The Northeast Atlantic is running out of excess carbonate in the horizon of cold-water corals communities
|Author(s)||Fontela Marcos1, 2, Perez Fiz F1, Carracedo Lidia3, Padín Xosé A.1, Velo Antón, García-Ibañez Maribel I.1, 4, Lherminier Pascale3|
|Affiliation(s)||1 : Instituto de Investigaciones Marinas, IIM-CSIC, 36208, Vigo, Spain
2 : Centre of Marine Sciences (CCMAR), University of Algarve, 8005-139, Faro, Portugal
3 : Ifremer, Univ. Brest, CNRS, IRD, Laboratoire d’Océanographie Physique et Spatiale (LOPS), IUEM, 29280, Plouzané, France
4 : Centre for Ocean and Atmospheric Sciences, School of Environmental Sciences, University of East Anglia, Norwich, UK
|Source||Scientific Reports (2045-2322) (Springer Science and Business Media LLC), 2020-09 , Vol. 10 , N. 1 , P. 14174 (10p.)|
The oceanic uptake of atmospheric carbon dioxide (CO2) emitted by human activities alters the seawater carbonate system. Here, the chemical status of the Northeast Atlantic is examined by means of a high-quality database of carbon variables based on the GO-SHIP A25 section (1997–2018). The increase of atmospheric CO2 leads to an increase in ocean anthropogenic carbon (Cant) and a decrease in carbonate that is unequivocal in the upper and mid-layers (0–2,500 m depth). In the mid-layer, the carbonate content in the Northeast Atlantic is maintained by the interplay between the northward spreading of recently conveyed Mediterranean Water with excess of carbonate and the arrival of subpolar-origin waters close to carbonate undersaturation. In this study we show a progression to undersaturation with respect to aragonite that could compromise the conservation of the habitats and ecosystem services developed by benthic marine calcifiers inhabiting that depth-range, such as the cold-water corals (CWC) communities. For each additional ppm in atmospheric pCO2 the waters surrounding CWC communities lose carbonate at a rate of − 0.17 ± 0.02 μmol kg−1 ppm−1. The accomplishment of global climate policies to limit global warming below 1.5–2 ℃ will avoid the exhaustion of excess carbonate in the Northeast Atlantic.