Movement of mirex from sediment and uptake by the hogchoker, Trinectes maculatus

Mirex contaminated sediments of the static test retained virtually all of the insecticide over a 4 week period. About 40% of the initial concentration was lost from the sediment under constant flow conditions. Mirex in water was directly related to levels of mirex in sediment. Mirex in water reached an equilibrium during the first week and declined over the following 3 weeks. Uptake of mirex by tissues showed a dose dependent relationship. Accumulation of the insecticide increased over time and did not appear to reach an equilbrium. Residues in the muscle of fish increased significantly with time (pless than.01) and test concentration (pless than.01). Mirex in the liver of fish increased significantly with time (pless than.05) of the flow-through test. Declinging levels of mirex in water indicated mirex was absorbed from the water by the fish. Considerably more mirex, however, was gained by the fish than was lost from the water. Thus the fish probably absorbed a significant amount of mirex from the sediments.