Vicki started with the National Fish Health Research Laboratory, Leetown Science Center (now the Eastern Ecological Science Center - Leetown Research Laboratory), Kearneysville, WV in1992. She was previously employed as the Assistant Leader of the Georgia Cooperative Fish and Wildlife Research Unit. She was also on the graduate faculty in the School of Forest Resources, University of Georgia, teac
She is active in numerous research projects within the Northeast as well as nationally and internationally. She is active in the American Fisheries Society Fish Health Section and a member of other scientific societies. She is an adjunct faculty member at West Virginia University and Penn State and serves on graduate student committees. Research areas include development of microscopic and molecular markers for understanding changes in the health and populations of wild fishes. Areas of focus include endocrine disruption, emerging diseases, fish tumor pathology and assessment at Great Lakes Areas of Concern, land use influences on fish health, reproduction and immunomodulation.
Professional Experience
Postdoctoral Research Associate, College of Veterinary Medicine, University of Georgia
Assistant Leader, Georgia Cooperative Fish and Wildlife Research Unit, School of Forest Resources, University of Georgia
Research Fishery Biologist, Leetown Science Center
Education and Certifications
B.S. in Marine Science and Biology Southampton College, Long Island University.
PhD in Fisheries, Aquaculture and Pathology, Rhode Island University
Affiliations and Memberships*
Adjunct Professor, West Virginia University
Adjunct Professor, Penn State University
Science and Products
PFAS Transport, Exposure, and Effects
USGS Integrates Findings about Endocrine-Disrupting Compounds in the Chesapeake Watershed
Groundwater Discharge is a Pathway for Phytoestrogen and Herbicide Entry to Streams in the Chesapeake Bay Watershed
Bioaccumulation of Mercury in Fish Varied by Species and Location in the Chesapeake Bay Watershed—Summary of Existing Data and a Roadmap for Integrated Monitoring
New Virus Identified in Melanistic Skin Lesions on Smallmouth Bass from the Chesapeake Bay Watershed
Land-use influences on estrogenic-endocrine disruption in fish within the Chesapeake Bay watershed
Prevalence of Malignant Melanoma in Brown Bullhead from Lake Memphremagog Greater than Expected—Linkages to Contaminant Exposure and Implications for Fish Population Health are Currently Unknown
Point and Non-Point Sources of Endocrine Disrupting Compounds and the Potential Effects on Fish and Frogs in the New Jersey Pinelands
Fishing and Hunting Integrated Science Team
Point and Nonpoint Sources of Endocrine Disrupting Compounds and the Potential effects on Fish and Frogs in the New Jersey Pinelands
Rainbow trout with bacterial lesions
Striped bass with mycobacteriosis
Biological Indicators and Mercury Concentrations in Smallmouth Bass
Immune Function of Wild Smallmouth Bass Collected from Sites within the Chesapeake Bay Watershed, 2016-2021
Water Chemistry and Smallmouth Bass Biological Data From the Potomac River, Dargan, Maryland, 2013-2019
Data supporting: Draft Genome Sequence of a Novel Calicivirus from a Brown Bullhead (Ameiurus nebulosus) from Lake Memphremagog, VT
Morphometric, Age, Visible Abnormalities, Skin and Liver Neoplasms, and Stable Isotopes in White Sucker Collected in the St. Louis River and Estuary, Minnesota/Wisconsin, 2011-2015
Morphometric, Age and Concentrations of Perfluoroalkyl Substances in Smallmouth Bass Plasma from Four Sites in the Chesapeake Bay Watershed
Effects of early life stage exposure of largemouth bass to atrazine or a model estrogen (17a-ethinylestradiol)
2004-2010 Chesapeake Bay Smallmouth and Largemouth Bass Estrogenic Biomarker Data
Abundance of 50 transcripts from microdissected liver samples of smallmouth bass
Total Mercury Concentrations in Smallmouth Bass from Chesapeake Bay Tributaries, USA Dataset, 2013-2017
Estrogen equivalents of surface water and smallmouth bass estrogenic biomarker data in New Jersey, 2016-2017
Toxicity of potassium chloride, active compound in the molluscicide potash, on salmonid fishes and their forage base (Leetown Science Center, 2018).
