Susan Badylak - Academia.edu (original) (raw)
Papers by Susan Badylak
Frontiers in Ecology and Evolution
IntroductionCultural eutrophication threatens numerous ecological and economical resources of Flo... more IntroductionCultural eutrophication threatens numerous ecological and economical resources of Florida’s coastal ecosystems, such as beaches, mangroves, and seagrasses. In April 2021, an infrastructure failure at the retired Piney Point phosphorus mining retention reservoir garnered national attention, as 814 million liters of nutrient rich water were released into Tampa Bay, Florida over 10 days. The release of nitrogen and phosphorus-rich water into Tampa Bay – a region that had been known as a restoration success story since the 1990s – has highlighted the potential for unexpected challenges for coastal nutrient management.MethodsFor a year after the release, we sampled bi-weekly at four sites to monitor changes in nutrients, stable isotopes, and phytoplankton communities, complemented with continuous monitoring by multiparameter sondes. Our data complement the synthesis efforts of regional partners, the Tampa Bay and Sarasota Bay Estuary Programs, to better understand the effects...
Frontiers in Ecology and Evolution
Seasonal patterns of phytoplankton biomass and composition in the inner continental shelf off Cap... more Seasonal patterns of phytoplankton biomass and composition in the inner continental shelf off Cape Canaveral on the east coast of Florida were examined for a 6-year period (2013–2019). In situ water samples were collected and analyzed for chlorophyll a, phytoplankton biomass and composition, along with water quality parameters. Regional satellite data on chlorophyll a, and temperature was also obtained from NASA. Average chlorophyll a values over the study period ranged from 0.63 ± 0.03 μg L−1 in the summer to 2.55 ± 0.10 μg L−1 in the fall. Phytoplankton community composition also showed seasonal differences, with persistent dominance by picoplanktonic cyanobacteria in the summer, but mixed dominance by picocyanobacteria and dinoflagellates in the fall. Seasonal differences were attributed to a shift in predominant seasonal wind directions, which drive water along the coast from the north in the fall and winter, but from the south in the spring and summer, including eddies and upwe...
Marine Ecology Progress Series, 2006
Over the last half of the 20th century Pyrodinium bahamense var. bahamense has been observed in a... more Over the last half of the 20th century Pyrodinium bahamense var. bahamense has been observed in a variety of locations in the western North Atlantic. Recent evidence of the toxinproducing capacity of this variety of P. bahamense has heightened interest in its habitat requirements and preferences. The objective of this study was to examine the environmental factors that relate to the spatial and temporal patterns of the distribution and abundance of P. bahamense var. bahamense. Based on the results of this study we view the factors as operating in one or more ways: (1) ecophysiological limitations for survival and successful reproductive cycle, (2) environmental regulation of growth and standing crop, and (3) competitive advantages in relation to other species. The focus of the study was the Florida peninsula, but information from other environments in the tropical Atlantic and Gulf of Mexico was included in the interpretation of the results. In terms of physiological limitations, 20°C appears to be the lower temperature limit for a significant presence of P. bahamense var. bahamense, and the salinity tolerance ranged from 10 to 45. The bloom potential of P. bahamense var. bahamense was most closely associated with shallow ecosystems with long water residence times, and peak biomass levels were correlated to nutrient concentrations in regions of high abundance. The ability of P. bahamense var. bahamense to compete effectively for habitat with other euryhaline warm-water phytoplankton is viewed in terms of existing theories on succession and competition, including Margalef's Mandala, Reynolds' Intaglio and C-S-R life-form strategies proposed by Smayda & Reynolds.
Within the Indian River Lagoon (IRL), blooms of the marine microalga Aureoumbra lagunensis in exc... more Within the Indian River Lagoon (IRL), blooms of the marine microalga Aureoumbra lagunensis in excess of 1310 cells ml 1 have occurred on three occasions after first being locally identified in 2012. All blooms coincided with times of peak reproduction and growth of the eastern oyster Crassostrea virginica in Mosquito Lagoon (northern IRL). Over six years of field data on monthly recruitment of C. virginica were compared to bi-monthly cell counts of A. lagunensis. In addition to expected temperature and salinity-driven variations in oyster recruitment, cell counts of A. lagunensis in excess of 10,000 ml 1 reduced oyster recruitment. A second method of analysis similarly found a negative association with oyster recruitment when cell counts exceeded 9658 ml . Understanding the impact of blooms of A. lagunensis is essential for managing harvesting, aquaculture, and restoration of this foundation shellfish species.
