Image courtesy of Tom Horton

Marine and citizen scientists take to the seas to help secure a future for Atlantic bluefin tuna in UK waters

Cefas and University of Exeter have launched a bluefin tuna tagging programme to try and find out more about the migration patterns of these enigmatic predators.

2018 represents the first year when the Centre for Environment, Fisheries and Aquaculture Science (Cefas) and the University of Exeter have run a sightings programme, asking members of the public to send in their records of Atlantic bluefin tuna. 2017 was a remarkable year for Atlantic bluefin tuna sightings and 2018 has been even more impressive.

Hannah and Duncan Jones, of Marine Discovery Penzance, a local wildlife tour operator, said: “We've already seen bluefin tuna on 45 occasions this year and our season isn’t over yet. Most of those instances have been large shoals with a mix in the size of fish, but recently most fish seen at the surface have been large. We have certainly seen more this year than ever, which has been the case every year now since 2015.”

This year, records have been sent in from the Scilly Isles, Scotland, Wales, England and even the Channel Islands and regularly detailing sightings of shoals of Atlantic bluefin tuna, hundreds of fish strong.   During the beginning of the electronic tagging programme, observers have witnessed over 100 separate Atlantic bluefin tuna feeding events. Whilst seeing these predators back in waters of the British Isles is incredibly exciting, it’s clearer now more than ever how little is known about the local ecology of these animals.

The Cefas and the University of Exeter are conducting a two-year scientific study, supported by the Department for Food, Environment and Rural Affairs (Defra) and the European Maritime and Fisheries Fund, to deploy state-of-the-art animal tracking devices to find out where Atlantic bluefin tuna in UK waters go. Scientists will work with commercial fishers, recreational anglers, wildlife watchers and NGOs to share knowledge, and to deploy around 40 satellite tracking devices. Tagging started in October, and the programme has been designed with the input and help of fishers.

The work will help scientists understand:

• where and when Atlantic bluefin tuna are found in British waters
• long-distance migrations, and where Atlantic bluefin tuna go when they are not in UK coastal waters
• where Atlantic bluefin tuna found in UK waters go to breed
• interactions between Atlantic bluefin tuna and both commercial and recreational fisheries

The information will improve knowledge on Atlantic bluefin tuna, ultimately aiding in the conservation of these remarkable animals into the future.

Following a summer in which sightings of bluefin were once again common, Dr David Righton, lead scientist on the project for Cefas, said: “This exciting collaboration will enable us to gather and share knowledge of this incredible species and uncover the role they play in UK waters. Cefas has a long history of investigating the behaviours and migrations of many species of fish, and we’re looking forward to using our expertise to address some of the fundamentally important questions that need answering about bluefin tuna.”

Dr Matthew Witt, lead scientist on the project for the University of Exeter, said: “This is a ground-breaking project for the UK and another important step towards the use of evidence-based approaches for conservation in our coastal seas. These are huge, exciting, top predators, yet with an uncertain future. We’ve already learned a huge amount about bluefin from talking to wildlife spotters and fishers who are out on the water every day. Our tagging programme will help build an even more detailed understanding at the level of individual fish. The next few years will be challenging, exciting, yet hugely revealing regards their movements and biology.”

Date: 15 November 2018