Cu, Pb, and Zn content in sediments and benthic organisms from San Jorge Bay (northern Chile): Accumulation and biotransference in subtidal coastal systems

Abstract

The concentration of Cu, Pb, and Zn was measured in order to evaluate their sediment enrichment and probable biomagnification trends in benthic trophic chains of the coastal zone of San Jorge Bay (northern Chile). The mean concentrations of Cu, Zn, and Pb were 103.6, 72.6, and 38.6 mg kg^–1, respectively, in sediments and 28.3, 32.5, and 21.9 mg kg^–1, respectively, in organisms. The geoaccumulation index indicated that sectors with industrial activities show some degree of metal enrichment; however, Zn and Pb contents have diminished in recent years, probably as a consequence of the closing of storage facilities for these minerals in the coastal zone of the bay. Evidence of biomagnification was observed in three of the seven coastal sectors studied, and herbivorous and carnivorous species showed the highest transfer factors of these metals. The results of this work suggest a high temporal variability of metal content in sediments and benthic organisms, which can be explained by changes in natural and anthropic factors that control the sources and accumulation of these metals in the coastal area of San Jorge Bay.