Razor clam

Ensis spp.

5: Avoid How we work out the ratings

What to check for

Location

Scotland

Technical location

Atlantic, Northeast, North Sea (Central), North Sea (North), West of Scotland

Caught by

Electrical fishing

Rating summary

There is very little information available about razor clams in the UK. There is concern for the population biomass and fishing pressure due to a lack of data. Electrofishing razor clams in Scotland is illegal except for scientific purposes, however, information gathered to date has not resulted in the development of stock assessments to define sustainable fishing limits or population levels despite the longevity of the trial period. Electrofishing is widely prohibited in Europe and the gear under trail data has not offered sufficient evidence that the method of fishing is appropriate to legalise.Rating last updated January 2024.

Technical consultation summary

Razor clams throughout the UK are data limited. Route 2 scoring has been applied to this rating owing to the lack of reference points for fishing pressure and biomass for Ensis species. Razor clams have a high resilience to fishing pressure. Reduction in LPUE in some areas may indicate that the population is being fished above sustainable limits, but the absence of stock assessments prevents full analysis. Electrofishing razor clams in Scotland is illegal except for scientific purposes, however, the information gathered to date has not resulted in the development of stock assessments to define sustainable fishing limits or population levels despite the longevity of the trial period (from 2018) and with multiple extensions. Minimum legal size (10cm) is likely to be smaller than the size at which razor clams mature (varying between species and region) which offers limited protection to juveniles. Electrofishing is widely prohibited in Europe and the gear under trail data has not offered sufficient evidence that this method of fishing is appropriate to legalise.

How we worked out this Rating

There is very little information available about razor clams in the UK. There is concern for the population biomass and fishing pressure due to lack of data.The species caught as razor clams (Ensis spp.) in this fishery are data limited due to the lack of information relating to biomass and fishing pressure. Consequently, Route 2 (data limited) scoring has been applied to this rating. Razor clams are assessed as having low vulnerability to fishing pressure (10 out of 100).There is no stock assessment data for razor clams in the UK. Thus, at present, there is no data to guide sustainable fishing pressure or healthy biomass levels. Despite razor clams having low vulnerability to fishing pressure, it could take several years for commercial stocks to recover in an area due to intermittent recruitment and the slow growing nature of these species. Because of the lack of data, there is concern for stock biomass.An electrofishing trial has been underway in Scotland since 2018. Only data for razor clams that are landed in this fishery is recorded. Information about wild populations overall is not collated. Between 2018 and 2022, landings have ranged between 1 and 120 tonnes per month. From Jan 2021 to Jan 2022, the average value of landings was £7,800 per tonne. Landings per unit effort (LPUE), often used as a proxy for abundance, has been recorded throughout the trial. LPUE from 2018-2021 shows reductions in some areas. LPUE data for 2021 onwards has not been published. As there is no assessment of the sustainability of the fishery, there is concern for fishing pressure.

Electro fishing is a widely prohibited in Europe and due to the lack of evidence from the electrofishing trial, to guide appropriate management, it receives a default red rating.Electrofishing has been prohibited in European waters since 1998, owing mainly to concerns over its efficiency and the health and safety risks. Electrofishing, therefore, has the potential to lead to over-harvesting and depletion of razor clam beds.Razor clams are found burrowed in sandy inter-tidal and sub-tidal areas throughout Europe. Electrofishing for razor clams involves electrical cables being pulled slowly over the seabed, stunning razor clams and causing them to emerge from their burrows, after which they are hand-collected by divers.Electrofishing:Is highly efficient.Is highly selective with zero bycatch.Is less destructive than other fishing methods, such as dredging.Presents limited impacts to the habitat.Medium to Long-term impacts on the ecosystem are currently unknown.In a 2014 study, electrofishing for razor clams was considered a relatively benign harvesting method (environmentally-speaking) compared to more conventional methods, such as dredging. The survey concluded that electrofishing did not impact short-term survival (5 days) in razor clams, surf clams, starfish or hermit crab. However, the fishing method has been shown to stun sandeels (which recovered within 10 minutes) and may increase other organisms' susceptibility to predation (particularly from shore crabs and squat lobsters).A project in collaboration with the Scottish Association of Marine Science (SAMS) which studies the organism and ecological impacts of electrofishing in Scottish shallow coastal habitats is currently underway. The project seeks to:Examine long-term physiological performance of organisms exposed to electrical fieldsInvestigate any detectable adverse effects of electrofishing on benthic communitiesAnalysis background data on the trial electrofisheryEvidence suggests that hand diving of razor clams is not commercially viable without the use of electrofishing to expose the shells for harvest. Before purchasing commercially available dive caught razor clams consumers should be aware that they are likely caught using electrofishing, unless there is reliable evidence otherwise.UK regulations to reduce the impacts of fishing on marine habitats and wider species are under development, in the meantime most EU regulations have been adopted. Under EU legislation, bycatch species should be managed within scientifically defined or, where data isn’t available, suitability precautionary sustainable exploration limits. If stocks fall below a certain threshold, measures can be brought in such as gear limitations (e.g., mesh size or depth of use), time and/or areas closures, and Minimum Conservation Reference Sizes (MCRS).

