WATER-QUALITY ISSUES ASSOCIATED WITH AQUACULTURE - A CASE-STUDY IN MINE PIT LAKES

Abandoned mine pit lakes in Minnesota are being used for intensive aqu aculture, and this has resulted in real and perceived water-quality im pacts. In current net pen aquaculture operations, metabolic wastes and uneaten food are dispersed into previously oligotrophic lakewater, re sulting in increased levels of phosphorus and nitrogen, oxygen depleti on, and increased deposition of organic matter. Conditions necessary f or algal blooms have been infrequent due to light limitation from inte nsive artificial aeration and circulation. Highly emotional conflicts arose over the novel use of a few of these man-made water bodies by an industry commonly perceived to be relatively ''green'' and heavily pr omoted by state and federal governments as a rapid growth industry. Th e combination of the industry's ''newness'' on the regulatory scene, c oupled with the current regulatory push toward antidegradation of grou ndwater and regulation of agriculture, necessitated consideration of c arcinogenesis, Alzheimer's disease, and antibiotic resistance transfer in addition to more conventional considerations, such as eutrophicati on and wildlife impacts.