The Scientific Committee of NAMMCO - the North Atlantic Marine Mammal Commission - met in Tromsø, Norway, 10-14 March 1997. The meeting was attended by scientific experts appointed to the Committee from NAMMCO member countries (Norway, Iceland, Greenland and the Faroe Islands). As well, a number of invited experts from across the North Atlantic, including Canada, Iceland, Norway, the UK and Russia, contributed to the Committee's special focus this year on questions related to the role of whales and seals in the marine ecosystem. Some of the major conclusions and
recommendations of the Scientific Committee can be summarised as follows:
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New information on the abundance of several whale stocks in the North Atlantic was reviewed. Data from the 1995 North Atlantic Sightings Survey for cetaceans (NASS-95), which was coordinated through NAMMCO, was used as the basis for revised estimates for the surveyed areas. The current best estimate of the central North Atlantic stock of minke whales is 72,000. Combined with the estimate of 112,000 from the Norwegian part of the survey in the Northeast Atlantic, which was reviewed by the Scientific Committee of the International Whaling Commission in 1996, this gives a total estimate of 184,000 minke whales in the central and northeast Atlantic. The Scientific Committee concluded that the bundance of fin and sei whales in North Atlantic waters east of Greenland was 22,800 and 9,250 respectively.
Pilot whales are of particular interest for the Faroe Islands. Data from the NASS-95 survey did not result in significantly different estimates of abundance, and the earlier number of 778,000 pilot whales in the northeast
Atlantic was still considered to be the best estimate. The Scientific Committee concluded that the effects of historic and present catches in the Faroe Islands have had a negligible effect on the long-term trends in the stock.
Based on a review of recent results from ecological studies, the Scientific Committee concluded that minke whales, harp seals and hooded seals may have substantial direct and/or indirect effects on commercial fish stocks. As an example it was shown that stocks of minke whales and harps seals in the
Barents Sea and off northern Norway may consume 2.5-3.5 million tons of prey per year, more than half of which is commercially important fish. To better understand the possible effects of this consumption, the Scientific Committee recommended that knowledge be improved in a number of areas, such as variations in abundance, distribution, diet, energy requirements and prey abundance of these marine mammals, the way in which marine mammals select their prey, and the extent of consumption of fish
species by other predators in the system.
Transmission of parasites (sealworm) from seal to fish has a significant economic impact on the fisheries sector in many parts of the North Atlantic. The Scientific Committee reviewed the current state of knowledge concerning the life cycle of sealworms. In relation to the influence of seal abundance on the level of sealworm infection in fish, the Scientific Committee concluded that: The presence of grey seals or harbour seals may lead to sealworm infection over the entire North Atlantic region; - because of their more
limited foraging range, harbour seals could be particularly responsible for high local infection in fish; - sealworm infection in fish is not necessarily directly correlated with seal abundance, as even a few seals can maintain high infection levels in fish in an area.
The full report of the Scientific Committee will be presented to this year's annual meeting of the Council of NAMMCO, which will be held in Tórshavn, Faroe Islands from 27- 30 May 1997.
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