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Norway lobster - Moray Firth, 2008
Marine Resource  Fact Sheet
ICES Advice 2009
Norway lobster - Moray Firth, 2008
Fact Sheet Citation  
Nephrops in Moray Firth (FU 9)
Owned byInternational Council for the Exploration of the Sea (ICES) – More
Related observationsLocate in inventorydisplay tree map
 
Species:
FAO Names: en - Norway lobster, fr - Langoustine, es - Cigala
Geographic extent of Norway lobster - Moray Firth
Main Descriptors
Considered a single stock: Yes        Spatial Scale: Sub-Regional
Management unit: Yes
 
 
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
Assessment
 
Assessment Model
Methodology

Scientific basis

Data and methods

UWTV survey estimates are available for 1993–1994 and from 1996 onwards. Length compositions from the commercial fishery are available from 1980. Potential bias in survey design has been detected and accounted for in the assessment this year (see “Data and methods” section at the start of section 6.4.14.)

Uncertainties in assessment and forecast

General comments are found at the start of section 6.4.14

Information from the fishing industry

The NSCFP survey (Figure 6.4.14.3) does not include specific information for the Moray Firth.

Comparison with previous assessment and advice

The perception of the stock in 2008 is similar to that of the stock in 2007

The advice in 2008 was based on recent landings as the UWTV surveys were considered inappropriate to use as absolute indices of abundance. Following the outcome of the benchmark in 2009, the major concerns of the UWTV survey have been addressed and the survey is now considered a reliable estimate of absolute abundance.

The landings forecast for 2010 (< 1 372 t) is considerably lower than for 2009 (< 1 800t). This is due to using the status quo F (F2008) as the target F for this stock in the current advice.
Overall Assessment Results


Figure 6.4.14.5.1 Nephrops, Moray Firth (FU 9). Long-term trends in landings, effort, lpues, and mean sizes of Nephrops.


Figure 6.4.14.5.2 Nephrops, Moray Firth (FU 9). Time-series of bias adjusted UWTV survey abundance estimates (in millions), with 95% confidence intervals, 1993–2008


Figure 6.4.14.5.3 Nephrops, Moray Firth (FU 9), Catch length frequency distribution and mean sizes (red line).


Table 6.4.14.5.2 Nephrops, Moray Firth (FU 9), Catch length frequency distribution and mean sizes (red line).
Year All Nephrops gears combined Single rig Multirig
  Landings Effort LPUE Landings Effort LPUE Landings Effort LPUE
1981 1298 36.7 35.4 1298 36.7 35.4 na na na
1982 1034 28.2 36.7 1034 28.2 36.7 na na na
1983 850 21.4 39.7 850 21.4 39.7 na na na
1984 960 23.2 41.4 960 23.2 41.4 na na na
1985 1908 49.2 38.8 1908 49.2 38.8 na na na
1986 1933 51.6 37.5 1933 51.6 37.5 na na na
1987 1723 70.6 24.4 1723 70.6 24.4 na na na
1988 1638 60.9 26.9 1638 60.9 26.9 na na na
1989 2102 69.6 30.2 2102 69.6 30.2 na na na
1990 1700 58.4 29.1 1700 58.4 29.1 na na na
1991 1284 47.1 27.3 571 25.1 22.7 713 22.0 32.4
1992 1282 40.9 31.3 624 24.8 25.2 658 16.1 40.9
1993 1505 48.6 31.0 783 28.1 27.9 722 20.6 35.0
1994 1178 47.5 24.8 1023 42.0 24.4 155 5.5 28.2
1995 967 30.6 31.6 857 27.0 31.7 110 3.6 30.6
1996 1084 38.2 28.4 1057 37.4 28.3 27 0.8 33.8
1997 1102 47.7 23.1 960 42.5 22.6 142 5.1 27.8
1998 739 34.4 21.5 576 28.1 20.5 163 6.3 25.9
1999 813 35.5 22.9 699 31.5 22.2 114 4.0 28.5
2000 1343 49.5 27.1 1068 39.8 26.8 275 9.7 28.4
2001 1188 47.6 25.0 913 37.0 24.7 275 10.6 25.9
2002 1526 35.5 43.0 649 27.2 23.9 234 7.9 29.6
2003 1718 41.1 41.8 737 25.3 29.1 135 3.6 37.5
2004 1818 36.9 49.3 1100 29.2 37.7 123 2.5 49.2
2005 1526 37.6 40.6 1309 34.0 38.5 217 3.6 60.3
2006 1718 41.1 41.8 1477 37.4 39.5 241 3.7 65.1
2007 1816 36.9 49.2 1502 32.4 46.4 314 4.5 69.8
2008 1443 30.1 47.9 1125 25.3 44.5 318 4.8 66.3


