Comprehensive review of the last 25 years regarding metals in the Atlantic coast of Patagonia

Abstract

This review assesses available data regarding metal concentration in biological samples (halophytes, macroalgae, invertebrates, birds and mammals), as well as oxidative stress potentially associated with these elements. The geographical zone was the Argentine coastal area of the South Atlantic Ocean, from Río Negro to Tierra del Fuego provinces. The elements Cd, Cr, Cu, Fe, Hg, Ni, Pb and Zn were chosen because they were the most studied metals in that area and due to their relevance on metal pollution and/or toxicity. After an exhaustive selection process between years 2000 and 2025, 66 articles were found, of which 33 were finally included in this review. Data evidenced high Cd concentrations in different trophic levels, which would be of natural origin. High concentrations of Hg were found in the liver of mammals, being differences among species probably attributed to diet, level of exposure, age and Hg metabolization. One study considered the food web where Hg was the only element analyzed, finding variation in concentrations primarily explained by site, rather than by trophic position. Spatially, San Antonio bay was identified as a hotspot, where abandoned mine residues are still leaching metals into the environment. It was observed that the toxicity of metals to organisms, measured through oxidative stress biomarkers, was not necessarily related to total accumulated concentration. Authors detected data gaps and made recommendations that could provide a take-off point for future research, following standardized protocols to enable harmonized data.