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.