n unusual rewilding mission is under way just off the M5 motorway. Eels the length of a little finger have finished their 6,600km (4,000-mile) migration from the salty Sargasso Sea in the Atlantic to the brackish water of the Bristol Channel. They have spent two years floating on ocean currents and are hoping to settle in the Somerset Levels. It is one of the planet’s most mysterious wildlife migrations. Three fishers wait for eels on the banks of the River Parrett outside Burrowbridge with a large square net at the ready. The new arrivals look like threads of glass, fizzing with energy. I let out an involuntary squeal as the first batch arrive, much to the mirth of the fishers. “That’s rubbish! You haven’t been doing this long enough if you’re getting excited about catching 10 [eels] at this time of year,” says Steve George, who is a fencer by trade. The glass eel migration should be at its peak – it’s mid-April, the moon is bright and the tides are right. In the past, hundreds of fishers would have been waiting quietly on the banks like herons, ready to scoop what they could from the water. This evening, it is only us. About 600 eels are caught, but apparently this is nothing compared with some days. Each year, 1.3 billion young “glass eels” come to European waters, 5-10% are funnelled between Wales and Cornwall into the Bristol Channel. This sounds like a lot, but the population of this critically endangered fish has declined by more than 95% since the 80s. For most fish, encountering a net is bad news. But the eels caught tonight will be taken to nursery habitats in King’s Sedgemoor drain, an artificial drainage channel, which they would not otherwise be able to reach because the estuary end is blocked by a sluice gate. Knowledge of how to fish eels is gradually being lost as they slowly disappear from river ecology, economy and culture. Paul Squire, who has been fishing them for 25 years, remains beguiled by their mysterious lives: “I don’t know what it is, it’s not so much about money for me. They are fascinating creatures.” For the past decade, eel numbers have been creeping up after centuries of decline. Legislation has been put in place to protect the European eel – considered one of the world’s most trafficked animals. These fishers’ local efforts to rewild eels in UK rivers is the latest chapter in the international fight to flip the fortunes of the species. Rewilding, or “restocking”, European rivers is nothing new. The UK has been shipping glass eels to Germany since 1908. In recent years, 10-15 million eels have been sent to Europe annually, 60% for rewilding – or restocking – and 40% for aquaculture. “Sadly, Brexit has spoiled the party overnight,” says Andrew Kerr, chair of the Sustainable Eel Group (SEG), which was set up in 2010. “The UK is no longer allowed to trade eels to Europe. So the 300 fishers of the Severn in the Parrett have no market, no customers. And that tradition in effect ends.” Peter Neusinger has been fishing eels since 1983 and was one of two glass eel collectors in the UK who shipped to Europe, initially for the fish to be farmed and eaten, but then for rewilding too. But in January, following Brexit, business fell off a cliff. “I think the craziness of the current situation is a fishery that’s reinvented itself has been left with absolutely nothing … we’ve hit an obstacle and, so far, no one has come to try to help.” Kerr is masterminding a movement to create a national rewilding programme. His aim is to move 10 million eels a year, which he thinks would cost £200,000. The fishers on the river tonight are doing it voluntarily, although their catch would probably only be worth £30. They are worth around €200 per kilogram for restocking and €300 per kilogram for consumption. Kerr says it would be “madness” if trade with the EU stopped permanently. Mortality rates are high for small eels, which are an important source of food for many creatures, including bittern, herons, cormorants and otters. “Leaving them to die in blocked river systems is crazy,” says Kerr. “They’re not adding anything to the wider ecosystem. We need to move them and rewild them so they can play a full role in UK and European freshwater.” Young eels traditionally heralded the arrival of spring, with the first coming at a similar time as the daffodils. A centuries-old staple, they are typically jellied, smoked or eaten in a pie. In the past, nobody lived far from a pond, a ditch or a river full of eels, but that relationship has been lost. The Huntspill sluicegate on the mouth of the River Parrett, a few miles downstream from where the eels are released, illustrates how hostile the environment has become for eels. “River is a misnomer,” says Kerr. “You see this incredible human engineering construction, massive lump of concrete, steel doors, all around controlling water. That side is freshwater, this side is saltwater. Nothing gets in or out unless man wants it to.” On the sea-side of the barrier, the flat landscape snakes out into glistening, wide mudflats, reminiscent of the watery and wild landscape that would have been there before humans drained it. Most of the barriers on the Somerset Levels date back to the second world war. Across Europe in the 20th century, leaky wooden structures were replaced by concrete and steel. The UK has focused on unblocking pathways as opposed to rewilding, and about 1,000 eel migration pathways have been restored in the past 10 years. “That’s a drop in the ocean. But they have been many of the most critical ones,” says Kerr, who is campaigning for eel passages such as runs, flaps and bristles to be put in place wherever possible. As glass eels arrive in freshwater they soon start to metamorphose into elvers (11-12cm long), which is the juvenile stage. The best eel habitat is the river margins, among fallen trees, under rocks and roots, and after 10 or 20 years in UK waters they can grow up to 1.5 metres. Once they have reached this age, they normally leave Europe’s rivers with autumn’s rain as “silver eels”, returning to their spawning grounds in the Sargasso Sea. No one has seen eels spawn, and they die after doing so. At one stage, it was believed spawning might be wrapped up in a few nights with one mass orgy, but now it’s thought to run over weeks. “The females give off a terrific whiff, we’re told, and that attracts the males,” says Kerr, who talks with enthusiasm about any part of eel ecology. In the 1980s, the international eel trade, which was not illegal at the time, ballooned because small glass eels could be flown live to aquaculture farms in Asia where they were then grown into mature silver eels and eaten. By 2018, gangs were smuggling up to 350 million glass eels annually from Europe to Asia, where they are an expensive delicacy. In 2007, the EU adopted the eel regulation to tackle the problem. It improved regulation of fisheries, encouraged the removal of obstructions to migration and introduced a programme of restocking. In 2010, the EU banned the import and export of European eels. This gave authorities the power to break up trafficking gangs with more than 100 arrests annually over the past few years. Populations increased at a “statistically significant rate” between 2011 and 2019, according to a report by the International Council for the Exploration of the Sea. Europol, the EU’s law enforcement agency, estimates that eel trafficking has fallen by 50% since its peak of 100 million tonnes in 2018. Kerr says the EU eel regulation set a “fantastic framework for countries to take action”. Annually, Europe produces about 5,000 tonnes of eel from about 20 certified aquaculture farms with transparent supply chains. Kerr said he was initially shocked when he found out eels were still being legally farmed for food but says this commercial activity is now a key part of funding conservation measures such as rewilding. “In Europe, just 4% of that 1.3 billion are used in aquaculture. That’s a harvest that this species can easily absorb. Taking 25% to Asia is lunacy. So yes, do it properly, do it responsibly, do it within the constraints and the environment that SEG and the EU regulation has created and it’s fine,” says Kerr. The changes on the Parrett illustrate the impact of EU regulations on local industries. When the rules came in, UK fishers had their ropes, floats and nets – which they used to catch the eels – taken away. The poles and nets fishers are allowed to use are significantly smaller. The fishers say it’s “pocket money” and they mainly do it for enjoyment, and spending time with people on the river that they would not see for the rest of the year. Squire estimates just 1% of fishers are operating illegally. He says it’s more of a pleasure to fish now and eel numbers are rising year on year. These small success stories are sprouting all over Europe. Old-school fishers become stewards of sustainable eel production because they have real interest in eels being abundant. Bringing back eels is a story about remembering wildlife, rewriting it into our landscapes and cultural traditions. Maybe, at some point, jellied eel may be on the menu again, too.