- Public Health, Marine Ecology, Health Communication, Toxicology, Fish Ecology, Environmental Toxicology, and 20 moreFish and Marine Ecology, Cetaceans, Sea Turtles, Fish Physiology, Ocean and Human Health, Enzymology, Fish Physiology and Biochemistry, Aquatic Biology, Biochemistry, Natural product research, Pharmacology, Medicinal Plants, Oil Spill, Fish Biology, Fisheries, Fisheries Management, Fisheries Biology, Ecosystem-Based Fisheries Management, Fisheries Science, and Sustainable fisheriesedit
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Variations in the expression of cytochrome P450 (CYP) isozymes in cells may affect the response of and consequent toxic effects in those cells during xenobiotic exposure. The expression of cytochrome P4501A (CYP1A), a major inducible CYP... more
Variations in the expression of cytochrome P450 (CYP) isozymes in cells may affect the response of and consequent toxic effects in those cells during xenobiotic exposure. The expression of cytochrome P4501A (CYP1A), a major inducible CYP in teleosts, was examined immunohistochemically in multiple toxicopathic hepatic lesion types, including neoplasms and several types of preneoplastic foci of cellular alteration (FCA), in
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ABSTRACT Induction of cytochrome P4501A (CYP1A), more specifically the associated enzyme activity aryl hydrocarbon hydroxylase (AHH), has been shown to be one of the most sensitive measures of exposure of vertebrate animals to a range of... more
ABSTRACT Induction of cytochrome P4501A (CYP1A), more specifically the associated enzyme activity aryl hydrocarbon hydroxylase (AHH), has been shown to be one of the most sensitive measures of exposure of vertebrate animals to a range of organic chemical contaminants. However, in order to reliably use this biochemical method for analyzing archived samples, the stability of the enzyme activity in storage must be ascertained. Stability of AHH activity was determined for both tissue sections and subcellular fractions of liver collected from English sole (Pleuronectes vetulus), and held in cryogenic storage for up to 24 months. Our overall recommendations for sample collection, handling, storage, and assay are given.
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ABSTRACT
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Research Interests: Sociology, Aquatic Toxicology, Resistance, Delta, Watershed, and 4 moreMixtures, Estuary, Metabarcoding, and Bay
Oil and gas extraction activities occur across the globe, yet species-specific toxicological information on the biological and ecological impacts of exposure to petrochemicals is lacking for the vast majority of marine species. To help... more
Oil and gas extraction activities occur across the globe, yet species-specific toxicological information on the biological and ecological impacts of exposure to petrochemicals is lacking for the vast majority of marine species. To help prioritize species for recovery, mitigation, and conservation in light of significant toxicological data gaps, a trait-based petrochemical vulnerability index was developed and applied to the more than 1700 marine fishes present across the entire Gulf of Mexico, including all known bony fishes, sharks, rays and chimaeras. Using life history and other traits related to likelihood of exposure, physiological sensitivity to exposure, and population resiliency, final calculated petrochemical vulnerability scores can be used to provide information on the relative sensitivity, or resilience, of marine fish populations across the Gulf of Mexico to oil and gas activities. Based on current knowledge of traits, marine fishes with the highest vulnerability scores primarily occur in areas of high petrochemical activity, are found at or near the surface, and have low reproductive turnover rates and/or highly specialized diet and habitat requirements. Relative population vulnerability scores for marine fishes can be improved with additional toxicokinetic studies, including those that account for the synergistic or additive effect of multiple stressors, as well as increased research on ecological and life history traits, especially for deep living species.