White perch health relative to urbanization and habitat degradation in Chesapeake Bay tributaries. II. Hepatic and splenic macrophage aggregates
White perch health relative to urbanization and habitat degradation in Chesapeake Bay tributaries. I. Biliary neoplasms and hepatic lesions
Assembling the right pieces: Developing an interdisciplinary team to study disease, decline, and recovery of a world-class Smallmouth Bass fishery
A multi-level assessment of biological effects associated with mercury concentrations in smallmouth bass, Micropterus dolomieu
Application of a lipopolysaccharide (LPS)-stimulated mitogenesis assay in smallmouth bass (Micropterus dolomieu) to augment wild fish health studies
A case study: Temporal trends of environmental stressors and reproductive health of smallmouth bass (Micropterus dolomieu) from a site in the Potomac River Watershed, Maryland, USA
Potential health effects of contaminant mixtures from point and nonpoint sources on fish and frogs in the New Jersey Pinelands
Draft genome sequence of a novel calicivirus from a brown bullhead (Ameiurus nebulosus) from Lake Memphremagog, Vermont/Quebec
Temporal trends in macroscopic indicators of fish health in the South Branch of the Potomac River
Reproductive health and endocrine disruption in smallmouth bass (Micropterus dolomieu) from the Lake Erie drainage, Pennsylvania, USA
Development of a multiplex fluorescence in situ hybridization assay to identify coinfections in young-of-the-year smallmouth bass
Targeted and non-targeted analysis of young-of-year smallmouth bass using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry
Science and Products
- Science
Filter Total Items: 20
PFAS Transport, Exposure, and Effects
The team is determining the movement and behavior of per- and poly-fluoroalkyl substances (PFAS) from their sources in the environment, as they move through exposure pathways in ecosystems including watersheds and aquifers, their incorporation into food webs, and molecular to population scale effects on fish and wildlife. These studies are accomplished at a variety of spatial scales from regional...USGS Integrates Findings about Endocrine-Disrupting Compounds in the Chesapeake Watershed
Issue: Studies in the Chesapeake Bay Watershed have documented the exposure of fish to toxic contaminants including endocrine-disrupting compounds (EDCs) - compounds which can alter normal hormonal function in organisms. Given the importance of fisheries to the economic and environmental health of the Watershed, observed endocrine disruption and fish kills in the Watershed have raised public and...Groundwater Discharge is a Pathway for Phytoestrogen and Herbicide Entry to Streams in the Chesapeake Bay Watershed
Groundwater discharge zones are important spawning areas for fish because they provide a thermally stable habitat. Research at three streams in the Chesapeake Bay Watershed with areas of focused groundwater discharge revealed that groundwater also is a source of phytoestrogens and herbicides that could result in fish exposure during sensitive life stages.Bioaccumulation of Mercury in Fish Varied by Species and Location in the Chesapeake Bay Watershed—Summary of Existing Data and a Roadmap for Integrated Monitoring
Fish mercury data from State monitoring programs and research studies within the Chesapeake Bay were compiled and summarized to provide a comprehensive overview of the variation in fish mercury concentrations among species and habitats within the watershed. These data are put into context with existing health benchmarks for humans, birds, and fish. Scientists also provide a roadmap for an...New Virus Identified in Melanistic Skin Lesions on Smallmouth Bass from the Chesapeake Bay Watershed
Scientists determined the risk factors associated with smallmouth bass melanistic skin lesions on smallmouth bass in the Susquehanna and Potomac Rivers, in the Chesapeake Bay watershed. A new virus, which appears to be a member of an emerging viral family, the Adomaviridae, was identified in the lesions. Questions remain about the full characterization of the virus and the role of environmental...Land-use influences on estrogenic-endocrine disruption in fish within the Chesapeake Bay watershed
Issue: Effects of exposure to estrogenic-chemical contaminants have been observed in many fish species worldwide. One effect is described as “intersex” because fish will take on characteristics of the other sex, such as immature eggs forming in male fish. Studies in the Chesapeake Bay watershed have also identified the exposure of fish to endocrine-disrupting compounds. The estrogenic-endocrine...Prevalence of Malignant Melanoma in Brown Bullhead from Lake Memphremagog Greater than Expected—Linkages to Contaminant Exposure and Implications for Fish Population Health are Currently Unknown
