Last updated on 28 September 2016

SUMMARY

SUMMARY

IDENTIFICATION

SCIENTIFIC NAME(s)

Nephrops norvegicus

SPECIES NAME(s)

Norway lobster, nephrops

There has been a particular focus on defining the parameters of importance for assessment and management, such as growth and maturation size as well as size frequencies at different depths and sediment types.  There are variations in the biological parameters of Nephrops from different grounds in the North Atlantic East and in the Mediterranean, which have received a lot of attention over the years (e.g.;Farmer 1975; Hoydal 2014; Ulmestrand 2001).

Differences in N. norvegicus population demographic structure among geographical sectors, as well as in total mortality, appear to be highly related to different exploitation levels. (Abelló et al. 2002)

Low levels of differentiation were found between Norway lobster populations and there were no signs of an Atlantic–Mediterranean divide or of an isolation-by-distance scheme of differentiation. (Stamatis et al. 2004)

Stocks are assessed at a Functional Unit (FU) level. Each FU correspond to a specific habitat area. However, this units are managed at ICES Division level.

Thus, Nephrops management areas fall within the TAC regime of the European CFP, although allocated TACs do not coincide totally with the Functional Units.

Currently, there are no management plans applicable to the species.

From 2012, ICES separated its advice for the southern Celtic Sea into two regions: Labadie, Baltimore, Galley, Jones and Cockburn (covered by the present profile) and the Smalls (ICES, 2012a).


ANALYSIS

Strengths

Harvest rates are estimated, based on a data-limited approach, to be decreasing and to be within a maximum sustainable yield (MSY) range.

Weaknesses

An analytical assessment is not conducted and stock status is not known. The TAC is set on too broad a scale to protect against local depletions. Discarding rates are high.

Options

Further information on ecosystem impacts is required.

FISHSOURCE SCORES

Management Quality:

Management Strategy:

< 6

Managers Compliance:

3.9

Fishers Compliance:

10

Stock Health:

Current
Health:

NOT YET SCORED

Future Health:

≥ 6


FIPS

No related FIPs

CERTIFICATIONS

No related MSC fisheries

Fisheries

Within FishSource, the term "fishery" is used to indicate each unique combination of a flag country with a fishing gear, operating within a particular management unit, upon a resource. That resource may have a known biological stock structure and/or may be assessed at another level for practical or jurisdictional reasons. A fishery is the finest scale of resolution captured in FishSource profiles, as it is generally the scale at which sustainability can most fairly and practically be evaluated.

ASSESSMENT UNIT MANAGEMENT UNIT FLAG COUNTRY FISHING GEAR
Labadie European Union, Division 7g,h France Multiple bottom otter trawls
Twin bottom otter trawls
Ireland Multiple bottom otter trawls
Twin bottom otter trawls

Analysis

OVERVIEW

Strengths

Harvest rates are estimated, based on a data-limited approach, to be decreasing and to be within a maximum sustainable yield (MSY) range.

Weaknesses

An analytical assessment is not conducted and stock status is not known. The TAC is set on too broad a scale to protect against local depletions. Discarding rates are high.

Options

Further information on ecosystem impacts is required.

1.STOCK STATUS

STOCK ASSESSMENT

A data-limited assessment is conducted by ICES based on habitat area, estimated burrow density and data from the fishery. LPUE and mean size are used as indicators. The assessment is expected to improve as data-limited methods are improved (ICES, 2012a). Landings and effort data are available from Nephrops-directed fleets, but a change to the French definition of effort has introduced some uncertainty. Other sources of uncertainty stem from a possible underestimation of LPUE and the incompleteness of the time series of discards (ICES, 2012a).

France
Multiple bottom otter trawls

Last updated on 4 January 2013

A data-limited assessment is conducted by ICES based on habitat area, estimated burrow density and data from the fishery. LPUE and mean size are used as indicators. The assessment is expected to improve as data-limited methods are improved (ICES, 2012a). Landings and effort data are available from Nephrops-directed fleets, but a change to the French definition of effort has introduced some uncertainty. Other sources of uncertainty stem from a possible underestimation of LPUE and the incompleteness of the time series of discards (ICES, 2012a).

