 76 26.9292 -82.3849 0 0.01 Nov-01 78 27.0901 -82.5464 0 0.01 Nov-01 84 26.1462 -83.1613 0 0.04 Nov-01 86 26.3042 -83.2197 0 0.01

PAGE 112

102 Appendix D: (Continued) Date station lat. (oN) long. (oW) depth DIN ( M) Nov-01 88 26.4625 -83.2782 0 0.05 Nov-01 90 26.6208 -83.3368 0 0.00 Nov-01 92 26.7791 -83.3953 0 0.01 Nov-01 94 26.9372 -83.4543 0 0.00 Nov-01 96 27.0956 -83.5130 0 0.00 Dec-01 1 27.5417 -82.8000 0 0.02 Dec-01 3 27.4655 -82.9663 0 0.00 Dec-01 5 27.3895 -83.1337 0 0.00 Dec-01 7 27.3135 -83.3010 0 0.00 Dec-01 9 27.2380 -83.4683 0 0.00 Dec-01 10 27.2000 -83.5517 0 0.00 Dec-01 11 26.4715 -84.3920 0 0.00 Dec-01 13 26.5490 -84.2264 0 0.00 Dec-01 15 26.6264 -84.0615 0 0.00 Dec-01 17 26.6918 -83.8891 0 0.00 Dec-01 19 26.7694 -83.7239 0 0.00 Dec-01 21 26.8500 -83.5604 0 0.00 Dec-01 23 26.9310 -83.3969 0 0.00 Dec-01 25 27.0122 -83.2333 0 0.00 Dec-01 27 27.0932 -83.0693 0 0.00 Dec-01 29 27.1744 -82.9052 0 0.00 Dec-01 30 27.2151 -82.8231 0 0.00 Dec-01 32 27.2960 -82.6592 0 0.04 Dec-01 33 27.1450 -82.6833 0 0.00 Dec-01 34 26.3795 -82.2707 0 0.00 Dec-01 35 26.3481 -82.3574 0 0.00 Dec-01 36 26.3169 -82.4435 0 0.00 Dec-01 37 26.2856 -82.5296 0 0.00 Dec-01 38 26.2545 -82.6157 0 0.00 Dec-01 39 26.2233 -82.7014 0 0.00 Dec-01 40 26.1919 -82.7875 0 0.00 Dec-01 44 26.0667 -83.1317 0 0.00 Dec-01 46 26.9900 -82.7467 0 0.00 Dec-01 48 26.6767 -82.8750 0 0.05 Dec-01 50 26.3650 -83.0083 0 0.00 Dec-01 51 26.2083 -83.0733 0 0.03 Dec-01 70 26.4870 -82.2260 0 0.00 Dec-01 72 26.6360 -82.3100 0 0.00 Dec-01 74 26.7870 -82.3890 0 0.00 Dec-01 76 26.9380 -82.4680 0 0.00 Dec-01 78 27.0890 -82.5460 0 0.02 Dec-01 80 27.2400 -82.6260 0 0.23

PAGE 113

103 Appendix D: (Continued) Date station lat. (oN) long. (oW) depth DIN ( M) Dec-01 82 27.3930 -82.7130 0 0.00 Dec-01 98 27.3351 -83.0231 0 0.00

PAGE 114

104 Appendix E: Dissolved inorganic ph osphorus concentrations from 2001 Date station lat. (oN) long. (oW) depth DIP ( M) Sep-01 1 27.5417 -82.8000 0 0.24 Sep-01 3 27.4655 -82.9664 0 0.03 Sep-01 5 27.3895 -83.1338 0 0.00 Sep-01 7 27.3135 -83.3010 0 0.00 Sep-01 9 27.2380 -83.4683 0 0.00 Sep-01 10 27.2000 -83.5517 0 0.00 Sep-01 13 26.5490 -84.2264 0 0.00 Sep-01 15 26.6264 -84.0615 0 0.03 Sep-01 17 26.6918 -83.8891 0 -0.01 Sep-01 19 26.7694 -83.7239 0 0.02 Sep-01 21 26.8500 -83.5604 0 0.00 Sep-01 23 26.9310 -83.3969 0 0.00 Sep-01 25 27.0122 -83.2333 0 0.00 Sep-01 27 27.0932 -83.0693 0 0.00 Sep-01 29 27.1744 -82.9052 0 0.02 Sep-01 30 27.2151 -82.8231 0 0.01 Sep-01 32 27.2960 -82.6592 0 0.09 Sep-01 33 27.1450 -82.6833 0 0.04 Sep-01 34 26.3795 -82.2707 0 0.02 Sep-01 35 26.3481 -82.3574 0 0.01 Sep-01 36 26.3169 -82.4435 0 0.00 Sep-01 37 26.2856 -82.5296 0 0.00 Sep-01 38 26.2545 -82.6157 0 0.01 Sep-01 39 26.2233 -82.7014 0 0.02 Sep-01 40 26.1919 -82.7875 0 0.05 Sep-01 42 26.1295 -82.9594 0 0.02 Sep-01 44 26.0667 -83.1317 0 0.05 Sep-01 46 26.9900 -82.7467 0 0.02 Sep-01 48 26.6767 -82.8750 0 0.08 Sep-01 50 26.3650 -83.0083 0 0.10 Sep-01 51 26.2083 -83.0733 0 0.09 Sep-01 70 26.4870 -82.2260 0 0.04 Sep-01 72 26.6360 -82.3100 0 0.11 Sep-01 73 26.7124 -82.3348 0 1.25 Sep-01 74 26.7870 -82.3890 0 0.39 Sep-01 76 26.9380 -82.4680 0 0.14 Sep-01 78 27.0890 -82.5460 0 0.13 Sep-01 80 27.2400 -82.6260 0 0.2 Sep-01 82 27.3930 -82.7130 0 0.17 Oct-01 3 27.3927 -82.7131 0 0.42 Oct-01 4 27.2394 -82.6267 0 0.31 Oct-01 6 27.7519 -82.9054 0 0.10

PAGE 115

105 Appendix E: (Continued) Date station lat. (oN) long. (oW) depth DIP ( M) Oct-01 7 27.8802 -82.9045 0 0.00 Oct-01 8 28.0001 -82.9049 0 0.00 Oct-01 9 28.1289 -82.9046 0 0.00 Oct-01 10 27.9998 -83.0035 0 0.02 Oct-01 11 28.0011 -83.1395 0 0.00 Oct-01 13 27.9927 -83.3684 0 0.00 Oct-01 16 27.8763 -83.1862 0 0.00 Oct-01 21 27.7501 -83.0184 0 0.06 Oct-01 23 27.7504 -83.2602 0 0.00 Oct-01 26 27.7554 -83.6189 0 0.00 Oct-01 29 27.2022 -83.5513 0 0.02 Oct-01 30 27.3131 -83.3005 0 0.00 Oct-01 31 27.4446 -83.0077 0 0.07 Oct-01 32 27.5417 -82.7989 0 0.17 Oct-01 2a 27.5374 -82.8014 0 0.29 Nov-01 1 27.5417 -82.8000 0 0.34 Nov-01 3 27.4655 -82.9664 0 0.08 Nov-01 5 27.3895 -83.1338 0 0.01 Nov-01 7 27.3135 -83.3010 0 0.03 Nov-01 9 27.2380 -83.4683 0 0.08 Nov-01 10 27.2000 -83.5517 0 0.11 Nov-01 11 26.4715 -84.3920 0 0.02 Nov-01 15 26.6264 -84.0615 0 0.05 Nov-01 17 26.6918 -83.8891 0 0.07 Nov-01 21 26.8500 -83.5604 0 0.03 Nov-01 23 26.9310 -83.3969 0 0.06 Nov-01 25 27.0122 -83.2333 0 0.01 Nov-01 27 27.0932 -83.0693 0 0.01 Nov-01 29 27.1744 -82.9052 0 0.01 Nov-01 30 27.2151 -82.8231 0 0.14 Nov-01 32 27.2960 -82.6592 0 0.10 Nov-01 40 26.1919 -82.7875 0 0.00 Nov-01 42 26.1295 -82.9594 0 0.00 Nov-01 44 26.0667 -83.1317 0 0.02 Nov-01 46 26.9900 -82.7467 0 0.06 Nov-01 48 26.6767 -82.8750 0 0.10 Nov-01 50 26.3650 -83.0083 0 0.13 Nov-01 51 26.2083 -83.0733 0 0.26 Nov-01 72 26.6360 -82.3100 0 0.00 Nov-01 76 26.9380 -82.4680 0 0.00 Nov-01 78 27.0890 -82.5460 0 0.00 Nov-01 84 26.1462 -83.1613 0 0.00