Bulletin of Marine Science, 1996
Bulletin of Marine Science, 2020
The abundance and composition of the phytoplankton community off the coast of Cape Canaveral, Flo... more The abundance and composition of the phytoplankton community off the coast of Cape Canaveral, Florida was examined from Fall 2013 to Summer 2015. The region is a shallow shelf environment. Water samples were collected quarterly at 24 sites from the surface and bottom of the water column; temperature and nutrient concentrations were determined. Photoautotrophic picoplanktonic prokaryotes were consistently important in terms of numerical abundance and biomass throughout the study. Among the cyanobacteria, a surface bloom of the nitrogen-fixing filamentous species Trichodesmium was observed in Fall 2013. Dinoflagellates and diatoms were also major contributors to phytoplankton biomass. Many of the dominant dinoflagellates were mixotrophic or heterotrophic species. Nanoplanktonic eukaryotic algae were also periodically an important group in terms of biomass, such as prasinophytes (Chlorophyta). No consistent and reoccurring spatial patterns were observed, likely due to the dynamic water...
Estuarine, Coastal and Shelf Science, 2021
Abstract In 2018, the presence of bottom water hypoxia along the SW Florida coast was investigate... more Abstract In 2018, the presence of bottom water hypoxia along the SW Florida coast was investigated during a bloom of the toxic dinoflagellate Karenia brevis. The bloom was first detected in November 2017. Monitoring of oxygen levels and bloom densities were carried out in 2018 and 2019 using sampling grids. Vertical profiles indicated a pycnocline at 3–4 m where warmer, lower salinity water was at the surface, while the deeper hypoxic layer was colder with higher salinity. There were significantly higher abundances of K. brevis in the surface water compared to the hypoxic bottom water in September 2018. At two fixed sites dissolved oxygen was measured continuously showing hypoxic conditions during that month. Geospatial analysis of vertical profile data yielded an estimate that the hypoxic layer covered an area of at least 655 km2. The possible influences of red tides on hypoxic conditions along the coast of the eastern Gulf of Mexico and are discussed within the context of the 2018 K. brevis bloom event. Hypoxia occurring in parallel to a red tide bloom is more likely to occur with warmer ocean temperatures and increased fluxes of nutrients and fresh water to the Gulf of Mexico after hurricanes.
Frontiers in Marine Science, 2021
The Indian River Lagoon (IRL), located on the east coast of Florida, is a complex estuarine ecosy... more The Indian River Lagoon (IRL), located on the east coast of Florida, is a complex estuarine ecosystem that is negatively affected by recurring harmful algal blooms (HABs) from distinct taxonomic/functional groups. Enhanced monitoring was established to facilitate rapid quantification of three recurrent bloom taxa, Aureoumbra lagunensis, Pyrodinium bahamense, and Pseudo-nitzschia spp., and included corroborating techniques to improve the identification of small-celled nanoplankton (<10 μm in diameter). Identification and enumeration of these target taxa were conducted during 2015–2020 using a combination of light microscopy and species-specific approaches, specifically immunofluorescence flow cytometry as well as a newly developed qPCR assay for A. lagunensis presented here for the first time. An annual bloom index (ABI) was established for each taxon based on occurrence and abundance data. Blooms of A. lagunensis (>2 × 108 cells L–1) were observed in all 6 years sampled and ac...
Frontiers in Marine Science, 2021
This paper examines the character of phytoplankton blooms in a restricted sub-tropical lagoon alo... more This paper examines the character of phytoplankton blooms in a restricted sub-tropical lagoon along the Atlantic coast of central Florida. The results of the 23-year study (1997–2020) provide evidence for multiple types of variability in bloom activity, including cyclical patterns, stochastic events, and most prominently a regime shift in composition and intensity. Cyclical patterns (e.g., El Niño/La Niña periods) and stochastic events (e.g., tropical storms) influenced rainfall levels, which in turn impacted nutrient concentrations in the water column and the timing and intensity of blooms. In 2011, a major change occurred in the character of blooms, with a dramatic increase in peak biomass levels of blooms and the appearance of new dominant taxa, including the brown tide species Aureoumbra lagunensis and other nanoplanktonic species. Results of quantitative analyses reveal system behavior indicative of a regime shift. The shift coincided with widespread losses of seagrass communit...
