Vera Trainer - Academia.edu (original) (raw)

Papers by Vera Trainer

Remote Sensing of the Coastal Oceanic Environment, 2005

Satellite remote sensing imagery is being used to identify and characterize upwelling conditions ... more Satellite remote sensing imagery is being used to identify and characterize upwelling conditions on the coast of Washington State, with an emphasis on detecting ocean features associated with harmful algal bloom events. Blooms of phytoplankton, including the domoic acid-producing diatom Pseudo-nitzschia, appear to be associated with a semi-permanent eddy bordering Washington and British Columbia that is observed in satellite imagery

Natural Toxins, 1998

A bloom of the pennate diatom Pseudo-nitzschia, several species of which are associated with the ... more A bloom of the pennate diatom Pseudo-nitzschia, several species of which are associated with the production of the potent excitotoxin domoic acid, was observed in a Puget Sound, Washington embayment in July and August of 1997. Penn Cove, which receives nutrients from the nearby Skagit River and abundant sunshine during summer months due to its location in the rain shadow of the Olympic Mountains, is the home of a commercial mussel farm which supplies shell®sh to many coastal areas of the USA. Levels of domoic acid in mussels increased to 3 ppm on 6 and 10 July, corresponding to the observation of a brown algal bloom in Penn Cove. Four species of Pseudo-nitzschia (P. pungens, P. multiseries, P. australis, and P. pseudodelicatissima) were present in our samples from the cove, corresponding to levels of domoic acid in seawater ranging from 0.1±0.8 mg l À1 as measured by a receptor binding assay. The highest Pseudo-nitzschia concentration during the time of our sampling was 13 million cells per liter on 28 July. The bloom of Pseudo-nitzschia occurred after a period of strong discharge from the Skagit River and rain accompanied by elevated south and southeasterly winds. Strati®cation of the cove, providing optimal bloom conditions, was facilitated by weak winds, sunshine, and a freshwater lens at the mouth of the cove. The position of the Pseudo-nitzschia bloom was in¯uenced by buoyancy fronts caused by exchange of water within the cove with that of Saratoga Passage. The decay of this bloom in Penn Cove was accompanied by decreasing nitrate levels at all measured depths. These and future observations aid in the development of a model for prediction of toxic bloom events in the shallow embayments of Puget Sound.

Neurotoxicology and Teratology, 2009

Environmental Health, 2008

Anthropogenically-derived increases in atmospheric greenhouse gas concentrations have been implic... more Anthropogenically-derived increases in atmospheric greenhouse gas concentrations have been implicated in recent climate change, and are projected to substantially impact the climate on a global scale in the future. For marine and freshwater systems, increasing concentrations of greenhouse gases are expected to increase surface temperatures, lower pH, and cause changes to vertical mixing, upwelling, precipitation, and evaporation patterns. The potential consequences of these changes for harmful algal blooms (HABs) have received relatively little attention and are not well understood. Given the apparent increase in HABs around the world and the potential for greater problems as a result of climate change and ocean acidification, substantial research is needed to evaluate the direct and indirect associations between HABs, climate change, ocean acidification, and human health. This research will require a multidisciplinary approach utilizing expertise in climatology, oceanography, biology, epidemiology, and other disciplines. We review the interactions between selected patterns of large-scale climate variability and climate change, oceanic conditions, and harmful algae.

Toxicon, 1988

Brevetoxin binding: molecular pharmacology versus immunoassay. Toxicon 26, 97-103, 1988.--Breveto... more Brevetoxin binding: molecular pharmacology versus immunoassay. Toxicon 26, 97-103, 1988.--Brevetoxin PbTx-3 isolated from Florida's red tide dinoflagellate Ptychodiscus brevis has been produced recently in tritiated form by reductive tritiation of brevetoxin PbTx-2. Tritiated PbTx-3 has been used as a specific probe in competitive radioimmunoassays developed to detect brevetoxins in food sources, and this probe has also been utilized to characterize the brevetoxin binding component in rat brain synaptosomes. Brevetoxins PbTx-2 and PbTx-3, possessing the same structural backbone (type-l) as the tritiated probe, and PbTx-l and PbTx-7, possessing a second structural backbone (type-2), have been compared quantitatively in their individual abilities to competitively displace tritiated PbTx-3 from its specific binding site in each assay. Type-l toxins displaced labeled probe with EDso values of 20-22 nM and 12-17 nM in radioimmunoassay and synaptosomes, respectively. Type-2 toxins displaced labeled probe with EDso values of 92 -93 nM and 3.5 -4.1 nM in RIA and synaptosomes, respectively. Synaptosome assays reflect potency of each toxin examined, while radioimmunoassay reflects structural similarities to the immunizing toxin PbTx-3.

