Dietary exposure of rainbow trout ( Salmo gairdneri) to Great Lakes coho salmon ( Oncorhynchus kisutch Walbaum). Bioaccumulation of halogenated aromatic hydrocarbons and host resistance studies

Abstract

Great Lakes coho salmon ( Oncorhynchus kisutch walbaum) contain a gradient of halogenated aromatic hydrocarbons (HAHs) naturally bioaccumulated from their environment which have immunomodulatory potential. Juvenile rainbow trout ( Salmo gairdneri) were fed diets of coho salmon from Lakes Michigan and Ontario, the Pacific Ocean and control trout chow, for a 20 weak period. The body burdens of organochlorines bioaccumulated in rainbow trout were similar to levels in the dietary coho salmon. The effect on natural resistance was assessed by challenge with a titrated dose of Vibrio anguillarum (VA-58). The ability to mount a protective immune response was determined by immunization with a VA-58 bacterin followed by challenge with virulent VA-58. These parameters of host resistance of rainbow trout were not compromised following dietary exposure to Great Lakes coho salmon.