Enantioselective Accumulation of α-Hexachlorocyclohexane in Northern Fur Seals and Double-Crested Cormorants: Effects of Biological and Ecological Factors in the Higher Trophic Levels

Abstract

Tissues of northern fur seals (Callorhinus ursinus) from the Pacific coast of Japan and double-crested cormorants (Phalacrocorax auritus) from the Great Lakes were analyzed in order to explore the enantioselective accumulation of α-hexachlorocyclohexane (HCH). The effects of biological and ecological factors such as species, tissue, sex, age, feeding habit, and habitat, which may be attributable to the differences in accumulation between enantiomers, were also investigated. The enantiomeric ratios (ERs) of (+)-/(−)-α-HCH in fat tissue of female fur seals, composed of different age groups, collected in 1986 (1.58 ± 0.25) exhibited greater values than those in abiotic and lower trophic levels previously reported. No age trend of ERs was found in female northern fur seals. There appeared to be a temporal transition of ERs in adult female northern fur seals collected in 1971−1988. Regression analysis showed a significant relationship between ERs and feeding habits (p = 0.003). Analysis of breast muscle of dou...