Polybrominated diphenyl ethers (PBDEs) in blubber of free-ranging bottlenose dolphins (Tursiops truncatus) from two southeast Atlantic estuarine areas

Blubber tissue samples from bottlenose dolphins collected during the summers of 2003 and 2004 were screened for 13 ( 17, 28, 47, 66, 71, 85, 99, 100, 138, 154, 153, 183, 190) polybrominated diphenyl ethers ( PBDEs) from dolphin populations in the Indian River Lagoon, FL (n = 58) and the Charleston Harbor estuary, SC (n = 53). Within each population, we investigated contaminant levels of PBDEs and the effects of factors including age, sex, the interaction of age and sex, and location. Six PBDE congeners (28, 47, 99, 100, 153, and 154) were routinely detected in all samples using gas chromatography/ mass spectometry methods. Significantly higher (p <= 0.0001) mean Sigma PBDE blubber concentrations were observed for Charleston dolphins (X = 5,860 ng/ g lipid; range = 429- 22,780 ng/ g lipid) when compared to Indian River Lagoon dolphins (X = 1,260 ng/ g lipid; range = 195 - 3,790 ng/ g lipid). PBDE 47 was the major congener representing similar to 61% of the SPBDE in both dolphin populations, followed by BDE100, BDE154, BDE99, BDE153, and BDE28, respectively. Significantly higher 0.0001) mean SPBDE were observed in adult male dolphins compared to pregnant and adult female dolphins at both sites, with gender differences two-fold in the Indian River Lagoon and twelve-fold for Charleston. For Charleston dolphins, the juveniles in addition to the adult males also had significantly higher levels compared to pregnant and adult females. This study establishes baseline levels of PBDEs in bottlenose dolphins for these two areas and is the first assessment of PBDEs in free- ranging dolphins. The levels of PBDEs in Charleston dolphins represent some of the highest measured in marine mammals and warrants further investigation of these emerging, bioaccumulative chemicals and their potential deleterious effects.