Scientific Reports, 2021
A microscopic study of microplankton in two coastal lagoons in the Florida Keys coincidently, and... more A microscopic study of microplankton in two coastal lagoons in the Florida Keys coincidently, and unexpectedly, revealed the widespread presence of high concentrations of polystyrene microplastic particles. The polystyrene particles were first observed in the second year of a 2-year study of phytoplankton communities, with peak densities in the spring/summer of 2019 at all ten sampling sites in the two lagoons. Polystyrene particle densities reached levels up to 76,000 L−1. The particles ranged in size from 33 to 190 µm, similar to the size range of microplanktonic algae (20–200 µm). Over the period of peak polystyrene densities, average particle densities were similar to average densities of microplanktonic algae cells. The latter observation highlights the potential significance of the microplastic particles for the ecology of the pristine waters of the Florida Keys, if they persist.
Botanica Marina, 2017
This study reports on the harmful algal bloom (HAB) dinoflagellate
ALGAE, 2014
This is the first recorded observation of Akashiwo sanguinea excreting mucilaginous substances fr... more This is the first recorded observation of Akashiwo sanguinea excreting mucilaginous substances from pores on the cell surface. Observations were from samples collected in the Caloosahatchee Estuary, Florida, USA during a bloom event, with densities of 672 cells mL-1 of A. sanguinea, including 51 cells surrounded by mucous. Scanning electron microscopy observations revealed that the mucous was secreted from thecal pores on the cell surface. The potential significance of mucous production is discussed.
Marine Environmental Research, 2015
The primary objective of this study was to examine trends in phytoplankton biomass and species co... more The primary objective of this study was to examine trends in phytoplankton biomass and species composition under varying nutrient load and hydrologic regimes in the Guana Tolomato Matanzas estuary (GTM), a well-flushed subtropical estuary located on the northeast coast of Florida. The GTM contains both regions of significant human influence and pristine areas with only modest development, providing a test case for comparing and contrasting phytoplankton community dynamics under varying degrees of nutrient load. Water temperature, salinity, Secchi disk depth, nutrient concentrations and chlorophyll concentrations were determined on a monthly basis from 2002 to 2012 at three representative sampling sites in the GTM. In addition, microscopic analyses of phytoplankton assemblages were carried out monthly for a five year period from 2005 through 2009 at all three sites. Results of this study indicate that phytoplankton biomass and composition in the GTM are strongly influenced by hydrologic factors, such as water residence times and tidal exchanges of coastal waters, which in turn are affected by shifts in climatic conditions, most prominently rainfall levels. These influences are exemplified by the observation that the region of the GTM with the longest water residence times but lowest nutrient loads exhibited the highest phytoplankton peaks of autochthonous origin. The incursion of a coastal bloom of the toxic dinoflagellate Karenia brevis into the GTM in 2007 demonstrates the potential importance of allochthonous influences on the ecosystem.
Marine and Freshwater Research, 2016
Concerns about global climate change have heightened awareness of the role changing rainfall regi... more Concerns about global climate change have heightened awareness of the role changing rainfall regimes play in altering plankton communities of coastal ecosystems. In this study spatial and temporal patterns of phytoplankton composition and biomass in a sub-tropical tidal creek in Florida were observed over three wet and dry seasons, which included the major storm year of 2005 and the drought year of 2006. Shifts in rainfall levels were associated with changes in phytoplankton composition and biomass, but the effects varied between the upper and lower reaches of the creek. The upper reach of the creek was fresh throughout the study period. The oligohaline to mesohaline lower creek alternated between fresh and marine species in response to shifts in salinity regimes. Blooms of the freshwater dinoflagellate Peridinium sp., small centric diatoms and nitrogen-fixing cyanobacteria were common in the upper Ten Mile Creek during low rainfall years. The euryhaline marine dinoflagellate Akashi...
