Paul Hershberger, Ph.D.
Paul Hershberger is the Chief of the Fish Heath Section at the U. S. Geological Survey - Western Fisheries Research Center (Seattle, WA) and the Station Leader at the Marrowstone Marine Field Station (Nordland, WA). He is an Affiliate Professor at the University of Washington – School of Aquatic and Fishery Sciences, and former President of the Fish Health Section - American Fisheries Society.
Paul has the pleasure of leading a team of fish health professionals who are experts in their respective fields of fish virology, immunology, toxicology, histopathology, parasitology, and disease ecology. Specific components of the Fish Health Section focus on:
- the development of immune-related tools for fishes and the impact(s) of environmental stressors (e.g. contaminants, pathogens, temperature) on the fish immune response.
- the use of gene knock outs in zebrafish and other model species to assess pathogen virulence and host immune response mechanisms.
- the evolution of virulence and other phenotypes in fish viruses using landscape-scale genotyping to identify patterns of virus occurrence, transmission, and disease impacts across borad temporal and geographic scales.
- the discovery and identification of new and emerging fish viruses in the Pacific Northwest and throughout North America.
- the integration of novel quantitative techniques to understand stochasticity of pathogen transmission and other mechanisms of basic and applied disease ecology.
- the use of histopathology and electron microscopy to assess pathogen / disease monitoring and research needs in populations of wild and hatchery-raised fishes.
- the effects of environmental contaminants, including PAH’s, PCB’s, and emerging contaminants like PFAS and 6-PPD quinone on fish health, survival, and immunological pathways.
- the range expansion of invasive amphibians and their susceptibility to native and exotic pathogens.
In addition, Paul’s personal research employs a combination of laboratory and field approaches to understand, forecast, and mitigate the impacts of infectious and parasitic diseases on populations of wild marine and anadromous fishes.
Professional Experience
2022 to Present: Fish Health Section Chief, U.S. Geological Survey, Western Fisheries Research Center, Seattle, WA
2003 to Present – Station Leader, U.S. Geological Survey, Western Fisheries Research Center, Marrowstone Marine Field Station, Nordland, WA
2004 to Present – Member of the Affiliate Faculty, School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA
Education and Certifications
Ph.D. Fisheries, School of Aquatic and Fisheries Sciences, University of Washington, Seattle, WA
M.S. Fisheries, School of Aquatic and Fisheries Sciences, University of Washington, Seattle, WA
B.S. Chemistry and Biology, Northland College, Ashland, WI
Science and Products
Nanophyetus salmincola - MMFS
Detection Protocols - Renibacterium salmoninarum
Ichthyobodo - FHP
Partnerships - Marrowstone Marine Field Station
Ichthyophonus hoferi - MMFS
Teaching Resources
Parasite collection and teaching slides
Viral Hemorrhagic Septicemia Virus (VHSV) - MMFS
Erythrocytic Necrosis Virus (ENV) - MMFS
Steelhead Trout (Oncorhynchus mykiss) - MMFS
Pacific Halibut (Hippoglossus stenolepis) - MMFS
Pacific Herring (Clupea pallasii) - MMFS
Research on Emerging Viruses of Salmonids - FHP
Anadromous coastal cutthroat trout Oncorhynchus clarkii clarkii as a host for Argulus pugettensis (Crustacea, Branchiura): Parasite prevalence, intensity and distribution
Pacific herring Clupea pallasii are not susceptible to vibriosis from Vibrio anguillarum or V. ordalii under laboratory conditions
Herring Disease Program II 19120111-E - 2019 Annual Report
Climate change can drive marine diseases
Ichthyophonus sp. Infection in Opaleye (Girella nigricans)
A geographic hot spot of Ichthyophonus infection in the southern Salish Sea, USA
Study 11. Effects of Nanophyetus on the swimming performance and survival of steelhead smolts AND studies to understand and manage the Nanophyetus cercaria
Susceptibility of Nanophyetus salmincola cercariae to formalin, hydrogen peroxide, and seawater
Herring Disease Program, February 1, 2018 - January 31, 2019
Ichthyophonus in sport-caught groundfishes from southcentral Alaska
