Organochlorine, organobromine, metal, and selenium residues in bottlenose dolphins (Tursiops truncatus) collected during an unusual mortality event in the Gulf of Mexico, 1990.

Polychlorinated biphenyls (PCBs), cis-chlordane, oxychlordane, heptachlor epoxide, mirex, hexachlorobenzene (HCB), lindane, octachlorostyrene (OCS), p,p'-DDE,p,p'-DDT, dieldrin, triphenylphosphate (TPP), polybrominated biphenyls (PBBs), and polybrominated diphenyl ethers (PB-DPEs) were measured in the blubber, and five metals (mercury, lead, cadmium, chromium, and manganese) and selenium were measured in the liver of bottlenose dolphins (Tursiops truncatus) obtained from the Gulf of Mexico during an unusual mortality event in 1990. The collection of animals included fetuses, sucklings (< 1 year old), immature dolphins (2-5 years old), and adults of both sexes. PCBs, p,p'-DDE, HCB, and PBDPEs were detected in the blubber of each animal. Mean concentrations of organic contaminants were generally highest in adult males. p,p'-DDE was the single component analyte measured at the highest concentration. Immature females had greater concentrations of most chlorinated organics than adult females. Mercury and cadmium concentrations in liver increased with increasing age-class. The correlation between mercury and selenium in all animals was r = 0.96, with a mole ratio of 0.90. Concentrations of lead, manganese, cadmium, and chromium did not follow any particular age-class trend.