PAGE 116

106 Appendix E: (Continued) Date station lat. (oN) long. (oW) depth DIP ( M) Nov-01 86 26.3042 -83.2197 0 0.00 Nov-01 88 26.4625 -83.2782 0 0.00 Nov-01 90 26.6208 -83.3368 0 0.00 Nov-01 92 26.7791 -83.3953 0 0.00 Nov-01 94 26.9372 -83.4543 0 0.00 Nov-01 96 27.0955 -83.5130 0 0.00 Dec-01 1 27.5417 -82.8000 0 0.11 Dec-01 3 27.4655 -82.9664 0 0.02 Dec-01 5 27.3895 -83.1338 0 0.00 Dec-01 7 27.3135 -83.3010 0 0.00 Dec-01 9 27.2380 -83.4683 0 0.00 Dec-01 10 27.2000 -83.5517 0 0.00 Dec-01 11 26.4715 -84.3920 0 0.00 Dec-01 13 26.5490 -84.2264 0 0.00 Dec-01 15 26.6264 -84.0615 0 0.00 Dec-01 17 26.6918 -83.8891 0 0.00 Dec-01 19 26.7694 -83.7239 0 0.00 Dec-01 21 26.8500 -83.5604 0 0.00 Dec-01 23 26.9310 -83.3969 0 0.00 Dec-01 25 27.0122 -83.2333 0 0.00 Dec-01 27 27.0932 -83.0693 0 0.00 Dec-01 29 27.1744 -82.9052 0 0.00 Dec-01 30 27.2151 -82.8231 0 0.00 Dec-01 32 27.2960 -82.6592 0 0.09 Dec-01 33 27.1450 -82.6833 0 0.00 Dec-01 34 26.3795 -82.2707 0 0.00 Dec-01 35 26.3481 -82.3574 0 0.00 Dec-01 36 26.3169 -82.4435 0 0.00 Dec-01 37 26.2856 -82.5296 0 0.00 Dec-01 38 26.2545 -82.6157 0 0.00 Dec-01 39 26.2233 -82.7014 0 0.00 Dec-01 40 26.1919 -82.7875 0 0.00 Dec-01 44 26.0667 -83.1317 0 0.00 Dec-01 46 26.9900 -82.7467 0 0.00 Dec-01 48 26.6767 -82.8750 0 0.02 Dec-01 50 26.3650 -83.0083 0 0.11 Dec-01 51 26.2083 -83.0733 0 0.20 Dec-01 70 26.4870 -82.2260 0 0.19 Dec-01 72 26.6360 -82.3100 0 0.11 Dec-01 74 26.7870 -82.3890 0 0.11 Dec-01 76 26.9380 -82.4680 0 0.11 Dec-01 78 27.0890 -82.5460 0 0.06

PAGE 117

107 Appendix E: (Continued) Date station lat. (oN) long. (oW) depth DIP ( M) Dec-01 80 27.2400 -82.6260 0 0.15 Dec-01 82 27.3930 -82.7130 0 0.13

PAGE 118

108 Appendix F: Dissolved organic n itrogen concentrations from 2001 Date station lat. (oN) long. (oW) depth DON ( M) Sep-01 1 27.5417 -82.8000 0 12.90 Sep-01 3 27.4655 -82.9664 0 10.17 Sep-01 5 27.3895 -83.1338 0 17.82 Sep-01 7 27.3135 -83.3010 0 11.23 Sep-01 9 27.2380 -83.4683 0 11.43 Sep-01 10 27.2000 -83.5517 0 27.19 Sep-01 13 26.5490 -84.2264 0 12.59 Sep-01 17 26.6918 -83.8891 0 10.72 Sep-01 19 26.7694 -83.7239 0 8.05 Sep-01 21 26.8500 -83.5604 0 6.93 Sep-01 23 26.9310 -83.3969 0 7.84 Sep-01 27 27.0932 -83.0693 0 6.42 Sep-01 29 27.1744 -82.9052 0 7.99 Sep-01 30 27.2151 -82.8231 0 10.75 Sep-01 32 27.2960 -82.6592 0 16.32 Sep-01 34 26.3795 -82.2707 0 12.91 Sep-01 36 26.3169 -82.4435 0 8.47 Sep-01 38 26.2545 -82.6157 0 8.00 Sep-01 40 26.1919 -82.7875 0 8.19 Sep-01 42 26.1295 -82.9594 0 8.29 Sep-01 44 26.0667 -83.1317 0 6.81 Sep-01 46 26.9900 -82.7467 0 15.97 Sep-01 48 26.6767 -82.8750 0 10.10 Sep-01 50 26.3650 -83.0083 0 14.49 Sep-01 51 26.2083 -83.0733 0 12.42 Sep-01 70 26.4848 -82.2249 0 11.73 Sep-01 72 26.6350 -82.2683 0 13.57 Sep-01 73 26.7124 -82.3348 0 17.26 Sep-01 74 26.7861 -82.3347 0 16.73 Sep-01 75 26.8633 -82.4294 0 22.29 Sep-01 76 26.9292 -82.3849 0 11.16 Sep-01 78 27.0901 -82.5464 0 10.31 Sep-01 80 27.2408 -82.6270 0 11.52 Sep-01 82 27.3936 -82.7132 0 13.82 Oct-01 2 27.5405 -82.8004 0 6.78 Oct-01 3 27.3927 -82.7131 0 0.00 Oct-01 4 27.2394 -82.6267 0 18.22 Oct-01 6 27.7519 -82.9054 0 12.52 Oct-01 7 27.8802 -82.9045 0 11.21 Oct-01 8 28.0001 -82.9049 0 15.49 Oct-01 9 28.1289 -82.9046 0 13.71 Oct-01 10 27.9998 -83.0035 0 9.14