Analytical and diagnostic performance of a qPCR assay for Ichthyophonus spp. compared to the tissue culture ‘gold standard’
Infection by Nanophyetus salmincola and toxic contaminant exposure in out‐migrating steelhead from Puget Sound, Washington: Implications for early marine survival
Science and Products
- Science
Filter Total Items: 29
Nanophyetus salmincola - MMFS
Fish Parasite - Nanophyetus salmincolaDetection Protocols - Renibacterium salmoninarum
Protocols for the Detection of Renibacterium salmoninarum in salmonIchthyobodo - FHP
Fish Diseases - IchthyobodoPartnerships - Marrowstone Marine Field Station
The disease ecology research program at the USGS - Marrowstone Marine Field Station leverages its unique strengths and capabilities through a robust network of collaborations with scientific partners. This collaborative approach enables us to consolidate the expertise of leading scientists from disparate backgrounds and organizational structures in addressing complex interdisciplinary research...Ichthyophonus hoferi - MMFS
Fish Parasite - Ichthyophonus hoferiTeaching Resources
Parasite collection and teaching slides
Viral Hemorrhagic Septicemia Virus (VHSV) - MMFS
Fish Virus - Viral Hemorrhagic Septicemia Virus (VHSV)Erythrocytic Necrosis Virus (ENV) - MMFS
Fish Virus - Erythrocytic Necrosis Virus (ENV)Steelhead Trout (Oncorhynchus mykiss) - MMFS
Species Studied - Steelhead Trout ( Oncorhynchus mykiss )Pacific Halibut (Hippoglossus stenolepis) - MMFS
Species Studied - Pacific Halibut ( Hippoglossus stenolepis )Pacific Herring (Clupea pallasii) - MMFS
Species Studied - Pacific Herring ( Clupea pallasii )Research on Emerging Viruses of Salmonids - FHP
At the request of the State of Washington, the Northwest Indian Fisheries Commission (NWIFC) and the US Fish and Wildlife Service (USFWS), the Western Fisheries Research Center has been providing technical advice and conducting research regarding the emergence of IHNV in the watersheds of coastal Washington State. - Data
- Multimedia
- Publications
Filter Total Items: 116
Anadromous coastal cutthroat trout Oncorhynchus clarkii clarkii as a host for Argulus pugettensis (Crustacea, Branchiura): Parasite prevalence, intensity and distribution
Coastal cutthroat trout [Oncorhynchus clarkii clarkii (Richardson, 1836)] from the marine waters of Puget Sound, WA, was documented as a new host for the ectoparasite Argulus pugettensis (Dana, 1852). The prevalence of A. pugettensis was 66% (49 of 74) on cutthroat trout and 0% (0 of 55) on coho salmon [O. kisutch (Walbaum, 1792)] collected during the winter of 2017/2018. Infestations occurred mosAuthorsJames P Losee, Simon R M Jones, Caitlin A E McKinstry, William N. Batts, Paul HershbergerPacific herring Clupea pallasii are not susceptible to vibriosis from Vibrio anguillarum or V. ordalii under laboratory conditions
The ubiquity of Vibrio spp. throughout the coastal marine waters of the Pacific Northwest of North America raises questions about the susceptibility of native marine fishes, including Pacific herring (Clupea pallasii). Early reports of Vibriolike disease (Rucker et al., 1954; Walford, 1958) and Vibrio sp. isolations (Pacha & Kiehn, 1969) in Pacific herring remain questionable because both occurredAuthorsPaul Hershberger, M.E.T Stinson, Brenda L Hall, Ashley MacKenzie, Jacob L. Gregg, William August Richards, James WintonHerring Disease Program II 19120111-E - 2019 Annual Report
We will investigate fish health factors that may be contributing to the failed recovery of Pacific herring populations in Prince William Sound. Field samples will provide infection and disease prevalence data from Prince William Sound and Sitka Sound that will inform the ASA model, serological data that will indicate the prior exposure history and future susceptibility of herring to VHS, and dietAuthorsPaul Hershberger, Maureen K. PurcellClimate change can drive marine diseases
As an ultimate driver of marine ecosystem processes, climate change is expected to influence proximate disease drivers in marine systems. The observable effects of climate change, including changes in temperature, hypoxia, CO2 accumulation, precipitation, and storm and cyclone frequencies and intensities, may directly act as proximate drivers of marine disease, especially in poikilotherms. These cAuthorsBurge Colleen A, Paul HershbergerIchthyophonus sp. Infection in Opaleye (Girella nigricans)
