Mercury in a marine trophic chain

Abstract

The mud of the northern zone of the Gulf of Arauco is considered an area of sediments rich in organic matter, due to the current regime and to the geomorphology of the gulf. The possible accumulation of heavy metals derived from industrial and human activities could occur. Mercury levels were researched insuspended particulate matter (organic and inorganic), sediment (using total and partial digestion from 26 sampling stations) and living organisms: Pleuroncodes monodon ("squat lobster") a crustacean that feeds on sediment organic matter, and Genypterus maculatus ("black ling"), a benthodemersal fish which feeds ca. 24% on P.monodon. Our working hypothesis was that sediments in the northern part of the Arauco Gulf become a temporary reserve for the potential or actual pollutants generated upriver by human activities in the Biobio basin. As an open system, it receives -in the northern sector of the gulf- all the contributions of the basin, mainly in the area of the Biobío canyon and the inmediate continental platform. In a previous report we informed about cadmium and lead behaviour in this trophic marine chain. (González et al. 1998)