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Abstract Crude oils are comprised of thousands of compounds, and after refining, many more products are derived from crude oils. When crude oils or refined petroleum products are released into the environment, they are altered through a... more
Abstract Crude oils are comprised of thousands of compounds, and after refining, many more products are derived from crude oils. When crude oils or refined petroleum products are released into the environment, they are altered through a series of processes known as weathering. Determining exposure of cetaceans to oil is a challenging task due to the complexity of the substances that make up oil as well as the rapid metabolism and excretion of oil-derived compounds by vertebrate species. The effects of oil in cetaceans have been investigated to some extent following oil spills and in a small number of past experimental exposure studies, which are now prohibited. The wide range of reported effects include poor body condition, calcium imbalance, inflammation, reproductive failure, lung and adrenal gland damage, altered hepatobiliary function, immune changes and increased susceptibility to infections, impaired stress response, and death. The three main routes of oil exposure in cetaceans are respiratory, dermal, and oral, as in most animals. The limited number of published reports including historical in vivo studies relating to effects linked to a specific route are discussed. In the wild, cetaceans are likely to be exposed to oil via more than one route, and reported effects are rarely attributed to a specific pathway of exposure. To date, the greatest and most detailed source of information on the effects of oil exposure on cetaceans is related to the 2010 Deepwater Horizon (DWH) oil spill in the northern Gulf of Mexico. It is extensively reviewed along with other studies. Effects observed at both the organismal level and population effects (mortality events, reproductive success, and growth rate) are discussed along with effects observed in other relevant species. Overall, the historical literature, combined with recent substantive findings following the DWH oil spill, suggests that cetaceans are at high risk of adverse effects from oil exposures, and these effects have importance at both the individual and population levels. Future research needs and recommendations are provided together with a list of specific and general research questions that remain unanswered regarding long-term oil toxicity in cetaceans.
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Ecosystems in the Sacramento–San Joaquin Delta are changing rapidly, as are ecosystems around the world. Extreme events are becoming more frequent and thresholds are likely to be crossed more often, creating greater uncertainty about... more
Ecosystems in the Sacramento–San Joaquin Delta are changing rapidly, as are ecosystems around the world. Extreme events are becoming more frequent and thresholds are likely to be crossed more often, creating greater uncertainty about future conditions. The accelerating speed of change means that ecological systems may not remain stable long enough for scientists to understand them, much less use their research findings to inform policy and management. Faced with these challenges, those involved in science, policy, and management must adapt and change and anticipate what the ecosystems may be like in the future. We highlight several ways of looking ahead—scenario analyses, horizon scanning, expert elicitation, and dynamic planning—and suggest that recent advances in distributional ecology, disturbance ecology, resilience thinking, and our increased understanding of coupled human–natural systems may provide fresh ways of thinking about more rapid change in the future. To accelerate fo...
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Few conceptual frameworks attempt to connect disaster‐associated environmental injuries to impacts on ecosystem services (the benefits humans derive from nature) and thence to both psychological and physiological human health effects. To... more
Few conceptual frameworks attempt to connect disaster‐associated environmental injuries to impacts on ecosystem services (the benefits humans derive from nature) and thence to both psychological and physiological human health effects. To our knowledge, this study is one of the first, if not the first, to develop a detailed conceptual model of how degraded ecosystem services affect cumulative stress impacts on the health of individual humans and communities. Our comprehensive Disaster‐Pressure State‐Ecosystem Services‐Response‐Health model demonstrates that oil spills, hurricanes, and other disasters can change key ecosystem components resulting in reductions in individual and multiple ecosystem services that support people's livelihoods, health, and way of life. Further, the model elucidates how damage to ecosystem services produces acute, chronic, and cumulative stress in humans which increases risk of adverse psychological and physiological health outcomes. While developed and...
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Water pollution is a global environmental challenge that nearly always involves the degradation of aquatic habitats by mixtures of chemical contaminants. Despite this practical reality, environmental regulations and resource management... more
Water pollution is a global environmental challenge that nearly always involves the degradation of aquatic habitats by mixtures of chemical contaminants. Despite this practical reality, environmental regulations and resource management institutions in most countries are inadequate to the task of addressing complex and dynamic combinations of chemicals. Moreover, our scientific understanding of mixture toxicity and the assessment of corresponding risks to aquatic species and communities have not kept pace with worldwide declines in biodiversity or the introduction of thousands of new chemicals into societal use. In this chapter, we review recent research specific to mixtures in three contexts that are broadly applicable to freshwater and marine ecosystems. These include oil spills, urban non-point source pollution, and the agricultural use of modern pesticides. Each of these familiar and geographically extensive forcing pressures is threaded with uncertainty about interactions between contaminants in mixtures. We also briefly consider relevant and often overlapping environmental regulations in the United States and Europe to illustrate why a proactive consideration of chemical mixtures remains elusive in institutional ecological risk assessment. As the case examples show, however, the problem of mixtures is not intractable and targeted research can guide effective conservation and restoration strategies in a chemically complex world.
