The 3-metre tuna is lifted from the net pen at Marine Harvest's farm at Colonsay. Photo: Marine Harvest

Tuna released after torpedoing through net pen

Marine Harvest staff off the Hebridean island of Colonsay have rescued a 300kg (47-stone) Pacific blue fin tuna after it "torpedoed" into one of their salmon pens.

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The fish farmers said they were stunned to see the fish, which is normally associated with the warmer waters of the Pacific, according to a report by the BBC.

They said they spotted the 3m-long tuna after noticing "a feeding frenzy" near their salmon enclosures.

The fish was eventually caught using a net and crane and returned to the sea.

'Feeding frenzy'

Farm manager Ali Geddes said: "We'd noticed a lot of activity around the southern part of the farm - there seemed to be a real feeding frenzy going on with the dolphins and porpoises.

"It's now clear they were chasing a tuna. These things can move at real speed - up to 50mph - and it seems to have burst through the foot of the pen like a torpedo.

"Thankfully the tuna seems to be unhurt and none of our own fish have escaped. They are very small at this stage – the site has only recently been stocked with smolts which tend to swim towards the top of the pens away from the base.

"The hole the tuna made was more like a slash than a round hole and we called in divers who repaired it within a few hours."

Prefer warmer waters

Atlantic blue fin tuna are common in Scottish waters, but Pacific blue fin tuna are rare because of their preference for the warmer waters of the North and South Pacific oceans.

The salmon farmers used a panel net, normally used during harvesting to allow smaller fish to swim through the gaps, to contain the huge tuna.

A crane was then used to lift the fish into a large basket before it was released into the open sea before swimming away.

Ben Hadfield, managing director of Marine Harvest Scotland, said: "It's testament to their skills that this beautiful fish is still alive and well.

“They’re skilled in handling fish but our salmon grow to about five kilos in size, so this was well beyond the norm. We believe it was a whacking 300 kilos, which is more than 47 stone.”

Marine Harvest’s salmon farm at Colonsay has 12 pens, each 120m in diameter. Ten people are employed at the farm, including the manager.

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