Estimates of stock size of cod, haddock, redfish and greenland halibut in the Barents Sea and the Svalbard area, autumn 1987

Abstract

Combined acoustic and bottom trawl survey for cod and haddock were carried out in the Svalbard area together with an acoustic survey in the Barents Sea in autumn 1987. The abundance index in numbers of cod continued to increase in the Svalbard area , mainly because a larger part of the stock has become aqoustically detectable. In the Barents Sea the index has decreased a little since previous autumn and same mole since last winter, partly because of an inadequate area coverage in southeast and more scattered registrations than during the winter survey. The results for haddock show that the stock is almost not present in the Svalbard area and that it is decreasing in the Barents Sea. The abundance of the redfish species Sebastes marinus and S. mentella have decreased both in the Svalbard area and in the Barents Sea, while the abundance index of S. viviparus show a huge increase, mainly because of better area coverage in southwest. The abundance of Greenland halibut is decreasing, probably because of recruitment failure.