Journal of Shellfish Research, 2008

Domoic acid (DA) is a potent toxin produced by bloom-forming phytoplankton in the genus Pseudo-ni... more Domoic acid (DA) is a potent toxin produced by bloom-forming phytoplankton in the genus Pseudo-nitzschia, which is responsible for causing amnesic shellfish poisoning (ASP) in humans. ASP symptoms include vomiting, diarrhea, and in more severe cases confusion, loss of memory, disorientation, and even coma or death. This paper describes the development and validation of a rapid, sensitive, enzyme linked immunosorbent assay test kit for detecting DA using a monoclonal antibody. The assay gives equivalent results to those obtained using standard high performance liquid chromatography, fluorenylmethoxycarbonyl high performance liquid chromatography, or liquid chromatography-mass spectrometry methods. It has a linear range from 0.1-3 ppb and was used successfully to measure DA in razor clams, mussels, scallops, and phytoplankton. The assay requires approximately 1.5 h to complete and has a standard 96-well format where each strip of eight wells is removable and can be stored at 4°C until needed. The first two wells of each strip serve as an internal control eliminating the need to run a standard curve. This allows as few as 3 or as many as 36 duplicate samples to be run at a time enabling real-time sample processing and limiting degradation of DA, which can occur during storage. There was minimal cross-reactivity in this assay with glutamine, glutamic acid, kainic acid, epi-or iso-DA. This accurate, rapid, cost-effective, assay offers environmental managers and public health officials an effective tool for monitoring DA concentrations in environment samples.

Proceedings of the National Academy of Sciences, 2010

Marine Ecology Progress Series, 2004

Marine Drugs, 2008

Traditionally, harmful algal bloom studies have primarily focused on quantifying toxin levels con... more Traditionally, harmful algal bloom studies have primarily focused on quantifying toxin levels contained within the phytoplankton cells of interest. In the case of paralytic shellfish poisoning toxins (PSTs), intracellular toxin levels and the effects of dietary consumption of toxic cells by planktivores have been well documented. However, little information is available regarding the levels of extracellular PSTs that may leak or be released into seawater from toxic cells during blooms. In order to fully evaluate the risks of harmful algal bloom toxins in the marine food web, it is necessary to understand all potential routes of exposure. In the present study, extracellular and intracellular PST levels were measured in field seawater samples (collected weekly from June to October 2004October -2007 and in Alexandrium spp. culture samples isolated from Sequim Bay, Washington. Measurable levels of intra-and extra-cellular toxins were detected in both field and culture samples via receptor binding assay (RBA) and an enzyme-linked immunosorbent assay (ELISA). Characterization of the PST toxin profile in the Sequim Bay isolates by pre-Mar. Drugs 2008, 6 104 column oxidation and HPLC-fluorescence detection revealed that gonyautoxin 1 and 4 made up 65 ± 9.7 % of the total PSTs present. Collectively, these data confirm that extracellular PSTs are present during blooms of Alexandrium spp. in the Sequim Bay region.

Marine Drugs, 2013

The illness of three people due to diarrhetic shellfish poisoning (DSP)

Marine Drugs, 2013

The illness of three people in 2011 after their ingestion of mussels collected from Sequim Bay St... more The illness of three people in 2011 after their ingestion of mussels collected from Sequim Bay State Park, Washington State, USA, demonstrated the need to monitor diarrhetic shellfish toxins (DSTs) in Washington State for the protection of human health. Following these cases of diarrhetic shellfish poisoning, monitoring for DSTs in Washington State became formalized in 2012, guided by routine monitoring of Dinophysis species by the SoundToxins program in Puget Sound and the Olympic Region Harmful Algal Bloom (ORHAB) partnership on the outer Washington State coast. Here we show that the DSTs at concentrations above the guidance level of 16 μg okadaic acid (OA) + dinophysistoxins (DTXs)/100 g shellfish tissue were widespread in sentinel mussels throughout Puget Sound in summer 2012 and included harvest closures of California mussel, varnish clam, manila clam and Pacific oyster. Concentrations of toxins in Pacific oyster and manila clam were often at least half those measured in blue mussels at the same site. The primary toxin isomer in shellfish and plankton samples was dinophysistoxin-1 (DTX-1) with D. acuminata as the primary Dinophysis species. Other lipophilic toxins in shellfish were pectenotoxin-2 (PTX-2) and yessotoxin (YTX) with azaspiracid-2 (AZA-2) also measured in phytoplankton

