Musseling in

By Tom MortonJanuary 26th 2018

Musseling in: The £1.7 million Stepping Stone mussel hatchery project in Shetland is showing encouraging results, and land-bred spat is now at sea.

It takes three years for Mytilus Edulis, that tasty mollusc, to grow to a size where it can be eaten, satisfactorily, and it seems a straightforward process: you just put some ropes in seawater and hope for the best. Don’t you?

Well, there’s a bit more to it, says Michael Tait, owner of Shetland Mussels, which produces over 2000 tonnes of mussels each year.

“That’s what we did when we first started,” he said. “We just put ropes in all the sites to try and catch spat. But we found that if we focus our efforts in certain areas we got more success, and that’s helped in building the industry to the point where well over 6000 tones of mussels came out of Shetland last year.”

In places like Spain and Holland, mussel spat is harvested from the wild and used as seed. Commercial hatcheries for salt water mussels are rare, but things are changing. Michael chairs the Stepping Stone Project at Shetland’s NAFC Marine Centre, part of the University of the Highlands and Islands. It’s a £1.7m attempt to establish a commercial mussel hatchery for the Scottish industry, and last October the first land-bred spat were taken offshore. Through the depths of a Shetland winter, they’ve been growing, slowly.

“They’re in the sea and marginally larger than when they went in, “ said Michael. “They’ll take two more summers to get to market size.”

But this is an important step towards ensuring the industry can cope with any accident of nature in the future:

“There is easily the chance at the moment that we could have a season of very poor spat falls and that industry tonnage could come tumbling back down. So we want to be ahead of that problem, and that’s why we’re working so hard in this area. We are hoping to begin the new spawning work in March at the NAFC and will hopefully be able to improve on our survival levels and get more reliable with the process. We have been able to secure some helpful SIC funding to cover come parallel trials so we can learn faster and we are looking forward to seeing many more batches going to sea this year.”

They'll take two more summers to get to market size

Daniel Cowing is project manager for Stepping Stone, and agrees that the hatchery solution is essential to future development:

“Using hatchery spat you’re able to have a bit more continuity and a bit more control over the process.”

Funded by Highlands and Islands Enterprise, the Scottish Aquaculture Innovation Centre, the Scottish Government and the European Maritime and Fisheries Fund, the project has been running for 16 months.
“With any research and development project there’s an element of the unknown and that’s what we’ve found,” says Daniel. “We’ve certainly come a long way. We’ve learnt a lot more about the animal itself, and we keep picking up key behaviours which really seem very important in keeping the larvae developing through to the spat stage. We keep on learning and we’re very optimistic for next year.”

The project’s findings and technology will be available to the entire Scottish industry, and the end result could be the establishment of either a central Scottish hatchery or several regional ones. Adding mussel capability onto oyster hatcheries would be possible, as this technology is already widely established in the UK.

“We want to move onto the commercial scale,” says Michael, “producing sufficient seed mussels for several thousand tones of output, and a big part is having a business plan that sees this move towards a commercial solution. The Scottish Seafood Marketing Group (of which Shetland Mussels is a part) and the NAFC could be part of the solution, we don’t know yet. But ultimately the door will be open for other people to take the lessons we’ve learned on and develop them.”

Shetland Mussels started in 1997 as a diversification from the salmon farm Michael’s father had established a decade earlier. The other major mussel producer in Shetland is Blueshell, based in the North Mainland, which started in 1997 and has grown into one of the major European suppliers.

“The mussel industry in Scotland overall is getting up to around 10,000 tons a year now,” said Michael, “with Shetland doing up to 75-76 per cent of that. Our output in Shetland has been growing between five and ten percent a year over the past two decades.” And there is capacity for growth. Hopefully people would agree that it’s a pretty sustainable way of growing food.”
And the mussel hatchery project aims to add more consistency and reliability to sustainable industry
“Reliability is the key driver, it’s about resilience for the industry. And even if we only reach that step, then that’s enough, the project is a success.

University of the Highlands and Islands

Shetland Select

Blueshell Mussels

Using hatchery spat you’re able to have a bit more continuity and a bit more control over the process.

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