Evaluating Vulnerability and Resilience of Mediterranean Sharks, Rays and Chimaeras Through Biological and Fishery Traits

Mediterranean sharks, rays, and chimaeras face substantial conservation pressures, yet comparative regional assessments integrating life-history, ecological, and fisheries-related traits remain limited. We compiled and standardized 1634 species-specific data points for 80 species and applied a multi-criteria framework to estimate resilience (R) and vulnerability (V), followed by an Index of Resilience and Vulnerability (IRV) assessment. Based on the predefined trait framework, 46 shark, 32 ray, and 2 chimaera species were assessed. Mean R and V scores were 1.80 and 2.27 for sharks, 1.85 and 2.38 for rays, and 1.64 and 2.10 for chimaeras, respectively. Mean IRV was highest in sharks (0.17), followed by rays (0.16) and chimaeras (0.16). Across all species, R scores ranged from 1.29 to 2.57, V scores from 1.60 to 3.00, and IRV scores from 0.05 to 0.37. No species occurred in the comparatively high-resilience, low-vulnerability region of the R–V space. Several shark species exhibited particularly low IRV scores, while Dipturus nidarosiensis and D. batis showed the highest vulnerability among rays. IRV increased with R and decreased with V, as expected from the mathematical construction of the index. Comparisons with FishBase revealed broadly similar vulnerability patterns, whereas the IRV scores provided a complementary continuous perspective on species-level resilience and vulnerability. The IRV framework provides a comparative trait-based approach for regional prioritization of Mediterranean cartilaginous fishes.