ABOUTquiet Friday evening, otter and fox run through Downtown Lincoln. The couple scurry past charity shops and down deserted streets, their encounter illuminated by the security lights of shuttered eateries. Each animal explores the nooks and crannies of the main street before disappearing into the night, ending an unlikely scene captured on CCTV last month.
Unlike the fox, the otter was a rare visitor to towns and cities across the UK. But after decades of intensive conservation work, the situation is changing. Just last year, an aquatic mammal was spotted on a riverboat pier in London's Canary Wharf, dragging huge fish on the river bank in Stratford-upon-AvonAnd robbery of garden ponds near York. One otter was even caught on video causing havoc in Shetland family cuisine in March.
Janice Bradley, Nottinghamshire Nature Restoration Manager Wildlife The trust says: “Twenty years ago they were almost non-existent. Then we saw them coming up the River Trent from other areas. Now we have records of otters in almost every river and watercourse in the area. It's wonderful.”
Nobody knows how many otters live in Britain, although it is widely believed that the population has increased since it was almost wiped out by polluted waterways in mid-20th century Britain. Some naturalists estimate there are 11,000 of them across the country, but admit that this is just a guess.
In the 1970s surveyors searched almost 3,000 sites throughout the UK, but animals were found in only 6% of them, mainly in fortresses in Scotland, Wales, Norfolk and south-west England. They are now widespread and use their sensitive whiskers and webbed feet to hunt in waters across the country.
Their return is fragile history of water quality improvementsay conservationists. The dumping of industrial waste from factories and toxic pesticides devastated fish populations in British rivers in the 19th and 20th centuries, with disastrous consequences for otters, which ended up eating many of the toxins.
Bans on harmful pollutants, improving water quality – despite recent events problems with the discharge of untreated wastewater by water utilities – and a targeted reintroduction campaign in the east of the country have all contributed to their return.
John Traill, from the Yorkshire Wildlife Trust, says: “I think the research in the 70s was a lightbulb moment for people when they realized that otters had been seen historically and they could no longer see them.
“There are old documents detailing otters' encounters with naturalists, but people haven't seen them for years.
“It's been a slow process. Otters usually have one, two, sometimes three cubs, which the female looks after for a year, so it's a slow rate of recolonization. In 10 years you might only have five or six cubs, so it always took a while. But now the tipping point has passed.”
Not everyone is happy about the otter's return to the UK. Fishermen blame them for eating fish in their favorite spots, blaming the animals for upsetting the river's balance, but many experts believe this claim is exaggerated.
Despite them traditional image Because otters hunt only fish, they eat a wide variety of rodents, birds and amphibians, and analysis of their diet shows that they rarely take the large fish valued by the fishing community.
Dr Elizabeth Chadwick, Head of Cardiff University Project Otterwhich tests dead otters across the country to monitor pollution levels, says: “When it comes to native fish species, there is no evidence that otters are responsible for decimating stocks. This is partly a misunderstanding, but it also reflects resource limitations.
“In British rivers, fish stocks are limited in some places. This is not because the otters have recovered,” she says.
The Otter Project results paint a complex picture of recovery, showing that heavy metals Pfas “forever chemicals”and pesticides still accumulates in mammals. But amid growing concerns about the health of Britain's rivers, Chadwick says the otter could become a symbol of the change many are demanding.
“Otters are a really good way to monitor the health of our waterways. Over time, a lot of chemical contaminants accumulate in the animal's body. They're often found in trace amounts in the water, so we can't detect them in samples. But if you test at the top of the food chain, they become detectable,” Chadwick says.
“If we can use otters as a kind of charismatic ambassador for river health, that could be a really powerful thing.”
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