MARFOR-SPOT

MarFor-SPOT is a project focused on the conservation of macroalgal forests, key marine ecosystems. Macroalgal forests of Cystoseira sensu lato are some of the most productive and biodiverse ecosystems in the Mediterranean Sea. For this reason, most Cystoseira species have been included in different conservation priority lists. Due to anthropogenic and natural stressors, such as pollution, habitat destruction and climate change, marine forests have been largely lost or have been poorly preserved in many areas of the Mediterranean Sea, including the French Riviera. However, their distribution, ecology, conservation status, and the stressors potentially affecting them are still poorly known. In recent decades, severe decline of Cystoseira species has been reported in the French Rivera. In 2022, we mapped the shallow Cystoseira populations along the coastline of Saint Honorat Island, (Natura2000 Site). We found 13 Cystoseira species, highlighting that Saint Honorat is an unexpected biodiversity hotspot in the French Riviera, a highly urbanized region. Some of the species were not previously documented and can no longer be found in other parts of the region. We combined traditional visual census with aerial surveys (drones), to obtain high-resolution georeferenced images that will be used for future monitoring of these important habitats. Drawing on this data, MarFor-SPOT aims at 1) improving the existing distributional and ecological data, 2) evaluating the effects of anthropogenic stressors, and 3) providing management tools for conservation and restoration actions based on new technologies. As performed in Saint Honorat, detailed traditional visual census and aerial surveys will be performed in Saint Marguerite Island and the continental zones of Cap d’Antibes and Cap Ferrat (two different Natura2000 Sites), to provide an accurate baseline map of Cystoseira distribution and conversation status. Given the Mediterranean Sea's vulnerability to climate change, temperature loggers will be deployed in some populations to assess the effects of climate change.

Results obtained in MarFor-SPOT will provide important information on the distribution of Cystoseira species (mapping), their conservation status (anthropogenic stressors) and their sensitivity to climate change (temperature loggers). All this information will represent a baseline for setting up long-term monitoring that will allow a better understanding of the effects of anthropogenic stressors on these essential coastal habitats. The interdisciplinary nature of this project lies in its combination of biology, ecology, geospatial science, traditional methodologies, and new technologies, which allows for a comprehensive approach to study Mediterranean biodiversity and its response to various stressors.