Seawilding: the Scottish community reviving a loch

Loch Craignish in Scotland is being ‘seawilded’ with oysters and seagrass meadows: some of the world’s most depleted habitats. Could it be a model for wider underwater restoration? Sally MacLeod can still remember the days when the loch she lives on teemed with life. As a family of passionate divers, swimmers and sailors, buying a house in 1994 near the banks of Loch Craignish, on Scotland’s west coast, was a dream come true. “Our kids could run down to the dinghy and catch cod,” MacLeod recalls. “You could easily pick up enough scallops for tea.” Almost three decades later, the views from her window are largely unchanged. The hills flanking the sea loch are still quilted with trees and the boats in the marina bob along idly, resting in the gateway to the ocean. Yet, beneath the water’s surface, the picture is very different. “When we snorkel we can see rake marks on the seabed. The dredgers have torn the bottom to bits ,” says MacLeod. “The small island in front of our house used to be white with gulls. Now there are none.” It is a story repeated often in Ardfern, a village of around 500 people scattered around Loch Craignish, where much of the underwater life of the loch has been decimated. But this small rural community is taking action to turn this around. For three years now, it has been home to one of Scotland’s most innovative marine restoration projects, which aims to rewild – or “seawild” – the loch. ‘Seawilding’ Aquatic life has disappeared from the UK’s lakes, rivers and seas at an alarming rate. Before the mid-1800s, the country was home to huge reserves of native oysters, but these are now at a fraction of their former level, with wild native oyster populations dwindling by 95% mainly due to overfishing. At the same time, the UK’s historic seagrass meadows – the flowering underwater plants that provide refuge for many underwater creatures – have shrunk by up to 92%, with roughly half this loss occurring in the past 90 years. The UK is not alone. Wild oyster beds have seen huge declines across Europe and become one of its most endangered marine habitats. Globally, an estimated 85% of oyster reefs have been lost. In the US, researchers have warned that Florida’s oyster reefs, already hard hit , could be being replaced by mangroves as the local climate shifts from subtropical to tropical . The disappearance of oyster beds is part of a wider picture of declining ocean ecosystems globally, as climate change , overfishing and nutrient pollution from sewage and agricultural fertiliser has stripped away marine habitats. Danny Renton, founding director of Seawilding, has been a driving force behind the lochs revival by applying grants and resources to rewild it (Credit: Frankie Adkins) For Ardfern, there remains hope this process can be reversed. Danny Renton, along with a small band of local conservationists, founded Seawilding, a marine charity based on the shores of Loch Craignish, in 2019 to restore two key habitats – native oysters and seagrass meadows. In a project mirroring the conservation pushes happening to rewild native forests and other types of land around Scotland , the charity aims to reintroduce one million native oysters and plant dozens of hectares of seagrass meadows over a period of five years, coaxing biodiversity back to the once-thriving loch. Ecosystem engineers With their ability to filter huge amounts of water, reduce erosion, sequester carbon and provide refuge for other species , oysters have gained a strong reputation in the scientific world as  ” ecosystem engineers”. “Each oyster can filter around 200 litres [44 gallons] of water a day , regulating water clarity and quality,” says Joanne Preston, a marine biologist at the University of Portsmouth in the UK and co-founder of the Native Oyster Network. As filter feeders, these shellfish are able to remove excess nutrients from the water, such as nitrogen and phosphate, which in high levels can encourage harmful algal blooms . They have even proven effective as protective buffers against rising seas . Farmed bivalves – a group which includes mussels, oysters, scallops and clams – are therefore widely considered the most sustainable source of farmed seafood for humans due to their positive environmental impact. Oyster reefs, a large cluster of many individual oysters, also stabilise sediment and decrease wave energy, says Preston, preventing the erosion of salt marshes and seagrasses. Seagrass has its own superpowers – a single acre can support nearly 40,000 fish and 50 million small invertebrates, such as lobsters and shrimp. These underwater meadows are also a sink for blue carbon – the carbon trapped by the world’s ocean and coastal ecosystems. Oyster restoration trials are now being rolled out all over the world – in a New York harbour , a vulnerable Bangladesh island and a Netherlands