Slaughter of seals feared as deadly virus returns

The deadly virus commonly known as canine distemper has not been forgotten on the north-east coast. In a single month 14 years ago it ripped through seal colonies from the Wash to the Orkneys, killing a total of 18,000 animals in European waters.

The deadly virus commonly known as canine distemper has not been forgotten on the north-east coast. In a single month 14 years ago it ripped through seal colonies from the Wash to the Orkneys, killing a total of 18,000 animals in European waters.

Yesterday, it was beginning to look as though phocine distemper virus (PDV) may soon be back. At least 300 common seals have washed up dead round the Kattegat and Skagerrak coasts of Denmark and Sweden in the past month, with symptoms which are now delivering convincing evidence of a return of PDV. An outbreak in that region was enough to infect every seal colony on the North Sea coast in 1988.

PDV, a disease spread on the breath by infected seals, suppresses the mammal's immune system and makes it susceptible to secondary infection by bacteria which may cause blood poisoning.

An outbreak two years ago killed 11,000 endangered Caspian seals along the Kazakh coast in just three months. In the early Nineties, the infection of crab-eating seals in Antarctica was linked with sled dogs used during expeditions.

The common seal's boundless energy for journeying makes the Scandinavian outbreak a real threat to British colonies. It took only four months to reach Northern Ireland last time from Anholt, the same Danish island to which it has now been traced again. Since a single infected seal can spread the disease and a swim from Scandinavia to the north-east coast of Britain is nothing unusual, the outbreak "is extremely worrying," Joan Edwards, director of the Wildlife Trusts marine programme, said. "The infectivity is alarming. There were lots of carcasses last time."

The breeding season has started, just like last time, and pups and female seals are particularly susceptible to infection. Seals spend more time out of the water during breeding and have increased contact with each other immediately after it, heightening their vulnerability to the disease. Symptoms include runny eyes and muzzle, sneezing, muscle spasms and lack of energy.

The likelihood of an epidemic of 1988 proportions depends primarily on the number of susceptible North Sea seals which were not exposed in 1988, or have been born since, the Sea Mammal Research Unit, at the University of St Andrews, said.

"Only about half of the population in the UK was exposed to PDV in 1988, so there is probably a large number of susceptible seals," John Harwood, of the research unit, said. "The possibility this could result in a mass mortality on a similar scale to 1988 can't be ruled out."

Tourists were urged yesterday to report any evidence of sick seals, but not to approach them. Ms Edwards warned: "Seals tend to carry other viruses, including one which can affect the [human] heart. If you go near a seal it could breathe something potentially deadly to you."