Marine Biology, 2005

Herring (Clupea harengus pallasi) spawning sites in Puget Sound, Washington overlap spatially and... more Herring (Clupea harengus pallasi) spawning sites in Puget Sound, Washington overlap spatially and temporally with blooms of Alexandrium catenella, a toxic dinoflagellate species responsible for paralytic shellfish poisoning. Consequently, newly hatched herring larvae may be regularly exposed to the suite of dissolved paralytic shellfish toxins that are released into the water column from toxic cells during blooms. To date, virtually nothing is known about the impacts of these neurotoxins on early developmental stages of marine fish. In the present study, herring larvae at three ages, 0 days post hatch (dph), 4 dph, and 11 dph, were exposed to dissolved saxitoxin (STX) in 24-h and multiday exposures. All larvae were examined for sensorimotor function (i.e. spontaneous swimming behavior and touch response). Significant reductions in spontaneous and touch-activated swimming behavior occurred within 1 h of exposure. EC 50 s at 1 h of exposure were 1,500, 840, and 700 lg STX equiv. l À1 for larvae introduced to STX at 0, 4, and 11 dph, respectively. This progressive age-specific increase in STX-induced paralysis suggests that older larvae were more sensitive to the toxin than younger larvae. Interestingly, herring larvae at all ages exhibited a significant degree of neurobehavioral recovery within 4-24 h of continuous exposure relative to the 1-h time point. This recovery of normal motor behaviors was not observed in previous studies with freshwater zebrafish (Danio rerio) larvae under the same continuous exposure conditions, suggesting that an adaptive detoxification or toxin sequestration mechanism may have evolved in some species of marine fish larvae. Our data reveal that (1) dissolved STX is bioavailable to marine finfish larvae, (2) the toxin is a paralytic agent with potencies that differ between developmental stages, and (3) STX-induced sensorimotor inhibition occurs rapidly but is transient in marine larvae. Collectively, these results suggest that dissolved algal toxins may have important sublethal effects on marine fish populations.

Limnology and Oceanography, 2010

... Northwest of the United States are used to examine the influence of large-scale climate varia... more ... Northwest of the United States are used to examine the influence of large-scale climate variations on aspects of Alexandrium catenella bloom dynamics on ... persist into the seasonal time period that shellfish in this region accumulate PSTs, which is typically in the summer and fall ...

Limnology and Oceanography, 2002

... Corresponding author (vera.l.trainer ... the Olympic Coast National Marine Sanctuary and the ... more ... Corresponding author (vera.l.trainer ... the Olympic Coast National Marine Sanctuary and the captain and crew of the NOAA research vessel McArthur, the captain and crew of the UNOLS vessel New Horizon, and N. Adams, K. Baugh, B. Bill, S. Geier, N. Kachel, A. Palmer, J. Postel ...

Limnology and Oceanography, 2001

The potential for in situ turbulence to inhibit dinoflagellate population growth has been demonst... more The potential for in situ turbulence to inhibit dinoflagellate population growth has been demonstrated by experimentally exposing dinoflagellate cultures to quantified shear flow. However, despite interest in understanding environmental factors that affect the growth of toxic dinoflagellates, little is known of the effect of shear on the growth of toxin-producing dinoflagellate species. Cultures of the dinoflagellate, Alexandrium fundyense, a producer of toxins responsible for paralytic shellfish poisoning, were exposed to quantified laminar shear generated in Couette flow for 1-24 h d Ϫ1 over 6-8 d. Shear stress in all experiments was 0.003 N m Ϫ2 , similar to levels expected in near-surface waters on a windy day. Net population growth decreased with shear exposures Ͼ1 h d Ϫ1 and became negative with exposures Ͼ12 h d Ϫ1 . Cellular toxin content at the end of each experiment was measured by a receptorbinding assay that used [ 3 H]saxitoxin. Toxin cell Ϫ1 of cultures sheared for Ͼ1 h d Ϫ1 increased up to three times that of control cultures. Cellular toxin content increased significantly as growth rate of sheared cultures decreased. However, varying culture growth rate using irradiance had no significant effect on toxin cell Ϫ1 . Because shear stress levels used in this study were plausible for near-surface turbulent flows, oceanic turbulence may inhibit population growth and increase cellular toxin content of A. fundyense. However, in natural populations it would be difficult to distinguish the effect of turbulence on toxin content from other influences on toxin variability, particularly if volumeor mass-specific, rather than cell-specific, measures of toxin are used.

