Organochlorine Pesticide Residues in Fish of River Ganga in West Bengal

The residues of persistent organochlorine pesticides were studied in some economically important fishes (7 species, total 26 samples) of the river Ganga from three locations of West Bengal. In general, DDT and its metabolites were the major constituents (∼98%) of the residues followed by HCH, heptachlor, endosulfan and aldrin. The total residues were in the range of 1.3–73.6 ng g−1 at Farakka, 7.9–90.4 ng g−1 at Barrackkore and 2.6–15.9 nn g−1 at Haldia (on fresh weight of fish) with observed mean values of 14.3, 37.9 and 7.6 ng g−1, respectively. The total pesticide residues yielded a positive correlation with fish weight (r = 0.450, p 0.021)) The residue levels observed in the present study were far below the permissible limits of these pesticides in fish (DDT 5000 ng g−1; heptachlor, chlordane, aldrin, dieldrin 300 ngg−1).