|Marine Resource Fact Sheet|
|Greenland halibut - Denmark Strait, 2012|
|Greenland halibut in Subareas V, VI, XII and XIV|
|FAO Names: en - Greenland halibut, fr - Flétan noir, es - Fletán negro, ru - Палтус черный (=палтус гренландский)|
|Considered a single stock: Yes Spatial Scale: Sub-Regional|
Management unit: Yes
Habitat and Biology
Depth zone: Slope (200 m - 1000 m). Vertical distribution: Demersal/Benthic.
Greenland halibut is a relatively slow-growing and long-lived species. Changes in stock dynamics may take several years. Available biological data and distribution of the fisheries suggest that Greenland halibut in Subareas XIV and V belong to the same entity and do mix, although precise stock associations are not known. Tagging studies suggest that some mixing occurs also with Greenland halibut in the Norwegian Sea/Barents Sea. Nursery grounds are unknown.
Jurisdictional distribution: Shared between nations
Water Area Overview
Spatial Scale: Sub-Regional
Ecoregion: Iceland and East Greenland
Considered a single stock: Yes
The fishery is distributed over a vast area, mainly conducted by factory trawlers operating with demersal trawl.
|Catch distribution ||Total landings (2011) are 26 424 t (96% bottom trawl and 4% gillnets/longlines). Discarding is considered to be minor (less than 1% by weight). |
ICES advises on the basis of the MSY approach that landings in 2013 should be no more than 20 000 t.
Overall Assessment Results
|Figure 22.214.171.124 Greenland halibut in Subareas V, VI, XII, and XIV. Summary of the stock assessment (weights in thousand tonnes). Lower panels: trends of biomass and fishing mortality relative to MSY reference points (medians) with indication of 25–75 percentiles (red curves) and 95% confidence intervals (error bars). Top right: relative SSB and F over the years with indication of BMSY (1.0), Blim (0.3BMSY), FMSY (1.0), and Flim (1.7FMSY). Bottom: Landings (thousand tonnes). |
Assessment ModelQuality consideration
Lack of knowledge on life history and stock structure of Greenland halibut in relation to the assessment area (Subareas V, VI, XII, and XIV) impede the interpretation and weighting of the different biomass indices. Lack of information on recruitment to the stock prevents an accurate short-term forecast.Scientific basis
|Assessment type ||A probabilistic (Bayesian) version of a surplus-production model. |
|Input data ||One cpue series of the Icelandic trawl fleet (since 1985) and two trawl surveys (Division Va: since 1996, Subarea XIV: since 1998). |
|Discards and bycatch ||Not considered relevant for the assessment. |
|Indicators ||None. |
|Other information ||A benchmark is planned for 2013 |
|Working group report ||NWWG |
Management unit: YesManagement plans
In 2012 the coastal states have initiated work on a common management plan for Greenland halibut in Subareas V, XII, and XIV. The plan will move in two steps; first, a gradual lowering of the total catches until biological reference points have been evaluated by ICES, and thereafter implementation of a harvest control rule in accordance with ICES MSY approach. The plan will include continuous monitoring of the resources and the requirements on information from the fishery.
Biological State and Trend
Exploitation rate: Above target
Abundance level: Undefined
|Figure 126.96.36.199 |
The assessment is indicative of stock trends, and provides relative measures of stock status. The stock has been below BMSY
since the early 1990s and is presently at 55% of BMSY
. Since the record-low biomass observed in 2004 the stock has been stable with signs of slow increase. Landings have for more than a decade been between 20 000 and 30 000 t. Present fishing mortality is estimated to be 1.4 times the FMSY
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 V, VI, XII, and XIV. Report of the ICES Advisory Committee, 2012. ICES Advice, June 2012. http://www.ices.dk/committe/acom/comwork/report/2012/2012/ghl-grn.pdf