Fisheries and Resources Monitoring System

Herring - West of Scotland
Fact Sheet Title  Fact Sheet
ICES Advice 2012
Herring - West of Scotland
Fact Sheet Citation  
Herring in Divisions VIa (South) and VIIb,c
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 - West 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 TrendAbove targetHigh fishing mortality
Aq Res State TrendUndefinedUncertain/Not assessed

An exploratory assessment (including survey data from the Malin shelf acoustic survey) shows that SSB is below Blim. The exploratory assessments show different trends in F: one assessment shows a stable trend at high values, whereas another one shows a decrease since 2006. In both cases F is still above FMSY. Recruitment has been low since 2000.
Habitat Bio
Depth Zone: Shelf (50 m - 200 m).   Vertical Dist: Pelagic.  

This autumn and winter/spring-spawning stock is considered a part of the Malin Shelf Stock Complex. The stock identity is complex as the juveniles mix with those from the west of Scotland and the adults mix with those from the Irish Sea and Division VIaN over the shelf areas to the west of Scotland after spawning. Fish of this stock are expected to mix with VIa North herring in that area. 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 available area for successful spawning.
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 fisheries take place using pelagic trawls in quarter 1 and 4. The low TAC has led to a much shorter fishing season now consisting of only a few days, compared to a five months fishery prior to 2003.
Catch distribution Total landings (2011) = 6919 t, 100% pelagic trawls.

Effects of the fisheries on the ecosystem

The human consumption fisheries for herring are considered relatively clean, with little bycatch of other fish and cetaceans.
Bio Assess
Sci Advice

ICES advises on the basis of MSY approach that there should be no catches of this stock unless a rebuilding plan is implemented.

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 Divisions VIa (South) and VIIb,c. ICES estimates of catches (tonnes), recruitment, SSB (‘000 tonnes) and fishing mortality from a separable VPA (terminal fishing mortality=0.5) and ICA run.
Assess Models

Quality consideration

The exploratory separable VPA assessment is uncertain as it is based on catch-at-age data only. The spatially and temporally truncated fishing season results in catch-at-age data that may be less informative of overall population age structure. The current survey-series is short (2008–2011) and has been used in a new exploratory ICA assessment. This ICA assessment gave similar results to the separable VPA for SSB, but resulted in very different trends in F. The inclusion of fisheries-independent information in the ICA run is considered to be an improvement in 2012. There is some evidence of a stronger (2008) cohort recruiting to the stock, but it is not yet possible to estimate its strength.

Efforts to split the Malin shelf acoustic survey data according to stock component should continue. Improved information is required to the extent to which catches of this component are taken in Division VIaN.

Scientific basis

Assessment type Trends-based exploratory assessments (Separable VPA, FLICA).
Input data

Commercial catch-at-age data.

Acoustic survey data (MSHAS).

Discards and bycatch Not considered relevant.
Indicators None.
Other information A benchmark is suggested for 2014.
Working group report HAWG
Management unit: Yes

Management plans

There is currently no explicit management plan for this stock. A rebuilding plan was proposed by the Pelagic RAC in 2011. ICES has not been requested to evaluate this plan.

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 Divisions VIa (South) and VIIb,c. Report of the ICES Advisory Committee, 2012. ICES Advice, June 2012. Click to open
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