Bioaccumulation patterns of polychlorinated biphenyls and chlorinated pesticides in Northwest Atlantic pilot whales

Contaminant exposure is widespread among marine mammals but is of unknown s ignificance. This study characterized organochlorine bioaccumulation in pil ot whales, and these bioaccumulation patterns are proposed as representativ e of Northwest (NW) Atlantic cetacea. Samples were collected from whales st randed in Massachusetts and caught in nets. Polychlorinated biphenyl (PCB) and chlorinated pesticide concentrations were determined via GC/ECD and fou nd to be similar to those reported for other NW Atlantic odontocetes. The o rganochlorine in highest concentration was 4,4'-DDE, followed by trans-nona chlor, 4,4'-DDD, dieldrin, cis-chlordane, C14(52), C15(95), C15(101), C15(1 18), C16(138), C16(149), C16(153), C17(180), and C17(187). The concentratio n of 19 pesticides was higher in blubber (21 +/- 26 mu g/g lipid "ppm") tha n liver (5.0 +/- 7.1 ppm). The concentration of 26 PCB congeners was also g reater in blubber (7.6 +/- 7.1 ppm) than liver (0.4 +/- 7.3 ppm). Principal component analysis and ANOVA indicated that blubber accumulated proportion ately more of the most recalcitrant compounds, such as 4,4'-DDE and nonmeta bolizable PCBs, compared to liver. Whales that stranded together had more s imilar bioaccumulation than animals of the same gender or maturity. The hig h variation among individuals in tissue concentrations;and the similarity w ithin a stranding group suggest that pilot whale pods are exposed to a larg e range of pollutant sources, such as through different prey and feeding lo cations.