Levels of Concentration and Incidence of Various Pesticide Toxicants in Some Species from Selected Bay Areas

Tissue samples analyzed indicate that residues of some pesticides are present in all Texas bay areas sampled, including Galveston Bay. The residues detected are DDT, Dieldrin and Endrin. The incident of DDT residues decreased slightly in both oyster, Crassostrea virginica, and fish samples during the study period. The incidence of Dieldrin increased dramatically in oyster samples while decreasing in fish samples. The incidence of Endrin remained essentially unchanged. Ovaries of speckled trout, Cynoscion nebulosus, contained enough DDT residue to cause concern over the possible impairment of reproductive ability.