Table 6.4.14.5.3 Nephrops, Moray Firth (FU 9). Survey indices with and without bias adjustment. Values after 2002 have been adjusted for revised camera parameters).
Year Mean
density
Abundance 95%
confidence
interval
Adjusted for bias 95%
confidence
interval
           
           
  burrows/m² millions millions millions millions
1993 0.19 418.0 94 345 78
1994 0.39 850.0 213 702 176
1995          
1996 0.26 563.0 109 465 90
1997 0.14 317.0 66 262 55
1998 0.18 391.0 115 323 95
1999 0.22 483.8 105 400 87
2000 0.212 466.8 118 386 98
2001 0.19 416.9 135 345 112
2002 0.29 629.7 146 520 121
2003 0.40 882.5 380 729 314
2004 0.35 757.5 225 626 186
2005 0.48 1051.8 239 869 198
2006 0.25 539.1 150 446 124
2007 0.29 641.6 189 530 157
2008 0.26 578.9 183 478 151

Reference Point
 


F

reference point

Harvest

ratio

Technical basis
F0.1 8.9% WKNEPH 2009
Fmax 16.6% WKNEPH 2009
(unchanged since 2009)


Scientific Advice

Single-stock exploitation boundaries

ICES advises on the basis of exploitation boundaries in relation to high long term yield and low risk of depletion of production potential that the Harvest Rate for Nephrops fisheries should not exceed F2008. This corresponds to landings of no more than 1 372 tonnes for the Moray Firth stock.


Basis: Bias corrected survey index (2008) = 478
Rationale Harvest rate

Landings

2010

(tonnes)

  5.0% 520
F0.1 8.9% 926
  10.0% 1040
F 2008 13.2% 1372
  15.0% 1560
Fmax 16.6% 1727
  20.0% 2080


Table 6.54.14.5.1 Nephrops, Moray Firth (FU 9). Single-stock exploitation boundaries (advice), management, and landings.
Year ICES advice

Recommended landings

Moray Firth

(FU9)

Recommended

landings

FU9+FU10

ICES landings

FU91)

1987       2.0
1988       2.0
1989       2.6
1990       2.0
1991       1.5
1992     ~2.4 1.6
1993     2.4 1.8
1994     2.4 1.5
1995     2.4 1.3
1996 Status quo TAC   2.4 1.5
1997 Status quo TAC   2.4 1.4
1998     2.4 1.0
1999     2.4 1.0
2000     1.85 1.5
2001     1.85 1.4
2002 Catches to be maintained at the 2000 level   2.0 1.1
2003 Catches to be maintained at the 2000 level   2.0 1.1
2004 Catches to be maintained at the 2000 level   2.0 1.3
2005 Catches to be maintained at the 2000 level   2.0 1.6
2006 No increase in effort   - 1.8
2007 No increase in effort, and harvest rate
below 15%
2.4 2.64 1.8
2008 No new advice, same as for 2007 2.4 2.64 1.5
2009 No increase in effort and recent average landings < 1.8    
2010 Harvest Rate no greater than that equivalent to fishing at F2008 < 1.4 --2)  

Weights in ‘000 t.

1) Does not include discards. 2) It is not advised to manage these stocks as a single unit.



Management
Management unit: Yes

Management Advice

Management considerations

To protect the stock in this Functional Unit, management is required to be implemented at the Functional Unit level.

A reduction of the catch corresponding to F2008 can be considered as an intermediate step toward F0.1 (as a proxy for Fmsy). Alternatively, a constraint on the year to year change in TAC as is typical of management plans and the Communication on Fishing Opportunities for 2010 [COM (2009) 224] might be considered.

There is a bycatch of other species in the Moray Firth area. It is important that efforts are made to ensure that unwanted bycatch is kept to a minimum in this fishery. Current efforts to reduce discards and unwanted bycatches of cod under the Scottish Conservation credits scheme, include the implementation of larger meshed square mesh panels and real time closures to avoid cod.

Factors affecting the fisheries and the stock

In the Moray Firth area the Nephrops stock inhabits a single continuous area of muddy sediment extending from north of Fraserburgh to Inverness.

The Moray Firth Nephrops ground is located close to the Scottish coast and is exploited almost exclusively by UK vessels. Landings from this fishery are predominantly reported from Scotland, with very small contributions from England in the mid-1990s, but none recently.

Regulations and their effects

Discarding rates averaged over the period 2006 to 2008 for this stock were about 6% by number. This represents a marked reduction in discarding rate compared to the average for the period 2003 to 2005. This may arise from the increasing use of larger size meshes in the northern North Sea, although reduction in recruitment may also account for this change.
Biological State and Trend
Exploitation rate: Undefined
Abundance level: Undefined

The evidence from the UWTV survey suggests that the population is stable, but at a lower level than that evident from 2003-2005. The UWTV survey information, taken together with information showing stable mean sizes, suggest that the stock is being exploited sustainably.


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 target

Comment

Unknown Unknown Unknown N/a  


Source of information
 
ICES.2009.Report of the ICES Advisory Committee, 2009. ICES Advice, 2009.
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