Dispute over use of invasive species could hit production at seafood farms
Seascape: the state of our oceans is supported byAbout this contentCharis McGowanMon 14 Oct 2024 01.00 EDTShareYou can see them on the specials boards of new restaurants and on chalkboards propped outside bars and pubs. Foodie TikTokers are eating them by the dozen. Healthy, available for £1 and even good for the environment, oysters are experiencing a boom in popularity.
But the UK industry is being hampered by a row over the farming of different species, with producers saying they are struggling to expand to meet demand. Brexit has also affected the UK shellfish industry by restricting imports and exports.
David Jarrad, chief executive of the Shellfish Association of Great Britain, said: “Government policy is trying to drive [the industry] into the ground … this coming year, it’s unlikely that farms will be able to restock.”
Oysters are an old culinary staple. “One oyster stall to every half-dozen houses … the streets lined with ’em,” Charles Dickens wrote in his 1837 novel The Pickwick Papers, when the UK’s native mollusc was abundant and cheap. By 1852, boats were dredging up to 30,000 oysters a week.
View image in fullscreenEmerson and Hadfield at work on their oyster beds in Essex. Photograph: Sophia Evans/The ObserverBut such practices led to the depletion of our native reefs: by the 1960s, the oyster population was crippled by overfishing, and the few remaining reefs were then wrecked by the Bonamia ostreae disease. This led to the introduction of the Pacific rock oyster to boost stocks – hardier and able to reproduce faster than its European counterpart, the abundant Pacific is fuelling the current boom.
“The Pacific oyster is fast-growing, it’s very nutritious and tastes good, and is quite disease-resistant,” said Jarrad.
But he warned that today’s oyster renaissance may be short-lived if policy doesn’t change, with the government’s priorities focused on rehabilitating native reefs while farmers are tied up in red tape.
Regulations can restrict farm expansion unless farmers use triploid Pacific oysters, which are sterile and unable to reproduce, if they pose a risk to protected marine sites. They also prohibit new oyster farms north of 52 degrees latitude – around Ipswich – to prevent Pacifics spreading in the wild where they don’t already live.
Pacific oysters (Magallana gigas), which are cultivated in estuaries and shallow waters, do not compete with the UK’s native oysters (Ostrea edulis), which belong in deeper waters offshore, so do not hamper efforts to restore native reefs.
However, when Pacific oysters were introduced to UK waters in the 1960s, it was under the mistaken belief that they couldn’t reproduce due to cool temperatures. Warming waters caused by climate change have resulted in oyster larvae escaping farms through waterways and colonising coastal habitats.
This has particularly been a problem in Devon and Cornwall, where 150,000 oysters were culled to control feral oyster reefs obstructing mud flats, creating problems for fish and bird species.
Joanne Preston, professor of marine biology at Portsmouth University and co-founder of the UK and Ireland Native Oyster Network, warned that unchecked reproduction from Pacific oyster farms can completely change coastal systems. “We need to limit this damage.”
Last year, the Duchy of Cornwall said it was planning to phase out Pacific oyster farms on its land, as they are an invasive species. However, Anthony Mangnall, the former MP for Totnes, said that the Department for Environment, Food and Rural Affairs (Defra) should recognise the Pacific as a naturalised species. “The future of the industry is still in jeopardy because we are failing to be clear about the status of Pacific oysters,” he said.
View image in fullscreenOysters have been experiencing a boom in popularity. Photograph: Karen Robinson/The GuardianMeanwhile, demand continues. Last week’s London oyster festival sold out within hours, while a video by content creator Georgiana Davies, nicknamed “Oyster Girl”, of her enjoying more than 60 oysters at the Wright Brothers’ £1 happy hour has been watched more than 30m times.
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The Shellfish Association’s Jarrad said the industry was struggling to secure supply of triploid oysters, the version some farmers must use if they want to expand. “The supply of triploid oysters is almost impossible for the next two years,” he said.
There are no UK hatcheries supplying them, and imports from France are restricted by regulations around disease. “We don’t have a supply of triploid oysters in the UK now,” said Jarrad.
“This is a threat to the existence of any oyster farm and therefore a fundamental threat to the entire oyster cultivation industry for the future.”
Chris Hadfield, general manager at Maldon Oysters, believes the state policy is to “stymie the growth of the Pacific oyster industry in the UK”.
‘I’ll have them with hot sauce’: should vegans eat oysters?Read moreMaldon currently sources triploid seed from France, and Hadfield does not think the government will back efforts to provide hatcheries in the UK. “They’re certainly not going to invest in homegrown hatcheries of a product that they’re not banning outright at this stage, but certainly trying to get us to stop farming or producing,” he said.
Jarrad said: “If we invested what we are currently investing in native oysters into Pacific oysters instead, you’ll get a much better return both in the numbers of oysters on the ground and developing a fishery.”
A Defra spokesperson said: “This government will always back our UK fishing and oyster industry. We continue to work closely with industry to ensure we have the most productive and sustainable sector possible.”