Herring larvae 15 days post-hatch. Food in the gut appears orange.
Jacob Gregg
Jacob is a Fish Biologist at the Marrowstone Marine Field Station, Nordland, WA.
Science and Products
PCB Exposure and Disease Susceptibility
PAH Exposure and Disease Susceptibility
Effects of Nanophyetus salmincola on the Health and Survival of Puget Sound Steelhead
Genomic Mechanisms that Underlie Lack of Recovery of Prince William Sound Herring Following the 1990s Collapse
Herring Disease Program
Caligus Clemensi prevalence and counts on Clupea pallasii from Port Angeles Harbor, WA and from a controlled laboratory experiment conducted at USGS Marrowstone Marine Field Station, WA
DNA sequences from Ichthyophonid parasites
Herring larvae 15 days post-hatch. Food in the gut appears orange.
Herring larvae 53 day post-hatch. Black pigmentation is evident.
Herring larvae 53 day post-hatch. Black pigmentation is evident.
Naturally-deposited herring eggs attached to submerged macrophytes. Coiled embryos are evident inside the eggs.
Naturally-deposited herring eggs attached to submerged macrophytes. Coiled embryos are evident inside the eggs.
Currently four age classes (0, 1, 2, and 4 year olds) of SPF herring are maintained at the Marrowstone Marine Field Station.
Currently four age classes (0, 1, 2, and 4 year olds) of SPF herring are maintained at the Marrowstone Marine Field Station.
Small herring spawning event in Puget Sound, evidenced by the presence of 'white water', caused by mass release of spawning products into the water.
Small herring spawning event in Puget Sound, evidenced by the presence of 'white water', caused by mass release of spawning products into the water.
Effects of temperature on viral load, inclusion body formation, and host response in Pacific Herring with viral erythrocytic necrosis (VEN)
Biological responses of Pacific herring embryos to crude oil are quantifiable at exposure levels below conventional limits of quantitation for PAHs in water and tissues
Temporal, environmental, and demographic correlates of Ichthyophonus sp. infections in mature Pacific herring populations
Characteristics of a sea louse (Caligus clemensi) epizootic in wild Pacific herring (Clupea pallasii)
A phylogeny based on cytochrome-c oxidase gene sequences identifies sympatric Ichthyophonus genotypes in the NE Pacific Ocean
Annual recurrences of viral hemorrhagic septicemia epizootics in age 0 Pacific herring Clupea pallasii Valenciennes, 1847
Long-term shedding from fully convalesced individuals indicates that Pacific herring are a reservoir for viral hemorrhagic septicemia virus
Differential susceptibility of Yukon River and Salish Sea stocks of Chinook salmon Oncorhynchus tshawytscha to ichthyophoniasis
Pacific herring Clupea pallasii are not susceptible to vibriosis from Vibrio anguillarum or V. ordalii under laboratory conditions
Ichthyophonus in sport-caught groundfishes from southcentral Alaska
High‐prevalence and low‐intensity Ichthyophonus infections in Pacific Halibut
Identification of the major capsid protein of erythrocytic necrosis virus (ENV) and development of quantitative real-time PCR assays for quantification of ENV DNA
Science and Products
- Science
PCB Exposure and Disease Susceptibility
Researchers at that MMFS are experimentally determining the impacts of high PCB body burdens on the immunocompetency and disease susceptibility of Pacific herring.PAH Exposure and Disease Susceptibility
Researchers at the MMFS are studying the immediate and delayed effects of petroleum hydrocarbon exposures to Pacific herring.Effects of Nanophyetus salmincola on the Health and Survival of Puget Sound Steelhead
Low early marine survival rates of Puget Sound steelhead ( Oncorhynchus mykiss ), the state fish of Washington, have contributed to its dramatic population decline and current listing as a “Threatened Species” under the Endangered Species Act. Determining the cause(s) of this elevated mortality remains a primary objective of the Salish Sea Marine Survival Project, a large US / Canada effort...Genomic Mechanisms that Underlie Lack of Recovery of Prince William Sound Herring Following the 1990s Collapse
In the decades following the Exxon Valdez Oil Spill (EVOS), it has become increasingly apparent that oil can be toxic at extremely low concentrations to developing fish embryos including herring, where some toxic phenotypes may be apparent during embryogenesis, but some are delayed until later in life. Therefore, acute and lingering oil may act as an insidious selective force within populations...Herring Disease Program
Using an approach that involves a combination of field- and laboratory-based studies, we are investigating fish health factors that may be contributing to the failed recovery of Pacific herring populations in Prince William Sound, AK. Field studies are providing infection and disease prevalence data to inform the population models, serological data that indicate the prior exposure history and... - Data
Caligus Clemensi prevalence and counts on Clupea pallasii from Port Angeles Harbor, WA and from a controlled laboratory experiment conducted at USGS Marrowstone Marine Field Station, WA
We characterized a natural sea louse epizootic of Caligus clemensi and the effects of parasitism on Pacific herring Clupea pallasii in Port Angeles Harbor, WA, USA. Infestation prevalence on newly metamorphosed age0 Pacific herring reached 100% prevalence by mid-August. At this time, the mean louse intensity was 4.6 lice and a positive correlation occurred between louse intensity and Pacific herriDNA sequences from Ichthyophonid parasites
Data included are DNA sequences used to identify species boundaries among Ichthyophonus-like parasites. Sequences were generated for three gene regions from each parasite isolate. DNA sequences can be downloaded from GenBank (https://www.ncbi.nlm.nih.gov/) as text or fasta files. Accession numbers for each sequence are included in the data table (.csv file). Data includes 87 sequences (99,383 tota - Multimedia
Pacific Herring larvae
Herring larvae 15 days post-hatch. Food in the gut appears orange.
