Last updated on 28 September 2016

SUMMARY

SUMMARY

IDENTIFICATION

SCIENTIFIC NAME(s)

Cancer pagurus

SPECIES NAME(s)

Edible crab, Brown crab

The stock structure of edible (brown) crabs around Scotland is not completely understood. Marine Scotland Science considers twelve assessment units, each of which assessed and managed separately (ICES, 2013; Barreto and Bailey, 2014).

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ANALYSIS

Strengths
  • An assessment is conducted with available data, allowing exploitation rates to be determined and growth overfishing detected.
  • The gear used has low environmental impacts.
Weaknesses
  • Stock assessment for 2009-2012 indicated that the current fishing mortality is above the recommended level (FMSY) for both females and males.
  • The assessment conducted only provides long-term trends assuming population equilibrium and cannot detect recruitment overfishing. Biomass or abundance can also not be estimated.
Options

Reliable effort data should be provided by fishers to enable LPUE to be determined and abundance estimated. If the currently assumed stock structure is accurate, growth parameters should be locally determined to improve the assessment quality. More regularity is required in discard sampling. It is important to assess the status of Nephrops caught in the fishery.

FISHSOURCE SCORES

Management Quality:

Management Strategy:

≥ 6

Managers Compliance:

≥ 6

Fishers Compliance:

≥ 8

Stock Health:

Current
Health:

NOT YET SCORED

Future Health:

< 6


RECOMMENDATIONS

CATCHERS & REGULATORS

1. Review the FishSource profile and publish or share online relevant missing information in your possession or those accessible to you.
2. Encourage scientists to share their studies/publications with FishSource by commenting on the profile and uploading a hyperlink to the document.
3. Work with scientists on the collection of data and make them accessible online.
4. Encourage the institutionalization of data collection and publication.

RETAILERS & SUPPLY CHAIN

1. Advise your suppliers that currently the FishSource profile reflects that there is not enough information publicly available on this fishery and you are unable to make an accurate determination of the sustainability status. Request that they advise the relevant authorities of the situation and that efforts need to be made to collect and publish data and disclose data sources to FishSource to better inform buying decisions.


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
East Coast Scotland Scotland East Coast United Kingdom Pots

Analysis

OVERVIEW

Last updated on 7 December 2014

Strengths
  • An assessment is conducted with available data, allowing exploitation rates to be determined and growth overfishing detected.
  • The gear used has low environmental impacts.
Weaknesses
  • Stock assessment for 2009-2012 indicated that the current fishing mortality is above the recommended level (FMSY) for both females and males.
  • The assessment conducted only provides long-term trends assuming population equilibrium and cannot detect recruitment overfishing. Biomass or abundance can also not be estimated.
Options

Reliable effort data should be provided by fishers to enable LPUE to be determined and abundance estimated. If the currently assumed stock structure is accurate, growth parameters should be locally determined to improve the assessment quality. More regularity is required in discard sampling. It is important to assess the status of Nephrops caught in the fishery.

RECOMMENDATIONS

Last updated on 28 July 2016

Improvement Recommendations to Catchers & Regulators

1. Review the FishSource profile and publish or share online relevant missing information in your possession or those accessible to you.
2. Encourage scientists to share their studies/publications with FishSource by commenting on the profile and uploading a hyperlink to the document.
3. Work with scientists on the collection of data and make them accessible online.
4. Encourage the institutionalization of data collection and publication.

Recommendations to Retailers & Supply Chain

1. Advise your suppliers that currently the FishSource profile reflects that there is not enough information publicly available on this fishery and you are unable to make an accurate determination of the sustainability status. Request that they advise the relevant authorities of the situation and that efforts need to be made to collect and publish data and disclose data sources to FishSource to better inform buying decisions.

1.STOCK STATUS

STOCK ASSESSMENT

Last updated on 8 December 2014

Assessments are conducted by Marine Scotland Science on triennial basis and the most recent assessment considered data from 2009-2012 (Barreto and Bailey, 2014). No effort data from the fishery is available.

