Toxicity of emamectin benzoate in commercial fish feed to adults of the spot prawn and dungeness crab

Sea lice infestations of net-penned Atlantic salmon can result in significant economic losses to the salmon aquaculture industry in Canada. As a means to control the deleterious effects of the sea lice infestations prophylactic drug treatments are prescribed to control the problem. Use and application in Canada of these drugs is regulated in order to protect indigenous species and the aquatic environment in general. To-date limited toxicological studies with these drugs have been conducted on non-targeted benthic organisms or opportunistic feeders. Even fewer toxicological studies have been conducted using geographically relevant species. Emamectin benzoate is a drug that has proven successful in the control of sea lice infestations in net-penned salmon. Other than toxicological studies from the United Kingdom and Scandinavia there are limited relevant studies that are applicable to Canadian waters or species. Until the work detailed here, the only other toxicological data available was from the East Coast of Canada. The St. Andrew´s Marine laboratory of the Canadian Department of Fisheries and Oceans (DFO) had been the sole laboratory to study the acute toxicological effects of emamectin benzoate in Canada. In this joint Schering-Plough/spl bsol/DFO- St. Andrew´s Marine Laboratory study the Atlantic lobster was the targeted organism for toxicological testing.