Concentrations of pesticide residues in tissues of fish from Kolleru Lake in India

Kolleru Lake is the largest natural freshwater lake of Andhra Pradesh in In dia. It is situated between latitudes 16 degrees 32' and 16 degrees 47'N an d longitudes 81 degrees 05' and 81 degrees 27'E. The use of pesticides for agricultural purposes is widespread in the Kolleru Lake region. The biologi cal indicators like fish help in the studies of aquatic pollution by pestic ides. Fish species Channa striata and Catla catla and water samples were co llected from Kolleru Lake in each of three seasons over a period of three y ears. Fish samples were analyzed according to a modified method which is pr oposed for the gas chromatographic determination for the pesticides viz., a lpha -BHC, gamma -BHC, malathion, chloirpyrifos, isodrin, endosulfan, dield rin, and p,p-DDT. Water samples were analyzed for selected physico-chemical parameters. The extraction efficiency for the selected pesticides is betwe en 82.8% and 91.2%. The maximum concentrations of pesticide residues in Kol leru Lake fish on wet weight basis are 123.8 mug/g for alpha -BHC, 98.7 mug /g for gamma -BHC, 2.5 mug/g for malathion, 88.6 mug/g for chlorpyrifos, 0. 91 mug/g for isodrin, 76.5 mug/g for endosulfan, 1.98 mug/g for dieldrin, a nd 157.4 mug/g for p,p-DDT These analyses were used to evaluate the baselin e data and the pesticide pollution in the lake's ecosystem. (C) 2001 by Joh n Wiley & Sons, Inc.