Regional assessments of crab stocks around Scotland are based on size compositions from commercial catches and biological parameters are used to estimate fishing mortality for males and females separately via Length Cohort Analysis (LCA), in the absence of other data (Jones et al., 2010; Mesquita et al., 2011). Short-term trends in the stock are not identified by LCA and although growth overfishing can be detected by changes in length composition, recruitment overfishing (depletion of spawners) cannot be diagnosed (ICES, 2011). The assessment is very sensitive to changes in the biological parameters used. An exploratory analysis of mean size trends was conducted for the first time in 2011, aiming to add information on recruitment and fishing mortality (Mesquita et al., 2011).

There are some concerns about the state of crab stocks, namely on whether the inshore and offshore are linked or part of the same population, and how fishing in one area may affect the stock. Tagging study to obtain information on migratory and life history patterns of brown crab to the north west of Scotland provided evidence of significant movements of crab stocks, in particular movements of female crab from offshore to inshore areas (Jones et al., 2010). However, more tagging studies are needed to access the linkage between inshore and offshore stocks in other areas.

SCIENTIFIC ADVICE

Last updated on 8 December 2014

No specific management actions have been advised, but overfishing on both males and females was noted in the 2009-2012 assessment. Higher yield and biomass per recruit in the long term could potentially be obtained by reducing the level of fishing mortality (effort) (Barreto and Bailey, 2014).

Reference Points

Last updated on 08 Dec 2014

Stock status is assessed in evaluated in terms of FMAX, the fishing mortality that maximizes yield per recruit and defines growth overfishing. FMAX is used as a proxy for FMSY. All FMSY proxy values remain preliminary and may be modified following further data exploration and analysis (Barreto and Bailey, 2014). FMAX for females was estimated at 0.29 and for males at 0.36.F0.1 is also determined (Mesquita et al., 2011).

CURRENT STATUS

Last updated on 7 December 2014

Fishing mortality was estimated to be above recommended levels (FMSY) for both males and females in East Coast (Barreto and Bailey, 2014). Landings have been increasing since 2009.

Males compose around 60% of landings. The exploratory trend analysis conducted for the first time indicated a decrease in size of larger crabs on the East Coast when compared to the early 1990s, but an increase when compared to earlier sizes, interpretable as either a recent increase in fishing mortality or as due to a change in fishing or discard practices (Mesquita et al., 2011).

Trends

Last updated on 07 Dec 2014

The mean 2006-2008 fishing mortality for female stocks (0.33) was close to FMAX (0.29) while males (0.54) are being fished above FMAX (0.36). Recruitment overfishing cannot be estimated (Mesquita et al., 2011).

Crab landings in Scotland have increased over the past 30 years as improved technology led to a larger offshore target fleet, and new markets have developed as live crab become transportable. Landings from the East Coast have been variable over the years but no overall trend is detectable (Mesquita et al., 2011).

High recruitment is thought to have occurred in 2003 and 2005, from market sampling data (Mesquita et al., 2011).

2.MANAGEMENT QUALITY

MANAGEMENT

Last updated on 5 September 2012

An EU-regulated minimum landing size of 130 or 140 mm, by area, is the principal management measure. Additionally, there are EU measures in place to restrict the fishing effort (kW days) of all vessels > 15 m (including creel boats) in ICES Subarea VI (Barreto and Bailey, 2014). A shellfish license is required and the only catch limit in place is 25 crabs/day for non-license holders (Mesquita et al., 2011). The retention of detached crab claws is also limited (EU, 1998).

Recovery Plans

Last updated on 05 Sep 2012

None in place.

COMPLIANCE

Last updated on 5 September 2012

Under-reporting of landings is thought to have been an issue in the past, but not since the 2005 introduction of buyers and sellers regulations (Mesquita et al., 2011).

3.ENVIRONMENT AND BIODIVERSITY

BYCATCH
ETP Species

Last updated on 5 September 2012

There are reports of otter, a protected species in Scotland, bycatch in creel fisheries (Marine Scotland, 2008) although impacts are estimated to be low (Hervás et al., 2012). Sea turtle and marine mammal entanglement in pot ropes is also an issue (Hervás et al., 2012); leatherback turtles are globally critically endangered (Sarti Martinez, 2008) and bycatch rates in fisheries may be threatening their survival (Marine Scotland, 2008). Bycatch rates of right whales (IUCN Endangered; Reilly et al., 2008a), humpback whales (IUCN Least Concern; Reilly et al., 2008b) or minke whales (IUCN Least Concern; Reilly et al., 2008c) are not quantified (Hervás et al., 2012).

