Mussels to play key part in Scotland’s aqua sector growth

Scotland has just launched an ambitious Vision 2030 growth strategy for aquaculture, to double the size of the sector to GBP 3.6 billion (USD 4.5 billion, EUR 4.2 billion) by 2030.

The strategy seeks to unleash the sector’s full potential contribution to Scotland’s economy, environment and communities, and predicts the generation of more than 9,000 new jobs.

Mussels already play a key and growing part in the sector, but research has shown that if all current lease sites were farmed at capacity, then production could double within a few years. Further expansion into new sites could see it treble by 2030 to around 21,000 metric tons per year.

However, one major barrier to growth has been identified as an unpredictable supply of mussel juveniles, known as spat. To address this, a two-year research and innovation project, known as Stepping Stone, is underway to test the commercial viability of a Scottish mussel hatchery.

Taking place at the NAFC Marine Centre on Shetland, part of the University of the Highlands and Islands (UHI), the multi-partner project recently saw completion of its core infrastructure. With algal culture, water treatment facilities and tank room resources for spawning, incubation and grow-out in place, the first batch of hatchery-reared spat has finally been produced.

According to Gregg Arthur, Aquaculture Manager at NAFC UHI, discussions have been ongoing for more than a decade about the pros and cons of a mussel hatchery.

“We all agreed that the pros included the ability to undertake selective breeding, extend the growth calendar, improve efficiency and biosecurity on farms, and increase the certainty of having mussel spat. However, for a long time the cons outweighed the pros, including the uncertainty of how well the spat would be transferred and retained on ropes, and particularly the issue of investment and the need to made a hatchery commercially sustainable in the long term,” he said.

The growing interest in aquaculture as part of Vision 2030 provided the impetus to get the project off the ground, and industry is excited by its potential.

Michael Tait, chairman of the Scottish Shellfish Marketing Group (SSMG) and managing director of one of Scotland’s largest mussel companies, finds that it is both empowering and daunting to reach this stage of the journey.

“We will be working with methodologies that have proven successful in Tasmania and New Zealand as our starting point, and exploring how and where they can be adapted to the specific mussel species and marine conditions found here in Scotland. This should enable us to produce spat on a commercial scale,” he said.

If the pilot project is successful, it is anticipated that the results will provide the foundation for a business case to set up a national hatchery, or a series of regional hatcheries that would ensure target development can be met.

Stepping Stone has already benefitted from add-on scientific projects, including one that seeks to develop genetic tools for successful management of mussel hatchery broodstock. According to Tom Ashton of Xelect, his project will help to develop SNP-based stock management tools for the blue mussel, suitable for broodstock selection and the establishment of a family selection program. The aim is to preserve genetic diversity.

In addition, the SAICHatch project, coordinated by the Scottish Aquaculture Innovation Centre, has been set up to improve production techniques.

To this end, researchers at the Scottish Association for Marine Science (SAMS), Marine Scotland Science, University of Stirling Institute of Aquaculture and NAFC UHI, are working respectively on algae production, the effects of different bacteria on larvae production, metamorphosis and settlement, and the growth and survival rates of spat transferred to sea.

“These are exciting times for the shellfish industry. A commercial-scale hatchery or hatcheries would lead to higher and more reliable yields, a more balanced distribution of sites, and more jobs within the sector. There is also the potential for the same hatchery technologies and techniques to be applied to other shellfish species such as oysters, delivering further benefit to the sector,” said SAIC CEO Heather Jones.