Mercury, a pollutant gas produced by coal combustion and mining activities, falls back into the ocean where it accumulates in the marine food chain, with serious consequences for food and human health. A new study, published on 29 September 2021 in Nature, shows that, contrary to previous hypotheses, mercury is not mainly brought in by rainwater but that the ocean 'breathes' it in. This work also suggests that the oceans are receiving less atmospheric mercury than previously estimated, although this does not currently point to a reduction in fish contamination. In the context of the Minamata Convention on mercury, which came into force in 20172, policies to reduce mercury emissions are being developed, which should have a direct impact on mercury in the oceans and on our plates. This work was carried out by an international team involving scientists from the Géosciences environnement Toulouse laboratory (CNRS/Université Toulouse III - Paul Sabatier/Cnes/IRD) and the Institut méditerranéen d'océanologie (CNRS/Aix-Marseille Université/IRD/Université de Toulon), and from the Environmental Geosciences laboratory at the University of Basel (Switzerland).
Bibliography
Mercury stable isotopes constrain atmospheric sources to the ocean. Martin Jiskra, Lars-Eric Heimbürger-Boavida, Marie-Maëlle Desgranges, Mariia V. Petrova, Aurélie Dufour, Beatriz Ferreira-Araujo, Jérémy Masbou, Jérome Chmeleff, Melilotus Thyssen, David Point & Jeroen E. Sonke. 29 September 2021, Nature. DOI : 10.1038/s41586-021-03859-8
Thanks from Lars-Eric :
"I would particularly like to thank Aurélie and my students Marie-Maëlle and Masha for their fantastic work in the field and in the laboratory; Olivier and Melilotus for putting together the project. SSL@MMDeny, Michel, Nagib, the 4 SAM team for setting up our own carousel, preparing the GOFLO bottles and their support during campaigns with the Antedon II. A big thank you also to our MIO managers for all the emergency orders and OMs and all the other essential things that enable us to carry out our research".