Habitat and Biology
Depth zone: Slope (200 m - 1000 m). Vertical distribution: Demersal/Benthic.
Greenland halibut is a long-lived species showing considerable sexual dimorphism in growth and maturation. Age-reading methodology for this stock has been reviewed in recent years and there is evidence to show that growth is slower than previously thought.
Tagging studies suggest that some mixing occurs with Greenland halibut in the Iceland/East Greenland area.
Jurisdictional distribution: Shared between nations
Water Area Overview
Spatial Scale: Sub-Regional
Ecoregion: Barents Sea and Norwegian Sea
Considered a single stock: Yes
From 2010 the ban against targeted fishery was lifted by the Joint Russian–Norwegian Fisheries Commission (JRNFC) and since then Greenland halibut has been fished in a directed fishery, and also as bycatch in the fishery for other demersal species.
||Total catch (2011) = 16.3 kt, where 100% landings (58% trawl, 31% longline, 10% gillnet, and 1% others). Not relevant for discards
ICES advises on the basis of precautionary considerations that catches should not be allowed to increase and should not exceed 15 000 t.
Overall Assessment Results
|Figure 184.108.40.206 Greenland halibut in Subareas I and II. Top left: Landings. Below left: Biomass (swept area) estimate of the mature female biomass (Norwegian Greenland halibut survey along the continental slope in August and Russian autumn trawl survey). Below right: Total biomass estimates from the Norwegian Greenland halibut survey along the continental slope in August and Russian autumn trawl survey. No Norwegian survey in 2010. example of description: Cod in Subareas I and II. Summary of stock assessment (weights in thousand tonnes). Top right: SSB/F for the time-series used in the assessment. |
Assessment ModelQuality consideration
None of the current surveys cover the complete stock distribution, but most of the adult distribution area is covered. Biomass estimates from the surveys are not consistent but give evidence of a stable or increasing stock.Scientific basis
||Survey trends-based assessment.
||Two survey indices (Norwegian slope survey (NO-GH-Btr-Q3), Russian autumn survey (RU-BTr-Q4)).
|Discards and bycatch
||Not included in the assessment.
||Survey indices. Discards are not included and are considered to be minor.
||A benchmark is planned for 2013.
|Working group report
Management unit: YesManagement plans
There are no explicit management objectives for this stock.
Biological State and Trend
Source of information
The above excerpts are from the first two pages of the ICES advice, the supporting information to this advice can be read in full at the following reference:
ICES. Greenland halibut in Subareas I and II. Report of the ICES Advisory Committee, 2012. ICES Advice, June 2012. http://www.ices.dk/committe/acom/comwork/report/2012/2012/ghl-arct.pdf