Assuring value
The Association of Scottish Shellfish Growers’ conference addressed the industry’s challenges, but also the benefits it offers to our food security and the environment. Robert Outram reports.
The 2024 conference of the Association of Scottish Shellfish Growers (ASSG), held over 29-30 October at the Corran Halls, Oban, included insights on shellfish aquaculture in Scotland, France and Chile. It also featured an update on progress towards finding a replacement rapid test for biotoxins, something which shellfish farmers have been eagerly awaiting for some time.
The theme of the conference was “Scottish cultivated shellfish: assuring value” but as Nick Lake, ASSG Executive Director, explained, it is important to be clear about how the industry will do that and what, specifically, is the value that it can deliver. As he pointed out, shellfish aquaculture not only represents a high quality food source, but it offers a net benefit to the environment, with shellfish farms providing a wildlife haven and bivalve molluscs helping to maintain a healthy marine ecosystem.
He also underlined, however, that for all this to happen we need a commercially viable shellfish industry that operates profitably and has access to the resources it needs.
Mike Spain, who recently took up his post as Director of Aquaculture and Marine Ecosystem Services at Crown Estate Scotland (CES) after several years as Head of Enterprise at the Scottish Association for Marine Sciences, explained the role played by CES. CES is not a regulator or a planning body, but as Spain put it, it is a self-financing public corporation created “to maintain and enhance asset values and income arising from the Crown Estate” with an additional mission to contribute to economic development, regeneration and social and environmental wellbeing in Scotland.
In practical terms, this makes CES the landlord for Scotland’s coastal waters and the owner of around half the Scottish foreshore. It is an asset manager, an investor and an enabler, and contributes more than £100m annually to the Scottish Consolidated Fund. It also supports local initiatives through the Sustainable Communities Fund.
CES has granted 577 leases, of which 288 are to shellfish farms. Spain said: “The Scottish Government has ambitions for the shellfish industry to grow.”
An international view
Chile is renowned as one of the world’s leading producers of Atlantic salmon, but it is also home to a shellfish industry. Félix Howard-Brown was General Manager for St Andrews Mussels between 1987 and 2021, and he continues to be a consultant to the company. He shared his perspective as a Chilean shellfish farmer.
St Andrews operates its farms on Chiloe, the island where the Chilean mussel aquaculture sector is based. The company started by producing the Chilean fresh oyster (Ostrea chilensis) and then switched to Pacific oysters (Magallana gigas), finally focusing on blue mussels when a virus affected the oyster population.
By 2021, production had reached 50,000 tonnes annually. All of the company’s mussel production is processed at its own two processing facilities and exported worldwide as IQF (individually quick frozen) meat, whole shell and frozen half shell. There is so far very little domestic appetite for mussels in Chile.
As Howard-Brown explained, there are more than 1,200 shellfish farmers in Chile, but only 3% of them harvest more than 5,000 tonnes. The vast majority (77%) harvest less than 1,000 tonnes and are typically small family firms. There is also very little scope for expansion other than through buying an existing licensed farm site.
For St Andrews, each platform can seed up to 4,800 10-metre ropes per day and the company can harvest up to 140 tonnes each day.
Although shellfish farming presents a successful export story for Chile, Howard-Brown said: “There is no recognition from government, only difficulties.”
For Seafood Scotland, Marie-Anne Omnes gave an overview of the shellfish industry in France. The country is a net importer of seafood, she said, and in a recent survey just over six in 10 French consumers said they eat seafood at least once a week.
France is Europe’s third largest producer of mussels and ranks fifth worldwide, and the country is Europe’s leading producer of oysters.
As part of her research, Omnes attended the shellfish conference Recontres Nationales de la Conchyliculture in Vannes, Brittany. There are a number of issues for the industry, as Omnes described:
• There is a need to expand beyond the customer base – typical consumers are over 50s and affluent;
• Sales fluctuate with the seasons;
• Product education is needed;
• There is persistent inflation;
• Warming seas mean the shellfish are increasingly at risk from bacterial infections;
• Population density and water quality issues – water quality is the industry’s top concern;
• Recruitment difficulties;
• High cost of “labels” certifying origin; and
• The “French paradox” of local supply vs constraining rules.
