E.P. Foster | Geology Reports

USGS2005

Evidence of detrimental effects of environmental contaminants on growth and reproductive physiology of white sturgeon in impounded areas of the Columbia River

This study sought to determine whether wild white sturgeon from the Columbia River (Oregon) were exhibiting signs of reproductive endocrine disruption. Fish were sampled in the free-flowing portion of the river (where the population is experiencing reproductive success) and from three reservoirs behind hydroelectric dams (where fish have reduced reproductive success). All of the 18 pesticides and almost all of the 28 polychlorinated biphenyls (PCBs) that were analyzed in livers and gonads were detected in at least some of the tissue samples. Metabolites of p,p???-dichlorodiphenyltrichloroethane (DDT) [p,p???-dichlorodiphenyldichloroethylene (DDE) and p,p???-1,1-dichloro-2,2-bis(4-chlorophenyl)ethane (DDD)] were consistently found at relatively high levels in fish. Some males and immature females showed elevated plasma vitellogenin; however, concentrations were not correlated with any of the pesticides or PCBs analyzed. Negative correlations were found between a number of physiologic parameters and tissue burdens of toxicants. Plasma triglycerides and condition factor were negatively correlated with total DDT (DDD + DDE + DDT), total pesticides (all pesticides detected - total DDT), and PCBs. In males, plasma androgens and gonad size were negatively correlated with total DDT, total pesticides, and PCBs. Fish residing in the reservoir behind the oldest dam had the highest contaminant loads and incidence of gonadal abnormalities, and the lowest triglycerides, condition factor, gonad size, and plasma androgens. These data suggest that endocrine-disrupting chemicals may be accumulating behind dams over time. Overall, results of this study indicate that exposure to environmental contaminants may be affecting both growth and reproductive physiology of sturgeon in some areas of the Columbia River.

Environmental Health Perspectives↗

USGS2001

Gonad organochlorine concentrations and plasma steroid levels in white sturgeon (Acipenser transmontanus) from the Columbia River, USA

Sturgeon are an important fishery resource world-wide, providing food and income through commercial, sport, and tribal fisheries. However, sturgeon populations are imperiled in many areas due to overharvest, habitat loss, and pollution. White Sturgeon ( Acipenser transmontanus ) are found along the west coast of North America from San Francisco Bay, USA to British Columbia, Canada. The Columbia River, located in the Pacific Northwest USA, supports active commercial, sport, and tribal white sturgeon fisheries. The white sturgeon fishery in the Columbia River estuary is one of the most productive sturgeon fisheries in the World. Despite the success of the Columbia River estuary white sturgeon fishery, the populations within the impounded sections (i.e. behind the hydroelectric dams) of the Columbia River experience poor reproductive success (Beamesderfer et al. 1995). This poor reproductive success has been attributed to hydroelectric development, but water pollution could also be a significant factor. The bottom dwelling life history and late maturing reproductive strategy for this species may make it particularly sensitive to the adverse effects of bioaccumulative pollutants. The Columbia River receives effluent from bleached-kraft pulp mills, aluminum smelters, municipal sewage treatment plants and runoff from agricultural. industrial, and urban areas. Bioaccumulative contaminants that have the potential for endocrine disruption have been detected in fish and sediments from the Columbia River (Foster et al. 1999). An integrated system of hormones control reproduction in vertebrates. Plasma steroids direct developmental events essential for reproduction. Disruption of endocrine control by contaminants has been linked to reproductive anomalies and failure in a number of vertebrate species (Guillette et al. 1996; Jobling et al. 1996). Because of this, it is important to understand if organochlorine compounds are accumulating in Columbia River white sturgeon and having an effect on their reproductive physiology. The objective of this study was to determine if sturgeon from an impounded section of the Columbia River (where reproductive success has been low) had higher levels of bioaccumulative pollutants than sturgeon from the estuary (where reproductive success has been high) and if these compounds were associated with decreased plasma steroid levels. Specifically, we measured chlorinated pesticides and PCBs in the gonads and plasma steroids in white sturgeon from the Columbia River fishery.

Columbia River↗