Ecological risk assessment in a large river-reservoir. 6: Bioindicators of fish population health
- Oak Ridge National Lab., TN (United States). Environmental Sciences Div.
- Univ. of California, Davis, CA (United States)
Spatial distribution of contaminants in the sediments and biota of a large reservoir ecosystem were related to a variety of biological responses in fish populations and communities to determine possible relationships between contaminant loading in the environment and fish health. Much of the contaminant inventory in the Clinch River/Watts Bar Reservoir (CR/WBR) system has originated from three US Department of Energy facilities on the Oak Ridge Reservation, which borders this system in its upper reaches. Fish sampled from areas of the CR/WBR system with the highest levels of contaminants in the sediments and biota, primarily mercury and PCBs, had the most dramatic bioindicator responses. The major changes observed were induction of detoxification enzymes, organ dysfunction, increased frequency of histopathological lesions, impaired reproduction, and reduced fish community integrity. Mercury, the dominant contaminant, displayed a decreasing concentration gradient from the upper reaches of Poplar Creek to the lower Clinch River, which was consistent with a downstream gradient in several of the biological responses. A multivariate analysis using all of the individual fish health responses at each site in a discriminant analysis procedure also revealed a downstream gradient in integrated fish health. In Poplar Creek where contaminant concentrations were the highest, statistical correlations were observed between individual bioindicator responses such as contaminant exposure indicators, organ dysfunction, histopathological damage, and reproductive impairment. Relationships between contaminant loading and fish community indices such as species richness and relative abundance, however, were more difficult to establish in Poplar Creek because of the possible dominating influence of food and habitat availability on fish community dynamics. Using a suite of bioindicators that encompass a range of levels of biological organization and response-sensitivity scales improves the probability of identifying cause and effect and helps in distinguishing between natural and anthropogenic sources of stress in aquatic ecosystems.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 361904
- Journal Information:
- Environmental Toxicology and Chemistry, Vol. 18, Issue 4; Other Information: PBD: Apr 1999
- Country of Publication:
- United States
- Language:
- English
Similar Records
Ecological risk assessment in a large river-reservoir. 4: Piscivorous wildlife
Remedial investigation/feasibility study for the Clinch River/Poplar Creek operable unit. Volume 2. Appendixes A, B, C, D