Clam, Razor, clams

Ensis spp.

Method of production — Caught at sea
Capture method — Hand-gathering
Capture area — North East Atlantic (FAO 27)
Stock area — Wales
Stock detail — All Areas
Picture of Clam, Razor, clams

Sustainability rating four info

Sustainability overview

Updated: November 2019.

There currently is no legal commercial razor clam fishery in Wales, and there are no licenced vessels targeting razor clam beds. There is however a recreational hand collection razor clam fishery, which operates on exposed areas during low tides. These areas have become increasingly popular in recent years as there are growing markets for razor clams in the Far East, particularly China.

The stock status of razor clams in Wales is unknown. They are subject to very few management measures. There is an EU minimum landing size of 100mm for all Ensis spp., but there are no catch limits. Due to increased reports of intensive harvesting in protected areas, there has been a temporary closure imposed on certain beaches. During the closure, studies are being conducted to determine the stock status in the area. More management is required to ensure that stocks are appropriately managed.

Hand-gathering is a very environmentally-friendly method of harvesting razor clams, though the large scale of their removal may be a cause for concern for the ecosystem and sediment structures.

Not of environmental concern, but of considerable importance is the health and safety and potential slavery. There are also food safety concerns since razor clams may be being harvested in areas that are not classified as a shellfish harvesting area.

Biology

Razor clams are bivalve molluscs. There are 6 species found in British intertidal waters. 2 are of commercial importance: Ensis siliqua and E arcuatus. Spawning occurs in summer, and fertilised eggs develop into mobile larvae hours after fertilisation. The larval phase includes several stages and lasts for about 3-4 weeks, during which time they drift with the current. They then settle, attaching themselves to sand or shell by byssal threads. At around 0.5cm length juveniles burrow into sand. Relative to other commercially important bivalves, Ensis are long-lived, slow growing, and attain sexual maturity late in life. They may survive to 10-15 years and an average adult can reach a size of 12.5cm, although growth will cease by age 10. They can live in excess of 20 years. E. arcuatus reaches sexual maturity between 73 and 130 mm and E. siliqua mature between 118 - 140 mm in Scotland. They are filter feeders and normally lie vertically in the sediment with 2 small siphons, through which they feed, visible on the surface. Razor clams burrow into the sediment around the extreme low water mark and in the shallow subtidal and are capable of rapid burrowing if disturbed.

Stock information

Criterion score: 0.75 info

Stock Area

Wales

Stock information

There are no assessments to determine the abundance and fishing mortality. The vulnerability of razor clams to fishing is low (10 out of 100), but the size of their populations is completely unknown. However, there have been concerns about overfishing and high exploitation levels on intertidal beds.

Previous intensive exploitation rates (e.g. Ireland, North Wales and Portugal) have led to depleted stocks. Once fished, razor clam beds can be re-colonised, but only if there are sufficient clams in surrounding areas. Intense harvesting has been shown to impact community structure, resulting in very slow rebuilding timeframes.

Management

Criterion score: 0.75 info

Welsh fisheries are managed through the Government of Wales Act 2006. The Welsh Government are responsible for territorial seas (0 to 12nm), through the Welsh Zone (Boundaries and Transfer of Functions) Order 2010).

Razor clams are managed using a minimum conservation reference size, which is 100mm for Ensis species. Razor clams are not managed using catch limits.

Byelaw 12 restricts fishing for bivalve molluscan shellfish in North Wales in the 0-6 nautical mile area and it limits fishing of razor clams to be conducted either by hand or dredge (provided the latter meets environmental requirements, e.g. area closures).

Concern has been raised about the lack of management measures to protect the stock, especially since there were reports of large gatherings of people harvesting the clams in a Special Scientific Interest (SSSI), Special Protection Area (SPA) and Special Area of Conservation (SAC) on Llanfairfechan beach.

To mitigate this, a notice for Byelaw 16 was instated in August 2017 until 31st December 2019 to temporarily close to prohibit removal, take or disturbance any razor clams for a bed or part of a bed of razor clams for the areas Llanfairfechan and Penmaenmawr. This closure is enabling the Welsh Government to conduct a survey on the status of the razor clams and implement further restrictions, and is likely to be extended into 2020 until more is known. However, there are multiple sources showing the byelaw is not being adhered to. Prior to this notice, razor clams could be gathered for personal consumption from the area although the area was not classified as a shellfish harvesting area (food safety requirements) and therefore, legally, the shellfish cannot be sold into the supply chain.

Capture Information

Criterion score: 0.25 info

Harvesting by hand is an environmentally-friendly method of harvesting razor clams (with no bycatch and little habitat damage). Though claims of localised intensive fishing of razor clams have raised concern for the impacts of the scale of their removal. There have been concerns regarding the impact of the large removals of razor clams changing the density of sand on the beach and impacts on the food chain e.g. predators including birds.

Trials have been conducted e.g. in Carmarthen Bay to determine the impact of both hydraulic dredging and electrofishing. These trials were discontinued due to management and monitoring constraints. Electrofishing trials in Carmarthen Bay, found no significant short or long term (28 days post-fishing) effects on benthic communities or relative species abundance of macrofauna. There was some disorientation among Epifauna and fish after the initial shock event but they displayed no impacts after 28 days. E. siliqua took more than five minutes to recover.

References

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

National Assembly for Wales. 2017. P-05-778 Protect the Razor Clams on Llanfairfechan Beach. Available at: http://senedd.assembly.wales/mgIssueHistoryHome.aspx?IId=19792. [Accessed 01.08.18].

Welsh Government, 2018. Llanfairfechan and Penmaenmawr razor clam fishery: public notice (temporary closure). Available at: https://gov.wales/llanfairfechan-and-penmaenmawr-razor-clam-fishery-public-notice-temporary-closure [Accessed on 07.11.2019].

Aitken, A., and Knott, M. 2018. Razor Clams in the North Western IFCA District: is there potential for a sustainable fishery?. Report for NWIFCA. Available at: https://www.nw-ifca.gov.uk/app/uploads/Agenda-Item-7-Annex-B-Razor-Clams-in-the-NWIFCA-District.pdf.

Cross, M.E. OaRiordan, R.M., Culloty, S.C. 2014. The reproductive biology of the exploited razor clam, Ensis siliqua, in the Irish Sea. Fisheries Research 150, 11-17.

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.