Over a 3-year-period, 17 wild-caught opaleye (Girella nigricans) housed in a public display aquarium were found dead without premonitory signs. Grossly, 4 animals had pinpoint brown or black foci on coelomic adipose tissue. Histologically, liver, spleen, heart, and posterior kidney had mesomycetozoan granulomas in all cases; other organs were less commonly infected. Four opaleye had goiter; additiAuthorsElise E. B LaDouceur, Judy St. Leger, Alexandria Mena, Ashley MacKenzie, Jacob Gregg, Maureen K. Purcell, William N. Batts, Paul HershbergerA geographic hot spot of Ichthyophonus infection in the southern Salish Sea, USA
The prevalence of Ichthyophonus infection in Pacific herring Clupea pallasii was spatially heterogeneous in the southern Salish Sea, Washington State, USA. Over the course of 13 mo, 2232 Pacific herring were sampled from 38 midwater trawls throughout the region. Fork length was positively correlated with Ichthyophonus infection at all sites. After controlling for the positive relationship betweenAuthorsPaul Hershberger, Ashley MacKenzie, Jacob Gregg, A Lindquist, T Sandell, Maya L. Groner, D LowryStudy 11. Effects of Nanophyetus on the swimming performance and survival of steelhead smolts AND studies to understand and manage the Nanophyetus cercaria
Recent field surveillances indicated that outmigrating steelhead smolts in several south Puget Sound watersheds are infected with the digenean trematode Nanophyetus salmonicola at high prevalence and intensity (Chen et al Accepted). The apparent severity of these infections, especially in the Nisqually and Green / Duwamish Rivers, lead to the hypothesis that Nanophyetus may play a role as a proximAuthorsPaul HershbergerSusceptibility of Nanophyetus salmincola cercariae to formalin, hydrogen peroxide, and seawater
The ability of formalin, PEROX‐AID (hydrogen peroxide), and seawater to kill waterborne Nanophyetus salmincola cercariae was evaluated in vitro. Newly emerged cercariae survived for extended periods in freshwater, with 53–73% survival occurring in negative control groups after 24 h. Exposure to dilutions of formalin reduced this survival time, with 0% of cercariae surviving after 30 min in 450 μL/AuthorsPaul Hershberger, Bonnie Besijn, Ashley Mackenzie, Mallory WilmotHerring Disease Program, February 1, 2018 - January 31, 2019
This report describes our laboratory and field results for the period February 1, 2018-January 31, 2019.AuthorsPaul Hershberger, Maureen PurcellIchthyophonus in sport-caught groundfishes from southcentral Alaska
This report of Ichthyophonus in common sport-caught fishes throughout the marine waters of southcentral Alaska represents the first documentation of natural Ichthyophonus infections in lingcod Ophiodon elongates and yelloweye rockfish Sebastes ruberrimus. In addition, the known geographic range of Ichthyophonus in black rockfish S. melanops has been expanded northward to include southcentral AlaskAuthorsBradley P. Harris, Sarah R. Webster, Nathan Wolf, Jacob L. Gregg, Paul HershbergerAnalytical and diagnostic performance of a qPCR assay for Ichthyophonus spp. compared to the tissue culture ‘gold standard’
Parasites of the genus Ichthyophonus infect many fish species and have a non-uniform distribution within host tissues. Due in part to this uneven distribution, the comparative sensitivity and accuracy of using molecular-based detection methods versus culture to estimate parasite prevalence is under debate. We evaluated the analytical and diagnostic performance of an existing qPCR assay in comparisAuthorsVanessa C. Lowe, Paul K. Hershberger, Carolyn S. FriedmanInfection by Nanophyetus salmincola and toxic contaminant exposure in out‐migrating steelhead from Puget Sound, Washington: Implications for early marine survival
Out‐migrating steelhead Oncorhynchus mykiss from four Puget Sound rivers and associated marine basins of Puget Sound in Washington State were examined for the parasite, Nanophyetus salmincola in 2014 to determine whether recent trends in reduced marine survival are associated with the presence of this pathogen. A subset of steelhead from three of these river–marine basin combinations was analyzedAuthorsM.F. Chen, S. M. O'Neill, A. J. Carey, R. H. Conrad, B. A. Stewart, K. R. Snekvik, G. M. Ylitalo, Paul Hershberger - News