Increased Susceptibility of Juvenile Chinook Salmon to Vibriosis after Exposure to Chlorinated and Aromatic Compounds Found in Contaminated Urban Estuaries

Abstract

Abstract Saltwater-adapted juvenile chinook salmon Oncorhynchus tshawytscha exposed to aromatic and chlorinated compounds, representative of contaminants found in urban estuaries in Puget Sound, have a higher susceptibility to vibriosis than do fish exposed only to the solvent vehicle. Susceptibility to vibriosis was assessed by examining the percent cumulative mortality of the salmon after exposure to the bacterial pathogen Vibrio anguillarum. The aromatic and chlorinated compounds examined consisted of a sediment extract from the Hylebos Waterway that was enriched in butadienelike compounds (chlorinated-enriched Hylebos Waterway sediment extract (CHWSE)), a model mixture of polycyclic aromatic hydrocarbons (PAHs), a polychlorinated biphenyl mixture (Aroclor 1254), hexachlorobutadiene (HCBD), and 7,12-dimethylbenz(a)anthracene (DMBA). Two trials were conducted. In trial l, the percent cumulative mortality of juvenile chinook salmon exposed to V. anguillarum after receiving either CHWSE, HCBD, or the mode...