Oil fouling in three subsistence-harvested ringed (Phoca hispida) and spotted seals (Phoca largha) from the Bering Strait region, Alaska: Polycyclic aromatic hydrocarbon bile and tissue levels and pathological findings

Oil spills of unknown origin were detected in three oil-fouled, ice-associated seals from the Alaska Bering Strait region collected by Alaska Native subsistence hunters during fall 2012. Bile analyses of two oiled seals indicated exposure to fluorescent polycyclic aromatic hydrocarbon (PAH) metabolites but levels of some metabolites were similar to or lower than biliary levels in harvested unoiled ice seals. Oiled seals had elevated tissue PAH concentrations compared to tissue levels of PAHs determined in unoiled ice seals. However, regardless of oiling status, tissue PAH levels were relatively low (<50 ng/g, wet weight) likely due to rapid PAH metabolism and elimination demonstrated previously by vertebrates. Hepatic, pulmonary, and cardiac lesions were observed in oiled seals in conjunction with measurable PAHs in their tissue and bile. This is the first study to report tissue and bile PAH concentrations and pathologic findings of oiled ice seals from the U.S. Arctic.