Velvet swimming crab
Necora puber
What to check for
Location
Scotland
Technical location
Atlantic, Northeast, North Sea (Central), North Sea (North), West of Scotland
Caught by
Pot, trap or creel
Rating summary
Velvet crabs have a medium vulnerability to fishing. This species is data limited but current assessments indicate a concern for fishing pressure. As there is a lack of biomass data, there is also a concern for biomass. Management requires considerable improvement. Further data is needed to reliably assess biomass and responsive effort controls are needed to improve velvet crab stocks around Scotland. Potting, or creeling, for velvet crab, is associated with negligible bycatch and habitat impacts but may result in the entanglement of marine mammals in this area.Rating last updated November 2025.
Technical consultation summary
Route 2 (data-limited) scoring has been applied to this rating, with velvet crabs having a medium vulnerability to fishing. There is a concern for fishing pressure as recent assessments indicate that fishing mortality is above FMSY across much of the region, for both sexes. There is also a concern for biomass due to the lack of data associated. Management requires considerable improvement, with few measures designated specifically for velvet crab. Further data is needed to reliably assess biomass and responsive effort controls are needed to improve velvet crab stocks around Scotland. Potting, or creeling, for velvet crab, is associated with negligible bycatch and habitat impacts but may result in the entanglement of marine mammals in this area.
How we worked out this Rating
Velvet crabs have a medium vulnerability to fishing. This species is data limited but current assessments indicate a concern for fishing pressure. As there is a lack of biomass data, there is also a concern for biomass.Route 2 (data limited) scoring has been applied to this rating owing to the lack of data about the species biomass. There is no available data on velvet crab resilience to fishing pressure, but they are considered to have medium (0.33) vulnerability to fishing.The most recent stock assessment available for Scotland was published in 2023 and uses data up to 2020. As there is an absence of biomass data, there remains a concern for biomass.Velvet crabs are caught as part of a mixed fishery alongside brown crab and European lobster, with only a small number of fishers targeting them directly. Landings in Scotland have declined from around 2800 tonnes in 2009 to approximately 1600 tonnes since 2018. Although landings fell to 1200 tonnes in 2018, they recovered to 1566 tonnes in 2020. In 2020, the highest proportions of landings came from Orkney (25.1%), the East Coast (20.0%), and the Hebrides (15.8%).Assessments of fishing mortality between 2016 and 2019 show that in the Clyde, East Coast, Orkney, and South Minch, both males and females were harvested at levels above FMSY. Whereas, in the Hebrides and South East, only females were fished above FMSY, while males were at FMSY. These patterns are largely similar to earlier assessments (2006-2008, 2009-2012, 2013-2015), though some changes have occurred. For example, male fishing mortality in the Hebrides has risen to FMSY in the most recent assessment, having previously been below that level. Simialrly, in the East Coast, both male and female fishing mortality increased to above FMSY between 2008 and 2009, whereas they had previously been at FMSY. As fishing mortality has consistently exceeded FMSY for one or both sexes across the region, there is concern for fishing pressure.Given the limited data on biomass and the potential influence of market value on landings it is difficult to assess how velvet swimming crab is doing overall. To improve future assessments of the stock, fishery-independent biomass surveys and inclusion of bycatch data is essential.
