Center for Coastal Environmental Health and Biomolecular Research

Charleston, United States

Center for Coastal Environmental Health and Biomolecular Research

Charleston, United States
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Louw D.C.,National Marine Information and Research Center Natmirc | Doucette G.J.,Center for Coastal Environmental Health and Biomolecular Research | Voges E.,National Marine Information and Research Center Natmirc
Journal of Plankton Research | Year: 2017

Phytoplankton data obtained from a 14-year data set off the coast of Namibia were analysed. The temporal distribution of species belonging to the diatom genus, Pseudo-nitzschia, was examined using samples collected quasimonthly at onshore and offshore locations. This data set revealed that Pseudo-nitzschia blooms occurred sporadically along the central coast of Namibia, and cell concentrations frequently exceeded 200 000 cells L-1, with levels close to or exceeding 1 000 000 cells L-1 noted occasionally. Two relatively cold years (2005 and 2010) and three relatively warm years (2001, 2003 and 2011) were found to be exceptional for high biomass Pseudo-nitzschia blooms, so possible drivers (wind, temperature and nutrients) were evaluated. Pseudo-nitzschia species abundance was associated with moderate temperature (13-16°C) and nutrient conditions. Climatology showed an increase in Pseudo-nitzschia blooms during austral summer, reaching a maximum in May, June or July. These blooms seem to initiate following periods of high total phytoplankton concentrations. Wind was determined to play an important role in controlling these blooms. Low biomass Pseudo-nitzschia blooms were observed during months with high or irregular winds that coincided with periods of upwelling, whereas high biomass blooms were associated with the decrease of wind afterthe main wind peak at the end of summer. © 2016 The Author.


Titcomb E.M.,Florida Atlantic University | Reif J.S.,Colorado State University | Fair P.A.,Center for Coastal Environmental Health and Biomolecular Research | Stavros H.-C.W.,Smart USA | And 3 more authors.
Marine Mammal Science | Year: 2017

Social network analysis has been shown to be effective in studying the social structure of cetacean populations. Common bottlenose dolphins (Tursiops truncatus) inhabiting the Indian River Lagoon (IRL), Florida, have among the highest concentrations of total mercury (THg) in blood reported worldwide. The purpose of this study was to examine the relationship between THg concentrations in IRL dolphins and their social affiliations. Whole blood samples from 98 dolphins with photo-identification sighting histories were collected between 2003-2007 and 2010-2012. Dolphins were categorized into approximate tertiles of low (mean 199.7 μg/L), medium (mean 366.8 μg/L), and high (mean 990.5 μg/L) THg exposure. Social associations between individual dolphins were defined by the proportion of sightings documented with another known individual. Social network measures of individuals and associations between dyads were examined to determine differences among THg categories. Strong social affiliations of individuals within the highest category of THg were found (P = 0.04), suggesting shared exposures among dolphins foraging in specific areas of the estuary. Network measures of strength and affinity were significantly higher in the highest exposure category. This report used social network analysis as a novel way to examine patterns of exposure to an environmental contaminant in a cetacean population. © 2017 Society for Marine Mammalogy.


Sorenson L.,Virginia Institute of Marine Science | Sorenson L.,University of California at Los Angeles | McDowell J.R.,Virginia Institute of Marine Science | Knott T.,Center for Coastal Environmental Health and Biomolecular Research | Graves J.E.,Virginia Institute of Marine Science
Conservation Genetics Resources | Year: 2013

Blue marlin (Makaira nigricans) stock status varies among ocean basins, and the Atlantic-wide stock is overfished. United States regulations prohibit commercial landing, importation and sale of Atlantic blue marlin, but not of Pacific or Indian Ocean conspecifics. We genotyped 344 blue marlin of known origin and 16 samples used as unknowns at 13 microsatellite loci and the mitochondrial control region. Assignment tests were conducted using GENECLASS2 to investigate the efficacy of available genotypic data to identify individual origin. We successfully discriminated Atlantic and Pacific blue marlin using genetic characters, providing more power to assign marketed blue marlin products to ocean of origin. © 2012 Springer Science+Business Media B.V.


Meek M.E.,College of Charleston | Meek M.E.,Center for Coastal Environmental Health and Biomolecular Research | Van Dolah F.M.,College of Charleston | Van Dolah F.M.,Center for Coastal Environmental Health and Biomolecular Research
Journal of Microbiological Methods | Year: 2016

Phytoplankton rarely occur as unialgal populations. Therefore, to study species-specific protein expression, indicative of physiological status in natural populations, methods are needed that will both assay for a protein of interest and identify the species expressing it. Here we describe a protocol for IF-FISH, a dual labeling procedure using immunofluorescence (IF) labeling of a protein of interest followed by fluorescence in situ hybridization (FISH) to identify the species expressing that protein. The protocol was developed to monitor expression of the cell cycle marker proliferating cell nuclear antigen (PCNA) in the red tide dinoflagellate, Karenia brevis, using a large subunit (LSU) rRNA probe to identify K. brevis in a mixed population of morphologically similar Karenia species. We present this protocol as proof of concept that IF-FISH can be successfully applied to phytoplankton cells. This method is widely applicable for the analysis of single-cell protein expression of any protein of interest within phytoplankton communities. © 2016 Elsevier B.V..


