Toxicity assessment of a waste water effluent using acute and chronic fish bioassays

Following guidance from the Norwegian Environment Agency (Miljødirektoratet) it is required to perform a risk assessment on the toxicity of a waste water effluent. The risk assessment needs to include the acute and chronic effects of the effluent to marine fish. Based on this information, it is proposed that the toxicity of the effluent will be assessed using the OECD203 (96 h fish acute bioassay) and the OECD215 (28 day fish growth test). The fish species used in the test will be lumpsuckers (Cyclopterus sp.). Five test concentrations plus a control will be used with a minimum number of fish (7 per treatment) in both tests. A flow-through seawater system will be used and the physicochemical parameters of the treatment water will be checked routinely to ensure the water is within optimal range for fish health. Fish will be feed during the 28 day growth test with fish food provided by the fish farm where the fish are purchased.