Biomonitoring of Environmental Status and Trends (BEST) Program: Environmental contaminants and their effects on fish in the Columbia River Basin

This project examined and analyzed 560 fish representing eight species from 16 sites in the Columbia River Basin (CRB) from September 1997 to April 1998. Ten of the 16 sampling locations were historical National Contaminant Biomonitoring Program (NCBP) sites where organochlorine and elemental contaminants in fish had been monitored from 1969 through 1986. Five sites were co-located at U.S. Geological Survey (USGS)-National Stream Quality Accounting Network (NASQAN) stations at which water quality is monitored. The sampling location at Marine Park in Vancouver, Washington did not correspond to either of the established monitoring programs. Eight of the sampling locations were located on the Columbia River; three were on the Snake River; two were on the Willamette River, and one site was on each of the Yakima, Salmon and Flathead Rivers.

Common carp (Cyprinus carpio), black basses (Micropterus sp.), and largescale sucker (Catostomus macrocheilus) together accounted for 80% of the fish sampled during the study. Fish were weighed and measured then field-examined for external and internal lesions, and liver, spleen, and gonads were weighed to compute somatic indices. Selected tissues and fluids were obtained and preserved for analysis of fish health and reproductive biomarkers. Composite samples of whole fish from each station were grouped by species and gender and analyzed for persistent organic and inorganic contaminants and for dioxin-like activity using H4IIE rat hepatoma cell bioassay.