Whelk, common whelk

Buccinum undatum

Method of production — Caught at sea
Capture method — Pot or creel
Capture area — North East Atlantic (FAO 27)
Stock area — Irish Sea, North-West coast of England
Stock detail — 7a: North Western IFCA District (0-6nm)
Picture of Whelk, common whelk

Sustainability rating four info

Sustainability overview

Updated: June 2020.

Whelk populations in English waters are largely unknown and localised stock assessments are needed. Although there is limited data available on whelk stocks, the data that does exist indicates that there could be concern for biomass levels. Whelk populations within the North Western IFCA district, in the North-West coast of England are likely to be subject to overfishing. There is little known about the species resilience to fishing pressure and vulnerability, but, the recent and significant increase in exploitation of whelk fisheries alongside the life history characteristics of the species, high larval mortality from urchin predation, occurrence of stocklets in small spatial scales, together suggests whelks are particularly vulnerable to overfishing, and possibly more so for certain localised populations. Some management measures are in place, including a Minimum Landing Size (MLS), fishing effort limitations and gear restrictions within the district. However, the current MLS is too small to protect the whelk stock in the North Western IFCA district and further management measures and population monitoring is required, particularly as whelk landings have increased substantially in recent years. Pots generally cause a very low impact to the seabed and bycatch is negligible.


Whelks are large marine gastropods, or snails, with strong, whitish shells. They are found from Iceland and northern Norway to the Bay of Biscay, and can be locally abundant around the UK except for the Isles of Scilly. They inhabit sandy and muddy areas, although they can be found on gravel and rocky surfaces, down to depths of 1,200 metres.

Whelks mate during autumn and winter and baby whelks emerge in the spring.

Whelks are carnivorous. They scavenge at depths between 3 - 600m. They have an exceptionally acute chemical sensory ability - which enables whelks to be commercially exploited in baited pots.

Whelks are a particularly vulnerable species because they are long-lived (up to about 15 years), mature late (5-7 years) and produce relatively low number of eggs. In addition, they aggregate together, lay their eggs on the seafloor and are easy to catch. Their exceptional acute sense makes it easy to attract them to whelk pots. These factors make them more susceptible to local overfishing, and once overfished, have a slow path to population recovery. This is further exacerbated when few whelks have had a chance to mature, which can lead to stock collapse e.g. in the Dutch Wadden Sea in the mid 1970as.

Stock information

Criterion score: 1 info

There is concern for the stock and fishing pressure is likely to be above sustainable levels.

Whelk (Buccinum undatum) populations around the UK are largely unknown and there have been anecdotal accounts of severely overexploited whelk stocks along the coast of England. The lack of comprehensive stock assessments has resulted in a level of uncertainty of the current status of English whelk populations. Whelks are a particularly vulnerable species and once overfished they can take a long time to recover. Whelk fishing has been increasing throughout England over the past few years. UK whelk landings have steadily increased from 8.4 to 22.7 thousand tonnes between 2003 and 2016 and were valued at over £22.9 million in 2016. Within England, whelk catches are regularly recorded along its entire coastline.

Whelk stocks within North Western IFCA district are not formally assessed. The recent increase in exploitation of whelk fisheries within England alongside the sedentary life history characteristics of the species, a high larval mortality from urchin predation, occurrence of sub-populations in small spatial scales, together suggests whelks are particularly vulnerable to overfishing, and possibly more so for certain localised populations. Mostly, it has only been within the last few decades that these biological vulnerabilities have been exacerbated, due to the overall (global) increase in demand for whelks, and have highlighted species vulnerabilities to overexploitation.

Historically, whelk fishing has been minimal within the North Western IFCA district. However, given a recent increase in value per tonne, interest in the fishery is increasing. Sea Fisheries Statistics over the last decade, show that the total whelk (B. undatum) landings in North Western IFCA have had a large increase between 2008 and 2016. MMO landings data from 2014-2016 identified the districts Whitehaven port as the 3rd top ranking port out of the ten IFCA districts, based on whelk landings (tonnage). Annual whelk landings in 2017 dropped ~100 tonnes (live weight) from the ~1700 recorded in the previous year of 2016.


Criterion score: 0.5 info

There are management measures in place for this fishery, which are partly effective in managing the stock.

Availability of UK whelk fishery data is generally quite poor, and the absence of stock assessments has prevented the definition of Total Allowable Catch (TAC) limits and presents a number of challenges for management.