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Research Interests: Petroleum, Biology, Environmental Monitoring, Medicine, Multidisciplinary, and 14 moreEnvironmental science and technology, Animals, Fishes, Weather, Aryl Hydrocarbon Receptor, Polycyclic aromatic hydrocarbons (PAHs), Crude Oil, Cardiac Arrhythmias, Edema, Pacific ocean, Environmental, Environmental Exposure, Bradycardia, and ovum
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... Mass Spectrometric Analysis for Aromatic Compounds in Bile of Fish Sampled after the Exxon Valdez Oil Spill Margaret M. Krahn," Douglas G. Burrows, Gina M. Ylitaio, Donald W. Brown,... more
... Mass Spectrometric Analysis for Aromatic Compounds in Bile of Fish Sampled after the Exxon Valdez Oil Spill Margaret M. Krahn," Douglas G. Burrows, Gina M. Ylitaio, Donald W. Brown, Catherine A. Wlgren, Tracy K. Collier, Sin-Lam Chan, and Usha Varanasi ...
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Biomarkers of contaminant exposure have been developed and are being successfully applied to a wide range of aquatic species. To improve the utility of biomarkers in the practical assessment of the impact of xenobiotics on aspects of... more
Biomarkers of contaminant exposure have been developed and are being successfully applied to a wide range of aquatic species. To improve the utility of biomarkers in the practical assessment of the impact of xenobiotics on aspects of ecosystem integrity requires the identification of biomarkers that are also indicators of adverse physiological effect. Moreover, it is important to determine if the use of biomarkers can improve the ability to diagnose potential adverse effects at the population level. Currently, the authors are evaluating the potential of a battery of molecular and cellular biomarkers in both fish and invertebrates to strengthen linkages between exposure and effects on growth, reproduction and survival of marine species. Concerted field and laboratory studies are employed to delineate dose-response for biomarkers, identify levels at which effects are observed in indigenous species, and to substantiate causality between exposure and the above physiological effects. However, to identify further causal relationships between physiological effects on individuals and population level impacts that are associated with xenobiotic exposure is currently a significant challenge. Their current efforts are focusing on constructing population models using estimates of mortality and reproductive success in a benthic fish, and on constructing population growth curves for a bivalve. Bothmore » species were sampled from a range of contaminated sites in Puget Sound, WA, and analyses included measurement of biomarkers to identify or strengthen associations between exposure and estimated population level impacts. Overall, these recent findings demonstrate that properly validated biomarkers are useful in substantiating linkages between environmental contamination and physiological effects that may lead to adverse population level impacts.« less
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Research Interests: Biology, Water Pollution, Medicine, Liver, Animals, and 15 moreGlutathione, Polycyclic Aromatic Hydrocarbon, Enzyme, Digestive System, Flounder, Flatfish, Enzyme activity, Glutathione Transferase, Species Specificity, Isozyme, Genetic Variability, Field Data, Bile, Liver neoplasms, and Pharmacology and pharmaceutical sciences
Tampa Bay is the largest estuary in Florida, mea-suring nearly 56 km in length and 16 km in width (Fig. 1). Approximately 2.5 million people live in the counties surrounding Tampa Bay, including the residents of the major cities of Tampa... more
Tampa Bay is the largest estuary in Florida, mea-suring nearly 56 km in length and 16 km in width (Fig. 1). Approximately 2.5 million people live in the counties surrounding Tampa Bay, including the residents of the major cities of Tampa and St. Petersburg. Activities ...
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Saltwater-adapted juvenile chinook salmon (Oncorhynchus tshawytscha) exposed in the laboratory to various aromatic and chlorinated hydrocarbons representative of those found in urban estuaries in Puget Sound have a higher susceptibility... more
Saltwater-adapted juvenile chinook salmon (Oncorhynchus tshawytscha) exposed in the laboratory to various aromatic and chlorinated hydrocarbons representative of those found in urban estuaries in Puget Sound have a higher susceptibility to infectious disease relative to carrier-exposed juveniles. Disease susceptibility was assessed by examining the temporal percent cumulative mortality in juvenile chinook salmon after exposure to the marine pathogen, Vibrio anguillarum. Aromatic and chlorinated compounds tested included a sediment extract from the Hylebos Waterway predominantly composed of butadiene-like compounds (CHWSE), a model mixture of polycyclic aromatic hydrocarbons (PAHs), hexachlorobutadiene (HCBD), a PCB mixture (Aroclor 1254), and a single PAH, dimethylbenz[a]anthracene (DMBA). The effect of these compounds on disease susceptibility was tested in two separate trials. In Trial I, the percent cumulative mortality in salmon exposed to bacteria after exposure to either CHWSE, HCBD, or the model mixture of PAHs ranged from 28 to 31%, as compared to 16% in the acetone:emulphor control group at 7 days after challenge. In Trial II, the cumulative mortality in salmon ranged from 46 to 49% after exposure to either DMBA or the PCB mixture compared to 25% in the acetone:emulphor control group at 9 days after challenge. These results suggest that juvenile chinook salmon migrating to the ocean through a contaminated estuary experience immunodysfunction, characterized by lowered resistance to disease, which potentially could affect survival of populations that are particularly threatened.
