Biological assays for aquatic toxicity testing

A number of aquatic toxicity tests have been established for South African use, which include fish and Daphnia lethality tests, microbiotests, and short-term chronic tests. Studies on effluents and surface waters showed that all the tests have a viable role to play in water quality management. The most advantageous use of the tests is in battery form, so that tests can complement each other. The fish and Daphnia lethality tests, and algal growth inhibition test are recommended for regulatory and management purposes of effluents. If receiving water is used for drinking water purposes, the Ames Salmonella mutagenicity and toad embryo teratogenicity tests should be included in the battery of tests. Some of the rapid microbiotests, e.g. the protozoan oxygen uptake test, bacterial growth test and enzyme tests, could be valuable screening tools to identify and categorize toxic effluents.