Marine Ecology Progress Series, 2015
Plankton and Benthos Research, 2014
Akashiwo sanguinea is a cosmopolitan dinoflagellate that has been observed to form major blooms i... more Akashiwo sanguinea is a cosmopolitan dinoflagellate that has been observed to form major blooms in coastal ecosystems around the world. A. sanguinea plays a major role in the ecology of many marine environments, including coastal ecosystems with variable salinities, where its euryhaline character makes it competitive. The study involved monthly water sampling and measurement of physical-chemical parameters at four sites from the upper reaches of the Caloosahatchee Estuary to San Carlos Bay bordering the Gulf of Mexico. Major A. sanguinea blooms were observed in the Caloosahatchee estuary, with biovolume up to 30.5 10 6 μm 3 mL 1 , equivalent to 740 cells mL 1 , in the upper estuary. The latter regions of the estuary also had the greatest range of salinity and the highest total nitrogen and total phosphorus concentrations. The dynamics of blooms are discussed within the context of spatial and temporal patterns of salinity, temperature and nutrient concentrations, as they relate to hydrologic and climatic conditions.
We analyzed spatial and temporal patterns and relationships in water quality in order to investig... more We analyzed spatial and temporal patterns and relationships in water quality in order to investigate causes and short-term consequences of a historically unprecedented phytoplankton bloom that afflicted the Indian River Lagoon (IRL) system during 2011. The 2011 ‘superbloom’ was unprecedented, not only for its magnitude (chlorophyll_a concentrations > 130 ug/L) and geographic scale (Banana, north Indian River and southern Mosquito sub-lagoons), but also for its long (7+ month) duration and its distinctive floral composition (co-dominated by green micro-flagellates and pico-cyanobacteria). We used a combination of statistical approaches to compare water quality during 2011 to that of antecedent periods, and to explore relationships between chlorophyll_a and other water quality constituents before and during the bloom. Bottom-up effects (nutrients) and other physical-chemical factors (e.g., salinity and water temperature) are explored as ‘drivers’ or ‘triggers’ of the bloom. The con...
Phycologia, 2004
The primary focus of this paper is to provide a detailed description of Pyrodinium bahamense from... more The primary focus of this paper is to provide a detailed description of Pyrodinium bahamense from the Indian River Lagoon, Florida. Recent reports of saxitoxin production by P. bahamense from the Indian River lagoon has heightened interest in the similarities between the Atlantic and Indo-Pacific forms of this species. Microscopic examinations of samples from the Indian River Lagoon using light and scanning electron microscopy suggest that the Atlantic form deserves the separate varietal designation of bahamense assigned to it in recent years, distinguishing it from the Indo-Pacific var. compressum. This conclusion was based on key morphological and dimensional characteristics.
Estuaries and Coasts, 2014
Relationships between shifts in climatic and other environmental conditions and changes in the ch... more Relationships between shifts in climatic and other environmental conditions and changes in the character and dynamics of phytoplankton blooms were examined in three interconnected subtropical lagoons on the east coast of Florida, i.e., Mosquito Lagoon, Indian River Lagoon, and Banana River Lagoon, from 1997 to 2013. Phytoplankton blooms were a common feature through most of the study period in two of the lagoons. From 1997 to 2009, blooms in the latter two lagoons were typically dominated by dinoflagellates in the warm wet season and diatoms in the cool dry season. Blooms of the dominant bloom-forming dinoflagellate species Pyrodinium bahamense were positively correlated to rainfall levels, indicating a link to enhanced external nutrient loads. In 2011-2013, major blooms were observed in all three lagoons, but unlike the previous 14 years, they were dominated by picoplanktonic eukaryotes, including a chlorophyte, Pedinophyceae sp., and the brown tide species Aureoumbra lagunensis. The results suggest that extreme climatic conditions, including record cold winter water temperatures and low rainfall levels, were major driving factors in this state shift in the character of blooms, through a wide range of effects including die-offs of benthic flora and fauna, suppression of grazer populations, alteration of nutrient regimes, and uncharacteristic water column conditions, such as elevated salinities and light attenuation.
