Stock characteristics, fisheries and management of Greenland halibut (Reinhardtius hippoglossoides Walbaum) in the northeast Arctic

Abstract

Greenland halibut (Reinhardtius hippoglossoides (Walbaum)) are widely distributed over wide geographic areas of the Northeast Atlantic Ocean, with no break in the continuity of the distribution from the arctic Frans Josef Land and Novaya Zemlya archipelagos in the north and east to beyond the boreal Shetland Islands in the south. Although the entire Greenland halibut resource in the North Atlantic is genetically homogeneous, they comprise a single interbreeding stock in the Barents Sea and Norwegian Sea areas, which is known as the Northeast Arctic stock. In general, and for most of the year, larger fish become more abundant and smaller fish less abundant in progressively deeper water with peak abundance occurring over a depth range of 400-1 000 m. But during the spring and summer, the mature and bigger fish may be shallower. Greenland halibut in the Northeast Atlantic were observed to be most abundant in bottom temperatures mainly between 0º C and 4º C. The fishery for Greenland halibut in the Northeast Arctic was unregulated until 1992, although since 1995 catches have substantially exceeded those advised. The spawning stock size reached historically low levels during the 1990s and recruitment to the spawning stock remained uncertain. The stock is now showing clear signs of improvement, and is at present rebuilt to above the long-term average of the past 20 years.