Developing conservation approaches for elasmobranchs in the Mediterranean Sea is an urgent matter. Within Italy's monitoring program under the European Union's Marine Strategy Framework Directive (Directive, 2008/56/EC), we investigated the release of juvenile commercial species (e.g., minimum conservation reference size, MCRS) as a management strategy. From 2020 to 2023, we evaluated the vitality, At-Vessel Mortality (AVM; 4940 individuals, 22 species) and Short-Term post-capture Mortality (STM; 2 h after capture, 1099 individuals, 17 species) of elasmobranch species caught during commercial operations (trawlers and static nets) in three areas (northern Adriatic Sea, Ligurian Sea, Strait of Sicily). AVM averaged 21.3 %, while STM averaged 8 %, indicating overall high survival. To evaluate the effect of abiotic and biotic variables associated with capture mortality, data were assessed by species, gear, and area. Temperature (sea bottom and air) and time on deck were positively related to mortality and worsening vitality, and emerged as the most common and strong influences across models. While the odds of survival and physical condition decreased with body size, even smaller fish showed high survival if unfavourable deck conditions, e.g., duration and temperature, were minimized. Using only commercially collected data, this study represents the first of its kind in the area in terms of scale and scope. These data can contribute directly to the development of feasible and effective practices for managing and conserving elasmobranchs in the Mediterranean Sea.

Marine recreational fishing has significantly increased in recent years, especially in the Northern Adriatic Sea, where it accounts for equivalent up to 45% of artisanal fishery catches. Despite its relevance, few studies have investigated the potential impact of recreational fishing, particularly on vulnerable elasmobranch species, some of which are commercially targeted but face significant conservation problems. In this study, through online questionnaires administered to recreational fishers, we collected information on recreational fishing activities and their interaction with the most common demersal elasmobranchs along the western coast of the Northern Adriatic Sea. The responses revealed an intense fishing effort throughout the coastal area, especially around port entrances. The target species resulted primarily in those with high commercial value, while elasmobranchs are mostly bycatch, particularly Mustelus spp. Although 83% of fishers claimed to release them alive, the lack of studies on post-release survival rates makes it difficult to assess the impact of this fishing activity on elasmobranch populations.

Shallow submarine hydrothermal vents (i.e. <200 m depth) are unique systems that receive energy from both the Earth’s interior and sunlight, can sustain high levels of biological productivity, structure associated communities and affect surrounding ecosystems. Yet, their ecological role remains understudied compared to their deeper counterparts. In this study, we analyse the fish fauna associated to shallow hydrothermal chimneys, and to rocky and soft-sediment habitats, in areas between 45 and 90m depth with and without the influence of hydrothermal emissions in the Western Mediterranean (Aeolian volcanic arc, Italy). By comparing these conditions, we tested the hypothesis that composition and structure of fish assemblages can be shaped by the interaction between different energy inputs and the structural complexity of vent and control habitats. Our results show that hydrothermal venting was associated with marked variation in fish assemblage composition across the investigated habitat mosaic. Hydrothermal chimney fields supported assemblages broadly comparable in taxonomic and functional composition to those of structurally complex rocky habitats, whereas both differed from assemblages occurring on soft sediments. Similarly, vent- and control-soft-sediment habitats differed in assemblage composition. Vent soft sediments also showed higher observed abundance and species richness in analyses restricted to these two habitat categories. The high occurrence of meso-predators of conservation interest, like the thornback ray Raja clavata, suggests that these habitats warrant further investigation. Overall, these findings highlight the contribution of shallow hydrothermal venting for fish biodiversity and emphasize the need to expand knowledge on these neglected ecosystems to inform management and conservation strategies.