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Spider crab

Maja squinado

3: OK - Needs improvement How we work out the ratings

What to check for

Location

UK: Southern IFCA District (0-6nm)

Technical location

27 - Atlantic, Northeast, 7: Irish Sea, Porcupine Bank, English Channel, Bristol Channel, Celtic Seas, West and Southwest of Ireland, 4: North Sea, 6: Rockall, West of Scotland

Caught by

Pot, trap or creel

Rating summary

This stock is data limited and the status of spider crabs around the UK is currently unknown. There is concern for biomass but no concern for fishing pressure. Few appropriate management measures are in place within the district, and their effectiveness cannot be fully assessed due to limited data. A minimum landing size is enforced, however, there are no catch limits responsive to stock status. Spider crabs are usually caught as bycatch in the potting fishery for brown crab and lobster. Crab pots have low seabed impacts when deployed and retrieved correctly.Rating last updated December 2025.

How we worked out this Rating

References

Corgos, A. and Freire, J., 2006. Morphometric and gonad maturity in the spider crab Maja brachydactyla: a comparison of methods for estimating size at maturity in species with determinate growth. ICES Journal of Marine Science, 63(5), pp.851-859.

Gall, 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. Manage your fishing effort: Western Waters crabs and scallops. Available at https://www.gov.uk/guidance/manage-your-fishing-effort-western-waters-crabs [Accessed on 24.11.2025].

Lyme Bay Fisheries and Conservation Reserve. Voluntary Codes of Conduct. Available at: Code of Conduct | Lyme Bay Fisheries & Conservation Reserve [Accessed on 03.12.2025]

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]

MMO, 2023. UK sea fisheries annual statistics report 2023. Available at: UK sea fisheries annual statistics report 2023 - GOV.UK [Accessed on 24.11.2025]

Öndes, F., Kaiser, M., & Murray, L. 2018. Fish and invertebrate by-catch in the crab pot fishery in the Isle of Man, Irish Sea. Journal of the Marine Biological Association of the United Kingdom, 98(8), 2099-2111. doi:10.1017/S0025315417001643

Palomares, M.L.D. and D. Pauly. Editors. 2025. SeaLifeBase. Maja squinado, spinous spider crab, World Wide Web electronic publication. www.sealifebase.org, version (04/2025) [Accessed on 03.12.2025].

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]

Southern IFCA, 2025. Pot & Trap Fishing. Available at: Pot & Trap Fisheries : Southern IFCA [Accessed on 03.12.2025]

Southern IFCA, 2025. PROHIBITION OF GATHERING (SEA FISHERIES RESOURCES) IN SEAGRASS BEDS BYELAW. Available at: AgreementBL [Accessed on 03.12.2025]

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