PAGE 119

109 Appendix F: (Continued) Date station lat. (oN) long. (oW) depth DON ( M) Oct-01 11 28.0011 -83.1395 0 10.22 Oct-01 13 27.9927 -83.3684 0 10.56 Oct-01 16 27.8763 -83.1862 0 9.93 Oct-01 21 27.7501 -83.0184 0 14.47 Oct-01 26 27.7554 -83.6189 0 8.62 Oct-01 31 27.4446 -83.0077 0 10.89 Oct-01 32 27.5417 -82.7989 0 9.84 Oct-01 5a 27.5399 -82.7973 0 17.00 Nov-01 1 27.5417 -82.8000 0 18.65 Nov-01 3 27.4655 -82.9664 0 14.05 Nov-01 5 27.3895 -83.1338 0 7.81 Nov-01 7 27.3135 -83.3010 0 7.97 Nov-01 9 27.2380 -83.4683 0 6.23 Nov-01 10 27.2000 -83.5517 0 12.75 Nov-01 11 26.4715 -84.3920 0 9.03 Nov-01 15 26.6264 -84.0615 0 6.21 Nov-01 17 26.6918 -83.8891 0 6.10 Nov-01 21 26.8500 -83.5604 0 6.94 Nov-01 23 26.9310 -83.3969 0 5.94 Nov-01 27 27.0932 -83.0693 0 7.70 Nov-01 29 27.1744 -82.9052 0 8.05 Nov-01 30 27.2151 -82.8231 0 12.50 Nov-01 32 27.2960 -82.6592 0 13.85 Nov-01 40 26.1919 -82.7875 0 6.27 Nov-01 42 26.1295 -82.9594 0 7.16 Nov-01 44 26.0667 -83.1317 0 8.01 Nov-01 46 26.9900 -82.7467 0 9.08 Nov-01 48 26.6767 -82.8750 0 11.21 Nov-01 50 26.3650 -83.0083 0 10.80 Nov-01 51 26.2083 -83.0733 0 15.92 Nov-01 72 26.6350 -82.2683 0 13.37 Nov-01 76 26.9292 -82.3849 0 13.23 Nov-01 78 27.0901 -82.5464 0 14.33 Nov-01 84 26.1462 -83.1613 0 6.27 Nov-01 88 26.4625 -83.2782 0 6.49 Nov-01 92 26.7791 -83.3953 0 6.59 Nov-01 96 27.0956 -83.5130 0 7.43 Dec-01 1 27.5417 -82.8000 0 17.27 Dec-01 3 27.4655 -82.9664 0 8.68 Dec-01 5 27.3895 -83.1338 0 16.03 Dec-01 7 27.3135 -83.3010 0 7.27 Dec-01 9 27.2380 -83.4683 0 7.61

PAGE 120

110 Appendix F: (Continued) Date station lat. (oN) long. (oW) depth DON ( M) Dec-01 10 27.2000 -83.5517 0 6.67 Dec-01 11 26.4715 -84.3920 0 6.73 Dec-01 13 26.5490 -84.2264 0 7.82 Dec-01 17 26.6918 -83.8891 0 5.97 Dec-01 19 26.7694 -83.7239 0 6.83 Dec-01 21 26.8500 -83.5604 0 6.42 Dec-01 23 26.9310 -83.3969 0 6.43 Dec-01 27 27.0932 -83.0693 0 8.60 Dec-01 29 27.1744 -82.9052 0 7.59 Dec-01 30 27.2151 -82.8231 0 7.62 Dec-01 32 27.2960 -82.6592 0 15.05 Dec-01 34 26.3795 -82.2707 0 7.67 Dec-01 36 26.3169 -82.4435 0 17.53 Dec-01 38 26.2545 -82.6157 0 21.24 Dec-01 40 26.1919 -82.7875 0 8.80 Dec-01 44 26.0667 -83.1317 0 14.23 Dec-01 46 26.9900 -82.7467 0 7.54 Dec-01 48 26.6767 -82.8750 0 19.10 Dec-01 50 26.3650 -83.0083 0 13.73 Dec-01 51 26.2083 -83.0733 0 15.06 Dec-01 70 26.4870 -82.2260 0 13.69 Dec-01 72 26.6360 -82.3100 0 12.52 Dec-01 74 26.7870 -82.3890 0 12.73 Dec-01 76 26.9380 -82.4680 0 11.66 Dec-01 80 27.2400 -82.6260 0 8.57

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111 Appendix G: Dissolved sili ca concentrations from 2001 Date station lat. (oN) long. (oW) depth Silica ( M) Sep-01 1 27.5417 -82.8000 0 0.02 Sep-01 10 27.2000 -83.5517 0 0.00 Sep-01 21 26.8500 -83.5604 0 0.00 Sep-01 32 27.2960 -82.6592 0 0.01 Sep-01 34 26.3795 -82.2707 0 0.00 Sep-01 36 26.3169 -82.4435 0 0.00 Sep-01 40 26.0667 -83.1317 0 0.02 Sep-01 44 26.1919 -82.7875 0 0.00 Sep-01 51 26.4108 -82.1850 0 0.00 Sep-01 Tampa Bay 27.7833 -82.5500 0 0.76 Oct-01 2 27.5405 -82.8004 0 13.77 Oct-01 2 27.5405 -82.8004 surface 17.57 Oct-01 3 27.3927 -82.7131 surface 8.98 Oct-01 3 27.3927 -82.7131 0 9.25 Oct-01 4 27.2394 -82.6267 surface 9.92 Oct-01 4 27.2394 -82.6267 0 9.88 Oct-01 6 27.7519 -82.9054 surface 8.96 Oct-01 6 27.7519 -82.9054 0 5.97 Oct-01 7 27.8802 -82.9045 surface 5.99 Oct-01 7 27.8802 -82.9045 0 2.82 Oct-01 8 28.0001 -82.9049 surface 2.92 Oct-01 8 28.0001 -82.9049 0 0.75 Oct-01 9 28.1289 -82.9046 surface 0.55 Oct-01 9 28.1289 -82.9046 0 1.18 Oct-01 10 27.9999 -83.0035 0 5.73 Oct-01 10 27.9998 -83.0035 surface 5.38 Oct-01 11 28.0011 -83.1395 surface 4.25 Oct-01 11 28.0011 -83.1395 0 1.46 Oct-01 13 27.9927 -83.3684 0 1.23 Oct-01 16 27.8763 -83.1862 surface 3.42 Oct-01 16 27.8763 -83.1862 0 1.43 Oct-01 26 27.7554 -83.6189 0 1.36 Oct-01 31 27.4446 -83.0077 surface 2.79 Oct-01 31 27.4446 -83.0077 0 2.78 Oct-01 32 27.5417 -82.7989 surface 9.17 Oct-01 32 27.5417 -82.7989 0 9.31 Oct-01 5a 27.5399 -82.7973 0 11.79 Nov-01 1 27.5417 -82.8000 0 2.93 Nov-01 3 27.4655 -82.9664 0 0.85 Nov-01 5 27.3895 -83.1338 0 0.00 Nov-01 11 26.4715 -84.3920 0 0.00 Nov-01 21 26.8500 -83.5604 0 0.00

PAGE 122

112 Appendix G: (Continued) Date station lat. (oN) long. (oW) depth Silica ( M) Nov-01 27 27.0932 -83.0693 0 2.84 Nov-01 29 27.1744 -82.9052 0 1.77 Nov-01 30 27.2151 -82.8231 0 3.08 Nov-01 40 26.1919 -82.7875 0 1.31 Nov-01 72 26.6350 -82.2683 0 10.70 Nov-01 76 26.9292 -82.3849 0 6.47 Nov-01 78 27.0901 -82.5464 0 6.55 Nov-01 88 26.4625 -83.2780 0 0.92 Nov-01 90 26.6208 -83.3370 0 1.57 Nov-01 92 26.7791 -83.3950 0 1.27 Nov-01 96 27.0956 -83.5130 0 0.98 Dec-01 1 27.5417 -82.8000 0 12.05 Dec-01 5 27.3895 -83.1338 0 0.67 Dec-01 7 27.3135 -83.3010 0 1.03 Dec-01 9 27.2380 -83.4683 0 0.92 Dec-01 21 26.8500 -83.5604 0 0.71 Dec-01 27 27.0932 -83.0693 0 1.41 Dec-01 30 27.2151 -82.8231 0 2.02 Dec-01 32 27.2960 -82.6592 0 9.82 Dec-01 34 26.3795 -82.2707 0 2.04 Dec-01 36 26.3169 -82.4435 0 1.58 Dec-01 42 26.1295 -81.9594 0 0.83 Dec-01 44 26.0667 -83.1317 0 1.25 Dec-01 48 26.6767 -82.8750 0 5.05 Dec-01 51 26.2083 -83.0733 0 25.91 Dec-01 82 27.3930 -82.7130 0 13.74 Dec-01 98 27.3351 -83.0231 0 3.98