Twin bottom otter trawls

Last updated on 4 January 2013

A data-limited assessment is conducted by ICES based on habitat area, estimated burrow density and data from the fishery. LPUE and mean size are used as indicators. The assessment is expected to improve as data-limited methods are improved (ICES, 2012a). Landings and effort data are available from Nephrops-directed fleets, but a change to the French definition of effort has introduced some uncertainty. Other sources of uncertainty stem from a possible underestimation of LPUE and the incompleteness of the time series of discards (ICES, 2012a).

SCIENTIFIC ADVICE

ICES previously advised for this fishery together with the remainder of the Celtic Sea fishery. Advice has been provided separately for Functional unit (FU) 20-21 for the first time in 2012. Based on the data-limited approach, landings are advised to be kept below 2,500 tons in 2013. This was determined based on average historical landings, known habitat area and assumed density of Nephrops, along with the known range of maximum sustainable yield (MSY) harvest rates for other Nephops units in the area. Management measures should be implemented at the FU level (ICES, 2012a).

Reference Points

No reference points are defined (ICES, 2012a).

France
Multiple bottom otter trawls

Last updated on 4 January 2013

ICES previously advised for this fishery together with the remainder of the Celtic Sea fishery. Advice has been provided separately for Functional unit (FU) 20-21 for the first time in 2012. Based on the data-limited approach, landings are advised to be kept below 2,500 tons in 2013. This was determined based on average historical landings, known habitat area and assumed density of Nephrops, along with the known range of maximum sustainable yield (MSY) harvest rates for other Nephops units in the area. Management measures should be implemented at the FU level (ICES, 2012a).

Reference Points

Last updated on 04 Jan 2013

No reference points are defined (ICES, 2012a).

Twin bottom otter trawls

Last updated on 4 January 2013

ICES previously advised for this fishery together with the remainder of the Celtic Sea fishery. Advice has been provided separately for Functional unit (FU) 20-21 for the first time in 2012. Based on the data-limited approach, landings are advised to be kept below 2,500 tons in 2013. This was determined based on average historical landings, known habitat area and assumed density of Nephrops, along with the known range of maximum sustainable yield (MSY) harvest rates for other Nephops units in the area. Management measures should be implemented at the FU level (ICES, 2012a).

Reference Points

Last updated on 04 Jan 2013

No reference points are defined (ICES, 2012a).

CURRENT STATUS

andings per unit effort (LPUE) series have decreased in recent years, indicating a decrease in abundance, but no reference points are set and stock status is not known. Mean size in landings and discarding rates suggest no major changes in status however (ICES, 2012a).

Harvest rates have recently decreased and are estimated to be within MSY ranges but could be even lower than those estimated (ICES, 2012a).

Trends

The stock appeared to be in a stable state for a long period, based on indications from LPUE, mean size and discarding rates. Strong recruitment led to an increase in LPUE in 2008 and 2009, but a decrease has occurred since then (ICES, 2012a).

Landings were stable during the 2000s, with small increases reported in 2002-2003 and 2008-2009, coinciding with lower mean size in landings and potentially due to recruitment increases. Landings fell in 2010 and 2011, possibly due to decreased targeting of Nephrops (ICES, 2012a).

France
Multiple bottom otter trawls

Last updated on 4 January 2013

Landings per unit effort (LPUE) series have decreased in recent years, indicating a decrease in abundance, but no reference points are set and stock status is not known. Mean size in landings and discarding rates suggest no major changes in status however (ICES, 2012a).

Harvest rates have recently decreased and are estimated to be within MSY ranges but could be even lower than those estimated (ICES, 2012a).

Trends

Last updated on 04 Jan 2013

The stock appeared to be in a stable state for a long period, based on indications from LPUE, mean size and discarding rates. Strong recruitment led to an increase in LPUE in 2008 and 2009, but a decrease has occurred since then (ICES, 2012a).

