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

Wales


Picture of Whelk, whelks

Sustainability rating five info

Sustainability overview

The stock status is unknown but there is concern for that this fishery is over-exploited. Whelks are a particularly vulnerable species because they are long-lived, mature late (5-7 years) and produce relatively low number of eggs. They aggregate together, lay their eggs on the seafloor and are easy to catch. These factors make them more susceptible to local overfishing, and once overfished, have a slow path to population recovery.

Current management is inadequate to protect the stock and to ensure the long-term sustainability of the fishery. The species is not subject to any management under the EU Common Fisheries Policy and there is an urgent requirement for a sustainable management plan for Welsh whelks.

Pots generally cause a very low impact to the seabed.

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

The common whelk is the most abundant gastropod mollusc in the North Atlantic. However, whelks are a particularly vulnerable species and once overfished they can potentially take a long time to recover.

The stock status of the whelk in Welsh waters is unknown. However trends in length data, an increase in effort and lack of a sustainable management plan show concern for the stock. There is growing national concern that whelk fisheries are being over exploited.

CPUE data (which measures the weight of whelks caught per pot) has shown low levels of whelk abundance, compared to levels of a biologically sustainable fishery.

The whelk fishery in Wales fluctuates but has experienced an increase in vessels on average, with both Welsh and non-Welsh vessels.

Whelks reach sexual maturity in Wales between 58mm - 76mm, but they are reaching sexual maturity at a greater size than previously thought. Therefore, it is likely that many whelks are being removed from the fishery before they are able to reproduce.

Management

Criterion score: 0.75 info

Current management is inadequate to protect the stock and to ensure the long-term sustainability of the fishery. The species is not subject to any management under the EU Common Fisheries Policy and there is an urgent requirement for a sustainable management plan for Welsh whelks. The current management is not protecting the spawning stock in Wales, and therefore, The stock is in danger of recruitment overfishing. There is growing national concern that whelk fisheries are being over-exploited.

The lack of formal stock assessments means that whelks in Wales are managed inconsistently with the Marine Strategy Framework Directive. There is very little monitoring in the fishery but recently, survey trials in Wales have used inshore vessel monitoring systems (IVMS) with a mobile phone app to provide detailed reporting on their catches.

Whelks are of national importance: the Welsh Government and must adhere to the Well-being of Future Generations Act (2015), have a statutory EU obligation under the Marine Strategy Framework Directive to ensure the species is managed within safe biological limits and achieves Good Environmental Status (GES) by 2020.

Therefore, the Welsh government have proposed new management measures including a permit scheme, a pot per vessel limit use, a cap on monthly landings, landing limits per bag/ box, an increased whelk Minimum Conservation Reference Size to 65mm, a closed season and improved data collection (for catch and effort data).

The Welsh whelk fishery undergoing increasing pressure. There has been an expansion of vessels (possibly caused by displacement of fisheries - fishing opportunities have declined in whitefish and trap fisheries).

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 European green crab Carcinus maenas). Bycatch are usually caught alive and undamaged and can be returned to the sea immediately. 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 0.25.

References

"Hollyman, P.R. 2017. Age, growth and reproductive assessment of the whelk, Buccinum undatum, in coastal shelf seas. Bangor University.

Welsh Government. 2017. Consultation Document: Sustainable Management Measures for the Welsh Whelk Fishery. WG 30201. Available at: https://beta.gov.wales/sites/default/files/consultations/2018-01/consultation_document-en_1.pdf

Welsh Government. 2017. Consultation summary of responses: Sustainable Management Measures for the Welsh Whelk Fishery. WG30201. Available at: https://beta.gov.wales/sites/default/files/consultations/2018-01/summary_of_responses-en_0.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."