PAGE 123

113 Appendix H: 15N of particulate organic matter from 2001 Date station lat. (oN) long. (oW) depth/sample 15N average st. dev Sep-01 5 27.3895 -83.1338 25m 6.162 0.71 Sep-01 10 27.2000 -83.5517 45m 6.018 0.50 Sep-01 13 26.5490 -84.2264 0m -0.619 0.11 Sep-01 13 26.5490 -84.2264 Tricho. spp. -0.612 0.11 Sep-01 21 26.8500 -83.5604 0m 3.663 0.27 Sep-01 27 27.9032 -83.0693 30m 5.162 0.10 Sep-01 27 27.9032 -83.0693 seagrass -0.204 0.16 Sep-01 32 27.2960 -82.6592 0m 3.028 0.24 Sep-01 34 26.3795 -82.2707 0m 3.679 0.73 Sep-01 40 26.0667 -83.1317 0m 4.783 0.40 Sep-01 51 26.4108 -82.1850 0m 5.076 0.21 Sep-01 70 26.4870 -82.2260 seagrass 1.924 0.17 Sep-01 71 26.5620 -82.2689 0m 4.934 0.03 Sep-01 73 26.7124 -82.3348 0m 5.102 0.08 Sep-01 75 26.8633 -82.4294 0m 3.272 0.16 Sep-01 Tampa Bay 27.7833 -82.5500 0m 9.175 0.47 Oct-01 2 27.5405 -82.8004 5m 3.474 0.09 Oct-01 2 27.5405 -82.8004 0m 3.331 0.01 Oct-01 2 27.5405 -82.8004 0m 6.545 1.08 Oct-01 2 27.5405 -82.8004 0m 6.263 0.02 Oct-01 2 27.5405 -82.8004 surf 6.316 0.08 Oct-01 2 27.5405 -82.8004 zoo. 6.545 1.08 Oct-01 2 27.5405 -82.8004 zoo. 6.263 0.02 Oct-01 3 27.3927 -82.7131 surf 5.259 0.16 Oct-01 3 27.3927 -82.7131 0m 4.521 0.03 Oct-01 3 27.3927 -82.7131 5m 5.298 0.26 Oct-01 4 27.2394 -82.6267 surf 2.754 0.13 Oct-01 4 27.2394 -82.6267 0m 0.457 0.12 Oct-01 4 27.2394 -82.6267 5m 0.798 0.25 Oct-01 6 27.7519 -82.9054 surf 4.988 0.14 Oct-01 6 27.7519 -82.9054 5m 5.461 0.52 Oct-01 6 27.7519 -82.9054 0m 6.123 0.31 Oct-01 6 27.7519 -82.9054 0m 5.451 0.13 Oct-01 6 27.7519 -82.9054 0m 3.193 0.20 Oct-01 6 27.7519 -82.9054 zoo. 6.123 0.31 Oct-01 6 27.7519 -82.9054 zoo. 5.451 0.13 Oct-01 7 27.8802 -82.9045 surf 3.149 0.00 Oct-01 7 27.8802 -82.9045 3m 5.156 1.84 Oct-01 7 27.8802 -82.9045 0m 4.255 0.37 Oct-01 8 28.0001 -82.9049 surf 3.251 0.41 Oct-01 8 28.0001 -82.9049 0m 3.636 0.05

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114 Appendix H: (Continued) Date station lat. (oN) long. (oW) depth/sample 15N average st. dev Oct-01 8 28.0001 -82.9049 5m 2.757 0.10 Oct-01 9 28.1289 -82.9046 surf 1.978 0.27 Oct-01 9 28.1289 -82.9046 0m 3.316 0.05 Oct-01 9 28.1289 -82.9046 5m 3.417 0.26 Oct-01 10 27.9998 -83.0035 10m 3.537 0.75 Oct-01 10 27.9998 -83.0035 0m 2.684 0.04 Oct-01 10 27.9998 -83.0035 0m 4.826 0.44 Oct-01 10 27.9998 -83.0035 0m 6.268 0.14 Oct-01 10 27.9998 -83.0035 surf 5.374 0.23 Oct-01 10 27.9998 -83.0035 5m 2.959 0.43 Oct-01 10 27.9998 -83.0035 zoo. 4.826 0.44 Oct-01 10 27.9998 -83.0035 zoo. 6.268 0.14 Oct-01 11 28.0011 -83.1395 5m 5.030 0.08 Oct-01 11 28.0011 -83.1395 surf 3.885 0.11 Oct-01 11 28.0011 -83.1395 0m 2.355 0.66 Oct-01 13 27.9927 -83.3684 20m 2.087 0.51 Oct-01 13 27.9927 -83.3684 0m 4.952 0.12 Oct-01 13 27.9927 -83.3684 0m 5.412 2.30 Oct-01 13 27.9927 -83.3684 zoo. 4.952 0.12 Oct-01 13 27.9927 -83.3684 zoo. 5.412 2.30 Oct-01 13 27.9927 -83.3684 seagrass 3.580 0.34 Oct-01 16 27.8763 -83.1862 surf 1.417 0.37 Oct-01 16 27.8763 -83.1862 0m -0.577 2.94 Oct-01 16 27.8763 -83.1862 20m 4.053 2.48 Oct-01 16 27.8763 -83.1862 0m 5.461 0.02 Oct-01 16 27.8763 -83.1862 zoo. 5.461 0.02 Oct-01 16 27.8763 -83.1862 seagrass 1.62 0.40 Oct-01 21 27.7501 -83.0184 0m 7.017 0.04 Oct-01 21 27.7501 -83.0184 0m 5.924 0.15 Oct-01 21 27.7501 -83.0184 5m 3.878 0.49 Oct-01 21 27.7519 -82.9054 0m 4.504 0.04 Oct-01 21 27.7501 -83.0184 zoo. 7.017 0.04 Oct-01 21 27.7501 -83.0184 zoo. 5.924 0.15 Oct-01 26 27.7554 -83.6189 0m 0.537 1.48 Oct-01 26 27.7554 -83.6189 0m 5.555 0.09 Oct-01 26 27.7554 -83.6189 0m 6.441 0.29 Oct-01 26 27.7554 -83.6189 zoo. 5.555 0.09 Oct-01 26 27.7554 -83.6189 zoo. 6.441 0.29 Oct-01 26 27.7554 -83.6189 Sarg spp. 3.201 0.21 Oct-01 26 27.7554 -83.6189 seagrass 3.616 0.10 Oct-01 29 27.2022 -83.5513 Tricho. spp. 1.007 Oct-01 31 27.4446 -83.0077 7m 4.247 0.05

