Bioaccumulation and Ecological Effects of Contaminant Stressors in Columbia River Aquatic Food Webs

Several interdisciplinary studies have been carried out in recent years to assess impacts of different classes of contaminants of emerging concern (CECs) in several levels of the food web in the Columbia River Basin. Organisms studied have included species of biological and cultural importance including largescale sucker (Catostomus macrocheilus), Pacific lamprey (Entosphenus tridentatus), white sturgeon (Acipenser transmontanus), and osprey (Pandion haliaetus). Chemical concentrations increased in largescale suckers along an exposure gradient towards the urbanized downstream sites. Biomagnification was shown to occur and environmental quality benchmarks were exceeded in some cases. Biomarker results showed that bioaccumulation caused negative effects in this food web. PBDEs and other CECs were also investigated in white sturgeon and were nearly an order of magnitude larger than those measured in largescale sucker. Concentrations exceeded cancer-screening levels in several fillet samples for several legacy contaminants. Flame retardants, pesticides, industrial, and personal care compounds were measured at levels of concern in tissues of larval Pacific lamprey and may contribute to the recent decline of this culturally and ecologically important species. These results have provided information about distributions, levels, bioaccumulation, transfer, persistence and effects of CECs on key species and food webs.