HOW PROTECTIVE OF AQUATIC-DEPENDENT WILDLIFE ARE PROPOSED FISH-TISSUE-BASED WATER QUALITY STANDARDS FOR SELENIUM?

High potential for selenium (Se) pollution is commonly associated with the extraction, refining, and combustion of fossil fuels; and with the mining of mineral ores such as copper, uranium, phosphate, and aluminum. As biota take up Se from water it bioaccumulates, becoming protein-bound in tissues of algae and aquatic invertebrates where it poses a dietary risk to higher-trophic-order fish and bird consumers of over-enriched aquatic food webs. The complex and variable biogeochemical mechanisms controlling the propensity of Se to bioaccumulate have led to a regulatory transition away from traditional aqueous water quality standards for Se and toward establishing fish-tissue-based water standards. Such efforts in the United States have focused solely on the protection of fish populations to the neglect of aquatic-dependent wildlife and therefore carry the potential for unnecessary conflict with major laws such as the Clean Water Act (CWA), Migratory Bird Treaty Act (MBTA), and Endangered Species Act (ESA); all of which legally mandate the protection of wildlife. The CWA mandates wildlife protection in its opening statement of purposes (Section 101(a)(2)) and repeatedly returns to the wildlife protection mandate in other sections of the law. The MBTA is a multilateral treaty implemented in both Canada and the United States.

Recently, the U.S. Environmental Protection Agency (EPA) approved the first fish-tissue-based Se standard on a site-specific basis for the state of Kentucky. The scientific basis for, and outcomes of, a wildlife risk assessment will be presented for the precedent-setting Kentucky standard. The Kentucky fish standard translates into as high as a 67% reduction of wildlife reproductive performance. For comparison, other proposed (but not yet approved) fish-tissue-based Se standards translate into as high as a 93% reduction of wildlife reproductive performance. The policy implications of these results will be presented, including the status of the ESA section 7 consultations on Kentucky’s standard. Fossil fuel and mineral ore commercial operations would be far better served by the establishment of Se standards that explicitly address protection of aquatic-dependent wildlife on the front-end rather than via after-the-fact conflict resolution with laws such as the CWA, MBTA, and ESA.