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 — North Sea, North-East coast of England
Stock detail — 4b: Northumberland 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 Northumberland IFCA district are unlikely 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 Northumberland IFCA district and further management measures and population monitoring is required, particularly as the value of and interest in the fishery has increased substantially in recent years across England. 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: 0.75 info

There is concern for the stock but fishing pressure is unlikely 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 recent 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 Northumberland 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.

Whelk fishing has been minimal within the Northumberland IFCA district over the past decade. However, given the increase in value per tonne, interest in the fishery is increasing and some whelks are now starting to be landed, but only as a bycatch product of the primary lobster fishery. Sea Fisheries Statistics over the last decade, show that the total whelk (B. undatum) landings in Northumberland IFCA have shown negligible increase between 2008 and 2016, although a spike in whelk landings was recorded in 2016. MMO landings data from 2014-2016 did not identify any of the districts ports within the top ten ranking ports out of the ten IFCA districts, based on whelk landings (tonnage). Comparable to recorded landings throughout the 2008-2017 period, the annual whelk landings in 2017 dropped to <50 tonnes (live weight) compared to ~200 tonnes recorded in the previous year of 2016.

Management

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). In August 2019, Northumberland IFCA district enacted a Fish, Mollusc and Crustaceans Minimum Size Emergency Byelaw 2019, however, the whelk MLS did not differ from the EU 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 Northern districts to be greater than the EU MCRS of 45mm and could reach >75mm in some North-Eastern areas. Therefore, the current emergency MLS of 45mm offers insufficient protection to the spawning stock and is not reflective of whelk SOM within northerly locations.

Permits are required for the collection of whelks within the Northumberland IFCA district, under the Shellfish Permit, and available to vessels up to 12m in length. The management measures set out within the Crustaceans and Molluscs Permitting and Pot Limitation, caps fishing efforts to 800-pots per vessel and pots must be tagged. Fishers must submit monthly catch returns detailing fishing areas, weight of catch, types of fishing gear used and any other information the authority may require. Further management measures which have been introduced in the district, which, as part of Marking of Fishing Gear and Keep Boxes, include the requirement of one sufficiently sized unobstructed escape hole of 80mm wide by 46mm high, located at the lowest part of the trap, and for pots to be marked by a marker buoy 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.

The whelk fishery in Northumberland IFCA, is minimal, and as such there has been no research or survey work conducted to date. Size of Maturity (SOM) research would support the development of appropriate MLS restrictions. Further whelk management measures may also be developed such as the use of appropriately sized riddles. Management actions will be valuable with growing interest in fishing for whelks, and if a targeted whelk fishery is established in the future.

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 as bycatch in Northumberland IFCA district, within the North Sea off the North-East coast of England.

There are no directed commercial whelk fisheries within the Northumberland IFCA district and any whelk landed from within the district is mostly the result of bycatch from the primary lobster fishery.

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. Whelks are typically collected within pots placed in subtidal depths between 10-30m. Within Northumberland IFCA district shellfish pots must not be baited with edible crab. It is common for shellfish pots to be left at sea permanently and hauled on a 1 to 3-day basis, re-baited and set again.

The risk of bycatch from 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.

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.

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]

Northumberland IFCA (2020). Byelaws Booklet May 2020. Northumberland Inshore Fisheries & Conservation Authority (NIFCA), Northumberland, 56pp.

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]