Trace Metals Occurrence and Geochemical Distribution in Sediments from Mar Chiquita Coastal Lagoon, Argentina

Abstract

Trace metals have proven to be significantly hazardous pollutants in aquatic environments, even at very low concentrations. In this sense, sediments have been recognised as the most important trace metals reservoir in the ecosphere. The study of their occurrence, distribution and concentration, particularly in marine and/or estuarine sediments, which are able to concentrate heavy metals to high values even in the absence of local point sources (Marcovecchio 2000). Knowledge of the environmental significance of heavy metals in coastal environments has resulted in the launching of environmental monitoring programs to assess metal contents and distribution within coastal ecosystems of Latin America (i.e. Patchineelam et al. 1988; Lacerda et al.1999). Moreover, not only the knowledge of both, the physical or physico-chemical processes controlling heavy metals behaviour, but also the geochemical partitioning of these elements in sediments, is basic for the understanding of potentially toxic events in the environments being considered. Research programs directed towards addressing these topics have been developed in different ecosystems, including those in Latin American ones (i.e. Campos and Gallo 1996; Cedeño et al.1996). Also, general reiews on heavy metal contamination at the regional, sub-continental level have been published on different occasions (Seeliger et al. 1988; Lacerda 1998; Marcovecchio 2000). Notwithstanding, the combined analysis of the geochemical processes controlling heavy metal distribution in coastal marine sediments of the region is still quite scarce, and is limited to a few isolated papers (Lacerda 1996; Lacerda et al. 1996, 1998; Aller 1999).