Development of methods to assess the effects of xenobiotics in outdoor artificial streams

Two collaborative research projects were designed to develop and validate m ethods for determining the chronic effects of xenobiotics in freshwater eco systems, The work reported here focuses on the development of methods for m easuring effects on fish, invertebrates, and algae in outdoor artificial st reams. 3,4-Dichloroaniline (3,4-DCA), has been used as a reference xenobiot ic in two artificial stream experiments. The first used five stream channel s: a control and treatments ranging from 70 to 2400 mu g/liter. The second used eight stream channels-a control and treatments ranging from 0.45 to 47 00 mu g/liter and four coupled, 510-liter-capacity, downstream ponds-a cont rol and treatments of 1.7, 37, and 820 mu g/liter. Effects on the biota of the stream channels and the downstream ponds were examined using a range of sampling techniques and in situ toxicity tests. (C) 2000 Academic Press.