Multidisciplinary approach to assess potential risk of mortality of benthic ecosystems facing climate change in the NW Mediterranean Sea

Climate change by the end of the 21
^st
century is expected to induce great changes of coastal benthic ecosystems at the sub-regional scale in the North Western Mediterranean Sea. In order to assess the impact of the expected warming, we developed a strategy for the definition of warming scenarios in coastal habitats and their potential sub-lethal to lethal impacts on key benthic species. This was achieved by combining numerical simulations under IPCC-A2 scenario with field observations and thermo-tolerance experiments. First, a model validation was conducted for the period 2001–2008 in contrasted coastal areas. Then, scenarios forecast run temperature outputs were analyzed in order to explore the expected changes in the stratification by the end of the 21
^st
century. These simulations were used together with species spatial distribution and thermo-tolerance functions to explore the potential risk of temperature induced mortality for the red gorgonian Paramuricea clavata, considered a key-species in coastal Mediterranean ecosystems, by the end of the century.