AZTI leads a project to study shark behaviour and protect the marine ecosystem in the Bay of Biscay

• 14 individuals will be monitored, and data will be collected between February and August 2024 to analyse their movements and avoid unwanted interactions with maritime and tourist practices.
• The project is supported and funded by the European Maritime, Fisheries and Aquaculture Fund of the European Union, in collaboration with the Basque Government.

17 October 2023- AZTI, a leading technology centre for marine and food research, is at the forefront of a crucial project to understand the behaviour of sharks in the Bay of Biscay, aiming to protect both these species and the marine ecosystem.

The Bay of Biscay is home to a diverse marine ecosystem in which sharks, particularly blue sharks and shortfin makos, play a key role. However, the coexistence of these species with human activities, such as fishing and tourism, can lead to undesirable interactions that contribute to altering the ecosystem’s sustainability.

To promote harmonious coexistence between these human activities and the marine species vital to the Gulf, AZTI has undertaken a shark tagging project in 2023. The main objective of this project is to study the behaviour and migrations of these sharks.

“It is important to understand the location and seasonal preferences of sharks, as this will allow us to develop management measures aimed at reducing the incidental fishing mortality of these species,” says Maite Erauskin-Extramiana, AZTI researcher and fisheries management expert.

To carry out this study, AZTI researchers are using a variety of techniques, from conventional tags, such as pieces of identifying plastic, to sophisticated satellite tags that collect data and transmit it to satellites after a certain period. Currently, 14 blue sharks, 7 females and 7 males are being monitored using conventional tags. In addition, five of these individuals are fitted with the most advanced satellite tags.

In this sense, it is important to stress that the collaboration of the fishing sector, both professional and recreational, is fundamental to the recovery of conventional tags and the reporting of sightings of tagged sharks. In fact, in the few days that the programme has been running, AZTI staff have already received some reports of sightings of tagged sharks.

Between February and August 2024, the AZTI team is expected to retrieve information from the satellite tags that will provide conclusive data on the movements and behaviour of these sharks. This in turn will allow the development of specific management measures to reduce the impact of blue shark and shortfin mako shark bycatch.

“It is important to stress that the sharks will be handled and tagged with the utmost care to ensure their welfare and survival and to obtain valuable scientific data, such as their origin, destination and migratory route,” adds the AZTI expert.

An essential tool for better management

The decline of shark populations in the oceans is an increasing concern due to their vulnerability and over-exploitation in fisheries. While conservation measures have been implemented for other marine predators such as tuna and billfish, sharks have not received the same level of attention, resulting in significant population declines and, in some cases, the complete collapse of some shark populations.

In the case of the blue shark and shortfin mako populations that visit us in the Bay of Biscay, both are regulated by the International Commission for the Conservation of Atlantic Tunas (ICCAT). The former is subject to maximum allowable catches (TACs), while shortfin tuna is banned from being kept on board due to its poor status.

The Bay of Biscay, and in particular the coast of the Basque Country, is an area where a large number of juveniles are sighted, which constitutes an area of special interest.

Shark tagging is a fundamental tool for scientific research, the protection of endangered species and the sustainable management of marine resources. It helps to conserve marine biodiversity and ensure that future generations will be able to enjoy the oceans and their wildlife.

“The presence of these species is a key indicator of the health of our marine ecosystems. Although this is a one-year pilot project, it will continue until at least the end of 2024,” says Erauskin-Extramiana.

The AZTI research centre, which enjoys local, national and international recognition, is leading this effort. Its privileged location in the area allows it to use different methodologies to address the key issues related to the presence and behaviour of sharks in the Bay of Biscay.

The initiative is supported and funded by the European Maritime, Fisheries and Aquaculture Fund of the European Union, in collaboration with the Basque Government, as well as with the support of various stakeholders in the region, such as sport fishermen, professional fishermen and the public.