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115 Appendix H: (Continued) Date station lat. (oN) long. (oW) depth/sample 15N average st. dev Oct-01 31 27.4446 -83.0077 surf 3.563 0.14 Oct-01 31 27.4446 -83.0077 15m 3.502 0.62 Oct-01 31 27.4446 -83.0077 0m 3.278 0.97 Oct-01 32 27.5417 -82.7989 surf 5.097 0.85 Oct-01 5a 27.5399 -82.7973 0m 4.514 0.03 Oct-01 5a 27.5399 -82.7973 5m 5.485 0.24 Oct-01 5a 27.5399 -82.7973 0m 6.195 0.18 Oct-01 5a 27.5399 -82.7973 0m 5.387 0.92 Oct-01 5a 27.5399 -82.7973 0m 9.213 0.16 Oct-01 5a 27.5399 -82.7973 zoo. 6.195 0.18 Oct-01 5a 27.5399 -82.7973 zoo. 5.387 92.00 Nov-01 1 27.5417 -82.8000 0m 5.431 0.07 Nov-01 3 27.4655 -82.9664 0m 3.879 0.90 Nov-01 5 27.3895 -83.1338 0m 1.356 1.00 Nov-01 11 26.4715 -84.3920 75m 4.474 0.81 Nov-01 21 26.8500 -83.5604 0m 2.657 0.67 Nov-01 21 26.8500 -83.5604 50m 4.450 1.37 Nov-01 27 27.0932 -83.0693 0m 8.527 1.29 Nov-01 27 27.0932 -83.0693 30m 4.903 0.19 Nov-01 29 27.1744 -82.9052 0m 1.018 0.49 Nov-01 29 27.1744 -82.9052 20m 2.803 0.49 Nov-01 30 27.2151 -82.8231 0m 3.447 0.47 Nov-01 32 27.2960 -82.6592 0m 5.401 0.16 Nov-01 40 26.1919 -82.7875 45m 2.057 2.36 Nov-01 40 26.1919 -82.7875 0m 4.278 0.50 Nov-01 72 26.6350 -82.2683 0m 4.795 0.21 Nov-01 76 26.9292 -82.3849 0m 4.676 0.11 Nov-01 88 26.4625 -83.2782 47m 1.381 0.31 Nov-01 90 26.6208 -83.3368 47m 2.121 0.27 Nov-01 90 26.6208 -83.3368 0m 11.923 5.53 Nov-01 92 26.7791 -83.3953 47m -0.220 0.52 Nov-01 96 27.0956 -83.5130 0m 3.881 0.19 Nov-01 96 27.0956 -83.5130 47m -1.062 3.21 Dec-01 1 27.5417 -82.8000 0m 3.215 0.26 Dec-01 5 27.3895 -83.1338 0m 4.057 0.18 Dec-01 7 27.3135 -83.3010 0m 4.116 0.81 Dec-01 9 27.2380 -83.4683 0m 4.596 0.61 Dec-01 9 27.2380 -83.4683 40m 5.273 0.27 Dec-01 9 27.2380 -83.4683 40m 4.275 0.17 Dec-01 21 26.8500 -83.5604 0m 3.104 0.37 Dec-01 21 26.8500 -83.5604 0m 5.139 1.22 Dec-01 21 26.8500 -83.5604 50m 4.015 0.28

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116 Appendix H: (Continued) Date station lat. (oN) long. (oW) depth/sample 15N average st. dev Dec-01 27 27.0932 -83.0693 30m 2.930 0.40 Dec-01 27 27.0932 -83.0693 0m 4.351 0.80 Dec-01 30 27.2151 -82.8231 0m 3.375 1.47 Dec-01 32 27.2960 -82.6592 0m 4.221 0.05 Dec-01 34 26.3795 -82.2707 0m 4.606 0.14 Dec-01 36 26.3169 -82.4435 0m 5.615 0.46 Dec-01 42 26.1295 -82.9594 0m 5.425 1.07 Dec-01 44 26.0667 -83.1317 0m 9.963 3.74 Dec-01 48 26.6767 -82.8750 0m 4.592 0.12 Dec-01 51 26.2083 -83.0733 0m 4.900 0.14 Dec-01 81 27.3187 -82.6691 0m 5.433 0.20 Dec-01 82 27.3930 -82.7130 0m 3.699 0.76 Dec-01 98 27.3351 -83.0231 0m 4.351 0.01

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117 Appendix I: 13C of particulate organic matter from 2001 Date station lat. (oN) long. (oW) depth/sample 13C average st. dev. Sep-01 1 27.5417 -82.8000 0 -20.464 0.01 Sep-01 5 27.3895 -83.1338 25 -22.274 0.12 Sep-01 7 27.3135 -83.3010 30 -23.451 0.28 Sep-01 10 27.2000 -83.5517 45 -25.169 0.01 Sep-01 13 26.5490 -84.2264 75 -25.014 0.17 Sep-01 13 26.5490 -84.2264 Tricho. spp. -13.146 0.70 Sep-01 21 26.8500 -83.5604 0 -23.790 0.20 Sep-01 21 26.8500 -83.5604 50 -26.586 4.77 Sep-01 27 27.9032 -83.0693 0 -23.629 0.08 Sep-01 27 27.9032 -83.0693 30 -21.258 1.24 Sep-01 27 27.9032 -83.0693 seagrass -11.829 0.34 Sep-01 32 27.2960 -82.6592 0 -20.591 0.29 Sep-01 34 26.3795 -82.2707 0 -22.934 0.22 Sep-01 36 26.3169 -82.4435 0 -23.450 0.12 Sep-01 40 26.0667 -83.1317 0 -19.580 4.20 Sep-01 40 26.0667 -83.1317 45 -23.398 0.07 Sep-01 51 26.4108 -82.1850 0 -20.465 0.07 Sep-01 70 26.4870 -82.2260 seagrass -13.108 0.06 Sep-01 71 26.5620 -82.2689 0 -24.166 6.89 Sep-01 73 26.7124 -82.3348 0 -18.649 0.01 Sep-01 75 26.8633 -82.4294 0 -22.116 0.19 Sep-01 Tampa Bay 27.7833 -82.5500 0 -19.402 0.01 Oct-01 2 27.5405 -82.8004 5 -19.124 0.73 Oct-01 2 27.5405 -82.8004 0 -19.551 0.03 Oct-01 2 27.5405 -82.8004 zoo. -22.185 2.84 Oct-01 2 27.5405 -82.8004 zoo. -15.826 0.46 Oct-01 2 27.5405 -82.8004 surface -16.635 0.09 Oct-01 3 27.3927 -82.7131 surface -17.362 0.13 Oct-01 3 27.3927 -82.7131 0 -20.099 3.18 Oct-01 3 27.3927 -82.7131 5 -17.613 0.25 Oct-01 4 27.2394 -82.6267 surface -19.372 0.10 Oct-01 4 27.2394 -82.6267 0 -17.309 0.57 Oct-01 4 27.2394 -82.6267 5 -17.835 0.72 Oct-01 6 27.7519 -82.9054 surface -17.013 0.04 Oct-01 6 27.7519 -82.9054 5 -17.897 0.24 Oct-01 6 27.7519 -82.9054 zoo. -16.617 0.18 Oct-01 6 27.7519 -82.9054 zoo. -14.976 0.37 Oct-01 6 27.7519 -82.9054 0 -17.995 0.81 Oct-01 7 27.8802 -82.9045 surface -17.984 0.14 Oct-01 7 27.8802 -82.9045 3 -16.726 0.38 Oct-01 8 28.0001 -82.9049 surface -19.958 0.43 Oct-01 8 28.0001 -82.9049 5 -19.054 2.10

