|The status of marine mammals in the southern North Sea|
Klinowska, M. (1986). The status of marine mammals in the southern North Sea, in: Peet, G. (Ed.) The status of the North Sea Environment: Reasons for Concern, Proceedings of the 2nd North Sea Seminar 1986, Rotterdam, 1, 2, 3 October 1986: vol. 2. pp. 73-95
In: Peet, G. (Ed.) (1986). The status of the North Sea Environment: Reasons for Concern, Proceedings of the 2nd North Sea Seminar 1986, Rotterdam, 1, 2, 3 October 1986: vol. 2. Werkgroep Noordzee: Amsterdam. ISBN 90-70643-03-0. 351 pp., more
Most seal populations in the general area of the southern North Sea are currently increasing. The exception is the common seal population of the dutch Wadden Sea, which has a comparative lack of reproductive success. PCB contamination, through the food chain, seems to be an important factor in this lack of success, although disturbance may also play a part. Since all the North Sea seal populations are known to be contaminated, to some extent, by PCB's, it is important that the population surveys and other studies continue, so that any changes in the situation can be detected at an early stage. It is also important that any proposals for new developments, which might result in disturbance to any of the seal colonies, are carefully monitored and, if necessary, representations made to the appropriate authorities at the planning stage. The status of the cetaceans (the whales, dolphins and porpoises) is not clear. There is a lack of quantitative information on former and present populations, and even on which species may reside in the area, although circumstantial evidence that the fishing industry may have been responsible for the deaths of individuals of the smaller species, particularly the harbour porpoise, and one study which indicates that substantial numbers may still be taken in this way. Unfortunately, without information on the populations from which these accident al takes are made, it is impossible to assess the significance of this, or any, level of removal. Besides increased support for the existing monitoring schemes, one simple, and very cost-effective, way to obtain quantitative information on North Sea cetacean populations is through cooperation with the regular ferries and shipping lines. A carefully designed project, of the type which has been successful elsewhere, would provide the means to establish population levels and distribution as well as to continue basic monitoring in future. It is also necessary to establish the ranges of local populations and any critical habitat which may need protection as well as the exact relationship between the fishing industry and the local cetaceans. The national and international legal status of the local seal and cetacean species is reviewed. There appears to be sufficient legal means to protect the animals and their habitat. The seal populations and their requirements are reasonably well known; there is some need to provide additional protection from human disturbance in some areas. The cetacean populations are not well known, nor is there any specific information on their habitat requirements or on real or potential problems. This information is required before effective protection programmes can be drawn up. There is therefore a clear and urgent need for increased research on the cetacean populations. This requires finance and coordinated efforts need to be made to bring this need for information to the attention of all the relevant national and international runding bodies.