Vaccine efficacy in preventing clinical disease has been well characterized. However, vaccine impacts on transmission under diverse field conditions, such as variable pathogen exposure dosages, are not fully understood. We evaluated the impacts of vaccination on disease‐induced host mortality and shedding of infectious hematopoietic necrosis virus (IHNV) in Rainbow Trout Oncorhynchus mykiss. Fish, in up to three different genetic lines, were exposed to different dosages of IHNV to simulate field variability….Read more with free access

Introduced Lake Trout Salvelinus namaycush threaten native Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri in Yellowstone Lake, Yellowstone National Park, where gill nets have been used to suppress subadult and adult Lake Trout since 1995. However, survival of embryonic and larval life history stages can have profound effects on the population dynamics of Lake Trout. Inducing additional mortality at those stages, especially if used in concert with intensive gillnetting of older fish, could enhance overall suppression efforts. Therefore, we conducted controlled field experiments at Yellowstone Lake to systematically evaluate the effects of sediment deposition and ground Lake Trout carcass deposition on Lake Trout embryos in pre‐positioned incubators….Read more with free access

Juvenile steelhead Oncorhynchus mykiss enter the northern California Current ecosystem from the Columbia River and other Pacific Northwest coastal rivers and include several populations that are listed under the U.S. Endangered Species Act. However, relatively little is known about the response of these populations to interannual variability in ocean conditions… These findings highlight the potential for warm ocean years to influence the diet composition and morphology of Columbia River steelhead populations and may lead to a better understanding of factors influencing survival of juvenile steelhead during early marine residence….Read more with free access

Photo Credit: NOAA Fisheries/Oregon State University