From past to future: exploring tools for the study of sharks’ populations of the Mediterranean Sea

Shark conservation must become one of the priorities for several biodiversity hotspots of the world, including the Mediterranean Sea, where the decline of the populations has been documented for several species of large predatory sharks and urgent measures need to take place. The major threats that sharks are facing in the area and identified by the IUCN are bycatch, pollution, habitat loss, habitat degradation, and human disturbance. The life-history traits of most of the shark species (late maturity and low fecundity) are also factors that aggravate the effects of these threats. In the Mediterranean Sea live nearly fifty species of sharks. In the 2016 IUCN regional assessment of the Mediterranean Sea, 57% of the species in the area are considered as threatened and 25% are listed as data deficient, which means that there is a lack of data to assess the local status of their populations. One of the most common and widespread problem in making assessments and consequential protection measures on sharks worldwide, but especially in the Mediterranean Sea, is the lack of data. Scientific campaigns and fisheries information seems not to have enough observation effort to collect data on large sharks, and especially for those species that inhabit high seas. Sharks seem to be at present time one of the rarest and elusive species in the area and new strategies need to take place. In that view, both historical ecology and genetics, as well as Citizen Science could be important tools for supporting data collection and try to make a clearer picture of the historical and present situation in terms of conservation of several species in the area. This work put in light how the integration and coordination of different scientific fields and expertise can efficiently contribute to researches on sharks, one of the most iconic and endangered group of animals in the world, providing important outcomes to improve conservation actions.

La conservazione degli squali deve diventare una delle priorità per diversi hotspot di biodiversità del mondo, tra cui il Mar Mediterraneo, dove è stato documentato il declino delle popolazioni per diverse specie di grandi squali predatori e devono essere adottate misure urgenti. Le principali minacce che gli squali stanno affrontando nell'area e identificate dalla IUCN sono le catture accessorie, l'inquinamento, la perdita di habitat, il degrado dell'habitat e il disturbo umano.