SUBMON has joined a team of marine biologists from up to 11 countries of the Mediterranean, that has set up a regional initiative to compile information about the population trend of Bluntonse sixgill shark relying on local fishermen.

Interest in shark conservation has substantially increased worldwide over the last decades. Underpinned by a constant flow of findings concerning the biology of many shark species, their role in the environment and their importance for fisheries as a commercial resource, various conservationist initiatives have emerged with the aim of engaging countries in guaranteeing the sustainability and protection of shark populations against their current threats.

Despite being considered a biodiversity hot-spot for elasmobranchs, the Mediterranean Sea is also home to the highest proportion of threatened species due to unregulated fishing. In a report published in 2016 by the IUCN, 39 of the 73 assessed species of sharks and rays in the Mediterranean were found to be regionally threatened and overfishing was acknowledged as the main driver of decline and local extinction.

The Bluntonse sixgill shark (Hexanchus griseus) is a common shark in the Mediterranean and it is the biggest member of its family (reaching up to more than 5 meters). It’s a predominantly commercial deep-water species which can be found at depths of up to 2500m and is accidentally taken by both bottom and mid-water trawlers but also gillnets, trammel nets, longline, hand lines and traps. Although H. griseus has been assessed as “Least Concern” in the Mediterranean by the IUCN, the fact that the species can get caught by diverse fishing gears and, in addition, not counting on any form of legal protection makes monitoring its population trend important for ensuring its preservation, especially under the current degree of fishing pressure.

SUBMON is part of the team of marine biologists from up to 11 countries of the Mediterranean (Spain, Algeria, France, Italy, Libya, Tunisia, Montenegro, Albania, Greece, Israel and Cyprus) that has set up a regional initiative to compile systematic information about the population trend of H.griseus relying on local fishermen and their impressions. Even though its latest assessment kept it out of threat, our aim is to detect whether the species is showing some signs of population dwindling in any of the studied regions given that fishing pressure in the Mediterranean has done nothing but increase.

This project is funded by the Shark Foundation.