Organochlorine Pesticides and Polychlorinated Biphenyls in California Sea Lions ( Zalophus californianus californianus ) from the Gulf of California, México

We report concentrations of several classes of organochlorines (OCs) in the blubber of California sea lions ( Zalophus californianus ) from the Gulf of California. Summed OC levels measured in 34 wild-ranging animals were, in general, lower than those previously reported in sea lions from the eastern Pacific. The rank order of OCs was ΣDDTs (mean = 3400 ng g −1 lipid weight [lw]) > ΣPCBs (1400 ng g −1 lw) > ΣHCHs (50 ng g −1 lw) ≥ ΣCHLORs (46 ng g −1 lw). The most abundant OC measured was the DDT metabolite, p,p′ -DDE. No significant differences in OC profiles were found between genders or rookeries. Although the mean concentrations of OCs measured in adult males and females were similar, only adult females had significantly higher ( p < 0.05) mean blubber concentrations of ∑DDTs and ∑HCHs than pups.