Whelk, whelks

Buccinum undatum

Method of production — Caught at sea
Capture method — Pot or creel
Capture area — North East Atlantic (FAO 27)
Stock area — UK
Stock detail

EIFCA and KEIFA


Picture of Whelk, whelks

Sustainability rating four info

Sustainability overview

The stock status of the whelk in English waters is unknown. Their populations vary between areas so stock assessments need to conducted for a localised whelk population.

There are improved management measures in these two IFCA districts e.g. larger minimum landing sizes than the national requirements.

Pots generally cause a very low impact to the seabed and bycatch is limited in EIFCA because they mandate that pots have escape gaps.

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

Stock Area

UK

Stock information

Whelk populations are largely unknown but their populations vary considerably between areas so stock assessments are required at a local level. Whelks are a particularly vulnerable species and once overfished they can potentially take a long time to recover. Landings have increased dramatically, doubling in both tonnage and value between 2002 and 2012, and in 2016, ranked third of all landings in England in 2016, worth over 10m pounds.

There have been anecdotal accounts of severely over exploited whelk stocks along the coast of England.

Management

Criterion score: 0.5 info

The 2010 analysis undertaken by SSFC Sussex Sea Fisheries Committee/ IFCA (Dapling et al., 2010) shows that the main weakness in the whelk fishery management is the lack of monitoring of the stock, a lack of a stock assessment and a lack of a harvest strategy.

However, EIFCA has permanently implemented a larger MLS (55 mm) and other technical measures (escape vents in pots, regulations to set the spacing on the on deck riddles). EIFCA generally employs better management, underpinned by the Whelk Permit Byelaw 2016, which requries permit, pot marking requirments, 500 pot limit (30 litres capacity each). Pots must have a minimum of two escape holes of at least 24mm diameter. All of the catch must be sorted immediately and any undersized individuals must be returned to the sea immediately. Permit holders must submit report forms monthly (which captures data on fishing effort, catch data, bycatch data). Edible crabs cannot be used as bait.

KEIFA
KEIFCA had previously employed a Whelk Pot Limitation Emergency Byelaw which included a variety of management measures but has recently proposed a suite of new management measures to encourage a long-term sustainable fishery. It is likely that the increase in fishing effort for whelks nationwide is also occuring in the KEIFCA district.

A UK stock assessment has not been completed but populations vary spatially and therefore, stock assessments need to be made at a localised level.

Capture Information

Criterion score: 0.25 info

The majority of whelks are caught in pots. The risk to bycatch caused by these pots is generally low: bycatch typically consists of starfish (Asterias rubens) and various crab species (particularly Carcinus maenas). Bycatch are usually caught alive and undamaged and can be returned to the sea immediately. To prevent bycatch, some IFCAs such as EIFCA have mandated escape holes in pots and riddles are used to separate the catch. Endangered, threatened or protected species are rarely caught, though leatherback turtles have very occasionally become entangled in pot ropes. There are a lack of data on these interactions.

Whelk potting is a passive method of fishing: whelks enter the pot when they are attracted by bait. Pots are generally hauled every 1 to 3 days. The pots are laid on the seafloor (on muddy sand, gravel and/ or rocky substrates) in depths of around 10-30 m. 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.

Whelks are important prey for species such as cod, thornback rays, dogfish, bass and crustaceans; their populations have to be maintained to ensure a healthy ecosystem.

Since whelk pots are associated with negligible bycatch (includes juveniles, overfished and/or vulnerable or ETP species); but there is a potential for distruption to sensitive habitats, capture method is scored 0.

References

"KEIFCA. 2012. Impact Assessment for KEIFCA whelk byelaw. Available at: https://www.kentandessex-ifca.gov.uk/wp-content/uploads/2014/03/whelk-ia.pdf

Pearson, E. 2017. A collaborative study to develop and facilitate a fisher-directed stock assessment of Cancer pagurus in the inshore potting area, south Devon. University of Leicester.

Seafish. 2016. Project UK: Southwest Crab & lobster pot FIP: brown crab pre-assessment. Available at: http://www.seafish.org/industry-support/fishing/project-uk/project-uk-fisheries-improvements/southwest-crab-lobster-pot-fip

Southern IFCA. 2018. District Fisheries: Whelk. Available at: http://www.southern-ifca.gov.uk/district-fisheries#whelk-potting. [Accessed 17.11.17].

Association of IFCAs. 2014. New Whelk Byelaw embodies the IFCA vision. Available at: http://www.association-ifca.org.uk/Upload/K%20and%20E%20IFCA%20Whelk%20story%20.pdf

Devon and Severn IFCA. 2016. Determination of the Size of Maturity of the Whelk Buccinum undatum within the Devon & Severn IFCA District Supplementary Report: Start Bay. Research Report KS012016. Available at: https://secure.toolkitfiles.co.uk/clients/15340/sitedata/4F/Focussed_research_reports/Whelk-Report-2016.pdf

Eastern IFCA. 2016. Whelk permit whelk permit byelaw 2016. Available at: http://www.eastern-ifca.gov.uk/emergency-whelk-byelaw. [Accessed 16.11.17]. Eastern IFCA. 2016. Whelk permit byelaw. Available at: http://www.eastern-ifca.gov.uk/wp-content/uploads/2016/05/2016_11_03_Whelk_Permit_Byelaw_2016_Final.pdf.

Lawler, A. 2013. Determination of the Size of Maturity of the Whelk Buccinum undatum in English Waters Defra project MF0231. Report for CEFAS. Available at: file:///C:/Users/bev.o'kane/Downloads/11208_C5383-whelkmaturitystudyfinalreport%20(1).pdf.

Swarbrick, J. and Arkley, K., 2002. The evaluation of ghost fishing preventers for shellfish traps. Seafish Report No SR549. 46 pp.

Pierpoint, C. 2000. Bycatch of marine turtles in UK and Irish waters. JNCC Report No 310. 32 pp.

Vause, B. 2009. Species sheets available at: http://www.sussex-ifca.gov.uk/index.php?option=com_content&view=article&id=77&Itemid=173

ABPmer, 2015. Summary of Evidence Sources on Impacts of Potting on Designated Features. Workshop 25th February 2015. ABPmer. P1-9."