Back from the brink - the remarkable otter recovery

11:13am Tuesday 3rd July 2007

LANDOWNERS and farmers using less pesticide is being credited for the recovery of the nation's otter population.

The creature, which was on the brink of extinction in the Fifties, has battled back and is now at healthy levels, with the North-East one of the success stories.

Evidence for the creature's recovery came in an Environment Agency report, based on the most comprehensive study undertaken in Europe into the health of otters.

The agency's Science Department looked at the deaths of nearly 1,000 otters between 1992 and 2003, looking in particular for evidence of pesticides used by farmers. Its research confirmed that otter populations have begun to expand nationally following the decline across England and Wales between the Fifties and Eighties.

A key reason is the decreasing presence in the countryside of organochlorines, such as the insecticides dieldrin and aldrin.

Dieldrin, blamed for causing widespread devastation to wildlife, was withdrawn from use in 1962 and banned in 1989.

Agency conservation officer Lyn Jenkins said: "Dieldrin was a very potent insecticide, used extensively by farmers, as it remained active for a long time after they applied it. But we now know it can take up to 25 years for 95 per cent of dieldrin in soil to disappear.

"This persistence, and the fact that it passes from animal to animal through the food chain, was the reason it was eventually banned.

"It had a devastating impact on animals. By interfering with vitamin A levels, it caused reproductive abnormalities and other conditions.

"Previous research has strongly linked its use to declines in predators such as the peregrine falcon, kestrel, sparrowhawk and heron.

"Otter numbers dropped significantly during the late Fifties, when dieldrin and aldrin first came into use and it seems otters in this country are only just recovering from the effects."

One of the areas where otters are recovering is County Durham and Wearside, where Durham Wildlife Trust recently reported the creatures were once more on every river catchment.

Trust director Jim Cokill, said: "Across the entire area, we are receiving increasing numbers of reports from every catchment, which seems to confirm what has been a remarkable recovery from a species that was in such a difficult situation.

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