Mediterranean benthic ecosystems in the face of the heat waves

Coastal benthic ecosystems are the most productive and diverse marine ecosystems, harbouring important ecological and socioeconomical services. They are characterized by the presence of habitat-forming species such as corals, seagrasses and macroalgae, which transform their environment with their structure, providing a habitat for many organisms. Unfortunately, they are subjected to high human pressure. Historically the Mediterranean Sea has been one of the most impacted regions and is currently considered a hotspot of climate change, with a higher warming rate than the rest of the oceans. Marine heatwaves are becoming more frequent, threatening the structure and functioning of our sea. Coralligenous communities are one of the Mediterranean habitats most affected by these extreme climatic events because they are dominated by calcareous algae and sessile macroinvertebrates with slow population dynamics, making them particularly vulnerable to disturbances. The most exemplary case of this phenomenon is that of gorgonian-dominated coralligenous communities, which form dense underwater forests that have lost 80% of their biomass as a result of recurrent marine heatwaves. The consequences of these heatwaves can be catastrophic, because the loss of habitat-forming species can lead to the collapse of ecosystems and the services they support. Therefore, it is more necessary than ever to delve deeper into the sea to detect these impacts and to act urgently to curb the causes of climate change.