My 13-hour trip in the North Atlantic witnessing Scotland's role in the UK bluefin tuna story

On board Harmony, Angus Campbell's fishing vessel based in Harris | Katharine Hay

I hopped on board a fishing vessel at 6am to a scientist winding up a fisherman by waving a banana skin in his face.

Bananas on a boat, according to some fishermen, bring bad luck. Women too, but apparently we are okay now “because the world’s moved on a bit.”

He responded to the playful gesture saying: “We need all the luck we can get.”

The sun came out as the day out looking for bluefin came to an end | Katharine Hay

I later understood why.

The crew of fishermen and scientists I joined had already been out at sea for about a week in the Outer Hebrides looking for bluefin tuna, but to no avail.

The species of fish has made a comeback to UK waters over the last decade since disappearing in the 1990s.

While the UK has sanctioned recreational catch and release, the UK Government said there is currently not a catch and release recreational fishery in Scotland. | Supplied

So much that this year saw the UK’s first ever catch-and-release bluefin tuna tournament held in Cornwall.

The UK Government has sanctioned a catch and release fishery for anglers, and there is also a gradual move to fish for bluefin commercially again, which are heavily sought after in Japan.

Last year, ministers gave the greenlight for some fishing boats to be given one year-long commercial licenses as part of a trial to evaluate the sustainability of a small scale bluefin tuna fishery.

One of those included skipper Angus Campbell, from Harris, who was the only fisherman in Scotland to be awarded one.

This year, just 13 British fishing vessels were given permission to catch a maximum of 39 tonnes of bluefin between them - some can weigh up to 600kg.

Mr Campbell didn’t make the cut a second time round, nor did any boats in Scotland to his knowledge, but he said he hopes to try again next year.

“The application process isn’t straightforward,” he said.

“Just because you get it one year doesn’t mean you get it the next.”

Skipper Angus Campbell, fisherman Andy Bolt, and associate professor in biology at the University of Exeter Dr Lucy Hawkes aboard Harmony near St Kilda | Katharine Hay

In the meantime, he continues to fish with a permit to catch, tag and release the species for research purposes.

While the UK has seen a resurgence in numbers, Scotland, according to scientists, is “the missing piece in the puzzle of bluefin tuna research.”

Tracking attempts have happened in the last decade, but nothing substantial enough to establish the migration route of the group of Atlantic bluefin found in Scottish waters, which researchers said are different to their peers in the south.

Preparing the rods to catch bluefin tuna from Angus Campbell's fishing vessel under a catch tag and release permit for research | Katharine Hay

I spent 13 hours at sea with Mr Campbell and his crew, including Dr Lucy Hawkes, associate professor in biology at Exeter University, on the last day of their expedition attempting to tag one.

They were nowhere to be seen.

Despite some reaching more than 3m in length and their ability to leap 3m above the surface when feeding, the deep, blue blanket of the North Atlantic Ocean kept these enormous torpedo-shaped fish with shimmering tinfoil-like bellies well hidden during our odyssey. 

I was a little gutted. Watching bluefin feed is often referred to as one of nature’s greatest spectacles.

Andy Bolt, a fisherman from Devon who was on board, said during the season between August and December in the south-west of England, schools of these marine monsters feeding is a regular sight. Because of the higher concentration of fishing boats in the area, there are more pairs of eyes on the sea, making tracing them a lot easier.

But the day spent on Harmony, Mr Campbell’s fishing vessel, involved stalking gannets in blustery weather in the hope they would start diving to give us clues as to where fish could be. We were instead met with a few judgemental looks from their piercing opal-coloured eyes at the fruitless task at hand.

The experience showed how different the story is in Scotland when we talk bluefin.

For a start, the fish found in Scottish waters appear to have a different migration route to the fish tagged in England and Wales, which only venture as far north as English channel and Celtic sea.

In between short breaks to calm the nausea - the swells were something else on the rainy October day - Dr Hawkes, who is one of the leading scientists with Thunnus UK, a collaboration researching the ecology of bluefin, said: “I have no idea really where these fish come from or where they go to.

“We’ve been tracking them in England, Wales and Jersey in the Channel Islands for the last seven years, but we’ve not tracked them here in Scotland.

“They are also, on average, about half a metre bigger. The biggest fish that have been caught here have been over 3m long that can weigh over 400kg, so nearly half a tonne.”

Thunnus UK research showing the annual migration of successfully tagged bluefin | Thunnus UK

Because of their bigger size, Dr Hawkes explained they can go into colder water, and could therefore venture as far as Iceland and over into the North Sea.

“We know you get very big bluefin tuna in Sweden, Denmark and Norway, and these tuna may be the same ones people have seen over there, but we just don’t know.

“Scotland is really the missing part of the puzzle in UK tuna research.”

There is also the added challenge of the location when it comes to looking for the fish this far north.

Not only can the weather off the Outer Hebridean coast interrupt days of fishing more often compared to fleets on the southern coast of England - Dr Hawkes’ team had to finish their trip early due to a storm forecast - but Mr Campbell is one of just a handful of fishermen scanning the area where you’re likely to spot them.

While bobbing on Harmony near the cliffs of St Kilda, some 40 miles out at sea, Mr Campbell said: “It’s really just me out here looking for them at the moment.”

He said the bluefin are there, and showed us several sites where he had more luck before, but just one or two active crow’s nests on the lookout for bluefin means expeditions in Scotland often require a bit more patience, and luck.

“That’s fishing for you,” Mr Campbell said.