Southern invasions due to climate change induces reorganization of communities in the Bay of Biscay

Mrs Marie Le Marchand1,2, Dr Tarek Hattab3, Dr François Le Loc’h2, Dr Frida Ben Rais Lasram4

1France Energies Marines , Plouzané, France, 2UMR 6539 LEMAR, UBO, CNRS, IRD, Ifremer , Plouzané, France, 3MARBEC, Univ Montpellier, CNRS, Ifremer, IRD Sète, Sète, France, 4Univ. Littoral Côte d’Opale, Univ. Lille, CNRS, UMR 8187, LOG, Laboratoire d’Océanologie et de Géosciences, Wimereux, France


Species suitable habitats are shifting under climate. A flourishing literature has highlighted the tropicalisation of marine communities as a consequence of the arrival of southern thermophilic species in different ecosystems throughout the world. Future assemblages will be driven by both the movements of local species and poleward invasions. In order to evaluate the impacts of climate change on fish and cephalopod communities in the Bay of Biscay, we used a new methodological framework combining the hierarchical filters approach (global scale Bioclimatic Envelop Model and local scale habitat model), generation of pseudo absences and consideration of the third dimension of depth. We considered two IPCC scenarios (RCP2.6 and RCP8.5) and two periods (2041-2050 and 2091-2100). Results consist in future potential suitable habitats for the 163 considered species as well as in future arrivals of southern species. We aggregated these results to map changes in species richness. Results revealed that coastal areas would undergo the highest species richness loss and project a variable extinction rate of Bay of Biscay species, depending on their habitat (benthic, demersal, benthopelagic or pelagic). In addition, a high rate of southern species invasions is expected. Assessment of the species spatial turnover and based on Baselga equation showed that changes in assemblage composition are driven by both replacement and nestedness. This could lead to a major reorganization of trophic networks and may alter socio-economic components.


I am a PhD student in marine biology. My subject is the modelisation of the impacts of floatting wind turbines on marine communities. This presentation is the result of the first year of my PhD.

Similar Posts