title: California sea lions (Zalophus californianus californianus) have lower chlorinated hydrocarbon contents in northern Baja California, México, than in California, USA.
abstract: Chlorinated hydrocarbons (CHs) were determined in blubber samples of 18 California sea lions (Zalophus californianus californianus) that stranded dead along Todos Santos Bay, Ensenada, Baja California, México, January 2000-November 2001. Summation operatorDDTs were the dominant group (geometric mean 3.8 microg/g lipid weight), followed by polychlorinated biphenyls ( summation operatorPCBs, 2.96 microg/g), chlordanes (0.12 microg/g) and hexachlorocyclohexanes (0.06 microg/g). The summation operatorDDTs/ summation operatorPCBs ratio was 1.3. We found CH levels more than one order of magnitude lower than those reported for California sea lion samples collected along the California coast, USA, during the same period as our study. This sharp north-south gradient suggests that Z. californianus stranded in Ensenada (most of them males) would probably have foraged during the summer near rookeries 500-1000 km south of Ensenada and the rest of the year migrate northwards, foraging along the Baja California peninsula, including Ensenada, and probably farther north.
authors.affiliation: Universidad Autónoma de Baja California (UABC), Facultad de Ciencias Marinas, Ensenada, Baja California, México.
authors.forename: Ligeia
authors.initials: L
authors.lastname: Del Toro
authors.forename: Gisela
authors.initials: G
authors.lastname: Heckel
authors.forename: Víctor F
authors.initials: VF
authors.lastname: Camacho-Ibar
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Schramm
mesh_terms: D000818:Animals; D001822:Body Burden; D002140:California; D003634:DDT / Q000032:analysis; D003632:Dichlorodiphenyldichloroethane / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods*; D006843:Hydrocarbons, Chlorinated / Q000032:analysis / Q000633:toxicity*; D008297:Male; D008800:Mexico; D010575:Pesticides / Q000032:analysis; D011078:Polychlorinated Biphenyls / Q000032:analysis; D046070:Sea Lions; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D006843:Hydrocarbons, Chlorinated; D010575:Pesticides; D014874:Water Pollutants, Chemical; D003634:DDT; D011078:Polychlorinated Biphenyls; D003632:Dichlorodiphenyldichloroethane