COPLANAR PCB AND METAL RESIDUES IN DOLPHINS FROM THE UNITED-STATES ATLANTIC COAST INCLUDING ATLANTIC BOTTLE-NOSED OBTAINED DURING THE 1987/88 MASS MORTALITY

Bottlenose dolphins (Tursiops truncatus) collected during the 1987/88 mass mortality event along the Atlantic coast of the United States have been analyzed for coplanar PCBs #77, 105, 126 and 169 in blubber, and for the metals Hg, Pb, Cd, Mn, and Cr, and the non-metallic element Se in liver. Results have been compared to two reference species, common (Delphinus delphis) and white-sided (Lagenorhynchus acutus) dolphins. The three most toxic PCB congeners (#77, 126 and 169) contributed less than 1% of the total TCDD toxic equivalent concentration (TEC) calculated for all di-, mono- and non-ortho chlorine substituted PCBs in adult male animals. The total TEC for the four PCBs was approximately 4.5 times lower in adult female bottlenose than in male. The mean concentrations of Pb, Cd, Mn and Cr in adult male bottlenose dolphins were at or below the mean concentrations in the two reference species. The mean concentration of mercury was highest in adult female bottlenose dolphins. However, mercury concentrations in all animals studied correlated with selenium concentrations (r=0.86) at a 1:1 mole ratio, indicating that selenium may protect these animals from mercury toxicity.