Frontiers in Ecology and Evolution
IntroductionCultural eutrophication threatens numerous ecological and economical resources of Flo... more IntroductionCultural eutrophication threatens numerous ecological and economical resources of Florida’s coastal ecosystems, such as beaches, mangroves, and seagrasses. In April 2021, an infrastructure failure at the retired Piney Point phosphorus mining retention reservoir garnered national attention, as 814 million liters of nutrient rich water were released into Tampa Bay, Florida over 10 days. The release of nitrogen and phosphorus-rich water into Tampa Bay – a region that had been known as a restoration success story since the 1990s – has highlighted the potential for unexpected challenges for coastal nutrient management.MethodsFor a year after the release, we sampled bi-weekly at four sites to monitor changes in nutrients, stable isotopes, and phytoplankton communities, complemented with continuous monitoring by multiparameter sondes. Our data complement the synthesis efforts of regional partners, the Tampa Bay and Sarasota Bay Estuary Programs, to better understand the effects...
Frontiers in Ecology and Evolution
Seasonal patterns of phytoplankton biomass and composition in the inner continental shelf off Cap... more Seasonal patterns of phytoplankton biomass and composition in the inner continental shelf off Cape Canaveral on the east coast of Florida were examined for a 6-year period (2013–2019). In situ water samples were collected and analyzed for chlorophyll a, phytoplankton biomass and composition, along with water quality parameters. Regional satellite data on chlorophyll a, and temperature was also obtained from NASA. Average chlorophyll a values over the study period ranged from 0.63 ± 0.03 μg L−1 in the summer to 2.55 ± 0.10 μg L−1 in the fall. Phytoplankton community composition also showed seasonal differences, with persistent dominance by picoplanktonic cyanobacteria in the summer, but mixed dominance by picocyanobacteria and dinoflagellates in the fall. Seasonal differences were attributed to a shift in predominant seasonal wind directions, which drive water along the coast from the north in the fall and winter, but from the south in the spring and summer, including eddies and upwe...
Marine Ecology Progress Series, 2006
Over the last half of the 20th century Pyrodinium bahamense var. bahamense has been observed in a... more Over the last half of the 20th century Pyrodinium bahamense var. bahamense has been observed in a variety of locations in the western North Atlantic. Recent evidence of the toxinproducing capacity of this variety of P. bahamense has heightened interest in its habitat requirements and preferences. The objective of this study was to examine the environmental factors that relate to the spatial and temporal patterns of the distribution and abundance of P. bahamense var. bahamense. Based on the results of this study we view the factors as operating in one or more ways: (1) ecophysiological limitations for survival and successful reproductive cycle, (2) environmental regulation of growth and standing crop, and (3) competitive advantages in relation to other species. The focus of the study was the Florida peninsula, but information from other environments in the tropical Atlantic and Gulf of Mexico was included in the interpretation of the results. In terms of physiological limitations, 20°C appears to be the lower temperature limit for a significant presence of P. bahamense var. bahamense, and the salinity tolerance ranged from 10 to 45. The bloom potential of P. bahamense var. bahamense was most closely associated with shallow ecosystems with long water residence times, and peak biomass levels were correlated to nutrient concentrations in regions of high abundance. The ability of P. bahamense var. bahamense to compete effectively for habitat with other euryhaline warm-water phytoplankton is viewed in terms of existing theories on succession and competition, including Margalef's Mandala, Reynolds' Intaglio and C-S-R life-form strategies proposed by Smayda & Reynolds.
Within the Indian River Lagoon (IRL), blooms of the marine microalga Aureoumbra lagunensis in exc... more Within the Indian River Lagoon (IRL), blooms of the marine microalga Aureoumbra lagunensis in excess of 1310 cells ml 1 have occurred on three occasions after first being locally identified in 2012. All blooms coincided with times of peak reproduction and growth of the eastern oyster Crassostrea virginica in Mosquito Lagoon (northern IRL). Over six years of field data on monthly recruitment of C. virginica were compared to bi-monthly cell counts of A. lagunensis. In addition to expected temperature and salinity-driven variations in oyster recruitment, cell counts of A. lagunensis in excess of 10,000 ml 1 reduced oyster recruitment. A second method of analysis similarly found a negative association with oyster recruitment when cell counts exceeded 9658 ml . Understanding the impact of blooms of A. lagunensis is essential for managing harvesting, aquaculture, and restoration of this foundation shellfish species.