estuary in an effort to boost coastal resilience. Seagrass meadows are also being planted at scale, from Florida, US to Swansea, Wales . A community effort, Seawilding has released 300,000 oysters and planted 300,000 seagrass seeds into the loch so far (Credit: Seawilding) In Loch Craignish, though, the reigns of conservation are being held by the community, with oyster and seagrass restoration going hand in hand – a particularly special match. “Ecologically speaking, they’re natural bedfellows,” says Preston. Oysters act as an “enabling environment”, improving water quality so that seagrass can flourish. An ideal testing ground There are countless sea lochs – long tidal inlets of the sea – in Scotland, but Loch Craignish’s mosaic of habitats makes it an ideal testing ground geared to providing a blueprint of oyster restoration. Within its 80km (50 mile) circumference, it’s home to lagoonal areas, rocky islets, tidal headlands and shingly beaches. Humans have also left their mark on the loch, with a commercial fish farm, a now-empty salmon river and a large marina of around 250 boats. “It’s a really interesting place to work because you can see the challenges of the sea loch, but also the potential opportunities,” says Renton. A group of future-conscious volunteers had formed the Craignish Restoration of Marine and Coastal Habitats (Cromach) and begun brainstorming ways to revive life in the loch. When Renton, a former documentary maker, appeared on the scene in 2018, he became the driving force behind Seawilding by applying for grants and resources to rewild the loch. Renton and other Seawilding staff regularly survey the loch on the charity’s small boat, which is retrofitted with an electric battery. He does the rounds, hoisting up oyster nurseries – small, floating cages where juveniles grow – mapping seaweed, testing water quality and registering wildlife as it flits in and out of the loch. Every so often, new boats drift into the loch, navigated by curious conservationists who have heard about Seawilding, and want to snorkel through the seagrass or quiz the community on how the scheme is fairing. The biggest threat to the loch in recent decades has come from two controversial forms of fishing – dredging and bottom trawling. In 1984, Scotland lifted a regulation known as the inshore limits , which prohibited industrial fishing within three nautical miles (3.5 miles/ 5.5km) of the shoreline. Ever since, fish stocks have rapidly declined – and calls have been made to reinstate these boundaries. “This incredibly destructive fishing practice came right into the shores, and you still get scallop dredgers coming in here within metres of the shoreline,” says Renton. Increasingly shunned from the community, these boats have started fishing under the cover of night, he adds. “They do it at night, they turn off the AIS [Automatic Identification System] so they can’t be identified and they creep in and creep out. It’s perfectly legal, that’s the problem.” Seagrass meadows take dedication to plant, with volunteers harvesting seeds by hand in the cold (Credit: Seawilding) All this fishing activity meant that, before the charity began returning lost species to the loch, it needed to piece together evidence like a jigsaw puzzle to establish a baseline of what was formerly there. Seawilding surveyed the loch at the start of the project and found 120 live oysters and plenty of shell relics lying on the shorelines. It also found straggly patches of seagrass, around 5.5 hectares (13.6 acres), but it was mostly mud left, says Renton. There is no scientific data on the full biodiversity of the loch in the days before dredging . But Seawilding’s anecdotal surveys with villagers paints a picture of a very different loch, says Renton. Long-standing residents recounted “shoals of herring” and times the water “boiled” with cuddy, as young coalfish – a type of pollock – are known. “They told me the challenge was not to sink the boat, there were so many fish,” says Renton. As part of its restoration mission, the charity has applied for status as a Demonstration and Research Marine Protected Area (DR MPA) by the Scottish government, which would see it become a designated site for carrying out research on sustainable methods of marine management. “It’s a chance for all the stakeholders to sit down together and work out what dynamics have changed in the loch, to try and improve biodiversity,” explains Renton.  