Key P.B.,Center for Coastal Environmental Health and Biomolecular Research | Chung K.W.,JHT Incorporated | Venturella J.J.,JHT Incorporated | Shaddrick B.,JHT Incorporated | Fulton M.H.,Center for Coastal Environmental Health and Biomolecular Research
Journal of Environmental Science and Health - Part B Pesticides, Food Contaminants, and Agricultural Wastes | Year: 2010

In this study, the toxicity of endosulfan sulfate, the primary degradation product of the insecticide endosulfan, was determined in three life stages of the grass shrimp (Palaemonetes pugio). After 96 h exposure to endosulfan sulfate, the grass shrimp adult LC50 was 0.86 μg/L (95% CI 0.56-1.31), the grass shrimp larvae LC50 was 1.64 μg/L (95% CI 1.09-2.47) and the grass shrimp embryo LC50 was 45.85 μg/L (95% CI 23.72-88.61 μg/L). This was compared to the previously published grass shrimp 96-h LC50s for endosulfan. The toxicity of the two compounds was similar for the grass shrimp life stages with adults more sensitive than larvae and embryos. The presence of sediment in 24h endosulfan sulfate-exposures raised LC50s for both adult and larval grass shrimp but not significantly. The USEPA expected environmental concentrations (EEC) for total endosulfan and endosulfan sulfate and the calculations of risk quotients (RQ) based on the more sensitive adult grass shrimp 96-h LC50 clearly show that environmental concentrations equal to acute EECs would prove detrimental to grass shrimp or other similarly sensitive aquatic organisms. These results indicate that given the persistence and toxicity of endosulfan sulfate, future risk assessments should consider the toxicity potential of the parent compound as well as this degradation product. © Taylor & Francis Group, LLC.


Key P.B.,Center for Coastal Environmental Health and Biomolecular Research | Chung K.W.,JHT Incorporated | Hoguet J.,JHT Incorporated | Sapozhnikova Y.,JHT Incorporated | Delorenzo M.E.,Center for Coastal Environmental Health and Biomolecular Research
Journal of Environmental Science and Health - Part B Pesticides, Food Contaminants, and Agricultural Wastes | Year: 2011

Phenothrin is a synthetic pyrethroid used as a contact insecticide in mosquito control programs. This study compared the toxicity of phenothrin to adult, larval and embryonic grass shrimp (Palaemonetes pugio) and examined oxidative stress responses in adult and larval grass shrimp. The adult 24-h LC50 was 0.341 μg/L (95 % confidence intervals 0.282-0.412) and the 96-h LC50 was 0.161 μg/L (95 % CI 0.128-0.203 μg/L). The larval 24-h LC50 was 0.50 μg/L (95 % CI 0.441-0.568) and the 96-h LC50 was 0.154 μg/L (95 % CI 0.139-0.170 μg/L). In the presence of sediment, the 24-h LC50 was 6.30 μg/L (95 % CI 5.00-7.44 μg/L) for adults and 0.771 μg/L (95 % CI 0.630-0.944) for larvae. The sublethal biomarkers glutathione and lipid peroxidase (LPx) were examined after 96-h phenothrin exposure at five concentrations, and there were no statistically significant differences in these levels in adults or larvae compared to controls. There was a significant downward trend in larval LPx levels. This research confirms that phenothrin is highly toxic to grass shrimp and suggests that both adult and larval grass shrimp are appropriate life stages for risk assessments.


Key P.B.,Center for Coastal Environmental Health and Biomolecular Research | Simonik E.,Vanderbilt University | Kish N.,University of South Carolina | Chung K.W.,Center for Coastal Environmental Health and Biomolecular Research | Fulton M.H.,Center for Coastal Environmental Health and Biomolecular Research
Journal of Environmental Science and Health - Part B Pesticides, Food Contaminants, and Agricultural Wastes | Year: 2013