Raised black lesions observed in 30 percent of the brown bullhead collected from two sites in Lake Memphremagog from 2014 through 2017 were identified microscopically as malignant melanoma. Malignant melanoma in freshwater fishes has been reported before, but this cancer occurrence cluster is raising questions about the cause of the tumors and the implications for the long-term health of fish...Point and Non-Point Sources of Endocrine Disrupting Compounds and the Potential Effects on Fish and Frogs in the New Jersey Pinelands
This project, in collaboration with the NJ Pinelands Commission and the USGS NJ Water Center, is evaluating potential effects of endocrine-disrupting chemicals from point and nonpoint sources in the Pinelands Area, a research cluster as part of the Delaware River Watershed Initiative.Fishing and Hunting Integrated Science Team
The Fishing and Hunting integrated science team focuses on contaminant and pathogen exposures in the environment that could impact the presence and vitality of fish and wildlife populations that drive commercial, recreational and subsistence activities such as hunting and fishing. If actual risks are identified this project will inform how to economically and effectively minimize risk by providing...Point and Nonpoint Sources of Endocrine Disrupting Compounds and the Potential effects on Fish and Frogs in the New Jersey Pinelands
Scientists from the NJ WSC, Leetown Science Center and New Jersey Pinelands Commission recently initiated a 4 year study designed to characterize the point and non-point sources of endocrine disrupting compound (EDCs) and their potential effects on fish and frogs in the NJ Pinelands.Rainbow trout with bacterial lesions
This rainbow trout is displaying clinical signs of enteric redmouth disease caused by a systemic bacterial infection.Striped bass with mycobacteriosis
Striped bass (Morone saxatilis) displaying ulcerative skin lesions and chronic wasting, both typical clinical signs of mycobacteriosis, a bacterial disease that is problematic among many types of fishes around the world. - Data
Filter Total Items: 13
Biological Indicators and Mercury Concentrations in Smallmouth Bass
Biological indicators including morphometric (length, weight), age, sex and health indicators including organismal (health assessment index, condition factor), organ (hepatosomatic index, gonadosomatic index), cellular (intersex, parasite density, macrophage aggregate density), subcellular (plasma vitellogenin, estradiol, testosterone, 11-keto testosterone) and molecular (hepatic transcript abundaImmune Function of Wild Smallmouth Bass Collected from Sites within the Chesapeake Bay Watershed, 2016-2021
Adult and young of the year smallmouth bass from the Chesapeake Bay watershed have faced health issues (mortality events, disease by a variety of pathogens, endocrine disruption in male fish, evidence of oxidative damage to tissues, and signs of exposure to chemical contaminants) at multiple sites within the Susquehanna and Potomac River basins. Functional immune assays were added to long-term comWater Chemistry and Smallmouth Bass Biological Data From the Potomac River, Dargan, Maryland, 2013-2019
Decades of poor reproductive success and young-of-the-year recruitment, in addition to adult mortality, has led to a decline in the smallmouth bass (SMB) population in subwatersheds of the Potomac River. Previous studies have identified numerous biologic and environmental stressors associated with negative effects on SMB health. To better understand the impact of these stressors, the current studyData supporting: Draft Genome Sequence of a Novel Calicivirus from a Brown Bullhead (Ameiurus nebulosus) from Lake Memphremagog, VT
We report a draft genome of a previously undescribed calicivirus from a single brown bullhead inhabiting Lake Memphremagog, Vermont/Quebec. The genome is 7413 nt in length and is most similar to the Atlantic salmon calicivirus (nucleotide identity: 64.7%).Morphometric, Age, Visible Abnormalities, Skin and Liver Neoplasms, and Stable Isotopes in White Sucker Collected in the St. Louis River and Estuary, Minnesota/Wisconsin, 2011-2015
The dataset provides length, weight, age, observations of visible external abnormalities, liver and skin histopathology and stable isotopes of white sucker captured within the St. Louis river and associated bays.Morphometric, Age and Concentrations of Perfluoroalkyl Substances in Smallmouth Bass Plasma from Four Sites in the Chesapeake Bay Watershed
Archived plasma from fish health monitoring sites within the Chesapeake Bay watershed was analyzed for 13 perfluoroalkyl compounds. Smallmouth bass were collected from two sites in the Potomac River drainage (Antietam Creek, Maryland and South Branch Potomac, West Virginia) and two in the Susquehanna River drainage (West Branch Mahantango Creek, Pennsylvania and Pine Creek, Pennsylvania). Site andEffects of early life stage exposure of largemouth bass to atrazine or a model estrogen (17a-ethinylestradiol)
Largemouth base histological development and transcriptomic changes in gonad tissue after early life stage exposure to Atrazine (1-Chloro-3-ethylamino-5-isopropylamino-2,4,6-triazine) or the model estrogen 17a-ethinylestradiol.2004-2010 Chesapeake Bay Smallmouth and Largemouth Bass Estrogenic Biomarker Data
