Effects Of Polybrominated Diphenyl Ethers (PBDEs) On Juvenile Chinook Salmon Immune System

Many bodies of water are becoming increasingly polluted. Pollutants can have drastic effects on the environment and the ecosystems of economically, culturally and recreationally important organisms. Species of specific concern are Pacific Northwest salmon. Populations of Pacific Northwest salmon have declined significantly over the last seventy years with over half of the populations listed as either threatened or endangered under the Endangered Species Act. Chemical exposure has been associated with the population declines along with other anthropogenic activities. Polybrominated Diphenyl Ethers (PBDEs) are a pollutant of growing concern. PBDEs are commonly used in home furniture as well as commercial products as a mixture of congeners. Some PBDE mixtures have been banned in the Northwest because PBDEs have been shown to bioaccumulate in many organisms including humans. In salmonids environmental concentrations of PBDEs have been linked to higher rates of infectious disease and greater disease susceptibility. This this study will look at the effect PBDEs have on the immune system of juvenile Chinook salmon. More specifically lysozyme which is an enzyme that breaks down bacterial cell walls. To do this lysozyme assays will be performed on various tissue samples of head kidney. The samples are collected from fish fed diets containing environmentally-relevant concentrations of PBDEs (2-230ng/g food) and a control. We expect that those fed PBDEs will have a decrease in lysozyme activity resulting in adverse effects on the immune system. PBDEs are just one of the many pollutants found in marine and freshwater habitats with little known of their sublethal health effects on aquatic organisms.