Bulletin of Marine Science, 1996
Bulletin of Marine Science, 2020
The abundance and composition of the phytoplankton community off the coast of Cape Canaveral, Flo... more The abundance and composition of the phytoplankton community off the coast of Cape Canaveral, Florida was examined from Fall 2013 to Summer 2015. The region is a shallow shelf environment. Water samples were collected quarterly at 24 sites from the surface and bottom of the water column; temperature and nutrient concentrations were determined. Photoautotrophic picoplanktonic prokaryotes were consistently important in terms of numerical abundance and biomass throughout the study. Among the cyanobacteria, a surface bloom of the nitrogen-fixing filamentous species Trichodesmium was observed in Fall 2013. Dinoflagellates and diatoms were also major contributors to phytoplankton biomass. Many of the dominant dinoflagellates were mixotrophic or heterotrophic species. Nanoplanktonic eukaryotic algae were also periodically an important group in terms of biomass, such as prasinophytes (Chlorophyta). No consistent and reoccurring spatial patterns were observed, likely due to the dynamic water...
Estuarine, Coastal and Shelf Science, 2021
Abstract In 2018, the presence of bottom water hypoxia along the SW Florida coast was investigate... more Abstract In 2018, the presence of bottom water hypoxia along the SW Florida coast was investigated during a bloom of the toxic dinoflagellate Karenia brevis. The bloom was first detected in November 2017. Monitoring of oxygen levels and bloom densities were carried out in 2018 and 2019 using sampling grids. Vertical profiles indicated a pycnocline at 3–4 m where warmer, lower salinity water was at the surface, while the deeper hypoxic layer was colder with higher salinity. There were significantly higher abundances of K. brevis in the surface water compared to the hypoxic bottom water in September 2018. At two fixed sites dissolved oxygen was measured continuously showing hypoxic conditions during that month. Geospatial analysis of vertical profile data yielded an estimate that the hypoxic layer covered an area of at least 655 km2. The possible influences of red tides on hypoxic conditions along the coast of the eastern Gulf of Mexico and are discussed within the context of the 2018 K. brevis bloom event. Hypoxia occurring in parallel to a red tide bloom is more likely to occur with warmer ocean temperatures and increased fluxes of nutrients and fresh water to the Gulf of Mexico after hurricanes.
Frontiers in Marine Science, 2021
The Indian River Lagoon (IRL), located on the east coast of Florida, is a complex estuarine ecosy... more The Indian River Lagoon (IRL), located on the east coast of Florida, is a complex estuarine ecosystem that is negatively affected by recurring harmful algal blooms (HABs) from distinct taxonomic/functional groups. Enhanced monitoring was established to facilitate rapid quantification of three recurrent bloom taxa, Aureoumbra lagunensis, Pyrodinium bahamense, and Pseudo-nitzschia spp., and included corroborating techniques to improve the identification of small-celled nanoplankton (<10 μm in diameter). Identification and enumeration of these target taxa were conducted during 2015–2020 using a combination of light microscopy and species-specific approaches, specifically immunofluorescence flow cytometry as well as a newly developed qPCR assay for A. lagunensis presented here for the first time. An annual bloom index (ABI) was established for each taxon based on occurrence and abundance data. Blooms of A. lagunensis (>2 × 108 cells L–1) were observed in all 6 years sampled and ac...
Frontiers in Marine Science, 2021
This paper examines the character of phytoplankton blooms in a restricted sub-tropical lagoon alo... more This paper examines the character of phytoplankton blooms in a restricted sub-tropical lagoon along the Atlantic coast of central Florida. The results of the 23-year study (1997–2020) provide evidence for multiple types of variability in bloom activity, including cyclical patterns, stochastic events, and most prominently a regime shift in composition and intensity. Cyclical patterns (e.g., El Niño/La Niña periods) and stochastic events (e.g., tropical storms) influenced rainfall levels, which in turn impacted nutrient concentrations in the water column and the timing and intensity of blooms. In 2011, a major change occurred in the character of blooms, with a dramatic increase in peak biomass levels of blooms and the appearance of new dominant taxa, including the brown tide species Aureoumbra lagunensis and other nanoplanktonic species. Results of quantitative analyses reveal system behavior indicative of a regime shift. The shift coincided with widespread losses of seagrass communit...
