Atlantic bluefin tuna: One of world's most expensive fish may have returned to UK waters in part due to warming seas, scientists say

·3-min read

Government scientists say one of the world's biggest and most expensive fish may have returned to UK waters in part due to rising sea temperatures.

Fishermen in Cornwall have teamed up with scientists to study Atlantic bluefin tuna, which have returned to seas off the south and south west coast of England after more than 60 years.

Fifteen skippers are working with The Centre for Environment, Fisheries and Aquaculture Science (CEFAS) to catch, tag and release the fish, which can grow up to 12ft in length.

"We need to know what's going on, we need to know the numbers, where they are, how many are there, the age structure, as much as we can get really," says Jo Ford, operations manager for the study.

Catching bluefin tuna is banned in the UK. For the first time, the government has been given a quota from The International Commission for the Conservation of Atlantic Tunas (ICCAT), in part to allow a three-month study of the fish to take place.

The study allows skippers to take paying recreational anglers out to catch bluefin tuna, before the fish is measured, tagged and released again.

Sky News was given exclusive access to the study, which has so far seen 100 fish tagged.

Ms Ford said: "It's brilliant. It's immense. We've got 15 vessels out here all catching and tagging these fish in British waters. It's the stuff of dreams.

"For Cornwall and Devon and the South coast where these [fish] are in some numbers now, we think, it's important. This is an important apex predator species. It's a big fish. The size range so far is 150cm to over 250cm fish."

Atlantic bluefin tuna are among the most sought-after gamefish in the world and are worth thousands of pounds.

In 2015, the fish went from 'endangered' to 'near threatened', reflecting an improvement in stock.

One reason for the return of the migratory fish to UK waters could be rising sea temperatures, according to Sophy Phillips, a senior fisheries scientist at CEFAS, who said: "There used to be a strong recreational business in the 1930s. In 2014 we started to see them again. We don't know why.

"One of the factors could be climate factors - increase water temperatures, an increase in numbers and distribution of bait fish or other factors which are as yet un-known, and these uncertainties is why we need a research programme like CHART (Catch and Release Tagging Programme) to help us get the data to understand why they are back," she added.

The CHART programme, funded by DEFRA, started in August and runs until November.

Sky News joined one of the official tagging trips setting off from Mevagissey in Cornwall.

The skipper, Chris Gill of Aquila Sports Fishing, hopes the study will lead to legalising fishing of bluefin tuna for sport and eventually commercial fishing, bringing an economic boost to coastal communities.

He said: "This season I'm running right into the middle of November so it's stretched out another two or three months - you've got all the B&Bs, pubs, restaurants…overall it's massive for the county and the country."

"I've got a commercial licence and many places around the world catch these commercially. They go on the market and they are sold. My aim in the future is to have that for the West Country and for the UK. It would be beneficial to me to have customers on the boat and occasionally sell one or two of the fish a week as a bonus," he added.

Recreational angler John Mayer, who'd travelled to Cornwall with his son from Coventry to join the trip, said: "It's the first time I've ever caught a bluefin tuna.

"It's brilliant, absolutely brilliant, and to do it in British waters is something I thought I'd never do."

Our goal is to create a safe and engaging place for users to connect over interests and passions. In order to improve our community experience, we are temporarily suspending article commenting