Page review/updated 23/04/2026

(Content of page last updated: 23rd April 2026)

THE WHELK FISHERY IN D&S IFCA’S DISTRICT

BIOLOGY

The common whelk (Buccinum undatum) is a gastropod mollusc that is widely fished commercially around the UK.  They inhabit both rocky/gravelly and muddy/sandy seabeds from the low water mark of the intertidal zone to depths of 1200m, but usually prefers depths of 20-30m.

Some aspects of whelk biology can vary widely over small spatial scales, including variation in size distribution, morphology and maturation size/age.

For example, the age of onset of sexual maturity is highly variable, ranging from 3.9 to 6.9 years. Their variable biology and slow growth can cause challenges for management of whelk fisheries.

Common whelk have two distinct sexes, which breed during autumn and winter in Europe. Females generally begin to lay their eggs once ambient water temperatures fall below 9 degrees. In the UK, whelks are close to their southern limit as warmer temperatures are thought to be a limiting factor to reproduction. Eggs are fertilised internally, and the female will lay clusters of yellow egg capsules on hard benthic substrate such as rocks.  Larval development occurs within the egg capsules and juveniles emerge after three to eight months and crawl onto the substrate. This reproductive strategy (no pelagic phase) results in limited dispersal potential. In addition, adult whelks have been shown to be relatively sedentary and exhibit limited movements. These two life history traits make the common whelk vulnerable to localised depletion and may lead to longer recovery times if over-exploitation did occur.

THE FISHERY

Whelk landings into the UK increased significantly to the mid-2010s, with 2003-2016 data showing a rise from 8,400 to over 22,700 tonnes. Over the last decade, landings have varied around an average of approximately 19,500 tonnes per year, with an average of approximately 12,000 tonnes per year of this being fished in English waters. However, landings have generally been lower across the board since 2022.

Most vessels fishing for whelk in English waters are smaller vessels: the whelk Fisheries Management Plan stated that in 2021, 87% of vessels landing whelks from English waters were 12m or under. Across England, the largest whelk fisheries are in southeast England. In the South West, Ilfracombe and Appledore are the main landing ports in the north of D&S IFCA’s District for the whelk fishing sector. Brixham, Teignmouth and Exmouth are the three main landing ports in the south of D&S IFCA’s District.

In 2023 landings into north Devon ports totalled 533 tonnes worth £731,416. Landings into the three main south Devon ports totalled 95.55 tonnes worth £147,624, some of which may be from vessels operating outside of D&S IFCA’s District. 

The increase in effort in the whelk fishery since the early 2000s is thought to be attributed to a boom in demand in the Far East, particularly in South Korea. This has seen the value of whelks increase from approximately £500 per tonne in 2005 to £1,200-£1,300 per tonne by 2019-2022. By late 2023, prices reached roughly £1,600 per tonne in some areas due to lower availability and sustained demand. The sustained increase in fishing effort has raised concerns over the sustainability of the fishery as stocks have never been formally assessed.

Fishers use specially designed whelk pots baited with fish and shellfish. Once hauled the catch from each pot is passed through a riddle: a set of parallel metal bars with spacing designed to allow undersized whelks to fall through, be collected and returned to the sea.

In August 2018, D&S IFCA published a guidance document to the industry on using whelk shell widths as guides for the setting of riddle widths and how this would affect the size of the retained catch. However, the effectiveness of a riddle is dependent on riddling speed and method.

European whelk fisheries are subject to management measures designed to safeguard against overfishing. A Minimum Conservation Reference Size (MCRS) of 45mm currently applies in England, being the only national management measure for this fishery, though some areas have increased this to provide suitable protection for spawning stocks. As outlined below, the whelk MCRS in D&S IFCA’s District was increased in a phased approach between 2018 and 2020, reaching 65mm in November 2020. Initial management interventions proposed in the national Whelk Fisheries Management Plan include consideration of a permit scheme and regional implementation of MCRS higher than 45mm.

RESEARCH AND MANAGEMENT

In 2012-13 Cefas undertook a study to determine the size of maturity (SOM) for both sexes of whelks in all the main fisheries around the country, including Exmouth and Ilfracombe in the D&S IFCA’s District, using one-off samples from each of these ports. The results of this survey indicated that for the sample taken from Ilfracombe the SOM was 75.5mm for both females and males, and for the Exmouth sample the SOM was 72.4mm for females and 69.2mm for males. This implies that the EU MCRS of 45mm is currently doing little to protect the spawning stocks and, therefore, the sustainability of the populations.

In 2013 D&S IFCA Officers collected monthly samples, over the course of a year, from Exmouth and Ilfracombe, in order to determine an appropriate MCRS for whelks and identify the time of year when the whelks breed and spawn within the D&S IFCA’s District. The 2015 report  found that estimates of SOM by shell height were 69.3mm for females and 70.9mm for males in Exmouth and 76.5mm for females and 76.4mm for males in Ilfracombe. It also highlighted that both spawning in females and copulation in males in Exmouth appears to take place in the winter between December to February. Whereas females appear to spawn in November and male copulation takes place throughout November to January in Ilfracombe.  However, samples could not be collected in January, therefore the extent of the spawning time could not be identified.

D&S IFCA conducted a second survey with samples being collected from Start Bay. This 2016 report found that estimates of SOM by shell height were 57.8 for females and 64.4 for males.

The results from the 2015 and 2016 reports indicated that the EU MCRS for whelks of 45mm was not adequate to protect the spawning stock within the D&S IFCA’s District. As a result, D&S IFCA introduced new management in November 2018 through its Potting Permit Byelaw’s Permit Conditions, and raised the MCRS of whelks within the District to 55mm, followed by another 10mm increase to 65mm in November 2020.

In 2017 and 2018 D&S IFCA Officers collected further whelk samples in December and January, respectively, to fill the data gaps from the 2015 report in order to accurately identify the breeding season. A report, identifying the breeding season was produced in 2019 and suggests the peak breeding activity in Exmouth occurs during November and December and in October and November in Ilfracombe. 

Monitoring of the Whelk Fishery to Evaluate Change in Management Measures

For the 2025/2026 Annual Plan, D&S IFCA identified the need to evaluate outcomes, for the industry and whelk stocks, of the change in management measures and to gain insight into industry perspectives of any change in the whelk fishery over time. This included reviewing evidence that might suggest movement into or out of the fishery, views on future management and a reflection on the amount of fishing effort.

At the end of 2025 stakeholder engagement, in the form of telephone interviews, was carried out to assess any impacts of the increase in MCRS on both the industry and whelk stocks within the District. The interviews consisted of a questionnaire containing 15 questions and focused on the following themes: perceived impact of MCRS management measures; bait use; economic viability and market access; fishing effort; gear types; spatial distribution; potential future management and the national Whelk Fisheries Management Plan (FMP).

A total of 19 responses were received across the north and south of D&S IFCA’s District. The consultation provided valuable insight into the fishers’ perspectives of any impact the increase in MCRS has had within the whelk fishery and a report summarising the responses was produced in April 2026. Key themes emerging from responses include; spatial variation in catch composition (particularly size); operational adjustments; reduction in landings and potential economic implications for vessels. Overall, the feedback highlights both practical and economic considerations that are important for understanding the effects of the MCRS change. The information gathered in the report could be used alongside other scientific evidence, landings data and other monitoring information to support future assessment and help inform any subsequent management decisions regarding the whelk fishery.

• The full report can be read here.