Other Species

Last updated on 7 December 2014

Scottish creel (pot) fisheries are mixed, also landing velvet swimcrab Necora puber and European lobster Homarus gammarus. Velvet crabs on the East Coast are being fished at FMAX but lobsters above this level (Mesquita et al., 2011). Red crab Chaceon quinquedens, stone king crab Lithodes maja and green crab Carcinus maenas make up a minority of landings. Common spiny lobster Palinurus elephas and Norway lobster Nephrops norvegicus may also be landed (Mill et al., 2011), but the state of the latter’s stock in the region is unknown (ICES, 2012). In addition to cod, undifferentiated ‘Rockling’ and ‘wrasse’ have been reported among finfish bycatch, as have ling, conger eel, dogfish, poor cod, pollack, saithe and haddock (Smith et al., 2010). Non-target species are usually released alive. Discards in crab fisheries are sampled only on an irregular basis (ICES, 2013)

HABITAT

Last updated on 5 September 2012

Habitat impacts due to the gear type used are negligible, but ghost fishing due to lost gear is possible.

Marine Reserves

Last updated on 05 Sep 2012

No closed areas are defined for the fishery on the East Coast. Special Protection Areas (SPAs) under the Birds Directive and Special Areas of Conservation (SACs) with marine components are defined on the East Coast and several potential MPA locations are being assessed off the East Coast related to habitat feature, sandeel and horse mussels (Marine Scotland, 2012).

FishSource Scores

SELECT SCORES

MANAGEMENT QUALITY

As calculated for 2012 data.

The score is ≥ 6.

There are no management objectives; the stock is not quota managed but there are effort limitations and minimum landing size in place. The stock status is assessed in relation to the FMSY reference point. FMAX, the fishing mortality rate that maximizes yield per recruit is used as a proxy for FMSY (Barreto and Bailey, 2014).

As calculated for 2012 data.

The score is ≥ 6.

No specific management actions have been advised, but overfishing on both males and females was noted in the 2009-2012 assessment and a reduction in effort advised (Barreto and Bailey, 2014). The need to collect effort data was similarly raised previously (Mill et al., 2009).

As calculated for 2012 data.

The score is ≥ 8.

There are no indications of under-reporting since the introduction of Buyers and Sellers regulations (Mesquita et al., 2011).

STOCK HEALTH:

As calculated for 2012 data.

The score is < 6.

Stock assessment for 2009-2012 indicated that the current fishing mortality is above the recommended level (FMSY) for both females and males (Barreto and Bailey, 2014).

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.
DATA NOTES
  1. FMAX levels are the only reference points defined – they are independent for males and females so score #5 is determined qualitatively.
  2. As no management plan is in use and no TACs are set, scores 1-3 are also determined qualitatively, based on available information.
  3. The assessment method cannot estimate biomass or abundance. Although length frequency data appears stable over time, as estimates of recruitment are not available the health of the stock (score #4) cannot be estimated.

