Abstract
Heavy metals are naturally occurring elements with global distribution. Industrial application of some heavy metals has led to ecosystem contamination and accumulation of unsafe levels in the food chain, even for those metals which normally function in organism homeostasis. Levels of heavy metals in tissues of the Atlantic bottlenose dolphin (Tursiops truncatus) from the Texas coast of the Gulf of Mexico have not been systematically explored. The large population of this species along the Gulf coast, their rather long lifespan and the high position of this species on the food chain permit the bottlenose dolphin to serve as a measure of metal dynamics within the Gulf. For this study, seven heavy metals (Cd, Cu, Fe, Hg, Pb, Se and Zn) were determined in liver, kidney, muscle, blubber and bone of bottlenose dolphins stranded along the Texas coast and in liver of those stranded along the Florida Gulf coast. Concentrations of all tested metals were comparable to those previously reported for populations of bottlenose dolphins in other geographic regions. Two metal-metal correlations were examined in liver, kidney and muscle tissue. Strong positive correlations were found between mercury and selenium in the three tissues. No correlations existed between cadmium and zinc. The effects of age, location and gender on metal concentrations were also analyzed. Because age was not available for all animals, a separate model was used substituting length for age. Length and age had the greatest impact, significantly associated with the concentrations of cadmium, mercury, lead and selenium. Copper was associated with gender in the kidney. Mercury was associated with geographic location in the muscle when the length model was used and in the liver when the age model was used.
Haubold, Elsa Maria (1995). Selected heavy metals in tissues of bottlenose dolphins (Tursiops truncatus) stranded along thr Texas and Florida Gulf coasts. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1995 -THESIS -H38.