Herring larvae 15 days post-hatch. Food in the gut appears orange.
Pacific Herring LarvaeHerring larvae 53 day post-hatch. Black pigmentation is evident.
Herring larvae 53 day post-hatch. Black pigmentation is evident.
Pacific Herring Eggs on MacrophytesNaturally-deposited herring eggs attached to submerged macrophytes. Coiled embryos are evident inside the eggs.
Naturally-deposited herring eggs attached to submerged macrophytes. Coiled embryos are evident inside the eggs.
Pacific Herring SchoolCurrently four age classes (0, 1, 2, and 4 year olds) of SPF herring are maintained at the Marrowstone Marine Field Station.
Currently four age classes (0, 1, 2, and 4 year olds) of SPF herring are maintained at the Marrowstone Marine Field Station.
Pacific Herring Spawning EventSmall herring spawning event in Puget Sound, evidenced by the presence of 'white water', caused by mass release of spawning products into the water.
Small herring spawning event in Puget Sound, evidenced by the presence of 'white water', caused by mass release of spawning products into the water.
- Publications
Filter Total Items: 43
Effects of temperature on viral load, inclusion body formation, and host response in Pacific Herring with viral erythrocytic necrosis (VEN)
ObjectiveThe primary objective of this study was to determine the effects of temperature on viral erythrocytic necrosis (VEN) progression under controlled conditions. Secondarily, this study was intended to evaluate the combined effects of temperature and VEN on the Pacific Herring Clupea palasii transcriptome.MethodsThe effects of temperature on VEN progression were assessed by waterborne exposurAuthorsJoanne Elizabeth Salzer, Justin Blaine Greer, Maya Groner, Ashley MacKenzie, Jacob L. Gregg, Paul HershbergerBiological responses of Pacific herring embryos to crude oil are quantifiable at exposure levels below conventional limits of quantitation for PAHs in water and tissues
Pacific herring (Clupea pallasii), a cornerstone of marine food webs, generally spawn on marine macroalgae in shallow nearshore areas that are disproportionately at risk from oil spills. Herring embryos are also highly susceptible to toxicity from chemicals leaching from oil stranded in intertidal and subtidal zones. The water-soluble components of crude oil trigger an adverse outcome pathway thatAuthorsJohn P. Incardona, Tiffany L. Linbo, James R. Cameron, Barbara L. French, Jennie L. Bolton, Jacob L. Gregg, Carey E. Donald, Paul Hershberger, Nathaniel L. ScholzTemporal, environmental, and demographic correlates of Ichthyophonus sp. infections in mature Pacific herring populations
Causes of population collapse and failed recovery often remain enigmatic in marine forage fish like Pacific herring (Clupea pallasii) that experience dramatic population oscillations. Diseases such as ichthyophoniasis are hypothesized to contribute to these declines, but lack of long-term datasets frequently prevents inference. Analysis of pathogen surveillance and population assessment datasets sAuthorsMaya Groner, Eliana D. Bravo-Mendosa, Ashley MacKenzie, Jacob L. Gregg, Carla M. Conway, John T. Trochta, Paul HershbergerCharacteristics of a sea louse (Caligus clemensi) epizootic in wild Pacific herring (Clupea pallasii)
We characterized a natural sea louse epizootic of Caligus clemensi and the effects of parasitism on Pacific herring Clupea pallasii in Port Angeles Harbor, WA, USA. Infestation prevalence on newly metamorphosed age 0 Pacific herring reached 100% prevalence by mid-August. At this time, the mean louse intensity was 4.6 lice/fish, and a positive correlation occurred between louse intensity and herrinAuthorsDavid James Páez, Jacob L. Gregg, Ashley MacKenzie, Sophie Amanda Hall, Paul HershbergerA phylogeny based on cytochrome-c oxidase gene sequences identifies sympatric Ichthyophonus genotypes in the NE Pacific Ocean
