Fisheries and Resources Monitoring System

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Herring - West of Scotland
Marine Resource  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) – More
Related observationsLocate in inventorydisplay tree map
 
Species:
FAO Names: en - Atlantic herring, fr - Hareng de l'Atlantique, es - Arenque del Atlántico, ru - Сельдь атлантическая
Geographic extent of Herring - West of Scotland
Main Descriptors
Considered a single stock: Yes        Spatial Scale: Sub-Regional
Management unit: Yes        Reference year: 2012
 
 
Biological State and Trend
State & Trend Descriptors
PartnerFIRMS
Exploitation rateAbove targetHigh fishing mortality
Abundance levelUndefinedUncertain/Not assessed
Figure 4.5.17.1

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 and Biology
Depth zone: Shelf (50 m - 200 m).   Vertical distribution: 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.
Geographical Distribution
Jurisdictional distribution: Shared between nations

Water Area Overview
Spatial Scale: Sub-Regional


Ecoregion: Celtic Seas
Geo References
Resource Structure
Considered a single stock: Yes
Exploitation
 

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.
Assessment
 
Scientific 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.
Overall Assessment Results
Figure 5.4.17.1 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.
Assessment Model

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
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.
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. Herring in Divisions VIa (South) and VIIb,c. Report of the ICES Advisory Committee, 2012. ICES Advice, June 2012. Click to openhttp://www.ices.dk/committe/acom/comwork/report/2012/2012/her-irlw.pdf
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