The effects of ivermectin, used to control sea lice on caged farmed salmonids, on infaunal polychaetes

The mortality of benthic polychaetes was examined after treatment with ivermectin, an agent to control sea lice on caged salmonids. Ivermectin had a significant effect on polychaete mortality at applications of 81 and 810 mu g m(-2). The potential exists for toxic levels of ivermectin to accumulate in sediments at fish farm sites if this product is used frequently. (C) 1997 Internationai Council for the Exploration of the Sea.