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
  1. Barreto, E., Bailey, N. 2014. Fish and Shellfish Stock. 2014 Edition. Marine Scotland Science. 65pphttp://www.scotland.gov.uk/Resource/0045/00458803.pdf
  2. Council Regulation (EC) No 850/98 of 30 March 1998 for the conservation of fishery resources through technical measures for the protection of juveniles of marine organisms.http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CONSLEG:1998R0850:20060117:EN:PDF
  3. Hervás, A, F. Nimmo, T. Southall and P. Macintyre, 2012. MSC Sustainable Fisheries Certification: The SSMO Shetland inshore brown & velvet crab, lobster and scallop fishery. Public Certification Report, January 2012.http://www.msc.org/track-a-fishery/certified/north-east-atlantic/shetland-inshore-crab-lobster-and-scallop/assessment-downloads-1/Public_Certification_Report_-_Final_-_ShetIS.pdf
  4. ICES. 2007. Report of the Working Group on the Biology and Life History of Crabshttp://www.ices.dk/products/CMdocs/CM-2007/LRC/WGCRAB07.pdf
  5. ICES, 2009. Report of the Working Group on the Biology and Life History of Crabs (WGCRAB), 20-24 April 2009, Scalloway, Shetland Isles, UK. ICES CM 2009/LRC:17.http://www.ices.dk/reports/SSGEF/2009/WGCRAB09.pdf
  6. ICES, 2011. Report of the Working Group on the Biology and Life History of Crabs (WGCRAB), 7–10 June 2011, ICES Headquarters, Copenhagen, Denmark. ICES CM 2011/SSGEF:20.http://www.ices.dk/reports/SSGEF/2011/WGCRAB11.pdf
  7. ICES, 2012. Report of the ICES Advisory Committee. Book 6: The North Sea. 6.4.14: Nephrops in Subarea IV (North Sea). http://www.ices.dk/committe/acom/comwork/report/2012/2012/Neph-IV.pdf
  8. ICES, 2013. Report of the Working Group on the Biology and Life History of Crabs (WGCRAB), 27–31 May 2013, Dublin, Ireland. ICES CM 2013/SSGEF:10. 83 pp. http://ices.dk/sites/pub/Publication%20Reports/Expert%20Group%20Report/SSGEF/2013/WGCRAB%202013.pdf
  9. Jones, G., Gibson, P., Dobby, H., McLay, A., 2010. Brown crab data collection and tagging study. Scottish Industry Sciencehttp://www.scotland.gov.uk/Resource/Doc/295194/0100111.pdf
  10. Marine Scotland, 2008. Consultation (second phase) on the European Fisheries Fund UK Operational Programme Part 17.http://www.scotland.gov.uk/Publications/2008/05/19100136/17
  11. Marine Scotland, 2012. Developing Marine Protected Areas (MPAs) – Fifth Workshop.http://www.scotland.gov.uk/Topics/marine/marine-environment/mpanetwork/engagement/270612
  12. Mesquita, C., H. Dobby and A. McLay, 2011. Scottish Marine and Freshwater Science Report Volume 2 No 11 - Crab and Lobster Fisheries in Scotland:-Results of Stock Assessments 2006 – 2008.http://www.scotland.gov.uk/Resource/Doc/356486/0120494.pdf
  13. Mill, A., H. Dobby, A. McLay & C. Mesquita, 2009. Marine Scotland Science Internal Report 16/09 Crab and Lobster Fisheries in Scotland: an Overview and Results of Stock Assessments, 2002-2005.http://www.scotland.gov.uk/Resource/Doc/295194/0101942.pdf
  14. Reilly, S.B., Bannister, J.L., Best, P.B., Brown, M., Brownell Jr., R.L., Butterworth, D.S., Clapham, P.J., Cooke, J., Donovan, G.P., Urbán, J. & Zerbini, A.N. 2008a. Eubalaena glacialis. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.1. [Downloaded on 30 July 2012.]http://www.iucnredlist.org/details/41712/0
  15. Reilly, S.B., Bannister, J.L., Best, P.B., Brown, M., Brownell Jr., R.L., Butterworth, D.S., Clapham, P.J., Cooke, J., Donovan, G.P., Urbán, J. & Zerbini, A.N. 2008b. Megaptera novaeangliae. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.1. [Downloaded on 30 July 2012.]http://www.iucnredlist.org/details/13006/0
  16. Reilly, S.B., Bannister, J.L., Best, P.B., Brown, M., Brownell Jr., R.L., Butterworth, D.S., Clapham, P.J., Cooke, J., Donovan, G.P., Urbán, J. & Zerbini, A.N. 2008c. Balaenoptera acutorostrata. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.1. [Downloaded on 30 July 2012.]http://www.iucnredlist.org/details/2474/0
  17. Sarti Martinez, A.L. (Marine Turtle Specialist Group) 2000. Dermochelys coriacea. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.1. [Downloaded on 30 July 2012.]http://www.iucnredlist.org/details/6494/0
  18. Smith, P., I. Burrett, D. Bailey, F. Neat, D. Donnan, K. Dunlop, J. Thorburn, R. Milligan, S. Bastiman, J. Dodd, 2010. Scottish Industry Science Partnership Project. Development of methods for surveying nearshore fish populations, Ref. MS/0114. Final Report, November 2010. http://www.gla.ac.uk/media/media_209693_en.pdf
References

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    Edible crab - East Coast Scotland

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