Scientific Reports, 2021
A microscopic study of microplankton in two coastal lagoons in the Florida Keys coincidently, and... more A microscopic study of microplankton in two coastal lagoons in the Florida Keys coincidently, and unexpectedly, revealed the widespread presence of high concentrations of polystyrene microplastic particles. The polystyrene particles were first observed in the second year of a 2-year study of phytoplankton communities, with peak densities in the spring/summer of 2019 at all ten sampling sites in the two lagoons. Polystyrene particle densities reached levels up to 76,000 L−1. The particles ranged in size from 33 to 190 µm, similar to the size range of microplanktonic algae (20–200 µm). Over the period of peak polystyrene densities, average particle densities were similar to average densities of microplanktonic algae cells. The latter observation highlights the potential significance of the microplastic particles for the ecology of the pristine waters of the Florida Keys, if they persist.
Botanica Marina, 2017
This study reports on the harmful algal bloom (HAB) dinoflagellate
ALGAE, 2014
This is the first recorded observation of Akashiwo sanguinea excreting mucilaginous substances fr... more This is the first recorded observation of Akashiwo sanguinea excreting mucilaginous substances from pores on the cell surface. Observations were from samples collected in the Caloosahatchee Estuary, Florida, USA during a bloom event, with densities of 672 cells mL-1 of A. sanguinea, including 51 cells surrounded by mucous. Scanning electron microscopy observations revealed that the mucous was secreted from thecal pores on the cell surface. The potential significance of mucous production is discussed.
Marine Environmental Research, 2015
The primary objective of this study was to examine trends in phytoplankton biomass and species co... more The primary objective of this study was to examine trends in phytoplankton biomass and species composition under varying nutrient load and hydrologic regimes in the Guana Tolomato Matanzas estuary (GTM), a well-flushed subtropical estuary located on the northeast coast of Florida. The GTM contains both regions of significant human influence and pristine areas with only modest development, providing a test case for comparing and contrasting phytoplankton community dynamics under varying degrees of nutrient load. Water temperature, salinity, Secchi disk depth, nutrient concentrations and chlorophyll concentrations were determined on a monthly basis from 2002 to 2012 at three representative sampling sites in the GTM. In addition, microscopic analyses of phytoplankton assemblages were carried out monthly for a five year period from 2005 through 2009 at all three sites. Results of this study indicate that phytoplankton biomass and composition in the GTM are strongly influenced by hydrologic factors, such as water residence times and tidal exchanges of coastal waters, which in turn are affected by shifts in climatic conditions, most prominently rainfall levels. These influences are exemplified by the observation that the region of the GTM with the longest water residence times but lowest nutrient loads exhibited the highest phytoplankton peaks of autochthonous origin. The incursion of a coastal bloom of the toxic dinoflagellate Karenia brevis into the GTM in 2007 demonstrates the potential importance of allochthonous influences on the ecosystem.
Marine and Freshwater Research, 2016
Concerns about global climate change have heightened awareness of the role changing rainfall regi... more Concerns about global climate change have heightened awareness of the role changing rainfall regimes play in altering plankton communities of coastal ecosystems. In this study spatial and temporal patterns of phytoplankton composition and biomass in a sub-tropical tidal creek in Florida were observed over three wet and dry seasons, which included the major storm year of 2005 and the drought year of 2006. Shifts in rainfall levels were associated with changes in phytoplankton composition and biomass, but the effects varied between the upper and lower reaches of the creek. The upper reach of the creek was fresh throughout the study period. The oligohaline to mesohaline lower creek alternated between fresh and marine species in response to shifts in salinity regimes. Blooms of the freshwater dinoflagellate Peridinium sp., small centric diatoms and nitrogen-fixing cyanobacteria were common in the upper Ten Mile Creek during low rainfall years. The euryhaline marine dinoflagellate Akashi...
