Razor clam

Ensis spp.

5: Avoid How we work out the ratings

What to check for

Location

Scotland: Dredge fishery

Technical location

4b: North Sea (Central), 4a: North Sea (North), 6a: West of Scotland

Caught by

Dredge

Rating summary

Razor clams caught using dredges in Scottish waters receive a critical fail rating as fishing for them using this method is prohibited.

Rating last updated December 2022.

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.

Razor clams caught using dredges in Scottish waters receive a critical fail rating as fishing for them using this method is prohibited. Therefore, management is not assessed in detail.

Razor clams caught using dredges in Scottish waters receive a critical fail rating as fishing for them using this method is prohibited. Therefore, the capture method impacts are not scored.

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 on 23.11.22].

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.

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://pure.uhi.ac.uk/en/publications/razor-clam-biology-ecology-stock-assessment-and-exploitation-a-re [Accessed on 23.11.22].

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 on 23.11.22].

Palomares, M.L.D. and Pauly, D. Editors. 2022. SeaLifeBase: Ensis siliqua, Sword razor shell. Available at https://www.sealifebase.se/summary/Ensis-siliqua.html [Accessed on 23.11.2022].

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/pages/3/ [Accessed on 23.11.22].