Over-planting and pollution pushed the UK’s rarest snails to extinction. From just two to 2,000: How have conservationists brought this asexual species back to life?
Just beneath the surface of a lucid Snowdonian lake, two snails drift slowly past each other, their translucent forms catching the green-tinged light of summer, filtering down from above. Clinging to hard rock surface, they engage in a jousting match like two ships sailing alongside each other, firing cannons. But their encounter is not a fight, it is a gentle act of mating.
These are glutinous snails, one of the UK’s rarest invertebrates and their love life is as elusive as their presence. Rather than seeking out mates, they rely on chance encounters, casting tiny packets of genetic material adrift in the water, hoping another of their kind will unknowingly pass through. Bala Lake in North Wales was their final habitat before conservationists intervened.
Extinct in England for 30 years and rare across Europe, these snails are being saved from water pollution and tree overshading by Welsh conservationists. In St. Davids, the UK’s smallest city, we met conservationist Ian selling his snail paintings with his family in celebration of St. David’s Day.
“Everybody loves trees,” Ian said while pulling out a transparent jar from his backpack, with several jelly-like snails clinging to it, “but when trees grow up around water bodies, it creates shade to the point that the snails don’t get high enough temperature to breathe and go through their life cycle.”
In addition to warmth, these snails need a high concentration of oxygen in the water. Unfortunately, climate change has led to warmer water which reduces oxygen levels, making suitable habitats scarce.
“Particularly hot, prolonged weather creates water that’s warm in the day, night, and through the winter, which puts stress on their metabolism,” Ian said. “People talk about climate change like it’s just tomorrow’s problem, but they’re missing what’s happening right now.”
This is evident in the dramatic decline of Atlantic salmon populations across Wales. Warming streams and tributaries are shrinking their habitat, resulting in record lows. In 2024, the total declared salmon catch was estimated at just 5,399 fish, a stark drop from the 20,000 seen in the years leading up to 2017.
Polluted waters have damaged aquatic species as well, and the glutinous snail is no exception. Historical records show they once thrived in human-made environments like ditches and canals. However, the rise of agricultural pollutants—phosphates and nitrates from fertilizers—and road traffic pollution, particularly nitrogen dioxide, has rendered their habitats toxic. As Ian explained, modern society is gradually pushing these creatures toward extinction, through farming and driving.
Conservationists are now striving to reverse this trend, achieving successful outcomes that offer hope for the snails.
Ian and his team from York captured six snails from Bala Lake in 2017 using just a paintbrush and a tiny plastic jar. “This is just a common paintbrush,” Hughes said, holding it up and gently sweeping across the snails, whose shells are so fragile they could crumble at the touch of a finger. They launched a breeding program then, but unfortunately, four of the snails died before maturing.
However, a year later, they successfully bred 2,000 snails from just two survivors.
Ian said, “We started off with bubbling tanks and lots of care, using only water from the lake. Over time, we discovered that we could keep them in simple washing up bowls or goldfish bowl type containers without aeration, as long as they had access to the surface.”
To better simulate their natural environment and minimize disturbance while observing the snails, Ian designed concrete bunkers that are hollow, allowing the snails to go underneath, so they can easily monitor them by eyes.
While positive outcome has been made, the biggest challenge for the breeding is finding unpolluted water bodies, which would allow them to release the snails back into nature and see if the newly bred snails can survive. “We must travel a long way to collect water from Bala, as it is the only source of unpolluted water available,” Ian said. “That’s really why we went to zoos, so they could create suitable environments because every zoo has gardens, land, and grazing areas.”
Last year, the critically endangered snails have found a new home in a semi-natural pond at Askham Bryan Wildlife Park, located on the outskirts of York.
Glutinous snails are lucky but not other freshwater life. The sturgeon and the burbot have vanished, salmon are disappearing and the European eel remains critically endangered in British waters. According to the World Wildlife Fund, much of the decline is driven by the poor state of rivers, mostly as a result of pollution, dams and sewage.
Ian runs a website of protecting Welsh wildlife and writes blogs suggesting ways we can all help save endangered species.
“If you’ve got a garden, it’s always worth having a pond. By creating more water bodies, we take the pressure off the ones that have the rarest species. Joining groups like Freshwater Habitats Trust is also important,” said Ian.
His previous conservation organization often faced funding shortages, prompting him to create art to help fill the gap. He designs T-shirts and merchandise featuring rare animals, which he sells online and at markets. We visited his small stall in the gallery, where children chatted with their parents and Ian’s wife. She kindly introduced the endangered British bats depicted on the shirts.
“The most important of all is talking about it. Because it’s only by advocating things that you can make a difference. A lot of people are shy about nature. Talking about it strongly and saying are important to me and it should be important to you because you are gonna lose those endangered animals. They are heritage,” Ian said.
Ian’s family has been influenced by his passion for conservation. His three children are involved in the field. Karen is a graphic designer and nature photographer, while Jake and Ben are both illustrators. They were home-educated and grew up participating in conservation projects for invertebrates.
“If you lose a castle, you can rebuild it. But if you lose a species, it’s not just DNA. It’s made up of behaviors, elements of its habitat. It’s the most precious thing for human that can not be lost,” Ian said while packing the snails back into his bag, those tiny creatures shining like crystals in the sunlight.