Deep Sea Mining and the possible increase of metals in the water column: how will echinoderms and mussels respond?

Marine pollution has been increasing as a consequence of human activities. In the near future will start the extraction of minerals from ocean depths, Deep Sea Mining (DSM). However, the impacts at the ecosystem level are still unknown. It is necessary to know the effects to contribute to the creation of rules, laws and mining codes that protect and conserve ecosystems and biodiversity. Sea urchin and mussels represents one of the most important seafood product, but also, a sentinel organism for ecotoxicological studies to assess aquatic environments quality. They are directly exposed to anthropogenic contaminants in their habitat. The aim of this study is to understand the influences of two trace element (which will probably be released into the water column by DSM) at three different environmentally realistic concentrations in Arbacia lixula and Mytilus galloprovincialis: Cu (0.6μg/l; 339.15 μg/l; 1709 μg/l), and Pb (1.0 μg/l; 619.16 μg/l; 2291 μg/l). We observed the short-term (3 and 7 days) effects at biochemical level (total cells count, cell mortality, total protein concentration and lysosomal membrane stability) and their bioaccumulation in different tissues. In A. lixula the bioaccumulation was studied in gonads while in M. galloprovincialis in gills and mantle. This study demonstrates the importance of biomonitoring contaminants and understanding how biomarkers relate to each other on exposure to particular contaminants in different species due to their wide application in environmental management. Few studies have used multiple biomarkers in more than a single species to learn about the variability of the sub-lethal effects of a contaminant