On the tiny Hebridean island of Gigha, a 20-minute ferry hop from Tayinloan village on the Scottish mainland, Marion Stevenson drives along the only main road, pointing out white beaches and new “wilderness paths”. The Isle of Gigha Heritage Trust recently built 14 miles of the paths to encourage eco-tourism. A site in the north of the seven mile-long island has been awarded “dark skies” status – on a clear night you can see the Milky Way.
On the west coast, there are just a handful of houses, cliffs and stunning views across the sea to Jura and Islay. But it is here that Bakkafrost, a Faroese salmon company, proposes siting eight 50-metre-wide cages and a feed barge.
“It will be about 100 metres out to sea,” says Stevenson, who is the treasurer of Gigha community council but stresses that she does not speak for them, as she points past the cliffs below. “There is nothing man-made. The Vikings on Gigha looked at the same view – can’t they just leave it this way?”
On this speck of land three miles west of the Kintyre peninsula, fish farming has brought well-paid employment and even a few much-needed newcomers. But Bakkafrost’s plan to site a third farm here has divided the community-owned island.
Despite the promise of five new jobs – a significant number among a population of just 170 – a survey by the community council, a statutory consultee to all planning applications, found 61% of respondents opposed the farm.
Concerns over the proposed new site, on this most southerly of the Hebridean islands, in Argyll and Bute, are not restricted to a spoiled view. John Aitchison, the chair of Friends of the Sound of Jura, a conservation charity based in Argyll, believes warming seas could be posing a bigger threat to salmon welfare in farms in southern and western Scotland than is being acknowledged.
Examination of regional differences in mortalities, from the Scottish government’s latest data on survival rates across a whole production cycle to harvest, “rang alarm bells” for him, he says.
“South and west Scotland had worse mortality than average, with lower mortalities further north,” Aitchison says. “In 2020, there was almost 39% mortality in the Western Isles and 31% mortality in the south-west, compared with around 20% in Orkney and Shetland.”
The south-north differences could be a “glimpse into the near future”, he says.
“The Scottish government should be pausing the consenting process [for new salmon farms] while they work out what to do, instead of just pressing on,” Aitchison says.
The average water temperatures across Scotland over the past two years have not dipped below 8C (46.4F), according to Ronnie Soutar, the head of veterinary services at Scottish Sea Farms, one of the leading producers. While this did not affect salmon directly, he told a webinar in January, it affected “everything else in the sea – pathogens and parasites and other organisms that can impact on the fish”.
Warming seas spur the growth of blooms of plankton and micro-jellyfish, or hydrozoans, which sting, cut and block the fishes’ gills, killing them or aggravating other problems.
Dr Iain Berrill, the head of technical at the industry body Salmon Scotland, rejects the idea that warmer waters could be killing salmon. “Even the abnormally high water temperatures of 2023 are well within the range that Atlantic salmon can thrive in, and warmer waters can even promote faster growth.”
However, he concedes that warm waters are having an impact less directly. “It’s other naturally occurring organisms, like algal blooms and micro-jellyfish, that flourish in warmer waters and can affect the survival of our salmon.”
The industry is adopting measures including oxygenation – adding pure oxygen directly into the water –and putting larger fish in the sea to overcome the jellyfish challenge, Berrill says.
It’s easy to see why the Scottish government might not be keen to curtail the growth of salmon farms. The circles of open-pen salmon farms dotting the sea lochs and jagged shorelines of Scotland’s west coast and islands mark a success story for the aquaculture industry, the fastest-growing food production sector in the world.
Farmed salmon was the UK’s top food export in 2023. The past decade has seen Scotland’s £1.2bn aquaculture sector increase its contribution to the economy by 154% to £472m, surpassing marine fishing at £321m. For the Scottish government, which supports aquaculture within environmental limits, it also brings jobs to rural communities, directly employing 2,300 people and indirectly supporting another 10,000.
However, rising death rates have sparked concern. About one in four Scottish salmon don’t live to harvest and data from the Fish Health Inspectorate reveals a trend of mostly rising mortality levels in seawater in recent years, from just over 4m in 2020 to more than 10m last year.
Campaigners point out that one of Bakkafrost’s salmon units off Gigha, Druimyeon Bay farm, had the highest cumulative mortality of all Scotland’s active fish farms in 2023, at 82.3%, according to industry figures. It is also one of Scotland’s most southerly salmon farms.
Joe Teale, who co-runs the post office and Ardminish Stores on Gigha, acknowledges that the island’s existing two Bakkafrost salmon farms have performed poorly recently. “But they’re not alone,” he says. “In the west of Scotland, it’s a difficult time to try to promote fish farming.”
Two families of fish-farm workers have settled here in as many years, and a third farm would encourage more, he says. “The fish farms have always been an important part of this island. Jura and Islay have whisky. We had a halibut farm. There’s barely a household in Gigha that hasn’t been employed by the fish farms.”
Gigha Halibut, an award-winning land-based farm, was forced to close last year citing rising costs of energy production and “biological challenges arising from climate change”.
Tony Philpin, 70, and Jayne Millar, 70, are among the few people living on the island’s west side, in an eco-house they built on crofters’ land. Philpin, a retired teacher who has also worked on Gigha’s salmon farms, says: “There is a peregrine’s nest and out there, a porpoise migration site. It’s absolutely the wrong place [for a salmon farm].
“In winter, the winds average 20 knots. There will be between 70 and 90 days where they can’t get out to the site. On a fish farm you only need one thing to go wrong and things can spiral very quickly.”
Other objectors to the proposal, which is awaiting a decision by Argyll and Bute council, include Ariane Burgess, Green MSP for the Highlands and Islands, citing the company’s recent “appalling” mortality rate, and the Clyde Fishermen’s Association, which says the site will impact local fishers, cause pollution and increase sea lice parasites. NatureScot says it will probably have a “significant effect” on the harbour porpoise of the Inner Hebrides and the Minches special area of conservation, although mitigation is possible.
When annual marine mortalities on salmon farms were 1.6m in 2018, a fraction of what they are today, a Scottish parliamentary inquiry declared them “too high” and that no expansion should be permitted at sites with high mortality levels unless they were addressed by regulators.
On the ferry, Mark Sheldrake, a lobster fisher, says: “I’m all for local employment but I’m concerned about chemicals and I don’t like salmon being crammed into cages.”
A spokesperson from Bakkafrost Scotland says the company is committed to “listening to the local community and relevant stakeholders” and updating them on the progress of the planning process. The matters raised by NatureScot and the Clyde Fishermen’s Association have already been addressed as part of this, they added. They did not comment on the reason for the high mortality figures on their existing fish farms.
The spokesperson added that the company is developing recirculation aquaculture systems (RAS) “that ensure the optimum environment for welfare and growth during the freshwater stages to ensure less time in the higher risk marine environment” as part of its sustainability aims.
A Scottish government spokesperson said: “We expect anyone wishing to develop any fish or shellfish farm to engage appropriately and fully with the local community to hear them and take their concerns and queries on board.
“Recent analysis of data by the Scottish government indicates that regional differences in mortality cannot be explained by temperature alone and therefore do not provide a basis for regional policy development.”
The government “expects that mortality must be managed to the lowest possible level” and continues to work with the sector, vets, regulators and others to understand the causes, the impact of the climate crisis and how to address these issues.
• This article was amended on 8 March 2024. The proposed cages are 50 metres wide, with a circumference of 160 metres, not width, as an earlier version said.
