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PERIPHYTON PHOTOSYNTHESIS AS AN INDICATOR OF EFFLUENT TOXICITY: RELATIONSHIP TO EFFECTS ON ANIMAL TEST SPECIES
Citation:
Lewis, M. PERIPHYTON PHOTOSYNTHESIS AS AN INDICATOR OF EFFLUENT TOXICITY: RELATIONSHIP TO EFFECTS ON ANIMAL TEST SPECIES. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-92/407 (NTIS PB93131829), 1992.
Description:
The use of aquatic plants in effluent toxicity evaluations is uncommon despite the availability of test methods and numerous recommendations for their use. It has been assumed that aquatic plants are less sensitive than animal test species and consequently, results from toxicity tests with invertebrates and fish have been used as a surrogate data base. This study evaluated the ability of such animal toxicity tests to provide safe concentrations far In-stream periphyton. The toxicity of several samples of a treated municipal effluent were determined during 5. month tests to monitor short-term changes in periphyton photosynthesis (carbon-14 uptake) and observe affects on young production and survival of cultured daphnite and the fathead minnow. The effect levels from the various tests were compared. The effluent was seldom acutely toxic to Daphnia magna and the fathead minnow but it was consistently acutely and chronically toxic to eriodaphnia dubla. ignificant inhibition and stimulation of periphyton photosynthetic activity occurred at concentrations of 6 to 30% effluent. Periphyton photosynthesis was a more sensitive effect parameter than animal survival and in some cases than Ceriodaphnia reproductive performance. Results indicate that effluent toxicity tests conducted routinely with daphnids and fish may not be sufficient to protect the aquatic flora in receiving waters. Therefore, estimates of phytotoxicity are need for effective risk assessments for effluents.