Ocean acidification (OA) is a serious consequence of climate change with complex organism-to-ecosystem effects that have been observed through field observations but are mainly derived from experimental studies. Although OA trends and the resulting biological impacts are likely exacerbated in the semi-enclosed and highly populated Mediterranean Sea, some fundamental knowledge gaps still exist. These gaps are at tributed to both the uneven capacity for OA research that exists between Mediterranean countries, as well as to the subtle and long-term biological, physical and chemical interactions that define OA impacts. In this paper, we systematically analyzed the different aspects of OA research in the Mediterranean region based on two sources: the United Nation’s International Atomic Energy Agency’s (IAEA) Ocean Acidification International Coordination Center (OA-ICC) database, and an extensive survey. Our analysis shows that 1) there is an uneven geographic capacity in OA research, and illustrates that both the Algero-Provencal and Ionian sub-basins are currently the least studied Mediterranean areas, 2) the carbonate system is still poorly quantified in coastal zones, and long-term time-series are still sparse across the Mediterranean Sea, which is a challenge for studying its variability and assessing coastal OA trends, 3) the most studied groups of organisms are autotrophs (algae, phanerogams, phytoplankton), mollusks, and corals, while microbes, small mollusks (mainly pteropods), and sponges are among the least studied, 4) there is an overall paucity in socio-economic, paleontological, and modeling studies in the Mediterranean Sea, and 5) in spite of general resource availability and the agreement for improved and coordinated OA governance, there is a lack of consistent OA policies in the Mediterranean Sea. In addition to highlighting the current status, trends and gaps of OA research, this work also provides recommendations, based on both our literature assessment and a survey that targeted the Mediterranean OA scientific community. In light of the ongoing 2021-2030 United Nations Decade of Ocean Science for Sustainable Development, this work might provide a guideline to close gaps of knowledge in the Mediterranean OA research.

Primary Presenter: Abed El Rahman Hassoun, GEOMAR Helmholtz Centre for Ocean Research Kiel (ahassoun@geomar.de)

Authors:

Abed El Rahman Hassoun, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany and National Centre for Marine Sciences, National Council for Scientific Research in Lebanon (CNRS-L), Beirut, Lebanon  (ahassoun@geomar.de)

Ashley Bantelman, IAEA International Atomic Energy Agency, Monaco  (a.bantelman@iaea.org)

Donata Canu, National Institute of Oceanography and Applied Geophysics-OGS, Trieste, Italy  (dcanu@ogs.it)

Steeve Comeau, Laboratoire d'Océanographie de Villefranche, CNRS and Sorbonne Université, Villefranche sur Mer Msida, France  (steeve.comeau@imev-mer.fr)

Charles Galdies, Institute of Earth Systems, University of Malta, Msida, Malta  (charles.galdies@um.edu.mt)

Jean-Pierre Gattuso, Laboratoire d'Océanographie de Villefranche, CNRS and Sorbonne Université, Villefranche sur Mer Msida, France and Institute for Sustainable Development and International Relations, Sciences Po, Paris, France  (jean-pierre.gattuso@imev-mer.fr)

Michele Giani, National Institute of Oceanography and Applied Geophysics-OGS, Trieste, Italy  (mgiani@ogs.it)

Michaël Grelaud, Institute of Environmental Science and Technology (ICTA-UAB), Universitat Autònoma de Barcelona, Barcelona, Spain  (michael.grelaud@uab.cat)

Iris Hendriks, Mediterranean Institute for Advanced Studies (IMEDEA - CSIC-UIB), Esporles, Spain  (iris@imedea.uib-csic.es)

Valeria Ibello, Middle East Technical University, Institute of Marine Sciences (METU-IMS), Mersin, Turkey  (valeria.ibello@ims.metu.edu.tr)

Mohammed Idrissi, Oceanography Department, Institut National de Recherche Halieutique (INRH), Casablanca, Morocco  (idrissi.inrh@gmail.com)

Evangelia Krasakopoulou, University of the Aegean, Department of Marine Sciences, University Hill, Mytilene, Greece  (ekras@aegean.gr)

Nayrah Shaltout, Marine Chemistry Lab, Marine Environment Division, National Institute of Oceanography and Fisheries, Cairo, Egypt  (nshaltout@gmail.com)

Cosimo Solidoro, National Institute of Oceanography and Applied Geophysics-OGS, National Institute of Oceanography and Applied Geophysics-OGS, Trieste, Italy and ICTP, International Centre for Theoretical Physic, Trieste, Italy  (csolidoro@ogs.it)

Peter Swarzenski, IAEA International Atomic Energy Agency, Monaco, Monaco  (pswarzen@usgs.gov)

Patrizia Ziveri, Institute of Environmental Science and Technology (ICTA-UAB), Universitat Autònoma de Barcelona, Barcelona, Spain and Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain  (patrizia.ziveri@uab.cat)