Aquaculture for all

Offshore investments pay off for Scottish salmon sector

Rearing salmon out to sea in the Hebrides while gales rage in from the Atlantic? It might not be everyone’s idea of fun, but for Marine Harvest Scotland, high-energy offshore aquaculture is the new frontier in fish production. Rob Fletcher braved the waves to visit one of the company’s extreme sites off the island of Muck.

Had I seen the chilling video footage before embarking on the 16 miles from Mallaig to Marine Harvest’s site off the Isle of Muck I might not have accepted their invitation to visit.

Standing in the safety of the company’s shore base on the island I watched on the screen amazed as a grey and angry Atlantic twisted the state-of-the-art salmon pens as though they were made of overcooked spaghetti and marvelled that these were the very same pieces of plastic we had just passed on this most serene of summer’s days.

Sean Anderson and Robert Wyvill.

Muck is the flagship for the new generation of salmon farms the company has been developing on Scotland’s west coast over the last decade. It can also be one of the Marine Harvest’s toughest sites to work on. Despite being only a few hundred yards from the island’s shore, it can be subjected to exceptionally violent weather – the footage providing graphic proof that it’s not a place you’d want to be standing in a south-easterly gale.

“Since I first started with Marine Harvest in 1996 I’ve worked at virtually all the company’s sites and this is the only one I’ve ever turned back from after setting out from shore,” reflects site manager Robert Wyvill – a man who, as a native of North Uist, would have seen a bit of weather in his time.

Mercifully, on the day I visit with Sean Anderson, who was instrumental in establishing the site, we’re treated to truly Caribbean conditions, and we glide across from Mallaig over a sea of polished turquoise – the sort of day that makes fish farming seem like one of the best jobs in the world. An hour, and 16 miles later, we’re standing on what must be one of Scotland’s most spectacular workplaces – with a panoramic backdrop provided by the hills of Rum, Skye, Eigg and Ardnamurchan.

The site endures some very rough conditions. © Robert Wyvill

Although the low-lying island of Muck does shield the pens from the worst of the south-westerly storms that regularly batter the Hebrides, the site is clearly much more exposed than its counterparts tucked away in comparatively sheltered sea lochs – and there’s a fair old fetch to the mainland, nine miles to the east.

“For working on the site itself, the worst direction is anything off the east, while southerly winds are the worst for getting out of the harbour. If it’s from the west it’s fine on site, up to around 35mph, but anything above that seems to bend round the island and you get waves from both sides whilst on the barge,” Robert explains.

“It’s not just the fact that it’s so far from the mainland,” adds Sean, who is now juggling the area manager’s job with looking after the company’s fleet of mechanical de-lousing devices, “but it’s also even further from any other farm sites: our two nearest, Loch Hourn to the north and Maclean’s Nose to the south, must both be close to 20 miles away.”

Such isolation means that the crew on the site can’t rely on the rapid arrival of back-up should they encounter any problems.

“We’ve got to be pretty self-sufficient,” says Sean, “and have had to learn to adapt to the conditions; even small problems can have a major impact if we can’t get them fixed quickly ourselves.”

Thankfully Sean, who helped to set up the site and managed it for its first one-and-a-half cycles, has an impressive track record, having previously manned the first of the company’s new generation – off Hellisay in the Outer Hebrides. “Hellisay could be a wild place, and experience some serious waves,” he explains, “but for constant movement I’d say that Muck is even more extreme.”

This movement has meant that some of the standard operating procedures used on most fish farms have had to be abandoned or modified.

“You might think the feed lines here look a bit messy,” says Sean, pointing to the white tubes that snake their way to the cages in somewhat disorderly fashion, “but that’s because they kept breaking.” To stop this occurring every time the wind got feisty, he’s adapted the pipes with flexible joints to accommodate the movement – it might not be the tidiest looking, but it works.

The use of heavy-duty equipment is another element that’s needed to ensure the farm is both secure and workable – Aqualine Midgard pens, at £120,000 a pop, have been installed after the previous ones failed to hold up to the constant pressure; nets, by the same company, are weighed down with nine-tonne Froya rings to keep their tension and add to the stability of the system; ropes are thicker; and the feed barge, a 400-tonne capacity Gaelforce Seamate, contains a hulking 900 tonnes of concrete to ensure it remains safe and stable for the crew.

Despite the need for such high-end kit, and the expense this incurs, Sean is adamant that the move towards such high-energy locations is the way forward as the company seeks to increase its harvest volumes – not least because of the excellent growth rates of the fish.

“The growth’s been phenomenal,” Sean enthuses. “The average weight at the first harvest, just 46 weeks in, was nearly five kilos and the condition of the fish is fantastic – 98 percent have been ‘superior’ grade.”

He’s also impressed by how healthy the fish have been so far and he takes us to admire the remaining few thousand – which resemble blue-backed, silver-bodied submarines as they cruise round the crystal-clear water of the pen – with evident pride. The company is looking to grow these final fish on to perhaps as large as 10kg apiece, Sean explains – a size that’s currently in high demand.

“We only needed two sea lice treatments in the first cycle and one this cycle – which is pretty good for a site without cleanerfish, especially given that our treatment threshold is for as few as 0.1 adult females per salmon,” he observes.

This cycle the company has deployed lice skirts to a depth of 5.4m. These help to prevent ambient lice – which tend to inhabit the top few metres of the water column – from drifting into the pens and have, according to Sean, “made a big difference”. They have also deployed four diffusers per pen to prevent any build-up of potentially harmful algae, but he notes that this is largely precautionary, as the water quality at the site is so good.

