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 — English Channel (West)
Stock detail — 7d, 7e: Southern IFCA District (0-6nm)
Picture of Whelk, common whelk

Sustainability rating five info

Sustainability overview

Updated: May 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 Southern IFCA district, in the Western English Channel 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.

There is a lack of appropriate management to suitably protect the stock. Measures currently include an EU-standard Minimum Landing Size (MLS) for whelks. MLS as an independent management measure is not an effective measure to manage whelks. The current MLS is too small to protect the whelk stock in Southern IFCA district and further management measures and population monitoring is required, particularly as whelk landings have increased substantially in recent years. Various management measures for the whelk fishery have been discussed but are yet to be decided upon and enacted.

Pots generally cause a very low impact to the seabed and bycatch is negligible.

Biology

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.

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.

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. 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, but are predominantly landed at ports in the Southern IFCA and Sussex IFCA districts.

Whelk stocks within Southern 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 stocklets 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.

Sea Fisheries Statistics over the last decade indicate that the English landings of whelk (B. Undatum) are highest at ports within the Southern, Sussex and Devon and Severn IFCA districts. Annual whelk landings in 2017 dropped to ~1600 tonnes (live weight) compared to >4000 tonnes in 2016. Annual landing fluctuations can be indicative of a boom and bust fishery. MMO landings data from 2014-2016, highlight Southern IFCA district s Portsmouth and Weymouth ports as the 4th and 7th top ports out of the ten IFCA districts, respectively, based on whelk landings (tonnage). Ports located on the south coast of England represent 50% of the top ten landing sites for B. undatum in the country.

Management

Criterion score: 0.75 info

There are management measures in place for this fishery, but they are not effectively managing the stock.

Whelk fishing in the Southern IFCA district is considered an emerging fishery, and although it is significant in comparison to other regions is not a priority fishery. As such, no whelk research has been conducted to date.

Availability of UK whelk fishery data is generally quite poor, and the absence of regional 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 EU-standard Minimum Conservation Reference Size (MCRS) for whelks. 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 indicated that the current EU MCRS of 45mm does virtually nothing to protect spawning stocks. The study found that SOM in the Southern IFCA district was generally greater than the EU MCRS of 45mm, and above 65mm in some areas. Therefore, the current MLS set within the district, offers insufficient protection to the spawning stock reflective of the entire district. MLS as an independent management measure is not an effective measure to sufficiently protect stocks.

Southern IFCA have signed a Memorandum of Understanding (MoU) and Voluntary Code of Conduct to limit pots within Lyme Bay Reserve to 500 per vessel, with no more than 30 pots on each string, and encompasses voluntary fitting of iVMS.

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.

Southern IFCA district have conducted a review of the management measures for sustainable fishing, within the district, which involved three stages, including public engagement events, evaluation of community feedback and the development of a timeline from the authority for the management themes scoring high priority. One of the priorities included the development of effective management in the whelk fishery which is currently ongoing and in evidence gathering phases. A call for information on the Southern IFCA inshore pot fisheries was conducted and a review of the summary of Responses was published in January 2019. Various management measures for the whelk fishery have been proposed by commercial fisherman and members of the Fisherman s Association. Proposals included, management intervention, pot limitations, escape holes for whelk pots, introduction of a riddle minimum size, temporal closures (closed season), an increase in the current MLS and further research to be undertaken to determine the relationship between whelk height and width at sexual maturity. These proposed management measures are encouraging but have not yet reached consultation or been enacted. Such measures could support better management of the stock 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 Southern IFCA district, within the Western English Channel.

Fishing with pots for whelks, in inshore waters has been carried out for generations across the coastal communities of Hampshire, Dorset and the Isle of Wight.

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. Southern IFCA whelk fishery uses baited whelk pots in subtidal depths between 10-30m. The pots are commonly baited with dogfish and shore crab and set using a number of pots attached to one string. Once hauled the catch from each pot is passed through a riddle with a minimum bar spacing of 25mm or greater. 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, particularly spider crab. 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.

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.

References

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]

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.

Lyme Bay Fisheries and Conservation Reserve (2020). The MoU and Voluntary Code of Conduct. Available at https://www.lymebayreserve.co.uk/about/the-mou.php [Accessed 27.05.2020]

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]

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]

Southern IFCA (2017). Southern Inshore Fisheries and Conservation Authority Byelaw Booklet. Version 2 dated November 2017, pp.5-67.

Southern IFCA (2019). ‘Call for information’: a review of the Southern IFCA inshore pot fisheries. Summary of Responses, January 2019, pp.3-12.

Southern IFCA (2020). District Fisheries. Available at http://www.southern-ifca.gov.uk/district-fisheries#whelk-potting [Accessed 27.05.2020]

Southern IFCA (2020). Live and Ongoing Consultations. Available at http://www.southern-ifca.gov.uk/consultations [Accessed 27.05.2020]

Southern IFCA (2020). Other Regulations. Available at http://www.southern-ifca.gov.uk/other-regulations [Accessed 27.05.2020]

Southern IFCA (2020). Review of Management Measures. Available at http://www.southern-ifca.gov.uk/review-of-management-measures [Accessed 27.05.2020]