The current management measure in place for this fishery is a Minimum Landing Size (MLS) of 45mm, which is the whelk EU Minimum Conservation Reference Size (MCRS). Cefas research between 2012-2013 estimated whelk Size of Maturity (SOM - the size at which 50% of the population is sexually mature) in the main fishing grounds across England. Cefas estimates of SOM for all sampled sites except the Solent indicate that the current EU MCRS of 45mm does virtually nothing to protect whelk spawning stocks across England. The study found that SOM in the North Western IFCA district was greater than the EU MCRS of 45mm, greater than 67mm and above 76 mm in some areas. Therefore, the current MLS of 45mm offers insufficient protection to the spawning stock, reflective of the entire district.

Permits are required to set pots for the collection of whelks within the North Western IFCA district. The management measures set out within the Potting Permit Byelaw 2019, caps fishing efforts for vessels with an established track record of fishing whelk, to a 1000-pot limitation and vessels <10m without a track record to a 400-pot limitation. Fishers must submit monthly catch returns. The Potting Permit Byelaw requires fishers to fish in accordance with flexible permit conditions, which was introduced in anticipation of a boom in the whelk fishery, given a recent increase in value per tonne and increased interest in the fishery. Further management measures which have been introduced in the North Western IFCA district, which, as part of Byelaws 11 and 25, include the requirement of one sufficiently sized unobstructed escape hole located at the lowest part of the trap, and for pots to be marked by a flag on a perch, buoy or pole, 1 meter above the surface of the sea.

Vessels >12m in length are required to use Vessel Monitoring Systems (VMS) and record and report catch data electronically. Vessels <10m must have a licence and collect data on fishing effort and landings.

North Western IFCA district conducted a review of the management measures for sustainable whelk fishing, within the district, which involved engagement with local fishers and a review of the available scientific data on SOM, for the proposal of new whelk management measures ready for consultation. Subsequently, an annual increase over three years has been included in a new bylaw to increase the current MLS of 45mm, to 55mm in year 1, 65mm in year 2 and 75mm in year 3; based on local SOM data. This proposed increase and other management measures were deliberated upon and approved by the NWIFCA Committee (18th June 2020). When enacted this measure will be incorporated into the districts potting permit byelaw. NWIFCA continue to research whelk SOM within the district to support decisions on whelk management. The approved MLS increase is encouraging but is yet to be officially signed off by the Secretary of State and enforced within the district.

Indeed, several viable management strategies have been suggested by various IFCA districts to protect and rebuild overexploited stocks, including compulsory sorting based on defined length-width relationships, gear and effort constraints (e.g. limits on pot size and quantity), and closed seasons during important reproductive periods. An increase to the current MLS has been suggested as another feasible management measure in numerous studies. Such measures, could support better management of the stock within the districts alongside localised stock assessments.

The Whelk Working Group (WWG) was formed in 2019 to facilitate the exchange of information relating to the common whelk, Buccinum undatum, between Fisheries and Conservation Authorities (IFCAS), other government agencies, fisheries authorities, academics, researchers and others interested in whelk fisheries. WWG aims to help improve and develop the understanding of whelk and look at the advantages of joint working to develop appropriate management. WWG is comprised of representatives from organisations engaged in the provision of evidence, advice and management of the whelk fishery on a national level. The WWG offers encouraging opportunities for future growth of effective whelk management by working together to improve communication, collaboration and consistency.

Both the EU and UK have fishery management measures in place, which can include catch limits, targets for population sizes and fishing mortality, and controls on what fishing gear can be used and where. In the EU, compliance with regulations has been variable, and there are ongoing challenges with implementing some of them. There was a target for fishing to be at Maximum Sustainable Yield by 2020, but this was not achieved. The Landing Obligation (LO), an EU law that the UK has kept after Brexit, requires all fish and shellfish to be landed, even if they are unwanted (over-quota or below minimum size). It aims to promote more selective fishing methods, reduce bycatch, and improve recording of everything that is caught, not just what is wanted. Compliance with the LO is generally poor and actual levels of discards are difficult to quantify using the current fisheries observer programme.

In the UK, it is too early to tell how effective management is, as the Fisheries Act only came into force in January 2021. The Act requires the development of Fisheries Management Plans (FMPs) (replacing EU Multi-Annual Plans) but there are no details yet on how and when these will be developed. FMPs have the potential to be very important tools for managing UK fisheries, although data limitations may delay them for some stocks. MCS is keen to see FMPs for all commercially exploited stocks, especially where stocks are depleted, that include:
Targets for fishing pressure and biomass, and additional management when those targets are not being met
Timeframes for stock recovery
Technologies such as Remote Electronic Monitoring (REM) to support data collection and improve transparency and accountability
Consideration of wider environmental impacts of the fishery

Capture Information

Criterion score: 0.25 info

Whelks are caught by pots in North Western IFCA district, within the Irish Sea off the North-West coast of England.

