The Mediterranean Sea is a global hotspot of climate change, with increasingly intense and frequent marine heatwaves driving rapid ecological shifts in underwater ecosystems. Coastal ecosystems such as rocky reefs and Posidonia oceanica meadows form the foundation of marine biodiversity, supporting high species richness, ecosystem services and fisheries productivity. These habitats are characterized by slow-growing, long-lived organisms that are particularly vulnerable to thermal stress and cumulative human pressures. Climate-driven marine heatwaves increasingly affect benthic communities, highlighting the need for standardized monitoring to detect degradation and ecosystem change.
The project Climate stress on marine habitats in Kalymnos will establish a standardized baseline assessment of marine habitats within selected coastal areas of Kalymnos, focusing on rocky reefs and Posidonia oceanica meadows. Surveys will assess benthic community composition and the associated fish fauna, using non-invasive underwater visual census methods. Sampling will be conducted before and after the summer season to capture short-term ecological variation related to seasonal climate stressors and human activity. Results will identify key habitats, highlight human and environmental pressures and provide a repeatable monitoring framework to support long-term coastal ecosystem protection.
In the Aegean Sea, and particularly around Kalymnos, these coastal habitats are subject to strong seasonal pressures such as tourism, recreational boating, anchoring and recreational fishing. Overfishing and pollution further increase ecosystem vulnerability, while marine heatwaves are emerging as the dominant long-term threat, driving mass mortality events across habitats and taxa.
Despite the importance and the vulnerability of key coastal ecosystems, there is a critical lack of baseline biodiversity data which limits the implementation of effective conservation strategies. This project aims to address this gap by generating standardized baseline data on coastal biodiversity allowing the evaluation of ecosystem vulnerability.