“The sea’s about 40m deep here and is very open and oceanic – the flow through the site is incredible and we never see the same water twice, which is awesome,” he reflects.

Such good biological performance – and the prospect of generous bonuses at the end of each cycle – has clearly helped to enthuse the site crew, but the attitude of the local community towards the farm has evidently also helped persuade the farmers that they’re part of an exciting and popular project.

The view from Galllanch Lodge, on the Isle of Muck.

Community backing

Travelling up from the shore base to Gallanach Lodge it is clear that the farm is already an integral part of both the island economy and community.

“Before we applied for the site we had a consultation with the people of the island and took those interested on a tour of our nearest site – Loch Hourn. After the tour only one person raised any objections,” Sean recalls.

It’s an attitude of general approval that clearly persists, to judge by the warm welcome they are given by the island’s owner, Lawrence MacEwen, and by the exceptional lunch of locally caught shellfish and home-smoked duck and pheasant laid on by his daughter and son-in-law, Mary and Toby, who run the lodge.

And it’s little surprise that the addition of the farm has proved popular as it’s brought numerous benefits to the island’s 35 or so inhabitants. Not only do the islanders receive an income from the lease of the land required by the shore base, but it has also secured valuable steady employment for several of them – a rarity in a community in which most people need to take on several bit-part jobs to get by – as well as stopping the population from falling below critical mass, which has allowed it to sustain valuable services.

“Jobs provided by the farm have boosted numbers at the school,” says Sean. “Since Robert and the assistant manager moved full time to the island with their families it now has more pupils than any of the other primary schools in the Small Isles.”

The company has built three attractive timber-clad houses, which we pass on our way to lunch – one for Robert and his family, while the other two are used to accommodate the other workers, who operate on a two-week-on, two-week-off rota. They have installed a brand-new pontoon, and concreted over the ground by the slipway – which was previously a quagmire of rubble and mud, while there are also all manner of benefits from having the farmers, and their state-of-the-art vessels, on hand – especially in emergencies.

“The islanders have been a huge support,” reflects Sean, “and we in turn try to help them as much as possible when we can – there have been so many times we’ve taken fuel, provisions and people to and from Mallaig when the weather’s been too bad for the ferry to get in.”

It’s a great story, and a welcome contrast to the conflict with other stakeholders that that farmers have, on occasion, faced in other parts of the country. But, while there are plenty of positives to be drawn from sites such as Muck – both from a community and fish-health perspective – it is a project that hasn’t come cheap.

Hefty investments

“You can build a small house for the same price as it costs for one of the pens,” jokes David MacGillivray, Marine Harvest’s seawater manager. “We spent £5 million even before we’d put our first fish in the water, and £15 million before we’d recouped a single penny.”

This is a significant outlay, even for a company on the scale of Marine Harvest, but David explains that such hefty investments would be more appealing should such sites not be limited to holding 2,500 tonnes of fish.

“The possibility of an increase in tonnage for suitable sites, such as Muck – which are essentially like farming in the middle of the sea and can deal with large volumes of fish – is what we’ve been chasing for some time now,” he says.

The Muck site, with the island of Eigg in the background

However, he believes any future increases – an idea which has recently been endorsed by the Scottish Environmental Protection Agency (SEPA) – are likely to be incremental, as he is well aware of the challenges that larger sites pose.

“Once you hit 5,000 tonnes you need more than one barge, and probably four boats per site. Trying to treat it would be like painting the Forth Rail Bridge – you’d be going round in circles,” he points out.

Mindful of such challenges, he is looking to initially increase the capacities of sites such as Muck to 3,500 tonnes.

“We’d just need to add two new cages and deepen the nets on the existing ones to do that,” Sean explains.

Sean and David are fortunate in that they have the full backing of the company. As well as making financial support available, Marine Harvest Scotland’s MD, Ben Hadfield, has been a key proponent of the move to more exposed sites. Such endorsements have only been strengthened by the promising results from Hellisay, Muck and, most recently, Colonsay, which is over a mile from the nearest land and 25 miles from the company’s base at Craobh Haven on the mainland.

“Hellisay had a difficult first cycle and Muck had a difficult start too, but we’re improving all the time and Colonsay, which is our most remote site, and possibly the most exposed site I’ve ever visited in any country, has had an excellent first cycle,” David notes.

Although he’s not getting carried away by their performance, he sees them as having huge long-term potential – hence his willingness to support the investment of such hefty sums.

“Overall, the high-energy sites have performed somewhere near the company average, but they should become leaders in the field once we’ve fine-tuned their operation, and even more so once their tonnage increases,” he explains.

Further developments

With at least two more isolated locations – one off the northeast of Rum and one off the east of Scalpay – due to receive fish at some stage next year, the hard-won experience of the high-energy veterans is going to be essential.

“One of the biggest problems we face is finding the right people,” says David, “because of the isolation and the sea conditions, not everyone can make it – you need fit, experienced people and you almost need to cherry pick the personnel.”

On a fine summer’s day on “Muck-aluf” with the sun beating down, hefty salmon feeding happily in the turquoise waters and a classic Hebridean skyline to admire on the horizon, it’s hard to imagine that recruiting for such roles can be too testing. But recalling Robert’s film, it clearly can be a tough two-week shift for those operating on the fish farming industry’s front line.

However, if Muck is anything to go by, those who do make it, their fish and the communities that support them all seem to be thriving.

“If only I could take everyone who was against fish farming out to Muck,” David reflects, “it would make a huge difference to how the industry was perceived.”

Editor's note

This article was originally published in the Aqua Nor issue of Sustainable Aquaculture Magazine.