The tags are part of the BITER project, an initiative led by the ICM-CSIC in which the Polytechnic University of Catalonia - BarcelonaTech (UPC) and the University of Girona (UdG) also participate.
The Institut de Ciències del Mar (ICM-CSIC) in Barcelona has initiated the tagging of small-spotted catshark (Scyliorhinus canicula) to study their movements and dispersal capacity. This study is part of the BITER project, a coordinated initiative led by the ICM-CSIC in which the Polytechnic University of Catalonia - BarcelonaTech (UPC) and the University of Girona (UdG) also participate.
A total of 5,000 cat sharks will be tagged between Vilanova i la Geltrú (Barcelona) and Cap de Creus (Girona) as part of this project. Monitoring devices will also be installed on individuals of other species such as the conger eel (Conger conger), the white octopus (Eledone cirrhosa) or the Norway lobster (Nephrops norvegicus). Underwater robots and artificial intelligence techniques will also be used to study their movements.
The most abundant shark in the Mediterranean
The small-spotted catshark is the most abundant shark in the Mediterranean thanks to its high resistance to fishing pressure. It can reach 80 centimeters in length and feeds on a wide range of organisms, mainly crustaceans, but also fish and cephalopods. As for its distribution, it can be found between 100 and 1,500 meters depth, being more abundant between 300 and 600 meters.
"The wide distribution of the species and its high survival rate facilitate the study of its movements. This allows us to know the types of habitat through which it moves and the degree of connectivity between them," explains Joan Navarro, leading researcher of the BITER project, who points out that "the marking methodology we use is ideal for this species, since it does not affect its activity in the wild.
For his part, Antoni Sánchez-Márquez, PhD of the project, is convinced that, apart from contributing to his training as a scientist, "the results of this project will allow us to improve our knowledge and understanding of the functioning of deeper marine ecosystems, which will also help to improve their management".
In addition, the tagging will allow the identification of the degree of spatial connectivity between different marine protected areas approved by the Spanish Government in Catalonia that are located between 300 and 450 meters deep and, finally, will contribute to assess the effectiveness of these protected areas, key to the restoration of highly exploited habitats and ecosystems.
The study of movements
The individual marking of specimens allows us to know the areas where they move, the way in which they use their habitat and the patterns of movement or migratory routes, among others. However, its use in deep-sea environments is quite limited, mainly due to technical issues related to the impossibility of using conventional GPS tracking methodologies.
Given this scenario, it is important to count on the collaboration of the fishing sector, which is essential to improve the capacity of marking and tracking marine organisms. In this sense, BITER has just launched a campaign to inform fishermen of what is being done and to teach them how to identify tagged individuals. In this way, they will be able to contact scientists in case of accidental capture.