Welcome back otter after 30-year vanishing act

The return of otters to Kent is a sign of improving water quality in England. Photo / Supplied

It has taken 30 years, but the otter's comeback is now complete. After disappearing across most of England in the 50s and 60s, one of Britain's best-loved animals has now returned to every English county, the Environment Agency announced this week.

The slow but steady recolonisation of its former haunts has been rounded off with the reappearance of otters in Kent, the last county to have been without them, the agency said.

The otter's return represents a happy ending to one of the worst episodes in modern British wildlife history: the sudden disappearance of one of the most widespread and charismatic mammals.

It began around 1956 and was almost certainly caused by the introduction of powerful organochlorine pesticides such as aldrin and dieldrin.

Residues of these chemicals were washed into the rivers where otters lived, poisoning them.

As wild otters are hard to spot - their presence is usually detected by their spraints, or droppings - it was several years before the scale of their disappearance began to dawn on people, but by then they had been wiped out over vast areas of lowland England.

Despite the banning of organochlorine pesticides in the mid-60s, otters continued to decline, their population reaching a low point by the end of the 1970s when they had effectively vanished from everywhere except the West Country and parts of northern England (although good numbers remained in Wales and Scotland).

The first national survey of the otter population, carried out between 1977 and 1979, detected the presence of otters in just over 5 per cent of 2940 sites surveyed, all known to have held the animals previously.

But a comeback gradually began. Helped by a substantial clean-up of England's rivers, which brought fish back to many once-polluted waterways, and by legal protection, otters began to spread eastwards into England from strongholds in Devon and parts of the Welsh borders, such as the Wye Valley.

By the time of the fourth otter survey, which was carried out between 2000 and 2002, more than 36 per cent of the sites examined showed otter traces.

And when the fifth survey was carried out, between 2009 and 2010, the figure had risen to nearly 60 per cent, with otters back in every English county except Kent.

Now wildlife experts at the Environment Agency have confirmed there are at least two otters in Kent, which have built their holts on the River Medway and the River Eden.

"The recovery of otters from near-extinction shows how far we've come in controlling pollution and improving water quality," said Alastair Driver, the Environment Agency's national conservation manager.

"Rivers in England are the healthiest for over 20 years and otters, salmon and other wildlife are returning to many rivers for the first time since the industrial revolution.

"The fact that otters are now returning to Kent is the final piece in the jigsaw for their recovery in England and is a symbol of great success for everybody involved in otter conservation."

Otters are at the top of the food chain and therefore an important indicator of river health.

The clean-up means they are now inhabiting once-polluted rivers running through cities - something which would have been unthinkable before the population crash - and they've been detected in places such as Stoke-on-Trent, Reading, Exeter and Leeds as well as more likely urban centres, such as Winchester.

But although they are widespread once more, otters' nocturnal habits and river habitat make them difficult to glimpse, let alone observe, in England.

The best place to see them is western Scotland, where they've become semi-marine and live along the coast.

Otters can regularly be seen foraging along the shoreline in the daytime, especially on some of the larger islands such as Mull and Skye.

Otter matters

* Otters are semi-aquatic carnivores in the mustelid family, which means they are related to stoats, weasels, badgers and polecats.

* Otters feed mainly on fish but they also eat shellfish, insects, frogs, birds and small mammals.

* An otter's den is called a holt. A male otter is a dog, a female is a bitch, and a baby is a cub (or sometimes a kit or a puppy).

* There are a dozen species of otter around the world, England's being the eurasian otter, Lutra lutra.

* Gavin Maxwell's famous story about living with otters in Scotland, Ring of Bright Water, actually features a smooth-coated otter from Iraq.

- INDEPENDENT