The data was gathered to document the extent and severity of biomarkers of exposure to estrogenic chemicals in smallmouth and largemouth bass. Samples were collected from 2004 through 2010 at sites in five watersheds within the Chesapeake Bay watershed. A total of 281 largemouth bass were collected from the Potomac, Susquehanna, Patuxent and Rappahannock rivers and 1,384 smallmouth bass from the PAbundance of 50 transcripts from microdissected liver samples of smallmouth bass
There is an increasing emphasis on effects-based monitoring to document responses associated with exposure to complex mixtures of chemicals, climate change, pathogens, parasites and other environmental stressors in fish populations. For decades aquatic monitoring programs have included the collection of tissues preserved for microscopic pathology. Consequently, formalin-fixed, paraffin-embedded (FTotal Mercury Concentrations in Smallmouth Bass from Chesapeake Bay Tributaries, USA Dataset, 2013-2017
This dataset includes fish scientific name, fish common name, site identification codes, latitude, longitude, site name, sample identification codes, collection date, tissue type, percent moisture content in fish samples, and wet and dry total mercury concentrations in fish tissues.Estrogen equivalents of surface water and smallmouth bass estrogenic biomarker data in New Jersey, 2016-2017
The data were gathered as a preliminary assessment of estrogenicity under base-flow conditions at over 100 sites (lakes and streams) throughout New Jersey followed by more targeted sampling of smallmouth bass at nine sites with varying levels of estrogenicity. In 2016, 102 sites (lakes and streams) for the preliminary estrogenicity assessment were selected utilizing compiled results of previous moToxicity of potassium chloride, active compound in the molluscicide potash, on salmonid fishes and their forage base (Leetown Science Center, 2018).
The data is supplemental to the 2018 USGS Open File Report, "An evaluation of the acute and chronic toxicity of potassium chloride, active compound in the molluscicide potash, on salmonid fishes and their forage base". This research was performed as a Science Support Partnership (SSP) study with USFWS in order to evaluate potential lethal and sublethal impacts of potassium chloride on salmonid fis - Multimedia
- Publications
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White perch health relative to urbanization and habitat degradation in Chesapeake Bay tributaries. II. Hepatic and splenic macrophage aggregates
Macrophage aggregate (MA) abundance in fish is a useful general biomarker of contaminant exposures and environmental stress. Hepatic and splenic MAs were evaluated in semi-anadromous white perch Morone americana (Gmelin, 1789) from the urbanized Severn River (S) and the more rural Choptank River (C), Chesapeake Bay. Fish were collected from different sites in the annual migratory circuit in each rAuthorsVicki S. Blazer, Mark A Matsche, Erin Lee PulsterWhite perch health relative to urbanization and habitat degradation in Chesapeake Bay tributaries. I. Biliary neoplasms and hepatic lesions
White perch Morone americana (Gmelin, 1789) from the Chesapeake Bay (USA) watershed have a high incidence of liver disease, including neoplasms of bile duct origin. Fish collected seasonally from spring 2019 to winter 2020 from the urban Severn River and the more rural Choptank River were evaluated for hepatic lesions. Biliary hyperplasia (64.1%), neoplasms (cholangioma and cholangiocarcinoma, 27%AuthorsVicki S. Blazer, Mark A Matsche, Erin Lee PulsterAssembling the right pieces: Developing an interdisciplinary team to study disease, decline, and recovery of a world-class Smallmouth Bass fishery
Managing and understanding fisheries dynamics are becoming more complex as new and seemingly more complicated environmental factors are identified. Often management requires resources beyond that of any one entity and calls for collaboration among partners with differing priorities and backgrounds to account for the complexity of factors influencing fisheries. We present a collaborative case studyAuthorsMegan K. Schall, Geoffrey Smith, Vicki S. Blazer, Heather L. Walsh, Timothy Wertz, Dustin R. Shull, Tyler WagnerA multi-level assessment of biological effects associated with mercury concentrations in smallmouth bass, Micropterus dolomieu
Total mercury (THg) was measured in muscle (fillet) and liver tissue of adult smallmouth bass Micropterus dolomieu collected at multiple sites in the Potomac and Susquehanna River drainages within the Chesapeake Bay watershed. Smallmouth bass in these drainages have experienced episodic mortality events, a high prevalence of skin lesions and reproductive endocrine disruption (intersex or testiculaAuthorsVicki S. Blazer, Heather L. Walsh, Adam Sperry, Brenna Raines, James Willacker, Collin Eagles-SmithApplication of a lipopolysaccharide (LPS)-stimulated mitogenesis assay in smallmouth bass (Micropterus dolomieu) to augment wild fish health studies