Limnology and Oceanography, 2009

In September 2004 a large, nearly monospecific diatom bloom of Pseudo-nitzschia cuspidata off the... more In September 2004 a large, nearly monospecific diatom bloom of Pseudo-nitzschia cuspidata off the coast of the state of Washington reached cell concentrations of 6.1 3 10 6 cells L 21 and produced maximum particulate domoic acid (pDA), dissolved domoic acid (dDA), and cellular domoic acid concentrations of 43 nmol L 21 , 4 nmol L 21 , and 63 pg cell 21 , respectively. This bloom co-dominated the phytoplankton assemblage with the euglenoid Eutreptiella sp. in the Juan de Fuca eddy region, a known initiation site for toxigenic Pseudo-nitzschia blooms. Two isolates of P. cuspidata collected during separate cruises produced domoic acid (DA) in culture. During the September 2004 survey, 84% of the stations (n 5 98) had detectable Pseudo-nitzschia and 78% had detectable pDA. There were no significant correlations between either pDA or cellular DA and ambient concentrations of macronutrients; however, when considering only those stations where Pseudo-nitzschia was present, pDA was positively correlated with chlorophyll a and negatively correlated with temperature (p # 0.01) at both 1-and 5-m depths. Correlations between cellular DA concentrations and total bacteria or cyanobacteria abundances were not significant. Variable ratios of pDA : dDA in the eddy region suggest that DA release was under cellular regulation by Pseudo-nitzschia. Stations where dissolved Fe concentrations were limiting (,0.5 nmol L 21 ) had the highest Pseudo-nitzschia abundances and pDA and cellular DA values. These results provide enticing field evidence of the role of Fe limitation in controlling cellular DA levels.

Remote Sensing of the Coastal Oceanic Environment, 2005

Satellite remote sensing imagery is being used to identify and characterize upwelling conditions ... more Satellite remote sensing imagery is being used to identify and characterize upwelling conditions on the coast of Washington State, with an emphasis on detecting ocean features associated with harmful algal bloom events. Blooms of phytoplankton, including the domoic acid-producing diatom Pseudo-nitzschia, appear to be associated with a semi-permanent eddy bordering Washington and British Columbia that is observed in satellite imagery

Natural Toxins, 1998

A bloom of the pennate diatom Pseudo-nitzschia, several species of which are associated with the ... more A bloom of the pennate diatom Pseudo-nitzschia, several species of which are associated with the production of the potent excitotoxin domoic acid, was observed in a Puget Sound, Washington embayment in July and August of 1997. Penn Cove, which receives nutrients from the nearby Skagit River and abundant sunshine during summer months due to its location in the rain shadow of the Olympic Mountains, is the home of a commercial mussel farm which supplies shell®sh to many coastal areas of the USA. Levels of domoic acid in mussels increased to 3 ppm on 6 and 10 July, corresponding to the observation of a brown algal bloom in Penn Cove. Four species of Pseudo-nitzschia (P. pungens, P. multiseries, P. australis, and P. pseudodelicatissima) were present in our samples from the cove, corresponding to levels of domoic acid in seawater ranging from 0.1±0.8 mg l À1 as measured by a receptor binding assay. The highest Pseudo-nitzschia concentration during the time of our sampling was 13 million cells per liter on 28 July. The bloom of Pseudo-nitzschia occurred after a period of strong discharge from the Skagit River and rain accompanied by elevated south and southeasterly winds. Strati®cation of the cove, providing optimal bloom conditions, was facilitated by weak winds, sunshine, and a freshwater lens at the mouth of the cove. The position of the Pseudo-nitzschia bloom was in¯uenced by buoyancy fronts caused by exchange of water within the cove with that of Saratoga Passage. The decay of this bloom in Penn Cove was accompanied by decreasing nitrate levels at all measured depths. These and future observations aid in the development of a model for prediction of toxic bloom events in the shallow embayments of Puget Sound.

