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DDT in endangered Galapagos sea lions (Zalophus wollebaeki)

Alava, Juan Jose, Ross, Peter S., Ikonomou, Michael G., Cruz, Marilyn, Jimenez-Uzcátegui, Gustavo, Dubetz, Cory, Salazar, Sandie, Costa, Daniel P., Villegas-Amtmann, Stella, Howorth, Peter, Gobas, Frank A.P.C.
Marine pollution bulletin 2011 v.62 no.4 pp. 660-671
DDE (pesticide), DDT (pesticide), Mirounga, Monachus schauinslandi, Zalophus, environmental impact, males, metabolites, pups, rats, risk characterization, toxicity, water pollution
We characterize for the first time the presence of DDT and its metabolites in tropical Galapagos sea lions (Zalophus wolleabeki). ∑DDT concentrations in Galapagos sea lion pups sampled in 2005 and 2008 ranged from 16 to 3070μg/kg lipid. Concentrations of ∑DDT in pups in 2008 averaged 525μg/kg lipid and were 1.9 times higher than that (281μg/kg lipid) detected in pups in 2005. These concentrations are lower than those reported in many pinnipeds elsewhere, comparable to those in Hawaiian monk seals, and higher than those in southern elephant seals. The health risk characterization showed that 1% of the male pups exceeded the p,p′-DDE toxic effect concentration associated with anti-androgenic effects reported in rats. The findings provide preliminary guidance on the relationship between DDT use and ecological impacts, serving as a reference point against which possible future impact of tropical DDT use can be assessed.