Harvest time has come for Scotland’s blossoming seaweed sector

But soon the long lines of ropes to which they’re attached will be hauled in, revealing for the first time just what the combination of the underwater ecosystem and a lot of patience has produced.

It’s a process which has been undertaken for centuries by seaweed farmers in the Far East: there are records of seaweed being cultivated as a crop in Tokyo Bay in the 1670s, when farmers used bamboo branches to collect seaweed spores and let the river’s nutrients encourage their growth.

These days, commercial seaweed operations in Japan, China, Indonesia, South Korea and the Philippines are responsible for around 98% of global seaweed production. In Japan alone, seaweed farming is said to be worth around $2 billion, globally the figure is $9 billion.

Hailed for its nutritional value and carbon capture properties – even as a substitute for plastics and as biofuel - seaweed has become increasingly visible to Scots and consumers around the world in sushi, savoury snacks and skincare.

Such is enthusiasm for the future of seaweed, a recent report from the Scottish Government’s Seaweed Review Steering Group to suggest what is currently a £510,000 per year sector employing 60 people, could increase substantially 2040, growing to £21.1million if food production sector continues at its current rate, or up to an impressive £71.2 million should it race ahead at a higher rate along with increases in the biotechnology sector’s use of seaweed.

Stove, currently counting down the days until it is time to harvest Seaweed Farming Scotland’s crop, is enthusiastic for Scotland’s future as a seaweed producer.

However, he is a little less convinced that we are on the cusp of a kelp klondike gold rush moment.

Seaweed farming is unlikely to make anybody very rich very fast, he says.

“There has been a lot of hype about seaweed,” he cautions. “A lot of money is pouring into it, and a lot of parallels are being made between seaweed farms and mussel farms. But there’s not been a new mussel farm in Scotland for ten years because the return on investment takes a long time.

“I’m a fan of rope grown Scottish seaweed,” he stresses, “but it’s never going to be the next whisky or the next big renewable product. We would be doing well to get the same size of the mussel industry.”

Comparisons with other sectors may be wishful thinking. He continues: “To use seaweed as a replacement product for plastic, for example, you would need enormous quantities.

“What we grow in Scotland is seasonal, you have an annual crop that doesn’t lead to high volume market.

“Everyone sees seaweed as something you can do many things with but realistically if you are farming it rope grown, like mussels, you have some significant costs at the start and ongoing operational costs. The margins are tight.”

Nevertheless, seaweed – which once sustained starving islanders during famines and which has been foraged for centuries – the monks of Iona are said to have collected dulse from the rocks - is entering a new era.

On the Ross of Mull, community-run Aird Fada Seaweed Farm has just been handed £67,000 funding from the Argyll and Bute Infrastructure Fund to develop onshore seaweed processing facilities at Bendoran, where it hopes to freeze and dry its crop.

The community venture received European Maritime and Fisheries Fund support last summer to create the onshore infrastructure it needed and to lay 6km of seeded line, around a third of the capacity of the farm.

It, too, is preparing for a springtime seaweed harvest – the community expects to haul up at least 20 tonnes of sugar kelp from the six-hectare farm in Loch Scridain, the country’s only community run seaweed farm.

The community farm, part of South West Mull & Iona Development, highlights the economic and environmental benefits of their crop: a project officer’s job has been created, the farm has led to sub-contract opportunities with members of the local fishing fleet and there are roles for fishermen for seeding, maintenance and harvesting.

“The first year of harvesting will fund next year’s seeding, with the aim of increasing capacity year on year to create a profit-making business,” the group says. Profits generated by Aird Fada will be re-invested in the farm or other community benefit projects.

The farm group point to the carbon capture benefits of growing seaweed, while farming is seen as a way to protect wild stocks. “By farming kelp,” they add, “we prevent the need to harvest from wild forests.”

Innovations within the sector have also received support: the Pebble Trust, which supports sustainable initiatives and projects, has recently provided funds for the development of a prototype solar-powered seaweed dryer which would enable small kelp producers to dry seaweed sustainably.

And while the Scottish seafood sector may currently be small, it is becoming increasingly visible.

Wick-based Shore uses hand-picked seaweed from the northeast coastline to create award-winning seaweed crisps, while Edinburgh-based Mara Seaweed, which produces seaweed flakes and seasonings, has recently received £600,000 of Scottish Government funding to increase its processing facility in Fife and explore new markets.

Owen Stevens, chair of the Scottish Seaweed Industry Association says: “The industry at the moment is what I’d describe as ‘nescient’, and probably equates to salmon farming in the 1970s, where it is pioneering and moving from being a backyard venture to the beginnings of an industry.

“In the past, seaweed had a wide range of uses but it fell out of favour. We are now revisiting the whole story of seaweed and doing it in a way that makes sense to our modern palates.

“It is a really exciting new sector of agriculture that is just developing.

“It’s well behind salmon and shellfish by quite some distance, but with the right investment and encouragement, it will get there.”

In the waters off Oban, Stove is hopeful of a bumper harvest. His farm, which spans 500 hectares of which just a fraction is currently used, has secured an order for 50 tonnes of wet weight seaweed – which will shrink to between five and ten tonnes once dried.

“The harvest only lasts from the end of March to the end of May, that’s just eight weeks as a fresh product, and then you have to freeze dry it or dry it into flakes. As a crop, it’s a relatively short harvest,” he adds.

“It’s no fast buck, it’s a long-term farming. Look how long it took to establish salmon and mussels, there’s a place for a sustainable seaweed industry but it won’t happen overnight, it will take years to build up.”