Sowing the seed Seawilding’s approach involves far more than marine experts. The charity is propped up by the community, whose lives and futures revolve around a healthy loch. It is volunteers, such as the MacLeod family, who help harvest, plant and monitor the seagrass and oysters nestling on their doorstep. The loch’s native oysters are sourced from a hatchery in Cumbria, in the northwest of England, and are reared until at least six months old in nursery cages floating in the loch. Around twice a year, dozens of helpers from the village congregate on the loch’s shoreline to scatter them into the water. Seagrass, however, takes more dedication. Volunteer snorkelers lumber in extra thick 7mm (0.3in) wetsuits to harvest seeds by hand in the cold. These seeds, which are roughly the size of grains of rice, are gathered into hessian bags and replanted on the seabed. Juvenile oysters are usually left to grow until they are six months old before they are released into Loch Craignish’s waters (Credit: Frankie Adkins) Cecile and Scott Mannion are two of the charity’s core volunteers, who previously ran a local gardening business together. The couple care for their terrestrial environment – the trees, plants and flowers surrounding the loch – and believe that underwater flora and fauna are no different. “You get emails asking you to donate to charities and sign petitions but you never know if anything actually happens,” says Scott Mannion. “This is doing something, it’s getting your hands, not dirty, but wet.” Hannah Tofts, an artist based in Ardfern, believes stewardship starts from a young age.  She runs educational activities, such as seaweed art classes, with children from the Craignish peninsula who are known as ” seawildlings “. “As soon as you see something in the flesh it becomes real,” says Tofts. “When the kids swim and snorkel and see the seagrass waving at them, they learn about it. The idea is to give the kids an early seed of loving and understanding their coastline,” she says. Biodiversity gain With the restoration project only three years old, the fruits of Seawilding’s labour are still in the early stages of growth. By 2022, some 300,000 oysters had been released into the loch with monitoring indicating a 56% survival rate. Similarly, 300,000 seagrass seeds had been planted, leading to 0.35 hectares of seagrass meadow . As seagrass takes time to grow and oysters to reproduce, regular monitoring over the next few years will indicate how well the scheme is fairing. Research is already showing the wider benefits these schemes could have, however. A 2023 study from Heriot-Watt University looked at data from Loch Ryan, Scotland’s last remaining native oyster fishery. It projected that a restored oyster habitat in Dornoch Firth – another oyster restoration project in Dornoch, some 175 miles (280km) away from Ardfern in the Scottish Highlands – could double one measure of biodiversity . However, restoring oyster habitats is “not that easy” for several reasons, says Bill Sanderson, a professor of marine biodiversity at Heriot-Watt University, who leads the Dornoch Environmental Enhancement Project (Deep). Local artist Hannah Tofts occasionally holds seaweed art sessions with children from the peninsula (Credit: Frankie Adkins) Firstly, the aquaculture industry must grow enough oysters to keep pace with new restoration projects. Plus, the type of oysters native to the UK, Ostrea edulis , are fickle, as they are prone to disease and require extra care around biosecurity – the measures taken to prevent the introduction and spread of pathogens, he says. But there can also be risks when introducing invasive non-native species into agricultural sites, he adds. “You don’t want to create a conservation home goal by bringing something into a site that’s going to cause more damage than the benefits your oysters produce.” Still, Sanderson is optimistic that with some patience, these ecosystem-based solutions offer marine habitats hope. “We’re pushing that boulder up the hill, and sooner or later it’ll start to roll down the other side,” he says. Ultimately, the success of community-led marine restoration projects such as Seawilding relies on “normalising” the idea of marine restoration, says Preston. “We do farming, agriculture and offshore oil extraction – we don’t think twice about doing these large-scale projects. This really isn’t rocket science. We just need the right policies in place to back it up.” Almost 30 years after moving to Ardfern, MacLeod’s sons now have two children of their own, who also enjoy splashing about in the loch in their summer holidays. MacLeod says she is hopeful that one day the spread of oysters and seagrass might create a sustainable oyster fishery, bringing more jobs to the village.  Up on the hill, MacLeod has a vantage point of the loch, where many residents hope that slowly but surely, signs of life are returning. “We noticed a big difference [in stewardship of the loch], that’s why we got involved with Seawilding,” says MacLeod. “We can see a future and it’s our grandchildren who will be the ones to benefit.” *This story was produced with support from Internews’ Earth Journalism Network. — Join one million Future fans by liking us on Facebook , or follow us on Twitter or Instagram . 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