Environmental Fate and Potential Biological Effects of the Anti-Parasitic Chemo-therapeutant Emamectin Benzoate (active ingredient of SLICE®) in the Canadian Marine Environment

Abstract

SLICE® is one of the chemotherapeutants used to control sea lice infestations at marine finfish aquaculture facilities in Canada. Concerns regarding the uptake and potential effects of the active ingredient of SLICE®, Emamectin Benzoate (EB), in non-target organisms have been raised by several stakeholder groups. EB was measured at parts per trillion (ppt) levels in water samples collected in the immediate vicinity of two salmon aquaculture sites in British Columbia following SLICE® treatment. EB was also detected at parts per billion (ppb) levels in sediment samples and in the muscle tissue of spot prawns collected within a 150 m radius of the net-pen. Sediment concentrations were related to the specific oceanographic conditions at each site. EB was found to be present in sediments up to 1.5 years following SLICE® treatment. Potential sub-lethal effects of EB on spot prawn were examined in a series of laboratory exposure experiments. Results suggest that short-term exposure to EB can impact this non-target crustacean.