References

BIM (2019). Shellfish Stocks and Fisheries Review 2019. The Marine Institute and Bord Iascaigh Mhara. Available at https://oar.marine.ie/bitstream/handle/10793/1591/Shellfish%20Stocks%20and%20Fisheries%20Review%202019_FINAL.pdf?sequence=1&isAllowed=y [Accessed 15.01.2024]Fishing News (2017). Electrofishing Razor Clam Trials in Scotland. Available at http://fishingnews.co.uk/news/electrofishing-razor-clam-trials-in-scotland [Accessed 16.01.2024]Fox, C. (2017). To Develop the Methodology to Undertake Stock Assessments on Razor Fish Using Combinations of Video Monitoring and Electrofishing Gear. Scottish Marine and Freshwater Science Vol 8 No 6, 92pp. DOI: 10.7489/1908-1 Available at https://data.marine.gov.scot/dataset/develop-methodology-undertake-stock-assessments-razor-fish-using-combinations-video [Accessed 15.01.2024]Fox, C. (2023). Report on Razor Clam Surveys on Tarbert Bank. Scottish Marine and Freshwater Science Report Vol 14 No 6. DOI: 10.7489/12480-1 Available at https://www.gov.scot/publications/report-razor-clam-surveys-tarbert-bank/documents/ [Accessed 15.01.2024]Fraser, S., Shelmerdine, R.L. and Mouat, B. (2018). Razor clam biology, ecology, stock assessment, and exploitation: a review of Ensis spp. in Wales. NAFC Marine Centre report for the Welsh Government. Contract number C243/2012/2013. pp 52. Available at https://www.gov.wales/sites/default/files/publications/2018-09/wales-marine-fisheries-advisory-group-razor-clams-in-wales-report.pdf [Accessed 16.01.2024]Holland, J. (2015). Illegal razor clam fishers caught in the act. Available at https://www.seafoodsource.com/news/food-safety-health/illegal-razor-clam-fishers-caught-in-the-act [Accessed 16.01.2024]MarLIN (2024). Common razor shell (Ensis ensis). Available at https://www.marlin.ac.uk/species/detail/1419 [Accessed 15.01.2024]Marine Scotland (2022). Areas where fishing of RAZOR CLAMS (Ensis spp.) is authorised for scientific purposes. Available at https://marine.gov.scot/maps/1636 [Accessed 16.01.2024]MCS (2023). MPA Reality Check. Available at https://mpa-reality-check.org/ [Accessed 17.01.2024]MMO (2018). Statutory guidance: Minimum Conservation Reference Size (MCRS) in UK waters. Available at https://www.gov.uk/government/publications/minimum-conservation-reference-sizes-mcrs/minimum-conservation-reference-sizes-mcrs-in-uk-waters [Accessed 15.11.2023]Murray, F., et al., (2014). Electrofishing for Razor Clams (Ensis siliqua and E. arquatus): Effects on Survival and Recovery of Target and Non-Target Species. Scottish Marine and Freshwater Science Vol 5 No 14. Edinburgh: Scottish Government, 44pp. DOI: 10.7489/1501-1 Available at https://www.gov.scot/binaries/content/documents/govscot/publications/progress-report/2014/10/scottish-marine-freshwater-science-volume-5-number-14-electrofishing-razor/documents/00460976-pdf/00460976-pdf/govscot%3Adocument/00460976.pdf [Accessed 17.01.2024]Palomares, M.L.D. and Pauly, D. Editors (2023). SeaLifeBase: Ensis siliqua, Sword razor shell. Available at https://www.sealifebase.se/summary/Ensis-siliqua.html [Accessed 15.01.2024]Palomares, M.L.D. and Pauly, D. Editors (2023). SeaLifeBase: Ensis magnus, Arched razor shell. Available at https://www.sealifebase.se/summary/Ensis-magnus.html [Accessed 15.01.2024]Regulation (EU) 2019/1241 of the European Parliament and of the Council. Available at https://www.legislation.gov.uk/eur/2019/1241/article/7 [Accessed 17.01.2024]Scottish Field (2020). BURIED TREASURE. Available at https://www.pressreader.com/uk/scottish-field/20200303/281539407944122 [Accessed 17.01.2024]Scottish government (2016). Electrofishing in Scotland: consultation. Available at https://www.gov.scot/publications/consultation-electrofishing-razor-clams-scotland/ [Accessed 16.01.2024]Scottish Government (2017). The Razor Clams (Prohibition on Fishing and Landing) (Scotland) Order 2017. Available at https://www.legislation.gov.uk/ssi/2017/419/contents/made [Accessed 16.01.2024]Scottish Government (2021). Electrofishing for razor clams trial: update report - 1 February 2020 to 31 January 2021. Available at https://www.gov.scot/publications/update-electrofishing-razor-clams-trial-1-february-2020-31-january-2021/ [Accessed 15.01.2024]Scottish Government (2023a). Electrofishing for razor clams trial: update report - 1 February 2021 to 31 January 2022. Available at https://www.gov.scot/publications/marine-directorate-update-electrofishing-razor-clams-trail-1-february-2021-31-january-2022/pages/7/ [Accessed 15.01.2024]Scottish Government (2023b). Innovation in inshore fishing. Available at https://www.gov.scot/news/innovation-in-inshore-fishing/#:~:text=Conducted%20by%20the%20Scottish%20Government,extended%20to%2031%20January%202025 [Accessed 15.01.2024]Scottish Government (2024). Policy - Sea fisheries. Available at https://www.gov.scot/policies/sea-fisheries/sea-fishery-management [Accessed 16.01.24]Woolmer, A., Maxwell, E. and Lart, W. (2011). Effects of electrofishing for Ensis spp. on benthic macrofauna, epifauna and fish species. Available at https://www.seafish.org/document/?id=be6b5830-9982-4ea8-996b-6e3982a8c21b [Accessed 16.01.2024]Y Gwasanaeth Ymchwil Research Service (2017). Petition: Protect the Razor Clams on Llanfairfechan Beach. Petition number P-05-0778. Petitions Committee 3 October 2017. Available at http://www.senedd.assembly.wales/documents/s66500/Research%20Brief.pdf [Accessed 17.01.2024]