Landings were stable during the 2000s, with small increases reported in 2002-2003 and 2008-2009, coinciding with lower mean size in landings and potentially due to recruitment increases. Landings fell in 2010 and 2011, possibly due to decreased targeting of Nephrops (ICES, 2012a).

Twin bottom otter trawls

Last updated on 4 January 2013

Landings per unit effort (LPUE) series have decreased in recent years, indicating a decrease in abundance, but no reference points are set and stock status is not known. Mean size in landings and discarding rates suggest no major changes in status however (ICES, 2012a).

Harvest rates have recently decreased and are estimated to be within MSY ranges but could be even lower than those estimated (ICES, 2012a).

Trends

Last updated on 04 Jan 2013

The stock appeared to be in a stable state for a long period, based on indications from LPUE, mean size and discarding rates. Strong recruitment led to an increase in LPUE in 2008 and 2009, but a decrease has occurred since then (ICES, 2012a).

Landings were stable during the 2000s, with small increases reported in 2002-2003 and 2008-2009, coinciding with lower mean size in landings and potentially due to recruitment increases. Landings fell in 2010 and 2011, possibly due to decreased targeting of Nephrops (ICES, 2012a).

2.MANAGEMENT QUALITY

MANAGEMENT

Current management sets a TAC for the entire ICES Subarea VII, and ICES warns that under this strategy localized effort could cause depletions within functional units (FUs). This TAC was set at 21,759 tons for all ICES Subarea VII in 2012. No management plan is in place.

Both minimum landing sizes and minimum mesh sizes are in use but vary by fleet (ICES, 2012b). The larger French minimum landing size has reportedly led to greater discarding by this fleet although increasing “tailing” has led to greater retention of previously discarded sizes (ICES, 2012a). Discarding of Nephrops is thought to be substantial although discarding by the Irish fleet has apparently decreased in recent years (ICES, 2012b). The substantial discarding is taken to mean that current fishing gear is not the most efficient at selecting marketable Nephrops(ICES, 2012b).

Recovery Plans

None in place.

France
Multiple bottom otter trawls

Last updated on 4 January 2013

Current management sets a TAC for the entire ICES Subarea VII, and ICES warns that under this strategy localized effort could cause depletions within functional units (FUs). This TAC was set at 21,759 tons for all ICES Subarea VII in 2012. No management plan is in place.

Both minimum landing sizes and minimum mesh sizes are in use but vary by fleet (ICES, 2012b). The larger French minimum landing size has reportedly led to greater discarding by this fleet although increasing “tailing” has led to greater retention of previously discarded sizes (ICES, 2012a). Discarding of Nephrops is thought to be substantial although discarding by the Irish fleet has apparently decreased in recent years (ICES, 2012b). The substantial discarding is taken to mean that current fishing gear is not the most efficient at selecting marketable Nephrops (ICES, 2012b).

Recovery Plans

Last updated on 04 Jan 2013

None in place.

Twin bottom otter trawls

Last updated on 4 January 2013

Current management sets a TAC for the entire ICES Subarea VII, and ICES warns that under this strategy localized effort could cause depletions within functional units (FUs). This TAC was set at 21,759 tons for all ICES Subarea VII in 2012. No management plan is in place.

Both minimum landing sizes and minimum mesh sizes are in use but vary by fleet (ICES, 2012b). The larger French minimum landing size has reportedly led to greater discarding by this fleet although increasing “tailing” has led to greater retention of previously discarded sizes (ICES, 2012a). Discarding of Nephrops is thought to be substantial although discarding by the Irish fleet has apparently decreased in recent years (ICES, 2012b). The substantial discarding is taken to mean that current fishing gear is not the most efficient at selecting marketable Nephrops (ICES, 2012b).

Recovery Plans

Last updated on 04 Jan 2013

None in place.

COMPLIANCE

Overall, total landings in ICES Subarea VII have historically been below the set TACs for the area. Landings for Subarea VII have also generally been below the sum of advised catch limits over the Subarea. At the level of the Celtic Sea, the scale at which ICES previously advised (FU 20-22), landings have generally exceeded ICES’ advice (ICES, 2012a). A degree of underreporting is thought to have occurred prior to 2007, subsequently reduced by Buyers and Sellers legislation in the UK and “sales notes” in Ireland, and an increase in the TAC in 2007 (ICES, 2012a). UK and Irish landings are currently close to their quotas whereas French and Spanish catches are well below quotas (ICES, 2012a).