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118 Appendix I: (Continued) Date station lat. (oN) long. (oW) depth/sample 13C average st. dev. Oct-01 9 28.1289 -82.9046 surface -18.478 1.05 Oct-01 9 28.1289 -82.9046 0 -18.789 0.70 Oct-01 9 28.1289 -82.9046 5 -19.315 0.99 Oct-01 10 27.9998 -83.0035 zoo. -19.178 0.40 Oct-01 10 27.9998 -83.0035 10 -20.388 0.57 Oct-01 10 27.9998 -83.0035 0 -19.043 0.84 Oct-01 10 27.9998 -83.0035 zoo. -15.416 1.01 Oct-01 10 27.9998 -83.0035 zoo. -16.491 0.10 Oct-01 10 27.9998 -83.0035 surface -19.105 0.13 Oct-01 10 27.9998 -83.0035 5 -20.415 0.16 Oct-01 11 28.0011 -83.1395 5 -21.561 0.01 Oct-01 11 28.0011 -83.1395 15 -21.810 0.08 Oct-01 11 28.0011 -83.1395 surface -20.418 0.22 Oct-01 11 28.0011 -83.1395 0 -21.887 1.43 Oct-01 13 27.9927 -83.3684 10 -22.129 0.15 Oct-01 13 27.9927 -83.3684 0 -22.525 0.28 Oct-01 13 27.9927 -83.3684 5 -22.858 0.50 Oct-01 13 27.9927 -83.3684 20 -23.815 0.69 Oct-01 13 27.9927 -83.3684 zoo. -18.012 0.33 Oct-01 13 27.9927 -83.3684 zoo. -22.473 0.08 Oct-01 13 27.9927 -83.3684 seagrass -9.483 0.25 Oct-01 16 27.8763 -83.1862 surface -20.378 0.15 Oct-01 16 27.8763 -83.1862 0 -20.934 1.57 Oct-01 16 27.8763 -83.1862 10 -24.123 0.21 Oct-01 16 27.8763 -83.1862 20 -22.308 0.31 Oct-01 16 27.8763 -83.1862 zoo. -18.911 0.15 Oct-01 16 27.8763 -83.1862 seagrass -12.491 0.16 Oct-01 21 27.7501 -83.0184 zoo. -13.706 0.97 Oct-01 21 27.7501 -83.0184 zoo. -20.101 0.08 Oct-01 21 27.7501 -83.0184 5 -19.020 0.20 Oct-01 21 27.7519 -82.9054 0 -18.882 0.16 Oct-01 23 27.7504 -83.2602 20 -22.836 0.42 Oct-01 26 27.7554 -83.6189 35 -21.777 0.49 Oct-01 26 27.7554 -83.6189 surface -23.932 0.29 Oct-01 26 27.7554 -83.6189 0 -24.294 0.03 Oct-01 26 27.7554 -83.6189 10 -23.689 0.71 Oct-01 26 27.7554 -83.6189 zoo. -18.545 0.25 Oct-01 26 27.7554 -83.6189 zoo. -23.654 0.29 Oct-01 26 27.7554 -83.6189 Sarg Spp. -18.698 0.09 Oct-01 26 27.7554 -83.6189 seagrass -11.575 0.01 Oct-01 31 27.4446 -83.0077 7 -17.631 0.42

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119 Appendix I (Continued) Date station lat. (oN) long. (oW) depth/sample 13C average st. dev. Oct-01 31 27.4446 -83.0077 surface -17.420 0.01 Oct-01 31 27.4446 -83.0077 15 -17.106 0.15 Oct-01 31 27.4446 -83.0077 0 -16.925 0.20 Oct-01 32 27.5417 -82.7989 surface -19.228 0.14 Oct-01 32 27.5417 -82.7989 0 -20.014 0.21 Oct-01 32 27.5417 -82.7989 5 -20.062 0.08 Oct-01 5a 27.5399 -82.7973 5a -22.063 0.35 Oct-01 5a 27.5399 -82.7973 5a -17.493 0.33 Oct-01 5a 27.5399 -82.7973 zoo. -17.295 0.05 Oct-01 5a 27.5399 -82.7973 zoo. -21.146 0.19 Oct-01 6a 27.7519 -82.9054 zoo. -22.893 0.42 Nov-01 1 27.5417 -82.8000 0 -20.884 0.63 Nov-01 3 27.4655 -82.9664 0 -19.723 0.86 Nov-01 5 27.3895 -83.1338 0 -23.131 1.22 Nov-01 11 26.4715 -84.3920 0 -25.227 0.11 Nov-01 11 26.4715 -84.3920 75 -23.963 2.73 Nov-01 21 26.8500 -83.5604 0 -24.218 0.44 Nov-01 21 26.8500 -83.5604 50 -24.800 0.77 Nov-01 27 27.0932 -83.0693 0 -25.285 0.57 Nov-01 27 27.0932 -83.0693 30 -22.270 2.22 Nov-01 29 27.1744 -82.9052 0 -21.885 0.02 Nov-01 29 27.1744 -82.9052 20 -20.232 0.08 Nov-01 30 27.2151 -82.8231 0 -21.318 1.21 Nov-01 32 27.2960 -82.6592 0 -19.532 0.09 Nov-01 40 26.1919 -82.7875 45 -22.305 1.07 Nov-01 40 26.1919 -82.7875 0 -23.728 0.11 Nov-01 72 26.6350 -82.2683 0 -19.535 2.24 Nov-01 76 26.9292 -82.3849 0 -20.861 0.34 Nov-01 78 27.0901 -82.5464 0 -19.442 Nov-01 88 26.4625 -83.2782 0 -23.851 Nov-01 88 26.4625 -83.2782 47 -23.570 1.15 Nov-01 90 26.6208 -83.3368 47 -23.513 0.35 Nov-01 90 26.6208 -83.3368 0 -24.159 1.16 Nov-01 92 26.7791 -83.3953 47 -22.240 1.35 Nov-01 92 26.7791 -83.3953 0 -24.044 Nov-01 96 27.0956 -83.5130 0 -23.115 1.54 Nov-01 96 27.0956 -83.5130 47 -24.636 3.99 Dec-01 1 27.5417 -82.8000 0 -19.332 0.79 Dec-01 5 27.3895 -83.1338 0 -22.926 0.99 Dec-01 7 27.3135 -83.3010 0 -23.818 0.04 Dec-01 9 27.2380 -83.4683 0 -24.705 1.00 Dec-01 9 27.2380 -83.4683 40 -22.740 0.38

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120 Appendix I: (Continued) Date station lat. (oN) long. (oW) depth/sample 13C average st. dev. Dec-01 9 27.2380 -83.4683 40 -21.451 2.52 Dec-01 21 26.8500 -83.5604 0 -23.559 0.03 Dec-01 21 26.8500 -83.5604 0 -24.044 0.85 Dec-01 21 26.8500 -83.5604 50 -23.798 0.56 Dec-01 27 27.0932 -83.0693 30 -21.188 0.51 Dec-01 27 27.0932 -83.0693 0 -22.968 0.16 Dec-01 30 27.2151 -82.8231 0 -22.501 0.30 Dec-01 32 27.2960 -82.6592 0 -20.747 0.39 Dec-01 34 26.3795 -82.2707 0 -22.032 0.38 Dec-01 36 26.3169 -82.4435 0 -22.748 0.44 Dec-01 36 26.3169 -82.4435 0 -21.588 Dec-01 42 26.1295 -82.9594 0 -24.052 0.35 Dec-01 44 26.0667 -83.1317 0 -20.757 0.10 Dec-01 48 26.6767 -82.8750 0 -20.342 0.32 Dec-01 51 26.2083 -83.0733 0 -19.195 0.35 Dec-01 81 27.3187 -82.6691 0 -20.412 0.28 Dec-01 82 27.3930 -82.7130 0 -20.397 0.13 Dec-01 98 27.3351 -83.0231 0 -21.126 0.06