ABSTRACT: In recent decades, evidence has accumulated to suggest that the widespread and highly variable parasite Ichthyophonus hoferi is actually a species complex. Highly plastic morphology and a general lack of defining structures has contributed to the likely underestimate of biodiversity within this group. Molecular methods are a logical next step in the description of these parasites, but maAuthorsJacob L. Gregg, Paul Hershberger, Abigail S. Neat, Hiruni T. Jayasekera, Jayde A. Ferguson, Rachel L. Powers, Maureen K. PurcellAnnual recurrences of viral hemorrhagic septicemia epizootics in age 0 Pacific herring Clupea pallasii Valenciennes, 1847
Throughout a 20 year biosurveillance period, viral hemorrhagic septicemia virus was isolated in low titers from only 6/7355 opportunistically sampled adult Pacific herring, reflecting the typical endemic phase of the disease when the virus persists covertly. However, more focused surveillance efforts identified the presence of disease hot spots occurring among juvenile life history stages from cerAuthorsPaul Hershberger, Theodore R. Meyers, Jacob L. Gregg, Maya Groner, Sophie Amanda Hall, Hiruni T. Jayasekera, Ashley MacKenzie, Abigail S. Neat, Ella N. Piatt, Kyle A. GarverLong-term shedding from fully convalesced individuals indicates that Pacific herring are a reservoir for viral hemorrhagic septicemia virus
Processes that allow viral hemorrhagic septicemia (VHS) virus to persist in the marine environment remain enigmatic, owing largely to the presence of covert and cryptic infections in marine fishes during typical sub-epizootic periods. As such, marine host reservoirs for VHS virus have not been fully demonstrated, nor have the mechanism(s) by which infected hosts contribute to virus perpetuation anAuthorsPaul Hershberger, Ashley MacKenzie, Jacob L. Gregg, M. D. Wilmot, Rachel L. Powers, Maureen K. PurcellDifferential susceptibility of Yukon River and Salish Sea stocks of Chinook salmon Oncorhynchus tshawytscha to ichthyophoniasis
Preliminary evidence suggests that Chinook salmon Oncorhynchus tshawytscha from the Yukon River may be more susceptible to Ichthyophonus sp. infections than Chinook from stocks further south. To investigate this hypothesis in a controlled environment, we experimentally challenged juvenile Chinook from the Yukon River and from the Salish Sea with Ichthyophonus sp. and evaluated mortality, infectionAuthorsDiane G. Elliott, Carla M. Conway, Constance L. McKibben, Ashley MacKenzie, Lucas M. Hart, Maya Groner, Maureen K. Purcell, Jacob L. Gregg, 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 WintonIchthyophonus 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 HershbergerHigh‐prevalence and low‐intensity Ichthyophonus infections in Pacific Halibut
Ichthyophonus occurred at high prevalence but low intensity in Pacific Halibut Hippoglossus stenolepis throughout the West Coast of North America, ranging from coastal Oregon to the Bering Sea. Infection prevalence in adults was variable on spatial and temporal scales, with the lowest prevalence typically occurring on the edges of the geographic range and highest prevalence consistently occurringAuthorsPaul Hershberger, Jacob L. Gregg, Claude L. DykstraIdentification of the major capsid protein of erythrocytic necrosis virus (ENV) and development of quantitative real-time PCR assays for quantification of ENV DNA
Viral erythrocytic necrosis (VEN) is a disease of marine and anadromous fish that is caused by the erythrocytic necrosis virus (ENV), which was recently identified as a novel member of family Iridoviridae by next-generation sequencing. Phylogenetic analysis of the ENV DNA polymerase grouped ENV with other erythrocytic iridoviruses from snakes and lizards. In the present study, we identified the geAuthorsMaureen K. Purcell, Schuyler Pearman-Gillman, Rachel L. Thompson, Jacob L. Gregg, Lucas M. Hart, James R. Winton, Eveline J. Emmenegger, Paul K. Hershberger