Spatial and cumulative organochlorine and mercury exposure assessments in Steller Sea lions of Alaska: Emphasizing pups

Steller sea lions (SSL) are sentinels for monitoring environmental contaminants in remote areas of the Aleutian Islands, Alaska. Therefore, concentrations of several organochlorines (OCs) were measured in blood from 123 SSL pups sampled from 3 regions; the western Aleutian Islands (WAI), central Aleutian Islands (CAI), and the central Gulf of Alaska. Blood, blubber, and milk from 12 adult female SSL from WAI, CAI and southeast Alaska also were analyzed. Findings included the following. SSL pups had higher concentrations of some OCs and mercury (Hg) on rookeries in the WAI than those more easterly. Pups had significantly higher blood concentrations of many OC classes than adult females sampled within the same region; some pups had PCB concentrations exceeding thresholds of concern (∑PCBs >8600 ng/g lw). ∑PCB concentration in pup whole blood was positively correlated with the trophic marker, δ