France
Multiple bottom otter trawls

Last updated on 4 January 2013

Overall, total landings in ICES Subarea VII have historically been below the set TACs for the area. Landings for Subarea VII have also generally been below the sum of advised catch limits over the Subarea. At the level of the Celtic Sea, the scale at which ICES previously advised (FU 20-22), landings have generally exceeded ICES’ advice (ICES, 2012a). A degree of underreporting is thought to have occurred prior to 2007, subsequently reduced by Buyers and Sellers legislation in the UK and “sales notes” in Ireland, and an increase in the TAC in 2007 (ICES, 2012a). UK and Irish landings are currently close to their quotas whereas French and Spanish catches are well below quotas (ICES, 2012a).

Twin bottom otter trawls

Last updated on 4 January 2013

Overall, total landings in ICES Subarea VII have historically been below the set TACs for the area. Landings for Subarea VII have also generally been below the sum of advised catch limits over the Subarea. At the level of the Celtic Sea, the scale at which ICES previously advised (FU 20-22), landings have generally exceeded ICES’ advice (ICES, 2012a). A degree of underreporting is thought to have occurred prior to 2007, subsequently reduced by Buyers and Sellers legislation in the UK and “sales notes” in Ireland, and an increase in the TAC in 2007 (ICES, 2012a). UK and Irish landings are currently close to their quotas whereas French and Spanish catches are well below quotas (ICES, 2012a).

3.ENVIRONMENT AND BIODIVERSITY

BYCATCH
ETP Species

There is no specific information on the impact of this fishery on Protected, Endangered and Threatened species.

France
Multiple bottom otter trawls

Last updated on 4 January 2013

There is no specific information on the impact of this fishery on Protected, Endangered and Threatened species.

Twin bottom otter trawls

Last updated on 4 January 2013

There is no specific information on the impact of this fishery on Protected, Endangered and Threatened species.

Other Species

Nephrops occur in several discrete areas of muddy sediment and fisheries targeting different areas have very different size structures of catches. These fisheries also have differences in non-Nephrops bycatch composition (cod, whiting, and to a lesser extent haddock and hake). Discarding rates are relatively high (ICES, 2012a).

France
Multiple bottom otter trawls

Last updated on 4 January 2013

Nephrops occur in several discrete areas of muddy sediment and fisheries targeting different areas have very different size structures of catches. These fisheries also have differences in non-Nephrops bycatch composition (cod, whiting, and to a lesser extent haddock and hake). Discarding rates are relatively high (ICES, 2012a).

Twin bottom otter trawls

Last updated on 4 January 2013

Nephrops occur in several discrete areas of muddy sediment and fisheries targeting different areas have very different size structures of catches. These fisheries also have differences in non-Nephrops bycatch composition (cod, whiting, and to a lesser extent haddock and hake). Discarding rates are relatively high (ICES, 2012a).

HABITAT

Nephrops are distributed in discrete patches, limited by sediment suitable for burrowing. There is a larval phase where there may be some mixing with Nephrops from other areas depending on the oceanographic conditions, but the mechanisms for this in the Celtic Sea are not currently known.

The characteristics of Nephrops sediment also mean that the seabed is vulnerable to trawling impacts, and trawl marks remain visible for some time. Although fishing intensity is very high in some regions, burrowing fauna can be seen re-emerging from freshly trawled grounds, implying that there is some resilience to trawling (ICES, 2012a).

Marine Reserves

No known marine protected areas are declared within FUs 20 and 21. Ireland and the UK have several (mostly coastal) MPAs declared under EU directives.

France
Multiple bottom otter trawls

Last updated on 4 January 2013

Nephrops are distributed in discrete patches, limited by sediment suitable for burrowing. There is a larval phase where there may be some mixing with Nephrops from other areas depending on the oceanographic conditions, but the mechanisms for this in the Celtic Sea are not currently known.

