The bluntnose sixgill shark : the unknown king of the deep on the Costa Brava

El País published, at the beginning of the month, news about the BOCADOLÇA Project, led by the biologist Manel Gazo, of the research group in trophic ecology and the movement of vertebrates (ECOVERT) and the Biodiversity Research Institute of Barcelona University. The news shares that the University of Barcelona has managed to mark two specimens of bluntnose sixgill shark (Hexanchus griseus) for the first time in the Mediterranean, obtaining five months of valuable information. These large sharks inhabit the seabed of the Begur canyon, on the Costa Brava, descending to a depth of 1,400 meters and ascending to a shallower depth during the night. 

This project, funded by the Barcelona Zoo Foundation and Barcelona City Council, aims to better understand the role of great deep-sea sharks in the Mediterranean marine ecosystem. Researchers have found that sharks spend most of their time between 300 and 800 meters deep, where they find the most food. 

The study has made it possible to collect geolocated data, temperature, and depth of the animals, improving knowledge about daily vertical movements, geographical displacements and their seasonality. 

This research also aims to develop a good practice protocol with fishermen to safely release accidentally caught sharks, ensuring the protection of both the animals and the fishermen. In collaboration with the fishing confraternities of Blanes, Palamós and Llançà, the researchers are working to establish a consensus on these protocols that will be sent to the entire fishing fleet affected. 

Source: RODRÍGUEZ, M. (2024) ‘El tiburón cañabota, el desconocido rey de las profundidades, reside en cañones submarinos de la Costa Brava’, EL PAÍS , 11 May. Available at: https://elpais.com/espana/catalunya/2024-05-11/el-tiburon-canabota-el-desconocido-rey-de-las-profundidades-reside-en-canones-submarinos-de-la-costa-brava.html (Accessed: 11 May 2024).