Elasmobranch species (rays, skates and sharks) are among the most impacted vertebrates. In the Mediterranean, more than one ray or shark species out of two is threatened with extinction, making this basin one of the most critical global hotspots for elasmobranchs. Over one third of these species are classified as threatened, while many others remain poorly studied or not yet assessed.

Elasmobranchs species play key ecological roles in maintaining the balance of marine ecosystems.

Sharks play a key role as top predators in marine ecosystems, contributing to the regulation of food webs and ecosystem balance. Some ray species also occupy important ecological positions within trophic networks and can influence seabed dynamics through their foraging activity. However, sharks and rays are increasingly threatened by multiple human pressures, primarily overfishing and bycatch, but also coastal habitat degradation, pollution and climate change. At the same time, these species remain poorly known to the general public, as scientific outreach and public engagement are still rarely integrated into research programs

A major obstacle to their protection lies in the lack of knowledge about their movements, breeding, feeding and nursery areas. Elusive, mobile and low in abundance, sharks and rays often escape conventional monitoring methods. In the absence of precise data, management and conservation measures remain partial and sometimes poorly adapted.

The Gulf of Lion and the Cerbère‑Banyuls Marine Reserve nonetheless provide a unique opportunity to address these gaps, thanks to an existing network of acoustic receivers and observations suggesting the seasonal presence of sensitive species.