CONSIDERATIONS ON THE STATUS OF ELASMOBRANCHS IN THE ITALIAN WATERS

Over thirty years of scientific cruises carried out by bottom trawl nets and a catch assessment survey allowed us to collect important information and data necessary for a better knowledge of biological features and fisheries where elasmobranch species are involved. In the Italian seas, during the national and international surveys (GRUND and MEDITS), 42 species of elasmobranchs and one of chimera were found. Through the analysis of the collected data (densities as n/km2 and biomass as kg/km2), a generally stable situation was observed for the most common species in all the FAO Geographic SubAreas (GSAs), even though all the analysed resources seem to be at quite low biomass levels in relation to pristine situations. Risk analysis through the use of natural history traits and fisheries information about all the species taken into account suggests a general low level of productivity and variable levels of susceptibility regarding bottom trawling and set gears. A preliminary a ssessment of the status of the populations was feasible only for the 4 stocks which off the Italian coasts are those more widely distributed and with better known biological features. A demographic and a yield per recruit analysis were used for preliminary definition of the status of these stocks in relation to their capacity of self-renewal. Assessments of the exploitation status were performed for (Raja asterias, R. clavata, S. canicula and G. melastomus). The assessments were done using both demographic (Leslie matrices) and Y/R analyses.