Mediterranean seagrass vulnerable to regional climate warming

Journal name:
Nature Climate Change
Year published:
Published online

The Mediterranean Sea, one of the regions warming fastest under climate change1, 2, harbours lush seagrass (Posidonia oceanica) meadows that form the basis for a key ecosystem in the region3. Recent field results have shown that increased maximum annual seawater temperature in the Mediterranean has already led to increased seagrass mortality4. Here we project the trajectory of P. oceanica meadows under the warming expected in the western Mediterranean through the twenty-first century to conclude that warming will lead to the functional extinction of P. oceanica meadows by the middle of this century (year 2049±10) even under a relatively mild greenhouse-gas emissions scenario. Efforts to alleviate local stresses adding to the loss of P. oceanica meadows will have a limited effect in conserving the meadows under climate change. Efforts to mitigate climate change are urgently needed to preserve this key ecosystem.

At a glance


  1. Annual SSTmax in the Balearic Islands region projected for the twenty-first century.
    Figure 1: Annual SSTmax in the Balearic Islands region projected for the twenty-first century.

    Grey lines: the outputs of single general (AOGCMs) models; purple and blue lines, respectively: the outputs of PROTHEUS and VANIMEDAT2 (regional) models; red line: the ensemble average.

  2. Percentage of P. oceanica shoot density in the twenty-first century.
    Figure 2: Percentage of P. oceanica shoot density in the twenty-first century.

    ac, Pink line: considering warming and local impacts (a), warming but local impacts removed by 2010 (b) and warming but local impacts removed by 2030 (c). Blue lines: the projected percentage of shoot density in the absence of warming. The shadowed areas show the uncertainty ranges (estimated as the 90% of the Monte Carlo distribution).


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  1. Department of Ecology and Marine Resources, IMEDEA (CSIC-UIB), Institut Mediterrani d’Estudis Avançats, Miquel Marquès 21, 07190 Esporles (Illes Balears), Spain

    • Gabriel Jordà
  2. Department of Global Change Research, IMEDEA (CSIC-UIB), Institut Mediterrani d’Estudis Avançats, Miquel Marquès 21, 07190 Esporles (Illes Balears), Spain

    • Núria Marbà &
    • Carlos M. Duarte
  3. The UWA Oceans Institute, The University of Western Australia, 35 Stirling Highway, Crawley (Perth) 6009, Australia

    • Carlos M. Duarte


G.J., N.M. and C.M.D. conceived and designed the study, discussed the results and wrote the manuscript and Supplementary Information. G.J. wrote the code, ran the model and analysed output data.

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The authors declare no competing financial interests.

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