Estimates of stock size of cod, haddock, redfish and Greenland halibut in the Barents Sea and the Svalbard area autumn 1988

Abstract

Combined acoustic and bottom trawl survey for cod, haddock and redfish were carried out in autumn 1988 in the Svalbard area together with an acoustic survey in the Barents Sea. The abundance indicies of cod decreased from 1987 to 1988 both in the Svalbard area and in the Barents Sea where the index has decreased since previous autumn and since last winter. The results for haddock show that the stock is almost not present in the Svalbard area and that it has decreased in the Barents Sea. The present stock situation of the redfish species Sebastes marinus in this northern part of the species' geographical distribution, show a decreasing trend since 1985-1986 slthough the aoustic sruvey give a higher index in 1988 compared to 1987. The abundance indices of S. mentella point to a more stable stock situation for this species after an alarming period of yearly decrease. Both the bottom trawl survey and the acoustic survey in 1988 confirm this. A huge variability in the indices of S. viviparus is probably caused by the fact that this survey only covers a minor part of the speciesæ geographical distribution. The indices are therefore probably not able of showing real trends in this stock. The abundance of Greenland halibut bas increased to the 1985-level.