Journal cover Journal topic
Ocean Science An interactive open-access journal of the European Geosciences Union

Journal metrics

  • IF value: 2.985 IF 2.985
  • IF 5-year<br/> value: 2.790 IF 5-year
    2.790
  • CiteScore<br/> value: 2.70 CiteScore
    2.70
  • SNIP value: 1.191 SNIP 1.191
  • SJR value: 1.885 SJR 1.885
  • IPP value: 2.589 IPP 2.589
  • h5-index value: 25 h5-index 25
doi:10.5194/os-2016-71
© Author(s) 2016. This work is distributed
under the Creative Commons Attribution 3.0 License.
Research article
13 Sep 2016
Review status
A revision of this discussion paper was accepted for the journal Ocean Science (OS) and is expected to appear here in due course.
Concomitant ocean acidification and increasing total alkalinity at a coastal site in the NW Mediterranean Sea (2007-2015)
Lydia Kapsenberg1, Samir Alliouane1, Frédéric Gazeau1, Laure Mousseau1, and Jean-Pierre Gattuso1,2 1Sorbonne Universités, Université Pierre et Marie Curie-Paris 6, CNRS-INSU, Laboratoire d'Océanographie de Villefranche, 06230, Villefranche-sur-Mer, France
2Institute for Sustainable Development and International Relations, Sciences Po, 27 rue Saint Guillaume, F-75007 Paris, France
Abstract. Monitoring of global ocean change is necessary in coastal zones due to their physical and biological complexity. Here, we document changes in coastal carbonate chemistry at the coastal time-series station, Point B, in the NW Mediterranean Sea from 2007 through 2015 at 1 and 50 m. The rate of surface ocean acidification (−0.0028 ± 0.0003 units pHT yr−1) was faster-than-expected based on atmospheric carbon dioxide forcing alone. Changes in carbonate chemistry were predominantly driven by an increase in total dissolved inorganic carbon (CT, +2.97 ± 0.20 μmol kg−1 yr−1), > 50 % of which was buffered by a synchronous increase in total alkalinity (AT, +2.08 ± 0.19 μmol kg−1 yr−1). The increase in AT was unrelated to salinity and its cause remains to be identified. Interestingly, concurrent increases in AT and CT were most rapid from May to July. Changes at 50 m were slower compared to 1 m. It seems therefore likely that changes in coastal AT cycling via a shallow coastal process gave rise to these observations. This study exemplifies the importance of understanding coastal ocean acidification through localized biogeochemical cycling that extends beyond simple air-sea gas exchange dynamics, in order to make relevant predictions about future coastal ocean change and ecosystem function.

Citation: Kapsenberg, L., Alliouane, S., Gazeau, F., Mousseau, L., and Gattuso, J.-P.: Concomitant ocean acidification and increasing total alkalinity at a coastal site in the NW Mediterranean Sea (2007-2015), Ocean Sci. Discuss., doi:10.5194/os-2016-71, in review, 2016.
Lydia Kapsenberg et al.

Data sets

Seawater carbonate chemistry in the Bay of Villefranche, Point B (France), January 2007–December 2015
J.-P. Gattuso, S. Alliouane, and L. Mousseau
doi:10.1594/PANGAEA.727120
Lydia Kapsenberg et al.

Viewed

Total article views: 429 (including HTML, PDF, and XML)

HTML PDF XML Total Supplement BibTeX EndNote
313 96 20 429 22 8 22

Views and downloads (calculated since 13 Sep 2016)

Cumulative views and downloads (calculated since 13 Sep 2016)

Viewed (geographical distribution)

Total article views: 429 (including HTML, PDF, and XML)

Thereof 428 with geography defined and 1 with unknown origin.

Country # Views %
  • 1

Saved

Discussed

Latest update: 28 Apr 2017
Publications Copernicus
Download
Short summary
In the interest of global ocean change, weekly water samples were collected at a coastal site in the northwestern Mediterranean Sea (2007 2015). Seawater pH declined faster than expected from anthropogenic carbon dioxide increase. Total alkalinity increased, but the driver could not be identified and it may be linked to changes in freshwater chemistry of watersheds. This study highlights the importance of coastal ocean monitoring as changes may differ from trends detected in the open ocean.
In the interest of global ocean change, weekly water samples were collected at a coastal site in...
Share