Climate change fragments Mediterranean seagrasses landscapes: a regional analysis

Seagrasses meadows represent a key habitat of the Mediterranean Sea, since they host a significant biodiversity. Projected changes in seagrasses distributions driven, for instance, by climate change, could dramatically alter the structure of the Mediterranean seascape, with relevant cascading effects on the biodiversity of the basin. In this work, first we combined post-processed COPERNICUS-CMEMS physical and biogeochemical variables and seagrasses occurrences from the Ocean Biodiversity Information System (OBIS) to setup Species Distribution Models (SDMs) for Posidonia Oceanica and Cymodocea nodosa: two dominant mediterranean seagrasses. Then, future changes in their distribution along the 21st century using high resolution physical and biogeochemical projections under two Representative Concentration Pathways (RCP), namely 4.5 and 8.5, have been assessed. In particular, the future changes in the range contraction and distances between suitable habitat patches have been estimated. A significant change in both quantities was detected. The potential implication of an increased fragmentation for metapopulations and metacommunities relying on this habitat is discussed.