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Research Interests: Environmental Science, Water Pollution, Biological Sciences, Environmental Sciences, Puget Sound, and 13 moreFishery, Polycyclic Aromatic Hydrocarbon, Polychlorinated Biphenyl, CHEMICAL SCIENCES, Estuary, Juvenile, Environmental Toxicology and Chemistry, Stomach Content, Chinook Salmon, Environmental, Oncorhynchus, Tissue distribution, and biological effect
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Our recent studies have investigated the applicability of the ‘resistance to cytotoxicity’ paradigm for chemically induced hepatocarcinogenesis in rats and mice to liver neoplasia in wild English sole (Pleuronectes vetulus). Sole resident... more
Our recent studies have investigated the applicability of the ‘resistance to cytotoxicity’ paradigm for chemically induced hepatocarcinogenesis in rats and mice to liver neoplasia in wild English sole (Pleuronectes vetulus). Sole resident at polycyclic aromatic hydrocarbon (PAH)-contaminated sites, such as the Duwamish Waterway in Puget Sound, Washington, exhibit high prevalences of hepatic neoplasms and precursor lesions related to the histogenesis
Research Interests: Biology, Image Analysis, Immunohistochemistry, Marine And Environmental Pollution, International Marine Environmental Law, and 11 moreBiological Sciences, Environmental Sciences, Puget Sound, Hepatocellular Carcinoma, Atlantic cod, Polycyclic Aromatic Hydrocarbon, CHEMICAL SCIENCES, Marine Environmental History, Hepatocyte, Carcinogen, and Histogenesis
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Flatfish from Puget Sound, WA are shown to develop liver diseases which are correlated with aromatic hydrocarbon (AH) contamination of sediment. However, due to the efficient metabolism of AHs by these fish, AHs cannot be readily... more
Flatfish from Puget Sound, WA are shown to develop liver diseases which are correlated with aromatic hydrocarbon (AH) contamination of sediment. However, due to the efficient metabolism of AHs by these fish, AHs cannot be readily monitored in biological samples. ...
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A complete copy of Ki-ras b cDNA from English sole (Pleuronectes vetulus), a benthic marine flatfish, was cloned and sequenced. The percent identity between the predicted amino acid sequence of English sole and human Ki-ras b was 97%,... more
A complete copy of Ki-ras b cDNA from English sole (Pleuronectes vetulus), a benthic marine flatfish, was cloned and sequenced. The percent identity between the predicted amino acid sequence of English sole and human Ki-ras b was 97%, whereas the percent identity between the English sole gene and rainbow trout or Rivulus Ki-ras b was 98%. Areas of amino-acid sequence conservation included codons 12, 13, and 61, the positions in which mutations are observed in ras cellular oncogenes in other species. The 5' untranslated region (UTR), consisting of 217 nt, was not highly GC rich but contained four ATG start codons upstream of the major open reading frame. The 3' UTR, containing 26 nt, was AU rich. Analysis of Ki-ras mutations was performed on a variety of necrotic, preneoplastic, and neoplastic lesions in livers from 13 English sole collected from contaminated waterways in Puget Sound, WA. Despite reports of Ki-ras mutations in hepatic tumors from other fish, no mutations in codons 12, 13, or 61 were found in hepatic lesions from English sole by direct DNA sequencing of polymerase chain reaction-amplified genomic DNA. Although mutations could exist at levels below the detection limits of this analysis, the results suggest that Ki-ras has a role in liver carcinogenesis that varies according to the fish species or carcinogen. Furthermore, future studies of the etiology of chemically induced cancer in feral English sole should consider mutations in other cancer-related genes, such a5p53, Ha-ras, and N-ras.