M3 AM Ecological Risk Assessment (Part 1)
Monday, 14 November 2005: 8:00 AM - 11:40 AM in Ballroom 3

(HIN-1117-637871) Piscivorous Wildlife Risk Assessment: Evaluations based on a national monitoring program.

Hinck, J¹, Tillitt, D¹, ¹ USGS-Columbia Environmental Reseach Center, Columbia, Missouri, USA

ABSTRACT- The Large River Monitoring Network (LRMN) of the BEST Program has measured organochlorine and elemental concentrations in fish from large river basins throughout the U.S. including the Mississippi, Rio Grande, Columbia, Yukon, and Colorado. Potential contaminant sources such as urban and agricultural runoff, industrial discharges, mine drainage, and irrigation varied among the sampling sites. Birds and mammals may be exposed to contaminants through the fish they consume from these sites; however, an assessment of potential risks to piscivorous wildlife has not been conducted. Allometric relationships, consumption rates, and other species-specific metrics of exposure models were estimated for selected mammalian and avian wildlife. Exposure and subsequent hazard evaluation models were developed for such species as mink, Northern river otter, bald eagle, Great blue heron, and belted kingfisher. Toxicity reference values (TRVs), which were derived from chemical specific effects on reproductive performance, growth, and survival in a species, were determined for each chemical and species combination. Hazard quotients (HQs) were then calculated by comparing the expected environmental concentrations (EEC) in a species, developed from fish concentrations and the species-specific exposure models, with the TRVs (HQ = EEC/TRV). The HQs indicted which contaminants pose a risk to piscivorous wildlife and which sites warrant further investigation.

Key words: ecological risk assessment, metals, pesticides, mammalian and avian wildlife