Hopp til hovedteksten
Greenland Halibut
Print friendly version

Northeast Arctic Greenland Halibut

Joint Norwegian-Russian research has demonstrated genetic differences between Greenland halibut from different regions. No differences were found between individuals collected from Haltenbanken and northward around Svalbard. 

However, differences were observed between these fish and individuals collected at the Faroe Islands, Greenland, and Canada. This indicates that the population of northeast Arctic Greenland halibut is isolated and has little exchange with other populations.

Recent research shows that the majority of adult Northeast Arctic Greenland halibut are distributed along the edge between mainland Norway and Svalbard throughout the year. There is very limited occurrence of adult Greenland halibut in east regions of the Barents Sea. Young fish are mainly observed north and east of Svalbard to White Island and Franz Josef Land.

The main spawning area is located in the upper edge of the continental shelf north and south of Bear Island. Northeast Arctic Greenland halibut primarily spawn in deep water (500-800 m) during autumn and winter at the shelf edge between 70 and 75 ° N. Eggs and larvae drift with the currents depending on where spawning takes place. During the last decade, most eggs and larvae have been carried north along the east to Svalbard and Franz Josef Land.

Towards the end of summer and early autumn young Greenland halibut, at lengths of approximately 6-7 cm, begin to settle into the bottom sediments. This occurs after a relatively long (8-10 month) pelagic phase during which larvae are spread over a large area extending to boundaries of the population. During the first 3-4 years halibut remain at or near the area where they settled to the bottom, usually in relatively shallow water (100-300 m). As they mature, they expand beyond their juvenile grounds toward the edge of the Continental Shelf and into deeper parts of the Barents Sea.

More than 40 different prey categories are found in the stomachs of Greenland halibut, but the dominant prey species are capelin, polar cod, squid, and shrimp; waste from fishing boats is also present. As the size of predatory Greenland halibut increases, the proportion of smaller prey groups (shrimp and capelin) decreases, and the proportion of cod, haddock, and fishing boat waste increases. There is little to suggest that Greenland halibut is subject to high grazing pressure. Young fish are only found in the stomachs of three species (Greenland shark, cod, and the halibut itself).  However, marine mammals such as seals and whales may be important predators for halibut.