The Southern Ocean ecosystem under multiple climate change stresses ‐ an integrated circumpolar assessment |
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| Authors: | Julian Gutt Nancy Bertler Thomas J. Bracegirdle Alexander Buschmann Josefino Comiso Graham Hosie Enrique Isla Irene R. Schloss Craig R. Smith Jean Tournadre José C. Xavier |
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| Affiliation: | 1. Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany;2. Joint Antarctic Research Institute, Victoria University of Wellington and GNS Science, Wellington, New Zealand;3. British Antarctic Survey, Natural Environment Research Council, Cambridge, UK;4. Cryospheric Sciences Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD, USA;5. Scott Polar Research Institute, SCAR Life Science, Cambridge, UK;6. Institut de Ciències del Mar‐CSIC, Passeig Marítim de la Barceloneta, Barcelona, Spain;7. Instituto Antártico Argentino, Ciudad Autónoma de Buenos Aires & CONICET, Argentina;8. Argentina & Institut des sciences de la mer de Rimouski, Rimouski, QC, Canada;9. Department of Oceanography, University of Hawaii at Manoa, Honolulu, HI, USA;10. Laboratoire d'Océanographie Spatiale, IFREMER, Plouzané, France;11. Institute of Marine Research, Department of Life Sciences, University of Coimbra, Coimbra, Portugal |
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| Abstract: | A quantitative assessment of observed and projected environmental changes in the Southern Ocean (SO) with a potential impact on the marine ecosystem shows: (i) large proportions of the SO are and will be affected by one or more climate change processes; areas projected to be affected in the future are larger than areas that are already under environmental stress, (ii) areas affected by changes in sea‐ice in the past and likely in the future are much larger than areas affected by ocean warming. The smallest areas (<1% area of the SO) are affected by glacier retreat and warming in the deeper euphotic layer. In the future, decrease in the sea‐ice is expected to be widespread. Changes in iceberg impact resulting from further collapse of ice‐shelves can potentially affect large parts of shelf and ephemerally in the off‐shore regions. However, aragonite undersaturation (acidification) might become one of the biggest problems for the Antarctic marine ecosystem by affecting almost the entire SO. Direct and indirect impacts of various environmental changes to the three major habitats, sea‐ice, pelagic and benthos and their biota are complex. The areas affected by environmental stressors range from 33% of the SO for a single stressor, 11% for two and 2% for three, to <1% for four and five overlapping factors. In the future, areas expected to be affected by 2 and 3 overlapping factors are equally large, including potential iceberg changes, and together cover almost 86% of the SO ecosystem. |
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| Keywords: | acidification habitats icebergs ice‐shelves ozone depletion sea‐ice warming |
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