Cadmium and zinc in Mar Chiquita coastal lagoon (Argentina): salinity effects on lethal toxicity in juveniles of the burrowing crab Chasmagnathus granulatus.

ORNELA BELTRAME,; SILVIA DE MARCO; JORGE MARCOVECCHIO

Archives of Environmental Contamination and Toxicology

Springer Sci.Publ.

Lugar: New York, USA; Año: 2008 vol. 55 p. 78 - 85

0090-4341

Abstract The large Argentine marine littoral zone is12 characterized by great number of wetlands and includes13 only one coastal lagoon, Mar Chiquita, which has been14 declared as a Biosphere Reserve by the Man and Biosphere15 Reserve Program from UNESCO. Its margins present16 populations of Chasmagnathus granulatus, a semiterres-17 trial crab distributed along wide salinity gradients that18 plays an important role as a key species within the corre-19 sponding trophic web. Dissolved cadmium (Cd) and zinc20 (Zn) concentrations present in this ecosystem were deter-21 mined. Cadmium concentrations ranged between n.d. and22 0.82 lg/L and zinc levels ranged between n.d. and 1224.3823 lg/L within the mentioned coastal lagoon. Cd and Zn acute24 semistatic toxicity bioassays were carried out for 96 h on25 juvenil crabs of C. granulatus. LC50 96-h values were 2.2426 mg Cd2+/L and 7.07 mg Zn2+/L at 5 psu, and 15.42 mg27 Cd2+/L and 11.41 mg Zn2+/L at 25 psu. Higher salinities28 resulted in lower metal toxicity. This effect was strongerfor Cd than for Zn. C. granulatus juveniles LC50 96-h 29values determined for Cd were three to four orders of 30magnitude higher than the corresponding dissolved metal 31concentrations in the Mar Chiquita coastal lagoon; never- 32theless, those Zn values determined were similar to several 33ones corresponding to natural water samples.