The group of seven seal experts appointed from the three countries involved, directs attention to the danger of introducing pathogens unknown to the wild when releasing seals that have been held in captivity. They also say that such reintroduction is no longer necessary as the seal stock is healthy and growing quickly in number. However, the environment ministers were not prepared to go any further than to say that the number of seals taken from and released into the Wadden Sea should be reduced to the “lowest possible level” by applying guidelines for handling diseased and weakened seals or evidently abandoned seal pups. The principles on which these future guidelines should be based are outlined in the ministerial declaration. They will make it more difficult, but probably still possible, for the Netherlands to maintain their practice of taking and nursing a large number of seal pups (up to sixty a year) for the purpose of reintroduction to the wild. The seal nurseries in the Netherlands, with the support of animal welfare groups, have protested strongly against the conclusion of the expert group, and have gained support from their politicians.
Scientists Knew Risks
In Denmark and Germany, the rescue looking after of abandoned seal pups has already more or less come to an end. “We ensure that abandoned seal pups are put down in a justifiable manner, either by doing it ourselves, or by taking them to a vet,” says Sven Tougaard to the High North News. He is a researcher at the Maritime and Fisheries Museum in Esbjerg and member of the Trilateral seal expert group. Tougaard emphasizes the fact that they leave the seal pups alone for at least 24 hours before the decision to put them down is taken, in case the mother should return. “The gathering of abandoned seal pups is not necessary today, nor is it desirable with a view to conservation. It is more like a way of buying a good conscience,” says Tougaard. He regards it as a problem that people no longer understand what is natural, and that they, in some misunderstood eagerness to save nature, are disturbing nature’s own laws. He draws attention to the obligation of science to provide information. The Maritime and Fisheries Museum in Esbjerg now only takes in seal pups as part of its research, something which involves about 3 a year.
Natural Selection
The harbour seal stock in the Danish part of the Wadden Sea is today about 2,500. The total stock of the Wadden Sea includes over 10,000 seals. The stock has a growth rate of close on 14% per annum all over its area of distribution. “The increase is at the maximum of what is theoretically possible,” says Tougaard. In 1989 the stock was halved by an virus epidemic. Even so, today it is back at a level higher than that of 1989.
One of the items in the “principles for guidelines” states that the seals released shall not be carriers of pathogens alien to the wild. In its recommendations to the ministers, the expert group refers to a number of examples of accidents and diseases spread in conjunction with the release of animals into wild populations. “In all the examples scientists knew the risks, but were not able to eliminate them,” the expert group warned. In spite of this, informed sources in the Netherlands believe that due to public sentiment and the work of pressure groups, the Dutch authorities will not interpret the guidelines in a restrictive way.
In the terms of the expert group’s recommendations it says, amongst other things, that “The present status of the harbour seal population in the Wadden Sea is characterized by high reproduction rates and high population growth rates ... the population in the wild does not, and in fact should not depend on rehabilitation (of abandoned seal pups) ... released seals from rehabilitation stations are potential carriers of pathogens, to which seals are usually not faced with in the wild. Therefore, released seals are a potential danger for the whole population ... (they) may (also) cause a disturbance to the natural selection mechanism of the wild population.” The normal pup mortality rate of a natural stock of harbour seals can be up to 50%. The strongest individuals survive, and their genes are carried further.