Neurotoxicology and Teratology, 2009

Environmental Health, 2008

Anthropogenically-derived increases in atmospheric greenhouse gas concentrations have been implic... more Anthropogenically-derived increases in atmospheric greenhouse gas concentrations have been implicated in recent climate change, and are projected to substantially impact the climate on a global scale in the future. For marine and freshwater systems, increasing concentrations of greenhouse gases are expected to increase surface temperatures, lower pH, and cause changes to vertical mixing, upwelling, precipitation, and evaporation patterns. The potential consequences of these changes for harmful algal blooms (HABs) have received relatively little attention and are not well understood. Given the apparent increase in HABs around the world and the potential for greater problems as a result of climate change and ocean acidification, substantial research is needed to evaluate the direct and indirect associations between HABs, climate change, ocean acidification, and human health. This research will require a multidisciplinary approach utilizing expertise in climatology, oceanography, biology, epidemiology, and other disciplines. We review the interactions between selected patterns of large-scale climate variability and climate change, oceanic conditions, and harmful algae.

Toxicon, 1988

Brevetoxin binding: molecular pharmacology versus immunoassay. Toxicon 26, 97-103, 1988.--Breveto... more Brevetoxin binding: molecular pharmacology versus immunoassay. Toxicon 26, 97-103, 1988.--Brevetoxin PbTx-3 isolated from Florida's red tide dinoflagellate Ptychodiscus brevis has been produced recently in tritiated form by reductive tritiation of brevetoxin PbTx-2. Tritiated PbTx-3 has been used as a specific probe in competitive radioimmunoassays developed to detect brevetoxins in food sources, and this probe has also been utilized to characterize the brevetoxin binding component in rat brain synaptosomes. Brevetoxins PbTx-2 and PbTx-3, possessing the same structural backbone (type-l) as the tritiated probe, and PbTx-l and PbTx-7, possessing a second structural backbone (type-2), have been compared quantitatively in their individual abilities to competitively displace tritiated PbTx-3 from its specific binding site in each assay. Type-l toxins displaced labeled probe with EDso values of 20-22 nM and 12-17 nM in radioimmunoassay and synaptosomes, respectively. Type-2 toxins displaced labeled probe with EDso values of 92 -93 nM and 3.5 -4.1 nM in RIA and synaptosomes, respectively. Synaptosome assays reflect potency of each toxin examined, while radioimmunoassay reflects structural similarities to the immunizing toxin PbTx-3.

Journal of Shellfish Research, 2008

Domoic acid (DA) is a potent toxin produced by bloom-forming phytoplankton in the genus Pseudo-ni... more Domoic acid (DA) is a potent toxin produced by bloom-forming phytoplankton in the genus Pseudo-nitzschia, which is responsible for causing amnesic shellfish poisoning (ASP) in humans. ASP symptoms include vomiting, diarrhea, and in more severe cases confusion, loss of memory, disorientation, and even coma or death. This paper describes the development and validation of a rapid, sensitive, enzyme linked immunosorbent assay test kit for detecting DA using a monoclonal antibody. The assay gives equivalent results to those obtained using standard high performance liquid chromatography, fluorenylmethoxycarbonyl high performance liquid chromatography, or liquid chromatography-mass spectrometry methods. It has a linear range from 0.1-3 ppb and was used successfully to measure DA in razor clams, mussels, scallops, and phytoplankton. The assay requires approximately 1.5 h to complete and has a standard 96-well format where each strip of eight wells is removable and can be stored at 4°C until needed. The first two wells of each strip serve as an internal control eliminating the need to run a standard curve. This allows as few as 3 or as many as 36 duplicate samples to be run at a time enabling real-time sample processing and limiting degradation of DA, which can occur during storage. There was minimal cross-reactivity in this assay with glutamine, glutamic acid, kainic acid, epi-or iso-DA. This accurate, rapid, cost-effective, assay offers environmental managers and public health officials an effective tool for monitoring DA concentrations in environment samples.