Management requires considerable improvement. Further data is needed to reliably assess biomass and responsive effort controls are needed to improve velvet crab stocks around Scotland.Some management measures are in place for this stock, but there are currently no catch limits to prevent overexploitation. Creel numbers are unrestricted, and there is no total allowable catch (TAC) is set – either for the fishery of individual vessels. While certain prohibitions on fishing activity, including creeling, exist in Scotland and may provide passive protection to velvet crabs, no spatial or temporal closures are currently designated specifically for this species. Furthermore, there are no tools available to implement a harvest control rule for quick management response to adverse stock trends.Regulations on the landing of velvet crab in Scotland include:Crabs must be landed whole.Landings of berried crab is prohibited.Vessels over 14m not permitted to deploy creels within Scottish inshore waters.Vessels over 12m, and catches of over 200 tonnes of brown crab and lobster in any 12 month period since 2020, must work outside of 6 nautical miles.Minimum Landing Size (MLS) of 70mm carapace width.The MLS for velvet crabs in Scotland is larger than the UK standard of 65mm and exceeds the estimated maturity size of 50mm. However, maturity varies spatially, meaning that the MLS may not optimise reproduction and landings as some stocks mature smaller or larger than this size.In the most recent stock assessment for velvet crab in Scotland, the majority of stocks were being fished at or above FMSY, indicating that fishing effort is not effectively managed. The assessment also highlighted that with improved management, and a reduction in fishing mortality, yields could be higher and greater biomass per recruit could be achieved. Additional measures, such as incorporating escape gaps into pots, may be used to help protect juveniles and other non-target species, however, the extent of their use remains unknown.All vessels registered in the UK must have a domestic fishing vessel license to fish within the UK EEZ for sea fish that will be sold on. Commercial vessels under 10m with a shellfish licence must submit weekly FISH1 forms, while vessels over 10m complete EU logbooks of catches. Licensed vessels without shellfish entitlement may land up to 25 crabs per day, while unlicensed vessels are restricted to 5 crabs per day. No new licences or entitlements are currently being granted, however there is potential from increased activity if existing non-active license entitlements are used.The Marine Conservation Society views Remote Electronic Monitoring (REM) with cameras is one of the most cost-effective tools for providing reliable fisheries data and aiding informed management decisions. Fully monitored fisheries enhance collaboration, data accuracy, stock recovery, and reduce impacts on marine wildlife and habitats. However, the full potential of REM may only be achieved when it tracks fishing location and documents catch and bycatch, particularly where vulnerable species and habitats are at risk. As of January 2024, the EU is introducing a Remote Electronic Monitoring (REM) mandate for EU vessels, including CCTV cameras on vessels 18m or more that pose a potential risk of non-compliance, within the next 4 years. Across the UK, different approaches to REM are being taken and legislation is expected to be in place across all 4 countries within the next few years.The Fisheries Act (2020) requires the development of Fisheries Management Plans (FMPs) (replacing EU Multi-Annual Plans) in the UK. 43 FMPs have been proposed and are at various stages of development and implementation, these should all be published by the end of 2028. FMPs have the potential to be very important tools for managing UK fisheries, although data limitations may delay them for some stocks. It is also essential the UK governments define and adopt a standardised approach or model across the four nations to a universally defined FMP design, to ensure the consistence, quality and coherence of all the proposal FMPs.The Marine Conservation Society is keen to see publicly available Fishery Management Plans for all commercially exploited stocks, especially where stocks are depleted, that include:An overview of the fishery including current stock status, spatial coverage, current fishing methods and impactsTargets for fishing pressure and biomass, and additional management when those targets are not being met, based on the best scientific evidenceTimeframes for stock recoveryImproved data collection, transparency, and accountability, supported by technologies such as Remote Electronic Monitoring (REM)Consideration of wider environmental impacts of the fishery, including habitat impacts and minimising bycatchStakeholder engagement
Potting, or creeling, for velvet crab, is associated with negligible bycatch and habitat impacts but may result in the entanglement of marine mammals in this area.Velvet crabs are fished within mixed creel/pot fisheries that also target brown crab, lobster, and whelk. These pots may be deployed individually or by fleets operating large numbers. These portable traps, made of wood, steel wire, or plastic, lure crabs into a chamber before they move into a parlour section where they become trapped. Bait choice for pots depends largely on availability and cost, often consisting of fish waste, or oily species like mackerel and herring.Bycatch from creel fishing can occur both during active fishing or when pots are lost, leading to ghost fishing. Juvenile cod and common starfish are among species hauled alongside velvet crab. Most non-target species eventually escape, particularly when pots include escape gaps for smaller animals. Survival is thought to be generally high in discarded bycatch from pots when stress remains low.Creel ropes also pose a bycatch risk through entanglement, particularly in the case of endangered, threatened, or protected (ETP) species. Minke and humpback whales, as well as basking sharks, are most at risk from creel rope entanglement – recent data indicates that annually up to 2.2% of the minke whale population on Scotland’s west coast may die from entanglement. Other species also at risk include fin, killer, pilot, and sei whales, harbour porpoises, and Risso’s dolphins. A 2021 study indicates that entanglement rates are lower in the shallow-water lobster and velvet crab fisheries compared to the deeper-water brown crab fishery. UK requirements for marine mammal bycatch reporting were only introduced in November 2021, meaning monitoring is still limited and current data likely underestimates marine mammal bycatch. Work with fishers to reduce risks is ongoing, but no large-scale mitigation measures are in place yet. As potting effort for velvet crab is relatively low, entanglement risks are considered less severe than in other fisheries.Habitat impacts from potting are low but can occur during deployment, soak time or hauling of the pot, impacting the benthic habitat and associated species through contact with the pot or end weight, or by scouring from ropes. Research that has taken place suggests that while some damage does occur, it is unlikely to be significant unless potting intensity is high (defined as approximately 30 pots per 500 square metres). The most damage occurs when traps are set in sensitive habitats such as rocky reefs, seagrass beds, and maerl beds. These ecosystems play a crucial role in supporting marine biodiversity by providing nursery grounds, shelter from predators, and settlement areas for invertebrate spat.To improve monitoring and reporting of fishing activity, MCS would like to see remote electronic monitoring (REM) with cameras implemented, used and enforced.