The characteristics of Nephrops sediment also mean that the seabed is vulnerable to trawling impacts, and trawl marks remain visible for some time. Although fishing intensity is very high in some regions, burrowing fauna can be seen re-emerging from freshly trawled grounds, implying that there is some resilience to trawling (ICES, 2012a).

Marine Reserves

Last updated on 04 Jan 2013

No known marine protected areas are declared within FUs 20 and 21. Ireland and the UK have several (mostly coastal) MPAs declared under EU directives.

Twin bottom otter trawls

Last updated on 4 January 2013

Nephrops are distributed in discrete patches, limited by sediment suitable for burrowing. There is a larval phase where there may be some mixing with Nephrops from other areas depending on the oceanographic conditions, but the mechanisms for this in the Celtic Sea are not currently known.

The characteristics of Nephrops sediment also mean that the seabed is vulnerable to trawling impacts, and trawl marks remain visible for some time. Although fishing intensity is very high in some regions, burrowing fauna can be seen re-emerging from freshly trawled grounds, implying that there is some resilience to trawling (ICES, 2012a).

Marine Reserves

Last updated on 04 Jan 2013

No known marine protected areas are declared within FUs 20 and 21. Ireland and the UK have several (mostly coastal) MPAs declared under EU directives.

FishSource Scores

SELECT SCORES

MANAGEMENT QUALITY

As calculated for 2012 data.

The score is < 6.

According to ICES, the management system is not precautionary enough to avoid potential local depletion of the stocks in separate functional units (ICES, 2012a).

As calculated for 2012 data.

The score is 3.9.

This measures the Set TAC as a percentage of the Advised TAC.

The Set TAC is 21.8 ('000 t). The Advised TAC is 15.8 ('000 t) .

The underlying Set TAC/Advised TAC for this index is 138%.

As calculated for 2011 data.

The score is 10.0.

This measures the Catch as a percentage of the Set TAC.

The Catch is 16.1 ('000 t). The Set TAC is 21.8 ('000 t) .

The underlying Catch/Set TAC for this index is 74.0%.

STOCK HEALTH:

As calculated for 2012 data.

The score is ≥ 6.

Although fishing mortality is not determined, ICES estimates, based on a data-limited approach, that harvest rates are decreasing and apparently within a desirable range.

No data available for biomass
No data available for biomass
To see data for catch and tac, please view this site on a desktop.
No data available for fishing mortality
No data available for fishing mortality
No data available for recruitment
No data available for recruitment
To see data for management quality, please view this site on a desktop.
To see data for stock status, please view this site on a desktop.

No related analysis

Download Source Data

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Fishery Improvement Projects (FIPs)

No related FIPs

Certifications

Marine Stewardship Council (MSC)

No related MSC certifications

Sources

Credits

ICES, 2012a. Report of the ICES Advisory Committee 2012. Book 5: Celtic Sea and West of Scotland. 5.4.34. Nephrops in Subarea VII. http://www.ices.dk/committe/acom/comwork/report/2012/2012/Nep-VII.pdf

ICES, 2012b. Report of the Working Group for Celtic Seas Ecoregion (WGCSE), 9-18 May 2012, Copenhagen, Denmark. ICES CM 2012/ACOM:12. http://www.ices.dk/reports/ACOM/2012/WGCSE/CelticSeasEcoregion_final_2012.pdf

Appended content

  1. ICES, 2012a. Report of the ICES Advisory Committee 2012. Book 5: Celtic Sea and West of Scotland. 5.4.34. Nephrops in Subarea VII. http://www.ices.dk/committe/acom/comwork/report/2012/2012/Nep-VII.pdf
  2. ICES, 2012b. Report of the Working Group for Celtic Seas Ecoregion (WGCSE), 9-18 May 2012, Copenhagen, Denmark. ICES CM 2012/ACOM:12.http://www.ices.dk/reports/ACOM/2012/WGCSE/CelticSeasEcoregion_final_2012.pdf
    References

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      Norway lobster - Labadie

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