Otters in Britain: Related to the badger and stoat, the European otter is a weasel that has adapted to life in the water. The otter is nocturnal and feeds chiefly on fish. By day it lies on land. By day it lies on land, usually in thick vegetation, or retires to its holt, or borrows. Until the 1950’s, almost every river and lake in Britain had its own otter populations.  The otter has no enemy except man, who, in the past, has hunted it for its fur, to protect fish stock, and simply for sport. In the late 1950’s and early 60s Britain’s otters in many areas were wiped out, while other populations became isolated.

Poisoned Water: The European otter’s decline coincided with the introduction of organochlorine insecticides. One of these, dieldrin, was first used in 1956 to coat wheat seed, and in sheep dips. Otter numbers fell dramatically with dieldrin’s widespread use.  Later it was found that poisons were being washed into waterways. Instead of breaking down, they slowly contaminated food chains, from plankton through invertebrates and fish to otters. With each poisoned fish an otter ate, pesticide traces built up in its system like a chemical time bomb, until, finally, they rendered a lethal dose.  These poisons not only killed outright, but they also reduced the otters ability to breed and increased its susceptibility to disease.

Habitat Destruction: The 1960s and 70s also saw a significant increase in the disturbance, destruction, and pollution of prime otter habitat. The otter is a shy animal and will only tolerate a certain amount of human disturbance. Pressured to produce more crops or keep more stock, farmers increasingly cleared and cultivated or grazed land right up to the edges of rivers and lakes. Trees whose roots sheltered otter holts were felled.  Government flood prevention plans involved “canalizing” river: Channels were deepened and straightened, then the banks were edged with concrete. Otter strong holds on rivers and streams in the English countryside all suffered in differing degrees.

People & Pollution: The ever increasing use waterways for pleasure boating and fishing has led to rivers congested with people, and has driven off the otter, which need quiet, undisturbed backwaters to lie in by day. Waterside building and development also has disturbed the otter and increased the numbers killed by traffic.  Pollution by fertilizers, silage effluent, sewage, and industrial waste has reduced the fertility of many rivers, killing off fish and, therefore, the otters that feed on them. Where fish are plentiful, ironically, many otters die by drowning in nets set for eels and crustaceans.

Action File: National Otter Survey: In 1977 the National Otter Surveys began in England, Scotland, and Wales. Surveyors searched key sites to assess the otter’s population and distribution. But before the surveys were complete, on January 1, 1978, the otter was declared endangered. Pesticides ere identified as a major cause of the otter’s decline. Pressure fro conservationists effected a voluntary ban on their use. Water authorities and farmers were informed of the otter’s plight and encouraged to manage their lands more sensitively.

Practical Conservation: The Nature Conservancy and the Vincent Wildlife Trust established “otter haven” in areas known to be inhabited by otters. This involved protecting lengths of wooded riverbanks. Where necessary, temporary artificial shelters for the otters were built, while trees and shrubs were planted to reestablish natural cover. The otter is extinct in many areas that are not suitable for decolonization. Since 1983, the Otter Trust has been breeding and reintroducing otters to these sites.

A Future for Otters: In 1984 a second otter survey was taken. Surveys and spot checks revealed that in some areas the otter population had decreased further, while in others numbers were rising. Only in west Scotland has the otter remained numerous. Experts agree that the European otter will never again be widespread, but with controls on pesticide use, reduced freshwater pollution, and more sensible management of river habitats, the others future can be safeguarded.

To return to animal menu click here