The overall message is that the Scottish shellfish industry may be smaller, but it shares its challenges with producers in France – and the Scottish industry is dynamic enough to find a response.
Sarah Evans, Aquaculture Policy Officer with the Marine Conservation Society (MCS), gave a talk on “The future of shellfish – an environmental NGO perspective”, looking at the opportunities and challenges for the industry.
She said: “The aquaculture industry needs to be innovative and we believe shellfish has a big part to play in that.”
Spatial planning will be key, Evans argued, pointing out that Scottish seas are already busy with competing commercial users – such as fisheries and offshore energy – and there is a pressing need to “make space for nature”.
Integrated multi-trophic aquaculture (IMTA), combining different species such as finfish, shellfish and/or seaweed, presents some opportunities but there is still a question over whether this would be profitable, she said.
Another potential approach, she added, is co-location of finfish or shellfish farms with offshore wind farms. A pilot project is already underway in Denmark, with the Kriegers Flak Wind Farm, which is co-located with a mussel and seaweed farming operation. The project will be evaluated when it finishes in 2026.
Shellfish farming is not just “low impact”, Evans stressed, but “positive impact” and the MCS is promoting sustainable farmed shellfish as a responsible choice.
Also on the first day, shellfish expert and journalist Nicki Holmyard gave a presentation on the place of cultivated shellfish in the seafood marketplace (see her column, page 28, for details).
Detecting biotoxins
Harmful algal blooms (HABs) pose a threat not only to marine life but also to human health. Potential hazards include amnesic (ASP), paralytic (PSP) and diarrhoetic (DSP) shellfish toxins.
Clearly, a rapid, affordable and accurate test that can be carried out in situ would be a massive benefit to farmers. Currently there is no such test available, or at least not one that has been officially accepted. A previously available test, from biotech business Neogen, is no longer in production.
At the conference in Oban, attendees heard about two potential routes to solving the problem: a project being developed by Robert Gordon University and the University of Aberdeen to develop a new lateral flow test for toxins, and a rapid test kit from Chilean company AquaBC.
For the former project, CyanoSol research group (RGU), co-directed by Professors Linda Lawton and Christine Edwards and project partners Scottish Biologics Facility (SBF, University of Aberdeen) and Lateral DX Ltd, are dedicated to developing new field tests using recombinant antibody technology for simple, individual, yes/no tests.
Christine Edwards, of Robert Gordon University, gave an update on this project, which has been making good progress. The University of Aberdeen has been developing “designer antibodies” for use as the basis of a lateral flow test, and evaluation of the tests is now underway, to see how well they detect a range of toxins. This has gone well so far, she said, and the tests are now being modified for further testing and production.
Also at the conference, Dr Andrew Turner, Principal Chemist and Natural Aquatic Toxins Topic Leader in the CEFAS (the Centre for Environment, Fisheries, and Aquaculture Science) Food Safety Group, gave an update on the evaluation of the AquaBC test.
He said that initially a lot of refinements had been necessary, with a large number of false negatives and false positives thrown up by the rapid test, when correlated with lab tests (which are more accurate but take much longer).
Dr Turner was optimistic that further changes will make the AquaBC tests more accurate. While the long-term goal is to develop the UK lateral flow test, an improved version of the test from AquaBC could present a solution at least for the time being.
Attendees at the conference were also invited to a practical demonstration of the AquaBC test and how to operate it.
More uses for mussels
Starting the second day, Aoife Martin, Director of Operations at Seafish, presented the findings of a Seafish study aimed at finding additional uses for mussels as a food ingredient. She stressed that this was not about replacing the classic role of mussels in dishes like moules mariniere and paella – instead it was about finding additional uses.
The UK has the capacity to double mussel production, but to make that commercially viable will depend on opening up new markets.
The working group tasked to look at this in 2022 concluded there is scope for “more, but different”. Following that, three workstreams were set up to explore three aspects:
• Can we make the ingredients?;
• Technical analysis; and
• What are the implications for the environment?
One of the big challenges regarding the first issue was deshelling – manual deshelling is not economically feasible, but cooking/steaming (for cooked mussels) or high pressure processing (for raw protein) were found to be viable.
The good news was that it is feasible to create a mussel-based protein product without losing key nutrients, and the process does not involve any worrying environmental implications. Mussel-based protein tastes good, and would compare favourably, price-wise, to competitor products.
