title: Heavy metals in the habitat and throughout the food chain of the Neotropical otter, Lontra longicaudis, in protected Mexican wetlands.
abstract: Top predators like the Neotropical otter, Lontra longicaudis annectens, are usually considered good bioindicators of habitat quality. In this study, we evaluated heavy metal contamination (Hg(tot), Pb, Cd) in the riverine habitat, prey (crustaceans and fish), and otter feces in two Ramsar wetlands with contrasting upstream contamination discharges: Río Blanco and Río Caño Grande in Veracruz, Mexico, during the dry, the wet, and the nortes seasons. Most comparisons revealed no differences between sites while seasonal differences were repeatedly detected for all of the compartments. Higher concentrations of Pb during the dry season and of Cd during the wet season in otter feces mirrored differences detected in the most seasonally consumed prey. Compared with fecal methylmercury values reported for the European otter (0.25-0.75 mg kg(-1)) in unprotected areas, the Hg(tot) levels that we measured were lower (0.02-0.17 mg kg(-1)). However, Pb (117.87 mg kg(-1)) and Cd (9.14 mg kg(-1)) concentrations were higher (Pb, 38.15 mg kg(-1) and Cd, 4.72 mg kg(-1)) in the two Ramsar wetlands. Protected areas may shelter species, but those with water-linked diets may suffer the effect of chemicals used upstream.
authors.affiliation: Red de Biologia y Conservacion de Vertebrados, Instituto de Ecologia AC, Carretera Antigua a Coatepec No 351, El Haya, 91070 Xalapa, Veracruz, Mexico.
authors.forename: Nadia N
authors.initials: NN
authors.lastname: Ramos-Rosas
authors.forename: Carolina
authors.initials: C
authors.lastname: Valdespino
authors.forename: Jaqueline
authors.initials: J
authors.lastname: García-Hernández
authors.forename: Juan P
authors.initials: JP
authors.lastname: Gallo-Reynoso
authors.forename: Eugenia J
authors.initials: EJ
authors.lastname: Olguín
mesh_terms: D000818:Animals; D003445:Crustacea / Q000378:metabolism; D004784:Environmental Monitoring; D005243:Feces / Q000737:chemistry; D005260:Female; D005399:Fishes / Q000378:metabolism; D020387:Food Chain; D005506:Food Contamination; D008297:Male; D019216:Metals, Heavy / Q000032:analysis*; D010041:Otters / Q000502:physiology*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D053833:Wetlands
chemical_list: D019216:Metals, Heavy; D014874:Water Pollutants, Chemical