The utility of a functional immune assay for smallmouth bass (Micropterus dolomieu) lymphocyte mitogenesis was evaluated. Wild populations in the Potomac River have faced disease and mortality with immunosuppression from exposure to chemical contaminants a suspected component. However, a validated set of immune parameters to screen for immunosuppression in wild fish populations is not available. PAuthorsCheyenne R. Smith, Christopher A. Ottinger, Heather L. Walsh, Patricia M. Mazik, Vicki S. BlazerA case study: Temporal trends of environmental stressors and reproductive health of smallmouth bass (Micropterus dolomieu) from a site in the Potomac River Watershed, Maryland, USA
Decades of poor reproductive success and young-of-the-year survival, combined with adult mortality events, have led to a decline in the smallmouth bass (SMB; Micropterus dolomieu) population in sections of the Potomac River. Previous studies have identified numerous biologic and environmental stressors associated with negative effects on SMB health. To better understand the impact of these stressoAuthorsHeather L. Walsh, Stephanie Gordon, Adam J. Sperry, Michael Kashiwagi, John E. Mullican, Vicki S. BlazerPotential health effects of contaminant mixtures from point and nonpoint sources on fish and frogs in the New Jersey Pinelands
Aquatic ecosystems convey complex contaminant mixtures from anthropogenic pollution on a global scale. Point (e.g., municipal wastewater) and nonpoint sources (e.g., stormwater runoff) are both drivers of contaminant mixtures in aquatic habitats. The objectives of this study were to identify the contaminant mixtures present in surface waters impacted by both point and nonpoint sources, to determinAuthorsSara Breitmeyer, Heather L. Walsh, Vicki S. Blazer, John F. Bunnell, Patrick M. Burritt, Jeff Dragon, Michelle Hladik, Paul Bradley, Kristin Romanok, Kelly SmallingDraft genome sequence of a novel calicivirus from a brown bullhead (Ameiurus nebulosus) from Lake Memphremagog, Vermont/Quebec
We report a draft genome sequence of a previously undescribed calicivirus from a single brown bullhead inhabiting Lake Memphremagog, Vermont/Quebec. The genome is 7,413 nucleotides long and is most similar to the Atlantic salmon calicivirus (nucleotide identity; 64.7%).AuthorsLuke R. Iwanowicz, Vicki S. Blazer, Tom Jones, Matthew Bodnar, Korin Ekholm, Julie Dragon, Peter EmmersonTemporal trends in macroscopic indicators of fish health in the South Branch of the Potomac River
Over recent decades, the South Branch of the Potomac River, WV, has experienced fish kills and episodes of suppressed health in adult fishes that have spanned small stretches to nearly 120 km of contiguous habitat. Although factors such as endocrine disruption, chemical contaminants, and infectious agents have been detected, no single causal mechanism has been identified. To gain information aboutAuthorsBrandon J. Keplinger, James Hedrick, Vicki S. BlazerReproductive health and endocrine disruption in smallmouth bass (Micropterus dolomieu) from the Lake Erie drainage, Pennsylvania, USA
Smallmouth bass Micropterus dolomieu were sampled from three sites within the Lake Erie drainage (Elk Creek, Twentymile Creek, and Misery Bay, an embayment in Presque Isle Bay). Plasma, tissues for histopathological analyses, and liver and testes preserved in RNALater® were sampled from 30 smallmouth bass (of both sexes) at each site. Liver and testes samples were analyzed for transcript abundanceAuthorsHeather L. Walsh, Sean D. Rafferty, Stephanie Gordon, Vicki S. BlazerDevelopment of a multiplex fluorescence in situ hybridization assay to identify coinfections in young-of-the-year smallmouth bass
Histopathological assessments of young-of-the-year (age-0) Smallmouth Bass Micropterus dolomieu in the Susquehanna River drainage identified a high prevalence of the myxozoan Myxobolus inornatus. This myxozoan infects the connective tissue of the muscle below the skin but is sometimes observed in the esophagus and buccal cavity. In some instances, shallow infections cause breaks in the skin, whichAuthorsHeather L. Walsh, Vicki S. Blazer, Patricia M. MazikTargeted and non-targeted analysis of young-of-year smallmouth bass using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry
Smallmouth bass in the Susquehanna River Basin, Chesapeake Bay Watershed, USA, have been exhibiting clinical signs of disease and reproductive endocrine disruption (e.g., intersex, male plasma vitellogenin) for over fifteen years. Previous histological and targeted chemical analyses have identified infectious agents and pollutants in fish tissues including organic contaminants, mercury, and perfluAuthorsPaige Teehan, Megan K. Schall, Vicki S. Blazer, Frank L Dorman - News
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government