title: Cadmium and zinc in Mar Chiquita coastal lagoon (Argentina): salinity effects on lethal toxicity in juveniles of the burrowing crab Chasmagnathus granulatus.
abstract: The large Argentine marine littoral zone is characterized by great number of wetlands and includes only one coastal lagoon, Mar Chiquita, which has been declared as a Biosphere Reserve by the Man and Biosphere Reserve Program from UNESCO. Its margins present populations of Chasmagnathus granulatus, a semiterrestrial crab distributed along wide salinity gradients that plays an important role as a key species within the corresponding trophic web. Dissolved cadmium (Cd) and zinc (Zn) concentrations present in this ecosystem were determined. Cadmium concentrations ranged between n.d. and 0.82 mug/L and zinc levels ranged between n.d. and 1224.38 mug/L within the mentioned coastal lagoon. Cd and Zn acute semistatic toxicity bioassays were carried out for 96 h on juvenile crabs of C. granulatus. LC(50) 96-h values were 2.24 mg Cd(2+)/L and 7.07 mg Zn(2+)/L at 5 psu, and 15.42 mg Cd(2+)/L and 11.41 mg Zn(2+)/L at 25 psu. Higher salinities resulted in lower metal toxicity. This effect was stronger for Cd than for Zn. C. granulatus juveniles LC(50) 96-h values determined for Cd were three to four orders of magnitude higher than the corresponding dissolved metal concentrations in the Mar Chiquita coastal lagoon; nevertheless, those Zn values determined were similar to several ones corresponding to natural water samples.
authors: Area de Oceanografía Química, Instituto Argentino de Oceanografía (IADO-CONICET), CCT-CONICET-BBca., C.C. 804, 8000, Bahía Blanca, Argentina. beltrame@criba.edu.ar
authors: M Ornela
authors: MO
authors: Beltrame
authors: Silvia G
authors: SG
authors: De Marco
authors: Jorge E
authors: JE
authors: Marcovecchio
mesh_terms: D000818:Animals; D001118:Argentina; D003386:Brachyura / Q000187:drug effects*; D002104:Cadmium / Q000633:toxicity*; D007928:Lethal Dose 50; D054712:Salinity; D012623:Seawater; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015032:Zinc / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D002104:Cadmium; D015032:Zinc