Palma, Feb 18 (EFE).- The Balearic Islands Fauna Recovery Consortium (Cofib) has started the first and most complete study on the islands on the populations of some endangered species of elasmobranchs in the archipelago and in the Mediterranean, the stingray twine (Rostroraja alba) and the mantelina or butterfly ray (Gymnura altavela).
The so-called “Rajibal” project has an expected duration of 4 years and its main objective is to improve the information available on these species in order to improve their conservation status, the Ministry of Environment and Territory has reported in a statement.
The study focuses mainly on these two protected species that are highly threatened, the twine skate and the mantenline, but the researchers do not rule out the possibility of including other elasmobranchs in the project.
Until now, only the data collected in the “MEDITS” campaigns of the Spanish Institute of Oceanography (IEO), the “DAPERA” program of the Government and the sightings collected in different citizen science platforms, such as “Observadores del Mar” and “Observadores del Mar” and “The Meco Project”. This information has been very useful to be able to detect in which areas its presence has been evidenced and thus be able to delimit the study area with foundation.
Based on this information, campaigns are being carried out at sea to obtain new records and obtain samples for analysis.
In relation to the twine ray, COFIB relies on the collaboration of the fishermen who fish in the areas of interest, so that they provide data in the event of accidental capture and to carry out campaigns on board their vessels to record and sample possible catches.
Regarding the butterfly ray, underwater transects are being carried out by diving to record new sightings and, if possible, to sample some specimens.
In addition, a remote-controlled underwater vehicle will be used to study and better understand the types of seabed where these species are found.
At the same time, throughout the project, the importance of sharing sightings will continue to be disseminated through citizen science platforms or from the diving centers themselves, where informative material has been distributed.
You can also report sightings of the twine ray (Rostroraja alba) or the butterfly ray (Gymnura altavela) by email at [email protected] or by calling 625 03 77 22, always trying to attach a photograph.
With the combination of these methodologies, and with the collaboration of fishermen and citizens, the aim is to better understand the habitat of these species and what use they make during the year, as well as to expand the information on their biology and behavior.
The results obtained will be very useful to assess the status of their populations and design possible conservation strategies if considered appropriate.
Sharks and rays are the most threatened group of fish, since, according to reports from the International Union for Conservation of Nature (IUCN), more than half of their species are in danger of extinction, both in the Mediterranean Sea as in the Balearic Sea.
These animals are of great importance within the balance of marine ecosystems, but their low resilience makes them very vulnerable to environmental factors and anthropogenic impacts, and for this reason it is essential to take measures for their conservation.
The twine ray (Rostroraja dawn) is a ray that can measure more than 2 meters in length, and feeds on fish, cephalopods and crustaceans. It is a benthic species, often found on sandy bottoms, between 10 and 500 meters deep.
The butterfly ray (Gymnura altavela) can measure more than 2 meters in width and feeds on fish, crustaceans and mollusks. It inhabits sandy or muddy bottoms but in shallower waters, not exceeding 150 meters deep.
Both are affected by artisanal and trawling, are protected in Spain and listed as endangered and critically endangered species in the Mediterranean, respectively, by the IUCN Red List.