Next steps will include a more detailed economic analysis and an examination of supply chain issues, but it looks as if the “mussel burger” could be on British menus in the foreseeable future.
Also at the conference, Tom Ashton gave a presentation on Native Aqua, a new name in Scotland’s shellfish sector, but one dedicated to reviving a traditional species, the native oyster (Ostrea edulis).
A former research scientist with breeding and genetics company Xelect, Ashton now farms native oysters at the Lochnell Oysters farm on the west coast of Scotland. As he explained, native oysters present particular challenges for aquaculture, as a “wild type”, essentially an undomesticated species. Native oysters grow more slowly than the more commonly farmed Pacific oysters (Magallana gigas) and they can suffer high mortality.
Ashton is farming his oysters in an exposed location, in OysterGro cages away from the shore and, he said, this has delivered excellent results in terms of growth, survival and quality.
As he explained: “It’s not a cheap way of doing it, but in the cages the oysters tumble every day and this toughens them up.”
The 2023 seeds are now harvest ready as small “cocktail oysters”. The success of the project can be measured by the fact that Native Aqua won a special prize in the Scottish Shellfish Awards (see panel on this page).
Shellfish benefits
Attendees also heard from Konstancja Wozniacka, a researcher at Seafish, who presented results of a study evaluating the benefits shellfish offer for the environment, particularly in terms of improving water quality and removing nutrients that can lead to eutrophication and harmful algae.
Based on an analysis of the cost of water treatment, she said, even a conservative estimate suggests that the shellfish industry brings water quality benefits worth £7m.
Kelly Wright, who was appointed at the start of this year as Scottish Farmed Shellfish Ambassador, talked about her first 10 months in post . The role was created, with support from Crown Estate Scotland, in order to help market the industry.
Wright has developed an overall brand “Eat Scottish Shellfish” and two sub-brands for mussels and oysters. The focus this year has been on mussels and, coinciding with the conference, a website www.eatscottishmussels.co.uk has been launched, to give consumers information and recipes to help them try Scottish mussels.
The marketing campaign is based on research into why people buy mussels – and why they don’t, with “I don’t like them”, “I’m not sure how to prepare them” and “I don’t know how to cook them” as the top reasons for the latter. The campaign will also use social media and has already involved celebrity chef Tom Kerridge.
Wright said: “What we have to say and how we say it is vital. Get involved and help us to build our message!”
The conference also saw presentations from James Fennell of the University of Stirling, on the mussel shell weakness; Graham Brown of JFC Marine on buoys and moorings; Graham Fielder of Fielder Marine Services on screw anchors for marine farms, and from Gary Harty on the Hexcyl and Flipfarm farming systems.
See Fish Farmer’s video report: https://youtu.be/sPkZhK4JbFo
The ASSG Conference was sponsored by Crown Estate Scotland, with additional financial support from Seafish, The Fishmongers’ Company and Seafood Scotland.
The next annual conference will take place, in Oban once again, on 1-2 October 2025.
Awards recognise the best in Scottish shellfish
The Scottish Shellfish Awards, held as part of the conference, recognised the best in farmed oyster and mussel production, including a new category for “cocktail oysters”.
The winners were selected by an expert panel of judges.
In the Native Oyster category, the winner was Craig Archibald of Islay Oysters, with Gerard Macdonald, Isle of Barra Oysters, being highly commended.
The winner in the Gigas (rock oyster, or Pacific oyster) category was Swein Thomson of Orkney Oysters. Andy Abrahams of Colonsay Oysters was highly commended.
In the Mussels category, the winner was Douglas Wilson of Inverlussa Shellfish and Loch Fyne’s Hebridean Mussels (part of the Associated Seafoods group) were highly commended.
This year, the judges also opted to make an extra award to Tom Ashton of Native Aqua for his “cocktail oysters”, small native oysters grown offshore using an innovative approach.
The judging panel was chaired by journalist and shellfish grower Nicki Holmyard and also included: Eleanor Adamson of the Fishmongers’ Company; Linda Wood, Aquaculture and Fisheries Manager, Marks & Spencer; Michael Leathley, Head Chef at the Pierhouse Hotel, Appin, and David Jarrad, Chief Executive of the Shellfish Association of Great Britain.