Whelks in the UK are almost exclusively caught using baited traps, set for approximately 24 hours, as attraction to bait reduces significantly beyond that period of time. North Western IFCA whelk fishery uses baited whelk pots, which are weighted and placed in subtidal depths between 10-30m. The pots are baited with brown crab or dogfish and set using a number of pots attached to one string. It is common for the pots to be left at sea permanently and hauled on a 1 to 3-day basis, re-baited and set again. Once hauled, the catch from each pot is passed through a riddle. A riddle or any like instrument is a piece of equipment made of parallel metal bars. The spacing between the bars allows for undersized whelks and bycatch to fall through the bars, collected and returned to the sea. This minimises bycatch of non-target species by filtering catch, whilst retaining the larger whelks.

The risk of bycatch from whelk potting is generally low and typically consists of starfish and various crab species. Bycatch is normally caught alive and undamaged and can be returned to the sea immediately. Endangered, threatened or protected species (ETP) are rarely caught. Leatherback turtles have been known to become entangled in pot ropes in UK waters, yet this is extremely rare and there is a lack of data on these interactions.

There is potential for potting to disrupt sensitive habitats. Where commercial potting occurs in Marine Protected Areas within the district, it undergoes an assessment to ensure the activity does not cause risk to conservation features.

Whelk potting is a passive method of fishing. Whelks enter the pot when they are attracted by the bait. Pots are generally hauled every 1 to 3 days after being laid on the seafloor (on muddy sand, gravel and/or rocky substrates) in depths of around 10-30m. The effect to the seafloor is likely to be insignificant compared with mobile fishing gears. Studies show that the impact on the habitat is insignificant to substantial cumulative damage from mechanical abrasion due to the deployment and retrieval of pots, especially on sessile, slow-growing or friable flora and fauna such as ross coral or sabellaria. Ghost fishing is generally rare.


Brown, J., Macfadyen, T., Huntington, J., Magnus and J. Tumilty (2005). Ghost Fishing by Lost Fishing Gear. Final Report to DG Fisheries and Maritime Affairs of the European Commission. Fish/2004/20. Institute for European Environmental Policy / Poseidon Aquatic Resource Management Ltd joint report. Available at https://ieep.eu/uploads/articles/attachments/4a24b509-013d-44ca-b26e-47c8f52e29c4/ghostfishing.pdf?v=63664509699 [Accessed 08.6.2020]

CFSC (1993). CFSC Byelaw 25 Requirement for Escape Gaps in Pots, Creels and Traps. Cumbria Sea Fisheries Committee, 1pp.

DEFRA (2015). Summary of Evidence on Impacts of Potting on Designated Features pp.16-44, ‘In’ DEFRA (2015) Evidence for Management on Potting Impacts on Designated Features, MMO1086, Final Report November 2015, pp.1-111.

FAO (2020). Species Fact Sheets: Buccinum undatum. Available at http://www.fao.org/fishery/species/2659/en [Accessed 22.05.2020]

Lawler, A. (2013). Determination of the Size of Maturity of the Whelk Buccinum undatumin English Waters - Defra project MF0231, DEFRA, pp1-39.

MRAG (2018). Management recommendations for English non-quota fisheries: Common whelk, Final Report 16th July 2018. Available at https://www.bluemarinefoundation.com/wp-content/uploads/2019/05/MRAG_Final_Whelk_Report.pdf [Accessed 27.05.2020]

North Western IFCA (2003). Byelaw 11 Marking of Fishing Gear and Keep Pots. North Western Inshore Fisheries and Conservation Authority, 1pp.

North Western IFCA (2019). Byelaw 4 Potting Permit Byelaw 2019. North Western Inshore Fisheries and Conservation Authority, 10pp.

North Western IFCA (2020). Annual Group Meeting 18th June 2020. Available at https://www.nw-ifca.gov.uk/events/18620qm/ [Accessed 25.06.2020]

North Western IFCA (2020). Byelaws. Available at https://www.nw-ifca.gov.uk/byelaws/ [Accessed 02.06.2020]

North Western IFCA (2020). Whelk. Available at https://www.nw-ifca.gov.uk/managing-sustainable-fisheries/whelk/ [Accessed 02.06.2020]

Piperpoint, C. (2000). Bycatch of marine turtles in UK and Irish waters. JNCC Report No 310. 32 pp. Available at https://www.researchgate.net/publication/245592683_Bycatch_of_marine_turtles_in_UK_and_Irish_waters [Accessed 26.05.2020]

Science Direct (2020). Buccinum undatum, Shellfish: Commercially Important Molluscs, in Duncan, P. (2003) Encyclopedia of Food Sciences and Nutrition (2nd Ed.). Available at https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/buccinum-undatum [Accessed 22.05.2020]

SeaLifeBase (2020). Waved whelk, Buccinum undatum. Available at https://www.sealifebase.se/summary/Buccinum-undatum.html [Accessed 21.05.2020]