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121 Appendix J: 15N of particulate organic matte r from ECOHAB: Florida 1998-2000 Date Station Lat. (oN) Long. (oW) depth/sample 15N average st. dev. Jul-98 15 26.6264 -84.0615 0 4.220 0.22 Jul-98 6 27.3515 -83.2174 25 4.167 0.02 Jul-98 10 27.2000 -83.5517 35 1.078 0.31 Jul-98 12 26.5101 -84.3095 40 3.219 0.20 Jul-98 22 26.8905 -83.4786 22 3.265 2.08 Jul-98 31 27.2559 -82.7414 10 2.023 0.50 Jul-98 41 26.0983 -83.0451 20 3.994 1.12 Jul-98 45 26.2233 -82.7014 15 2.468 0.76 Jul-98 49 26.3481 -82.3574 8 1.287 1.11 Aug-98 2 27.5033 -82.8833 0 1.204 0.40 Aug-98 6 27.3515 -83.2174 0 1.629 0.22 Aug-98 10 27.2000 -83.5517 0 2.207 2.41 Aug-98 12 26.5101 -84.3095 0 3.033 1.08 Aug-98 22 26.8905 -83.4786 0 2.068 0.93 Aug-98 31 27.2559 -82.7414 0 5.123 0.19 Aug-98 41 26.0983 -83.0451 0 4.254 0.71 Aug-98 45 26.2233 -82.7014 0 4.803 0.59 Aug-98 49 26.3481 -82.3574 0 3.691 0.74 Sep-98 2 27.5033 -82.8833 0 5.190 0.20 Sep-98 22 26.8905 -83.4786 0 12.430 0.77 Sep-98 31 27.2559 -82.7414 0 5.726 0.35 Sep-98 41 26.0983 -83.0451 0 7.550 1.65 Sep-98 45 26.2233 -82.7014 0 6.884 0.70 Sep-98 49 26.3481 -82.3574 0 13.221 0.47 Sep-98 6 27.3515 -83.2174 0 21.498 13.27 Nov-98 2 27.5033 -82.8833 0 5.156 0.51 Nov-98 6 27.3515 -83.2174 0 6.932 0.85 Nov-98 12 26.5101 -84.3095 0 5.463 1.54 Nov-98 22 26.8905 -83.4786 0 8.264 0.08 Nov-98 41 26.0983 -83.0451 0 7.377 0.05 Nov-98 45 26.2233 -82.7014 0 7.668 0.14 Nov-98 49 26.3481 -82.3574 0 5.846 1.08 Nov-98 51 26.4108 -82.1850 0 4.562 0.40 Dec-98 2 27.5033 -82.8833 0 4.782 0.00 Dec-98 6 27.3515 -83.2174 0 6.599 0.16 Dec-98 10 27.2000 -83.5517 0 6.064 0.80 Dec-98 12 26.5101 -84.3095 0 5.777 0.13 Dec-98 22 26.8905 -83.4786 0 5.619 0.20 Dec-98 31 27.2559 -82.7414 0 5.485 0.17 Dec-98 41 26.0983 -83.0451 0 7.274 0.04 Dec-98 49 26.3481 -82.3574 0 4.875 0.15 Dec-98 45 26.2233 -82.7014 0 6.317 0.15

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122 Appendix J: (Continued) Date Station Lat. (oN) Long. (oW) depth/sample 15N average st. dev. Jan-99 2 27.5033 -82.8833 0 4.408 0.87 Jan-99 6 27.3515 -83.2174 0 6.278 0.07 Jan-99 10 27.2000 -83.5517 0 5.709 1.24 Jan-99 12 26.5101 -84.3095 0 4.981 0.75 Jan-99 22 26.8905 -83.4786 0 6.678 1.05 Jan-99 31 27.2559 -82.7414 0 4.223 0.27 Jan-99 41 26.0983 -83.0451 0 6.696 0.40 Jan-99 45 26.2233 -82.7014 0 7.087 0.90 Jan-99 49 26.3481 -82.3574 0 5.174 0.99 Apr-99 10 27.2000 -83.5517 0 0.658 3.98 Apr-99 11 26.4715 -84.3920 0 -6.769 0.05 Apr-99 22 26.8905 -83.4786 0 -2.167 0.04 Apr-99 31 27.2559 -82.7414 0 1.377 1.03 Apr-99 41 26.0983 -83.0451 0 1.640 1.07 Apr-99 45 26.2233 -82.7014 0 2.610 1.76 Apr-99 49 26.3481 -82.3574 0 2.709 0.28 May-99 22 26.8905 -83.4786 0 0.144 0.80 May-99 31 27.2559 -82.7414 0 2.676 0.55 May-99 41 26.0983 -83.0451 0 -0.537 1.30 May-99 45 26.2233 -82.7014 0 0.143 0.55 May-99 49 26.3481 -82.3574 0 1.861 0.26 May-99 2 27.5033 -82.8833 0 5.170 0.44 May-99 6 27.3515 -83.2174 0 3.610 0.54 May-99 10 27.2000 -83.5517 0 2.716 1.74 May-99 12 26.5101 -84.3095 0 1.657 1.60 Jun-99 12 26.5101 -84.3095 0 4.200 4.71 Jun-99 22 26.8905 -83.4786 0 8.166 3.30 Jun-99 31 27.2559 -82.7414 0 14.239 0.53 Jun-99 41 26.0983 -83.0451 0 10.611 4.96 Jun-99 45 26.2233 -82.7014 0 4.622 0.63 Jun-99 49 26.3481 -82.3574 0 5.427 0.66 Sep-99 2 27.5033 -82.8833 0 2.613 0.55 Sep-99 6 27.3515 -83.2174 0 3.257 0.59 Sep-99 10 27.2000 -83.5517 0 7.311 0.13 Sep-99 12 26.5101 -84.3095 0 3.197 0.16 Sep-99 22 26.8905 -83.4786 0 2.658 0.49 Sep-99 31 27.2559 -82.7414 0 2.881 0.08 Sep-99 41 26.0983 -83.0451 0 2.089 2.82 Sep-99 45 26.2233 -82.7014 0 3.005 0.19 Sep-99 49 26.3481 -82.3574 0 3.602 0.17 Oct-99 49 26.3481 -82.3574 0 3.714 0.51 Oct-99 45 26.2233 -82.7014 0 4.171 0.45

