Fisheries and Resources Monitoring System

Herring - Northwest of Scotland
Fact Sheet Title  Fact Sheet
ICES Advice 2012
Herring - Northwest of Scotland
Fact Sheet Citation  
Herring in Division VIa (North)
Owned byInternational Council for the Exploration of the Sea (ICES) – ownership
Monitoring Range Max2012. Monitoring Evolution: Herring - West of Scotland, West of Ireland and Porcupine Bank
ident Blockident Blockdisplay tree map
Species List:
Species Ref: en - Atlantic herring, fr - Hareng de l'Atlantique, es - Arenque del Atlántico, ru - Сельдь атлантическая
ident Block Herring - Northwest of Scotland
Aq Res
Biological Stock: Yes         Value: Sub-Regional
Management unit: Yes        Reference year: 2012
Aq Res State Trend
Aq Res State Trend
Aq Res State Trend Aq Res State Trend
Aq Res State TrendBelow targetModerate fishing mortality
Aq Res State TrendAbove limitIntermediate abundance

ICES considers that the stock over recent years has been fluctuating at a low level. Fishing mortality has fluctuated around FMSY in recent years. The current recruitment is lower than in the historical period.
Habitat Bio
Depth Zone: Shelf (50 m - 200 m).   Vertical Dist: Pelagic.  

This autumn-spawning stock is considered a part of the Malin Shelf stock complex. Components of the neighbouring herring stocks to the south are known to be present seasonally in Division VIa (North). Studies in the acoustic survey are ongoing to evaluate the level of mixing. Spawning and nursery areas are sensitive and vulnerable to anthropogenic influences. Gravel extraction or disturbance in the close vicinity of any herring spawning will disturb that spawning activity and will reduce the area available for successful spawning.

Environmental influence on the stock

Temperatures and salinity in this area have been increasing over recent decades. It is known that similar environmental changes have affected the North Sea herring. Productivity of the Division VIa (North) stock has been reduced since the late 1980s.
Geo Dist
Geo Dist: Shared between nations

Water Area Overview
Spatial Scale: Sub-Regional

Ecoregion: Celtic Seas.
Water Area Overview
Aq Res Struct
Biological Stock: Yes

The fisheries

The fishery is conducted by single and pair Refrigerated Sea Water (RSW) trawlers and single-trawl freezer trawlers. Prior to 2006 there was a fairly even distribution of effort, both temporally and spatially. Since 2006 the majority has been fished in the northern part of Division VIa (North) in the 3rd quarter.
Catch distribution Catch (2011) = 17 759 t (50% pelagic freezer trawlers and 50% pelagic RSW trawlers).

Effects of the fisheries on the ecosystem

Herring fisheries tend to be clean with little bycatch of other fish. Scottish discard observer programmes since 1999 indicate that discarding of herring in these directed fisheries are at a low level. These discard observer programmes have recorded occasional catches of seals and zero catches of cetaceans.
Bio Assess
Sci Advice

ICES advises on the basis of the agreed West of Scotland herring management plan that landings in 2013 should be no more than 27 480 t.

ICES advises that activities that impact on the seabed should not take place in spawning grounds unless they can be shown not to have a negative impact on spawning, larval production, or stock dynamics.
Figure Herring in Division VIa (North). Summary of stock assessment (weights in thousand tonnes). Estimates are shaded. Top right: SSB and F over the time-series used in the assessment.
Assess Models

Quality consideration

The assessment is considered to be noisy, but unbiased. Area misreporting continues to be a problem, with almost all countries taking catches of herring in other areas and reporting it into Division VIa (North). However, routine use of VMS has reduced the problem.

Minimum sampling requirements are met in some quarters of the fishery. Samples from all quarters where there is fishing activity would improve allocation of sampled métiers in the stock-raising process.
Figure Herring in Division VIa North. Historical assessment results (final-year recruitment estimates included).

Scientific basis

Assessment type Age-based analytical (FLICA).
Input data One acoustic survey index (MSHAS_N); commercial landings data.
Discards and bycatch Not considered relevant.
Indicators None.
Other information Last informal full range of model settings tested in 2009.
Working group report HAWG
Management unit: Yes

Management plans

A management plan has been adopted by the EU in 2008 (Council Regulation (EC) 1300/2008, Annex 5.4.30). The main aim of the plan is to manage the fisheries on the basis of maximum sustainable yield. ICES has evaluated the plan and concludes that it is in accordance with the precautionary approach.

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. Herring in Division VIa (North). Report of the ICES Advisory Committee, 2012. ICES Advice, June 2012. Click to open
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