Proceedings of the National Academy of Sciences, 2010

Marine Ecology Progress Series, 2004

Marine Drugs, 2008

Traditionally, harmful algal bloom studies have primarily focused on quantifying toxin levels con... more Traditionally, harmful algal bloom studies have primarily focused on quantifying toxin levels contained within the phytoplankton cells of interest. In the case of paralytic shellfish poisoning toxins (PSTs), intracellular toxin levels and the effects of dietary consumption of toxic cells by planktivores have been well documented. However, little information is available regarding the levels of extracellular PSTs that may leak or be released into seawater from toxic cells during blooms. In order to fully evaluate the risks of harmful algal bloom toxins in the marine food web, it is necessary to understand all potential routes of exposure. In the present study, extracellular and intracellular PST levels were measured in field seawater samples (collected weekly from June to October 2004October -2007 and in Alexandrium spp. culture samples isolated from Sequim Bay, Washington. Measurable levels of intra-and extra-cellular toxins were detected in both field and culture samples via receptor binding assay (RBA) and an enzyme-linked immunosorbent assay (ELISA). Characterization of the PST toxin profile in the Sequim Bay isolates by pre-Mar. Drugs 2008, 6 104 column oxidation and HPLC-fluorescence detection revealed that gonyautoxin 1 and 4 made up 65 ± 9.7 % of the total PSTs present. Collectively, these data confirm that extracellular PSTs are present during blooms of Alexandrium spp. in the Sequim Bay region.

Marine Drugs, 2013

The illness of three people due to diarrhetic shellfish poisoning (DSP)

Marine Drugs, 2013

The illness of three people in 2011 after their ingestion of mussels collected from Sequim Bay St... more The illness of three people in 2011 after their ingestion of mussels collected from Sequim Bay State Park, Washington State, USA, demonstrated the need to monitor diarrhetic shellfish toxins (DSTs) in Washington State for the protection of human health. Following these cases of diarrhetic shellfish poisoning, monitoring for DSTs in Washington State became formalized in 2012, guided by routine monitoring of Dinophysis species by the SoundToxins program in Puget Sound and the Olympic Region Harmful Algal Bloom (ORHAB) partnership on the outer Washington State coast. Here we show that the DSTs at concentrations above the guidance level of 16 μg okadaic acid (OA) + dinophysistoxins (DTXs)/100 g shellfish tissue were widespread in sentinel mussels throughout Puget Sound in summer 2012 and included harvest closures of California mussel, varnish clam, manila clam and Pacific oyster. Concentrations of toxins in Pacific oyster and manila clam were often at least half those measured in blue mussels at the same site. The primary toxin isomer in shellfish and plankton samples was dinophysistoxin-1 (DTX-1) with D. acuminata as the primary Dinophysis species. Other lipophilic toxins in shellfish were pectenotoxin-2 (PTX-2) and yessotoxin (YTX) with azaspiracid-2 (AZA-2) also measured in phytoplankton

Marine Biology, 2005

Herring (Clupea harengus pallasi) spawning sites in Puget Sound, Washington overlap spatially and... more Herring (Clupea harengus pallasi) spawning sites in Puget Sound, Washington overlap spatially and temporally with blooms of Alexandrium catenella, a toxic dinoflagellate species responsible for paralytic shellfish poisoning. Consequently, newly hatched herring larvae may be regularly exposed to the suite of dissolved paralytic shellfish toxins that are released into the water column from toxic cells during blooms. To date, virtually nothing is known about the impacts of these neurotoxins on early developmental stages of marine fish. In the present study, herring larvae at three ages, 0 days post hatch (dph), 4 dph, and 11 dph, were exposed to dissolved saxitoxin (STX) in 24-h and multiday exposures. All larvae were examined for sensorimotor function (i.e. spontaneous swimming behavior and touch response). Significant reductions in spontaneous and touch-activated swimming behavior occurred within 1 h of exposure. EC 50 s at 1 h of exposure were 1,500, 840, and 700 lg STX equiv. l À1 for larvae introduced to STX at 0, 4, and 11 dph, respectively. This progressive age-specific increase in STX-induced paralysis suggests that older larvae were more sensitive to the toxin than younger larvae. Interestingly, herring larvae at all ages exhibited a significant degree of neurobehavioral recovery within 4-24 h of continuous exposure relative to the 1-h time point. This recovery of normal motor behaviors was not observed in previous studies with freshwater zebrafish (Danio rerio) larvae under the same continuous exposure conditions, suggesting that an adaptive detoxification or toxin sequestration mechanism may have evolved in some species of marine fish larvae. Our data reveal that (1) dissolved STX is bioavailable to marine finfish larvae, (2) the toxin is a paralytic agent with potencies that differ between developmental stages, and (3) STX-induced sensorimotor inhibition occurs rapidly but is transient in marine larvae. Collectively, these results suggest that dissolved algal toxins may have important sublethal effects on marine fish populations.

