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Plaice - Eastern Channel
Marine Resource  Fact Sheet
ICES Advice 2009
Plaice - Eastern Channel
Fact Sheet Citation  
Plaice in Division VIId (Eastern Channel)
Owned byInternational Council for the Exploration of the Sea (ICES) – More
Related observationsLocate in inventorydisplay tree map
 
Species:
FAO Names: en - European plaice, fr - Plie d'Europe, es - Solla europea, ru - Камбала морская
Geographic extent of Plaice - Eastern Channel
Main Descriptors
Considered a single stock: Yes        Spatial Scale: Sub-Regional
Management unit: Yes        Reference year: 2008
 
 
Biological State and Trend
State & Trend Descriptors
PartnerFIRMS
Exploitation rateUnknownUncertain/Not assessed
Abundance levelUnknownUncertain/Not assessed


Spawning biomass in relation to precautionary limits Fishing mortality in relation to precautionary limits Fishing mortality in relation to high long-term yield Fishing mortality in relation to agreed management targets

Comment

Unknown Unknown Unknown Unknown  



The assessment is indicative of trends only. The SSB trends suggest that the spawning-stock biomass has declined through the last 15 years to a stable historical low level. The current level of SSB is low. F varies without trend around the long-term average. Recruitment in 2006 and 2007 have been above average.
Habitat and Biology
Depth zone: Shelf (50 m - 200 m).   Vertical distribution: Demersal/Benthic.  

Geographical Distribution
Jurisdictional distribution: National

Water Area Overview
Spatial Scale: Sub-Regional

Geo References
Resource Structure
Considered a single stock: Yes
Exploitation
 

Factors affecting the fisheries and the stock

The effects of regulations

In previous years, effort from the beam trawl fleet has not been restricted. The new EU Council Regulation (EC) N°43/2009 does not reduce the effort for this fleet.
Assessment
 
Assessment Model
Methodology

Scientific basis

Data and methods

The XSA exploratory assessment is valid for trends only and is based on reported landings data, three commercial cpue indices, and three survey indices. Time-series of discard data are not available, but observations from all fisheries from 2003 indicate that discards are high.

Uncertainties in assessment and forecast

There is uncertainty about the stock structure. Historical tagging information shows that around 40% of the juvenile plaice in Division VIId come from nursery grounds in the North Sea, while the Eastern Channel supplies very few recruits to the North Sea. Similarly, around 20% of the recruits in Division VIIe come from VIId, while VIId does not receive significant numbers of juvenile from VIIe. There is also an adult migration between the North Sea and the Channel – 20–30% of the plaice caught in the winter in VIId were from migratory North Sea fish. The available information also suggests that plaice may migrate from the VIIe into the VIId and the North Sea after spawning.

Lack of discarding information also adds to the uncertainty. Routine discard sampling began in 2003 following the introduction of the EU Data Collection Regulations and indicates percentages of discards up to 50% in number, depending on the trip and on fishing practices. However, the time-series of discards is not yet long enough to be used in an analytical assessment.

Comparison with previous assessment and advice

The assessment was considered unreliable due to problems in stock structure identity and the absence of discards in the assessment. This year’s advice is similar to last year’s advice which was not to exceed average recent landings.
Overall Assessment Results


Figure 6.4.8.1 Plaice in Division VIId (Eastern Channel). Landings (in ‘000 t), fishing mortality, recruitment, and SSB. Indicative of trends only.


Figure 6.4.8.2 Plaice in Division VIId. Catches/landings by country and by area (in '000 t).

Reference Point
 


  Type Value Technical basis
Precautionary approach Blim 5,600 t Bloss (~1995)
  Bpa 8,000 t 1.4 Blim
  Flim 0.54 Floss (~1995)
  Fpa 0.45 5th percentile of Floss; long-term SSB >Bpa
and P(SSBMT<Bpa) < 10%.
Targets Fy Not defined  
(unchanged since 1998)


Scientific Advice

Single-stock exploitation boundaries

In the absence of a short-term forecast, ICES advises on the basis of exploitation boundaries in relation to precautionary considerations that landings in 2010 should not increase above the average of landings from the last three years (2006–2008), corresponding to landings less than 3 500 t.


Table 6.4.8.1 Plaice in Division VIId. Single stock exploitation boundaries (advice), management and landings.
Year

ICES Advice

(Single-stock Exploitation Boundaries since 2004)

Predicted catch corresp. to advice

Agreed

TAC1

Official

landings

ICES

landings

1987 Precautionary TAC1 6.81 8.3 7.9 8.4
1988 Precautionary TAC1 6.91 9.96 9.1 10.4
1989 No increase in effort1 11.71 11.7 6.72 8.8
1990 No increase in F; TAC 10.71 10.7 7.82 9.0
1991 TAC 8.81 10.7 7.42 7.8
1992 Status quo F gives mean SSB 7.63 9.6 6.2 6.3
1993 Within safe biological limits 6.43 8.5 4.8 5.3
1994 No long-term gains in increased F - 9.1 5.6 6.1
1995 No increase in F 5.6 8.0 4.6 5.1
1996 No long-term gains in increasing F 6.5 7.53 4.6 5.4
1997 No advice - 7.09 5.3 6.3
1998 Reduce F in 98 by 30% from 96 value 4.3 5.7 4.8 5.8
1999 Fishing at Fpa 6.3 7.4 5.4 6.3
2000 Fishing at Fpa 4.9 6.5 5.2 6.0
2001 Fishing at <Fpa <4.4 6.0 5.0 5.3
2002 Fishing at <Fpa <5.8 6.7 5.5 5.8
2003 Fishing at <Fpa <5.3 6.0 4.5 4.5
2004 Fishing at <Fpa *) <5.4 6.06 4.0 4.0
2005 Fishing at <Fpa *) <4.4 5.15 3.0 3.4
2006 No effort increase *)   5.15 3.3 3.3
2007 Average landings *) <4.0 5.08 3.7 3.7
2008 Average landings *) <3.5 5.05 3.5 3.5
2009 Average landings *)

<3.5

4.64    
2010 Average landings *) <3.5      

Weights in ‘000 t.

1TACs for Divisions VIId,e.

2For France Division VIId landings are estimated by ICES from the combined VIId,e landings.

3 Catch at status quo F.

*) Single-stock boundary and the exploitation of this stock should be conducted in the context of mixed fisheries.

Management
Management unit: Yes

Management Objectives

There are no explicit management objectives for this stock.
Management Advice

Management considerations

There is a limited directed fishery on plaice at the beginning of the year on the spawning grounds. This fishery catches plaice that originates from both the North Sea and VIId components. However, plaice is mainly taken as bycatch in the demersal fisheries, especially in the fisheries targeting sole.

Due to the minimum mesh size (80 mm) in the mixed beam trawl fishery, a large number of undersized plaice are discarded. The 80-mm mesh size is not matched to the minimum landing size of plaice (27 cm). Measures taken specifically directed at sole fisheries will also impact the plaice fisheries.

Following the EU Commission consultation paper on TACs for 2010 (COM(2009) 224, 12 May 2009) this stock would be categorised based on the average of SSB in the last 2 years compared to the average of the 3 preceding years. For this stock only relative measures of stock biomass are available but these show a reduction of 3%, resulting in an unchanged TAC. ICES has not evaluated this rule in relation to the precautionary approach.
Source of information
 
ICES.2009.Report of the ICES Advisory Committee, 2009. ICES Advice, 2009.
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