Ecological risk assessment of piscivorous wildlife of the Clinch River
- Oak Ridge National Lab., TN (United States)
A weight-of-evidence approach was employed to assess risks to osprey, great blue heron, and mink along the Clinch River, downstream of the Oak Ridge Reservation (ORR). Available data consisted of comparisons of exposure estimates to literature-derived NOAELs and LOAELs (all three species), field surveys (osprey and heron only), and toxicity tests (mink only). Contaminants of potential concern (COPCS) were identified by comparing exposure estimates generated using point estimates of parameter values to NOAELS. COPCs included mercury, PCBs and selenium. Exposure to COPCs was re-estimated using Monte Carlo simulations then compared to LOAELS. Exposure of osprey to mercury was identified as a significant risk at only one location. This location did not present a risk when the foraging area of osprey was included in the exposure model. Estimated exposure for heron or mink was not sufficient to present a risk for any COPC or location. Field surveys of four heron rookeries indicated that while contaminant levels are elevated in eggs and chicks near the reservation, reproduction is not affected. Fledgling success at three osprey nests near the ORR exceeded the mean for US osprey. Mink fed fish from the Clinch River displayed impaired reproduction only in the most contaminated of five toxicity test diets. Mercury in all diets was less than the literature-based LOAEL. PCBs in the highest diet that produced no adverse effects were 16 times greater than the literature-based LOAEL. The maximum exposure estimated for mink along the Clinch River was significantly lower than the toxicity test exposure that produced adverse effects The weight-of-evidence indicates that contaminants from the ORR do not present a risk to piscivorous wildlife along the Clinch River.
- OSTI ID:
- 212059
- Report Number(s):
- CONF-9511137--; ISBN 1-880611-03-1
- Country of Publication:
- United States
- Language:
- English
Similar Records
Ecological risk assessment of aerial insectivores of the Clinch River/Poplar Creek system
Ecological risk assessment in a large river-reservoir. 8: Experimental study of the effects of polychlorinated biphenyls on reproductive success in mink