Limnology and Oceanography, 2010

... Northwest of the United States are used to examine the influence of large-scale climate varia... more ... Northwest of the United States are used to examine the influence of large-scale climate variations on aspects of Alexandrium catenella bloom dynamics on ... persist into the seasonal time period that shellfish in this region accumulate PSTs, which is typically in the summer and fall ...

Limnology and Oceanography, 2002

... Corresponding author (vera.l.trainer ... the Olympic Coast National Marine Sanctuary and the ... more ... Corresponding author (vera.l.trainer ... the Olympic Coast National Marine Sanctuary and the captain and crew of the NOAA research vessel McArthur, the captain and crew of the UNOLS vessel New Horizon, and N. Adams, K. Baugh, B. Bill, S. Geier, N. Kachel, A. Palmer, J. Postel ...

Limnology and Oceanography, 2001

The potential for in situ turbulence to inhibit dinoflagellate population growth has been demonst... more The potential for in situ turbulence to inhibit dinoflagellate population growth has been demonstrated by experimentally exposing dinoflagellate cultures to quantified shear flow. However, despite interest in understanding environmental factors that affect the growth of toxic dinoflagellates, little is known of the effect of shear on the growth of toxin-producing dinoflagellate species. Cultures of the dinoflagellate, Alexandrium fundyense, a producer of toxins responsible for paralytic shellfish poisoning, were exposed to quantified laminar shear generated in Couette flow for 1-24 h d Ϫ1 over 6-8 d. Shear stress in all experiments was 0.003 N m Ϫ2 , similar to levels expected in near-surface waters on a windy day. Net population growth decreased with shear exposures Ͼ1 h d Ϫ1 and became negative with exposures Ͼ12 h d Ϫ1 . Cellular toxin content at the end of each experiment was measured by a receptorbinding assay that used [ 3 H]saxitoxin. Toxin cell Ϫ1 of cultures sheared for Ͼ1 h d Ϫ1 increased up to three times that of control cultures. Cellular toxin content increased significantly as growth rate of sheared cultures decreased. However, varying culture growth rate using irradiance had no significant effect on toxin cell Ϫ1 . Because shear stress levels used in this study were plausible for near-surface turbulent flows, oceanic turbulence may inhibit population growth and increase cellular toxin content of A. fundyense. However, in natural populations it would be difficult to distinguish the effect of turbulence on toxin content from other influences on toxin variability, particularly if volumeor mass-specific, rather than cell-specific, measures of toxin are used.

Limnology and Oceanography, 2009

In September 2004 a large, nearly monospecific diatom bloom of Pseudo-nitzschia cuspidata off the... more In September 2004 a large, nearly monospecific diatom bloom of Pseudo-nitzschia cuspidata off the coast of the state of Washington reached cell concentrations of 6.1 3 10 6 cells L 21 and produced maximum particulate domoic acid (pDA), dissolved domoic acid (dDA), and cellular domoic acid concentrations of 43 nmol L 21 , 4 nmol L 21 , and 63 pg cell 21 , respectively. This bloom co-dominated the phytoplankton assemblage with the euglenoid Eutreptiella sp. in the Juan de Fuca eddy region, a known initiation site for toxigenic Pseudo-nitzschia blooms. Two isolates of P. cuspidata collected during separate cruises produced domoic acid (DA) in culture. During the September 2004 survey, 84% of the stations (n 5 98) had detectable Pseudo-nitzschia and 78% had detectable pDA. There were no significant correlations between either pDA or cellular DA and ambient concentrations of macronutrients; however, when considering only those stations where Pseudo-nitzschia was present, pDA was positively correlated with chlorophyll a and negatively correlated with temperature (p # 0.01) at both 1-and 5-m depths. Correlations between cellular DA concentrations and total bacteria or cyanobacteria abundances were not significant. Variable ratios of pDA : dDA in the eddy region suggest that DA release was under cellular regulation by Pseudo-nitzschia. Stations where dissolved Fe concentrations were limiting (,0.5 nmol L 21 ) had the highest Pseudo-nitzschia abundances and pDA and cellular DA values. These results provide enticing field evidence of the role of Fe limitation in controlling cellular DA levels.