Publications

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 diet

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 c

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; additi

Bio-physical models are a useful tool for understanding dispersal and transmission of marine pathogens. While utilized for larval dispersal models, they are only recently being used in epidemiological studies and are currently underutilized by the marine epidemiology field. Bio-physical models are useful for spatial planning and coastal management. For example, they have been used for spatial pla

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 between

Increasing usage of non-medicinal methods (NMMs) to control sea louse infestations on salmon farms has raised questions about whether sea lice may be able to evolve tolerance of NMMs. Of particular concern is the potential for sea lice to evolve freshwater tolerance as a result of freshwater treatments. Wild trout and some juvenile salmonids swim into freshwater to control infestations and regain

An analysis of daily water samples collected from an index site on Big Soos Creek, Washington indicated intra‐annual differences in the concentrations of waterborne Nanophyetus salmincola. Waterborne concentrations, quantified as gene copies/L, peaked during the fall (October–November 2016), decreased to very low concentrations over the winter (January–March 2017), and then increased in the spring

Atlantic salmon farming is one of the largest aquaculture sectors in the world. A major impact on farm economics, fish welfare, and potentially nearby wild salmonid populations, is the sea louse ectoparasite Lepeophtheirus salmonis. Sea louse infestations are most often controlled through application of chemicals, but in most farming regions sea lice have evolved resistance to the small set of ava

Risks associated with disease spread from fish and shellfish farming have plagued the growth and public perception of aquaculture worldwide. However, by processing nutrients and organic material from the water column, the culture of many suspension-feeding bivalves has been proposed as a novel solution toward mitigating problems facing coastal water quality, including the removal of disease-causin

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 proxim

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/

This report describes our laboratory and field results for the period February 1, 2018-January 31, 2019.