References
Calderan, S., Cisternino, B., De Noia, M., Leaper, R., MacLennan, E. and Philp, B., 2025. Successful collaborative trials of simple gear modifications to reduce entanglement of whales and other megafauna in Scotland’s static pot (creel) fisheries. ICES Journal of Marine Science, 82(6), p.fsae157. Coleman, R.A., Hoskin, M.G., von Carlshausen, E. and Davis, C.M., 2013. Using a No-take Zone to Assess the Impacts of Fishing: Sessile Epifauna Appear Insensitive to Environmental Disturbances From Commercial Potting. Journal of experimental marine biology and ecology, v. 440 ,. pp. 100-107. doi: 10.1016/j.jembe.2012.12.005Gall, S.C., Rodwell, L.D., Clark, S., Robbins, T., Attrill, M.J., Holmes, L.A. and Sheehan, E.V., 2020. The impact of potting for crustaceans on temperate rocky reef habitats: Implications for management, Marine Environmental Research, Volume 162, 105134, https://doi.org/10.1016/j.marenvres.2020.105134.GOV.UK, 2025. Guidance: Record your catch. Available at: Record your catch - GOV.UK [Accessed on 20.11.2025]GOV.UK, 2025. Marine Mammal Reporting Requirements. Available at: Marine Mammal Reporting Requirements - GOV.UK [Accessed on 20.11.2025]Leaper, R., 2021. An evaluation of cetacean bycatch in UK fisheries: problems and solutions. A report to WDC and HIS. Available at https://uk.whales.org/wp-content/uploads/sites/6/2021/02/cetacean-bycatch-uk-fisheries-problems-solutions.pdf [Accessed on 20.11.2025]MacLennan, E., Hartny-Mills, L., Read, F.L., Dolman, S.J., Philp, A., Dearing, K.E., Jarvis, D. and Brownlow, A.C. 2021. Scottish Entanglement Alliance (SEA) - understanding the scale and impacts of marine animal entanglement in the Scottish creel fishery. NatureScot Research Report 1268. Available at: https://www.nature.scot/doc/naturescot-research-report-1268-scottish-entanglement-alliance-sea-understanding-scale-and-impacts#Entanglements+in+Scotland [Accessed on 20.11.2025]Mesquita, C., Ellis, A., Miethe, T. and Dobby, H. 2023. Crab and Lobster Fisheries in Scotland: Results of Stock Assessments 2016-2019. Scottish Marine and Freshwater Science Vol 14 No 05. DOI: https://doi.org/10.7489/12451-1 MMO, 2025. Minimum Conservation Reference Sizes (MCRS) in UK waters. Available at: Minimum Conservation Reference Sizes (MCRS) in UK waters - GOV.UK [Accessed 19.11.2025]Palomares, M.L.D. and D. Pauly. Editors. 2025. SeaLifeBase. Necora puber, Velvet swimming crab, World Wide Web electronic publication. www.sealifebase.org, version (04/2025) [Accessed on 18.11.2025].Scottish Government, 2025. Crab and lobster landing controls: poster. Available at: Crab and lobster landing controls: poster - gov.scot [Accessed on 18.11.2025]Scottish Government, 2023. Fishing - managed areas. Available at: Fishing - managed areas | marine.gov.scot [Accessed on 21.11.2025]Scottish Government, 2022. Marine compliance: FISH1 form. Available at: Marine compliance: FISH1 form - gov.scot [Accessed on 20.11.2025]Seafish. Pots and Traps – General. Available at: seafish.org/responsible-sourcing/fishing-gear-database/gear/pots-and-traps-general/#target-species [Accessed on 18.11.2025]Spoors, F., Mendom T., Khan, N., James, M. (2021) Assessing bait use by static gear fishers of the Scottish Inshore fisheries: A preliminary study. Available at: Spoors_2021_Assessing_bait_use_by_static_FisheriesRes_AAM.pdf [Accessed on 20.11.2025]Tallack, S. 2007. The reproductive cycle and size at maturity observed in the velvet swimming crab, Necora puber, in the Shetland Islands, Scotland. Journal of the Marine Biological Association of the United Kingdom, 87(5), 1161-1168. doi:10.1017/S0025315407059784
Sustainable swaps
Learn more about how we calculate our sustainability ratings.
How our ratings work