Organochlorine insecticide concentrations in fish of the Des Moines River, Iowa, 1977-78

Organochlorine insecticides were measured in fish of the Des Moines River, Iowa, in 1977 and 1978 to determine whether concentrations exceeded allowable levels and to compare differences among species. Significant differences in mean concentrations of dieldrin, sigma DDT, and heptachlor epoxide in whole-body samples of seven species of fish, Dorosoma cepedianum, Carpiodes carpio, Cyprinus carpio, Ictalurus punctatus, Pomoxis annularis, Micropterus salmoides, Stizostedion vitreum, could not be adequately explained by body size, position of species in the food chain, or percent body fat.