Almost all species of elasmobranchs (mainly sharks and rays) present in the Balearics are threatened, with a decline of more than 90% in the western Mediterranean compared to the beginning of the 20th century. Of the 56 species of selachians (sharks) recorded in the islands, 34 are threatened (60 %) and of these, 17 are critically endangered or already extinct in the Balearic Sea.
The data was presented today by the Director General of Fisheries, Antoni Grau, during the second of the Marine Biodiversity Conference, organised by the Marilles Foundation, directed by Aniol Esteban.
The reason for this decline is to be found, above all, “in fishing pressure that has had a serious impact on large marine predators. Added to this is the traditional bad reputation of sharks and the little fishing and scientific interest they aroused a few decades ago, until their key role in the food chain and in the balance of marine ecosystems was discovered.
The situation is changing because Balearic fish stocks have been reduced by 75% since 1986 and there is greater social awareness of the conservation of these species. Marine protected areas have also been created in recent decades, with tens of thousands of hectares, of which 4,400 are integral, but this is not enough to guarantee their conservation,” the director general pointed out.
The Marilles Foundation proposes to recover sharks in the Balearic Sea with reintroduction and less fishing pressure
Grau has indicated that “the greatest impact occurred between the 40s and 60s of the last century, with the mechanisation of fishing, but all is not lost.” The General Directorates of Fisheries and Medi Natural have launched a Balearic strategy for the conservation of sharks and rays in the Balearics, which has already held its first meeting with experts and fishermen, and which will include private collaborations. The participants in this strategy have already proposed measures relating to recreational and professional fishing, new minimum sizes, training fishermen to release sharks safely, locating areas of concentration and reproduction to establish temporary local closures, breeding and release projects, improvement and expansion of monitoring networks to have more data on their movements, and studies on biology or catches.
Agustí Torres, from Shark Med, also took part in the conference, explaining the blue shark monitoring project (diversity, presence and seasonality) that this organisation has in place through underwater filming, satellite tagging and the collection of environmental DNA samples. Torres explained that “while a few years ago 50% of blue sharks were victims of accidental fishing and many of them died of their wounds, we have detected that the situation has now changed and there is no longer such a high incidence”. However, Torres stressed that “in our monitoring of blue sharks, we have found that there is very little presence of other species of sharks”.
For his part, Biel Morey, from Save the Med, presented the study that this organisation is carrying out on the manta ray, specifically the Mobula mobular species, which is present in the Balearics. Morey indicated that “on a global level, the manta ray is critically endangered, that is, it is worse than the panda bear or the lynx, which are classified as vulnerable. The manta ray is threatened by pollution, plastics, the remains of nets and the effects of different types of fishing”.
