Ecotoxicity testing involves the use of biological systems of varying levels of complexity to predict or assess the ecological effects of chemicals. The practice currently endorsed are single species toxicity tests involving an algae, an invertebrate and a fish. The implicity hypothesis is that, on the basis of bioassays carried out individually, extrapolations to the response of an aquatic ecosystem can effectively be made so that standards for environmental concentrations of chemicals can be stated at levels which do not cause adverse ecological effects. The present project will address this by the development of a theoretical model which will validate the observations made in the laboratory, in single and/or multi-species tests, to make predictions that will be tested in experimental stream mesocosms. Furthermore, a new and cost-effective recirculating test system, which will incorporate a novel "active control" will be developed. This will integrate existing and new test systems, representative of the different aquatic environmental compartments: i.e. sediments, producers and primary and secondary consumers (e.g. sediment-dwelling animals, an algae, an invertebrate and a fish). The genotoxicity of the test substances to invertebrates (particularly to Daphnia magna) will be explored using standard developmental techniques and restriction map analysis of DNA. The system will be developed using poorly water-soluble compounds and/or chemicals that are currently of some importance throughout Europe (i.e. chemicals present in paper and pulp mill effluents in Portugal and used by the fish farming industry in Scotland). Although the development of the system will concentrate on freshwater, the possibility exists of applying it to brackish waters.
Funding SchemeCSC - Cost-sharing contracts
S10 2TN Sheffield
FK9 4LA Stirling