This study assessed the in vitro and in vivo effects of an acetylcholinesterase enzyme inhibitor (chlorpyrifos) in two estuarine crustaceans: grass shrimp (Palaemonetes pugio) and mysid (Americamysis bahia). The differences in response were quantified after lethal and sublethal exposures to chlorpyrifos and in vitro assays with chlorpyrifos-oxon. Results from the in vitro experiments indicated that the target enzyme, acetylcholinesterase (AChE), in the two species was similar in sensitivity to chlorpyrifos inhibition with IC50s of 0.98 nM and 0.89 nM for grass shrimp and mysids, respectively. In vivo experiments showed that mysids were significantly more sensitive to chlorpyrifos-induced AChE inhibition after 24 h of exposure. The in vivo EC50s for AChE inhibition were 1.23 μg L-1 for grass shrimp and 0.027 μg L-1 for mysids. Median lethal concentrations (24h LC50 values) were 1.06 μg L-1 for grass shrimp and 0.068 μg L-1 for mysids. The results suggest that differences in the response of these two crustaceans are likely related to differences in uptake and metabolism rather than target site sensitivity. © 2013 Copyright Taylor and Francis Group, LLC.


Tiedeken J.A.,Center for Coastal Environmental Health and Biomolecular Research | Muha N.,Center for Coastal Environmental Health and Biomolecular Research | Ramsdell J.S.,Center for Coastal Environmental Health and Biomolecular Research
Toxicologic Pathology | Year: 2013

The amnesic shellfish toxin, domoic acid, interferes with glutamatergic pathways leading to neuronal damage, most notably causing memory loss and seizures. In this study, the authors utilized a recently developed rat model for domoic acid-induced epilepsy, an emerging disease appearing in California sea lions weeks to months after poisoning, to identify structural damage that may lead to a permanent epileptic state. Sprague Dawley rats were kindled with several low hourly intraperitoneal doses of domoic acid until a state of status epilepticus (SE) appears. This kindling approach has previously been shown to induce a permanent state of epileptic disease in 96% animals within 6 months. Three animals were selected for neurohistology a week after the initial SE. An amino cupric silver staining method using neutral red counterstain was used on every eighth 40 μm coronal section from each brain to highlight neural degeneration from the olfactory bulb through the brain stem. The most extensive damage was found in the olfactory bulb and related olfactory pathways, including the anterior/medial olfactory cortices, endopiriform nucleus, and entorhinal cortex. These findings indicate that damage to olfactory pathways is prominent in a rat model for domoic acid-induced chronic recurrent spontaneous seizures and aggressive behavior. © 2013 by The Author(s).


Ramsdell J.S.,Center for Coastal Environmental Health and Biomolecular Research | Gulland F.M.,Marine Mammal Center
Marine Drugs | Year: 2014

Domoic acid epileptic disease is characterized by spontaneous recurrent seizures weeks to months after domoic acid exposure. The potential for this disease was first recognized in a human case study of temporal lobe epilepsy after the 1987 amnesic shellfish-poisoning event in Quebec, and was characterized as a chronic epileptic syndrome in California sea lions through investigation of a series of domoic acid poisoning cases between 1998 and 2006. The sea lion study provided a breadth of insight into clinical presentations, unusual behaviors, brain pathology, and epidemiology. A rat model that replicates key observations of the chronic epileptic syndrome in sea lions has been applied to identify the progression of the epileptic disease state, its relationship to behavioral manifestations, and to define the neural systems involved in these behavioral disorders. Here, we present the concept of domoic acid epileptic disease as a delayed manifestation of domoic acid poisoning and review the state of knowledge for this disease state in affected humans and sea lions. We discuss causative mechanisms and neural underpinnings of disease maturation revealed by the rat model to present the concept for olfactory origin of an epileptic disease; triggered in dendodendritic synapases of the olfactory bulb and maturing in the olfactory cortex. We conclude with updated information on populations at risk, medical diagnosis, treatment, and prognosis. © 2014 by the authors; licensee MDPI.


PubMed | Center for Coastal Environmental Health and Biomolecular Research
Type: | Journal: Journal of microbiological methods | Year: 2016

Phytoplankton rarely occur as unialgal populations. Therefore, to study species-specific protein expression, indicative of physiological status in natural populations, methods are needed that will both assay for a protein of interest and identify the species expressing it. Here we describe a protocol for IF-FISH, a dual labeling procedure using immunofluorescence (IF) labeling of a protein of interest followed by fluorescence in situ hybridization (FISH) to identify the species expressing that protein. The protocol was developed to monitor expression of the cell cycle marker proliferating cell nuclear antigen (PCNA) in the red tide dinoflagellate, Karenia brevis, using a large subunit (LSU) rRNA probe to identify K. brevis in a mixed population of morphologically similar Karenia species. We present this protocol as proof of concept that IF-FISH can be successfully applied to phytoplankton cells. This method is widely applicable for the analysis of single-cell protein expression of any protein of interest within phytoplankton communities.

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