Marine Ecology Progress Series, 2015
Plankton and Benthos Research, 2014
Akashiwo sanguinea is a cosmopolitan dinoflagellate that has been observed to form major blooms i... more Akashiwo sanguinea is a cosmopolitan dinoflagellate that has been observed to form major blooms in coastal ecosystems around the world. A. sanguinea plays a major role in the ecology of many marine environments, including coastal ecosystems with variable salinities, where its euryhaline character makes it competitive. The study involved monthly water sampling and measurement of physical-chemical parameters at four sites from the upper reaches of the Caloosahatchee Estuary to San Carlos Bay bordering the Gulf of Mexico. Major A. sanguinea blooms were observed in the Caloosahatchee estuary, with biovolume up to 30.5 10 6 μm 3 mL 1 , equivalent to 740 cells mL 1 , in the upper estuary. The latter regions of the estuary also had the greatest range of salinity and the highest total nitrogen and total phosphorus concentrations. The dynamics of blooms are discussed within the context of spatial and temporal patterns of salinity, temperature and nutrient concentrations, as they relate to hydrologic and climatic conditions.
We analyzed spatial and temporal patterns and relationships in water quality in order to investig... more We analyzed spatial and temporal patterns and relationships in water quality in order to investigate causes and short-term consequences of a historically unprecedented phytoplankton bloom that afflicted the Indian River Lagoon (IRL) system during 2011. The 2011 ‘superbloom’ was unprecedented, not only for its magnitude (chlorophyll_a concentrations > 130 ug/L) and geographic scale (Banana, north Indian River and southern Mosquito sub-lagoons), but also for its long (7+ month) duration and its distinctive floral composition (co-dominated by green micro-flagellates and pico-cyanobacteria). We used a combination of statistical approaches to compare water quality during 2011 to that of antecedent periods, and to explore relationships between chlorophyll_a and other water quality constituents before and during the bloom. Bottom-up effects (nutrients) and other physical-chemical factors (e.g., salinity and water temperature) are explored as ‘drivers’ or ‘triggers’ of the bloom. The con...
Phycologia, 2004
The primary focus of this paper is to provide a detailed description of Pyrodinium bahamense from... more The primary focus of this paper is to provide a detailed description of Pyrodinium bahamense from the Indian River Lagoon, Florida. Recent reports of saxitoxin production by P. bahamense from the Indian River lagoon has heightened interest in the similarities between the Atlantic and Indo-Pacific forms of this species. Microscopic examinations of samples from the Indian River Lagoon using light and scanning electron microscopy suggest that the Atlantic form deserves the separate varietal designation of bahamense assigned to it in recent years, distinguishing it from the Indo-Pacific var. compressum. This conclusion was based on key morphological and dimensional characteristics.
Estuaries and Coasts, 2014
Relationships between shifts in climatic and other environmental conditions and changes in the ch... more Relationships between shifts in climatic and other environmental conditions and changes in the character and dynamics of phytoplankton blooms were examined in three interconnected subtropical lagoons on the east coast of Florida, i.e., Mosquito Lagoon, Indian River Lagoon, and Banana River Lagoon, from 1997 to 2013. Phytoplankton blooms were a common feature through most of the study period in two of the lagoons. From 1997 to 2009, blooms in the latter two lagoons were typically dominated by dinoflagellates in the warm wet season and diatoms in the cool dry season. Blooms of the dominant bloom-forming dinoflagellate species Pyrodinium bahamense were positively correlated to rainfall levels, indicating a link to enhanced external nutrient loads. In 2011-2013, major blooms were observed in all three lagoons, but unlike the previous 14 years, they were dominated by picoplanktonic eukaryotes, including a chlorophyte, Pedinophyceae sp., and the brown tide species Aureoumbra lagunensis. The results suggest that extreme climatic conditions, including record cold winter water temperatures and low rainfall levels, were major driving factors in this state shift in the character of blooms, through a wide range of effects including die-offs of benthic flora and fauna, suppression of grazer populations, alteration of nutrient regimes, and uncharacteristic water column conditions, such as elevated salinities and light attenuation.