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123 Appendix J: (Continued) Date Station Lat. (oN) Long. (oW) depth/sample 15N average st. dev. Oct-99 41 26.0983 -83.0451 0 6.031 0.09 Oct-99 31 27.2559 -82.7414 0 5.019 0.40 Oct-99 22 26.8905 -83.4786 0 5.937 0.41 Nov-99 2 27.5033 -82.8833 0 4.099 0.68 Nov-99 6 27.3515 -83.2174 0 1.774 2.79 Nov-99 31 27.2559 -82.7414 0 2.428 0.27 Nov-99 41 26.0983 -83.0451 0 2.772 2.08 Nov-99 45 26.2233 -82.7014 0 3.608 0.57 Nov-99 48 26.3169 -82.4435 0 3.466 0.05 Dec-99 2 27.5033 -82.8833 0 6.187 0.16 Dec-99 6 27.3515 -83.2174 0 6.117 0.48 Dec-99 10 27.2000 -83.5517 0 5.240 0.87 Dec-99 12 26.5101 -84.3095 0 3.709 0.60 Dec-99 22 26.8905 -83.4786 0 5.146 0.27 Dec-99 31 27.2559 -82.7414 0 3.960 0.36 Dec-99 49 26.3481 -82.3574 0 4.214 0.29 Dec-99 45 26.2233 -82.7014 0 5.655 0.23 Dec-99 41 26.0983 -83.0451 0 5.497 0.32 Jan-00 2 27.5033 -82.8833 0 5.970 0.22 Jan-00 6 27.3515 -83.2174 0 5.732 0.73 Jan-00 10 27.2000 -83.5517 0 3.769 1.29 Jan-00 12 26.5101 -84.3095 0 4.471 0.91 Jan-00 22 26.8905 -83.4786 0 5.553 0.10 Jan-00 31 27.2559 -82.7414 0 5.102 0.17 Jan-00 49 26.3481 -82.3574 0 5.307 0.92 Jan-00 45 26.2233 -82.7014 0 5.331 1.12 Jan-00 41 26.0983 -83.0451 0 4.458 0.13 Mar-00 2 27.5033 -82.8833 0 6.106 0.11 Mar-00 6 27.3515 -83.2174 0 5.460 1.01 Mar-00 10 27.2000 -83.5517 0 1.674 0.64 Mar-00 12 26.5101 -84.3095 0 1.144 1.04 Mar-00 22 26.8905 -83.4786 0 -1.413 1.58 Mar-00 31 27.2559 -82.7414 0 0.710 0.95 Mar-00 49 26.3481 -82.3574 0 2.240 0.17 Mar-00 45 26.2233 -82.7014 0 1.136 0.72 Mar-00 41 26.0983 -83.0451 0 -0.997 1.39 Apr-00 2 27.5033 -82.8833 0 2.160 1.38 Apr-00 49 26.3481 -82.3574 0 2.486 0.72 Apr-00 45 26.2233 -82.7014 0 2.820 0.19 Apr-00 41 26.0983 -83.0451 0 -0.554 2.04 Apr-00 10 27.2000 -83.5517 0 -0.244 1.36 Apr-00 6 27.3515 -83.2174 0 1.557 0.06

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124 Appendix J: (Continued) Date Station Lat. (oN) Long. (oW) depth/sample 15N average st. dev. Apr-00 2 26.0983 -83.0451 0 2.252 0.04 May-00 2 27.5033 -82.8833 0 -5.794 0.56 May-00 10 27.2000 -83.5517 0 -2.739 1.98 May-00 12 26.5101 -84.3095 0 -3.186 1.21 May-00 22 26.8905 -83.4786 0 -2.694 0.45 May-00 31 27.2559 -82.7414 0 -2.669 0.19 May-00 49 26.3481 -82.3574 0 -0.403 0.09 May-00 47 26.2856 -82.5296 0 2.304 2.41 May-00 41 26.0983 -83.0451 0 4.061 0.28 Jun-00 6 27.3515 -83.2174 0 0.628 3.44 Jun-00 10 27.2000 -83.5517 0 4.668 1.63 Jun-00 12 26.5101 -84.3095 0 -0.190 6.50 Jun-00 22 26.8905 -83.4786 0 -2.544 3.94 Jun-00 31 27.2559 -82.7414 0 0.138 0.33 Jun-00 49 26.3481 -82.3574 0 5.983 0.92 Jun-00 45 26.2233 -82.7014 0 2.901 2.43 Jun-00 41 26.0983 -83.0451 0 4.198 1.14 Jul-00 2 27.5033 -82.8833 0 4.602 0.68 Jul-00 7 27.3135 -83.3010 0 5.076 1.00 Jul-00 10 27.2000 -83.5517 0 0.804 3.45 Jul-00 12 26.5101 -84.3095 0 -0.387 5.76 Jul-00 22 26.8905 -83.4786 0 6.190 0.72 Jul-00 31 27.2559 -82.7414 0 1.573 0.03 Jul-00 49 26.3481 -82.3574 0 2.159 0.52 Jul-00 45 26.2233 -82.7014 0 2.553 0.03 Jul-00 41 26.0983 -83.0451 0 0.795 0.56 Aug-00 3 27.4655 -82.9664 0 3.795 0.24 Aug-00 6 27.3515 -83.2174 0 4.144 0.04 Aug-00 10 27.2000 -83.5517 0 7.426 3.06 Aug-00 12 26.5101 -84.3095 0 11.259 1.95 Aug-00 22 26.8905 -83.4786 0 8.423 1.24 Aug-00 31 27.2559 -82.7414 0 3.539 0.32 Aug-00 49 26.3481 -82.3574 0 6.191 0.54 Aug-00 45 26.2233 -82.7014 0 8.814 1.37 Aug-00 41 26.0983 -83.0451 0 9.270 Nov-00 2 27.5033 -82.8833 0 4.184 0.48 Nov-00 6 27.3515 -83.2174 0 -1.384 2.53 Nov-00 10 27.2000 -83.5517 0 -2.178 0.43 Nov-00 31 27.2559 -82.7414 0 -0.148 2.41 Nov-00 74 26.7870 -82.3890 0 -1.523 2.79 Nov-00 49 26.3481 -82.3574 0 -0.784 3.09 Nov-00 45 26.2233 -82.7014 0 -0.554 3.38


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Havens, Julie Ann.
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A stable isotopic examination of particulate organic matter during Karenia brevis blooms on the central west Florida shelf
h [electronic resource] :
hints at nitrogen sources in oligotrophic waters /
by Julie Ann Havens.
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[Tampa, Fla.] :
University of South Florida,
2004.
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Thesis (M.S.)--University of South Florida, 2004.
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Includes bibliographical references.
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Text (Electronic thesis) in PDF format.
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ABSTRACT: Blooms of the red tide dinoflagellate Karenia brevis occur annually on the west Florida shelf. In the late summer/early fall months, background concentrations increase from 10 cells L to excesses of 10 cels L. Blooms are most common between Tampa Bay and Charlotte Harbor, and may be maintained for months. The region's hydrography may play a role in the initiation, maintenance and termination of blooms. The west Florida shelf is depauperate in inorganic nutrients. Inorganic nitrogen and phosphorus rarely exceed the limits of detection, whereas dissolved organic nitrogen is often present at concentrations of 15 to 20 µ M. Because K. brevis exhibits ability to utilize both organic nitrogen and phosphorus, the organic pool may serve as an important nutrient source. The source of nutrients for K. brevis blooms is the focus of much scientific research. Nitrogen is considered to be the limiting nutrient in marine waters and may have several sources. Potential sources of inorganic and organic nitrogen are estuarine outflow, atmospheric deposition, upwelling, dissolved organic nitrogen released from N fixing cyanobacteria, diatom blooms, decaying seagrasses, fish or other organic matter. The natural abundance stable isotopic signatures of particulate bloom material (δN and δC) associated with K. brevis blooms during 1998 to 2001 was analyzed and compared with known isotopic values of potential nutrient sources. Data was analyzed from blooms occurring from 1998 to 2001. Extensive analysis of the 2001 bloom showed that the δN of bloom material ranged from 2% to 5%. δC bloom material ranged from -22% and -17%. Non-bloom material was considerably more variable in both δN and δC. δC values were higher near shore than offshore during the 2001 bloom, suggesting lower disolved inorganic carbon levels due to high temperature and/or high biomass. δN of bloom material fell within the range of the δN values of potential nitrogen sources. It appears that K. brevis utilizes the available nitrogen sources opportunistically, and that isotopically more depleted sources are more important. More enriched sources such as upwelled nitrate or sewage nitrogen can be excluded as significant sources based on the isotopic data.
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Adviser: Gabriel A. Vargo.
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stable isotope.
nitrogen.
carbon.
phytoplankton.
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