King scallop

King scallops from the Lyme Bay area of the western English Channel are increasing in abundance but are subject to overfishing. Therefore, there is no concern for biomass but there is concern for fishing pressure.Since 2017, Cefas has conducted annual stock assessment for king scallops in ICES Divisions 27.7.e, 27.7.d, 27.7.f, and 27.4.b. Specific assessment areas were selected within these based on regional differences in scallop growth and fishery exploitation rates. This rating focuses on the Lyme Bay stock (7.e.L), in the western English Channel. Between 2017 and 2023, international landings from this stock averaged around 1,900 tonnes per yearScoring for this stock is based on assessments published in 2025, using data up to 2023/2024. Due to the absence of a biomass reference pointed needed to estimate Maximum Sustainable Yield (MSY), there is some uncertainty in the assessment. As a result, Route 2 scoring has been applied, with king scallops considered to have a high resilience to fishing pressure.Harvestable biomass (the weight of scallops above the minimum landing size and within areas open to dredging) has fluctuated between 2,600 and 4,500 tonnes from 2017 to 2024. A gradual increase has been observed in recent years – from 2,808 tonnes in 2022 to 4,524 tonnes in 2024. Without reference points, it remains unclear whether this represents a healthy stock level. However, as this latest figure (4,524 tonnes) is above the average from 2021 to 2023 (3,103 tonnes), there is currently no concern for biomass.Fishing pressure is assessed using the harvest rate (HR), defined as the proportion of harvestable biomass removed by fishing in the 12 months following each stock survey. Cefas estimates that a harvest rate of 24.4% corresponds to MSY, which would maintain the stock at 35% unfished levels. In 2023, the estimated HR was 63.84%, a decrease from 2022 at 73.1%. However, as HR continues to remain above the MSY proxy (24.4%), there is concern for fishing pressure.Nonetheless, there remains some uncertainties with this assessment. Biomass surveys use both dredging and underwater video systems to account for areas where dredging is not possible (e.g., conservation zones or unsuitable habitats). Additional scallop stocks are known to exist outside of survey areas, but it remains unclear how these unfished areas interact with fish stock, and specifically, whether larval exchange occurs or if dredged areas are self-sustaining.

Some appropriate management measures are in place for king scallops in Lyme Bay, including minimum sizes, vessel and gear restrictions, and seasonal closures. However, the stock remains at risk due to the absence of catch and effort limits within 6 nautical miles and ongoing fishing pressure above sustainable levels.Stock assessments for king scallops in the English Channel only began in 2017. While data quality has improved since then, some uncertainties still remain, which may limit the effectiveness of evidence-based management measures. It is also possible that inshore and offshore scallop stocks are connected, potentially through larval exchange, which suggests a more coordinated approach is needed across management areas.This rating focuses on the inshore dredge fishery for scallops in Lyme Bay (ICES area 7e), where the majority of catches are made by UK vessels. Some of the scallop beds fall within 6 nautical miles of the coast and are managed by two Inshore Fisheries and Conservation Authorities (IFCAs): Southern and Devon & Severn. However, some beds extend beyond the 6nm boundary into areas management under national legislation, again highlighting the need for coordination between local and national management frameworks.The two IFCA districts have introduced local management measures aimed at reducing pressure on the stock, but these lack significant catch or effort limits to ensure long-term stock sustainability.Devon & Severn IFCA measures:Permit requiredMaximum vessel length: 15.24mDredge limits: maximum 12 dredges (maximum 6 in Inshore Potting Agreement Area)Fishing curfew: 1900-0700Minimum Conservation Reference Size (MCRS): 100mmBan on bottom towed gear in areas of Lyme Bay SACScallop removal prohibited in July, August, and SeptemberElectronic monitoring for vessels 6.99-15.25m (ping at least every 3 minutes)Southern IFCA measures:Fishing for sale permit requiredMaximum vessel length: 12mDredge limits: maximum 12 dredgesFishing curfew: 1900-0700Minimum Conservation Reference Size (MCRS): 100mm in 7e, 110mm in 7dBan on bottom towed gear in areas of Lyme Bay SACThere is no set Total Allowable Catch (TAC) for scallops, meaning there are no binding catch limits to prevent overfishing. However, some seasonal closures have been introduced in Lyme Bay (7e) in recent years to manage effort and avoid displacement during spawning closures in adjacent areas – Eastern English Channel (7d). In 2025, scallop dredging in 7d will be closed from 1 July to 30 September for both UK and EU vessels over 10m. In Lyme Bay (ICES rectangles 29E6, 29E7, 30E6 and 30E7), a similar closure applies from 1 July to 30 September for vessels over 12m. Approximately 76.5% of scallops landed in this area are by vessels over 12m. However, the closure does not apply to vessels under 12m, meaning a significant portion of the inshore fleet can continue to fish during this period.Beyond these spatial restrictions, broader national measures also apply, including the Western Waters Effort Regime. This caps the effort of vessels 15 metres and over to 70 days at sea within ICES area 7 between 1 January and 31 March. While not specific to Lyme Bay, this effort reduction contributes to lowering fishing pressure on scallop stocks, which may be reproductively connected across the region.This fishery is also part of the UK King Scallop Fishery Improvement Project (FIP), a six-year initiative launched in March 2025. The project aims to elevate king scallop fisheries to a level which meets the certification standards set by the Marine Stewardship Council (MSC).Management compliance in the EU and UK has been inconsistent, with ongoing challenges in enforcing some regulations.The Marine Conservation Society views Remote Electronic Monitoring (REM) with cameras is one of the most cost-effective tools for providing reliable fisheries data and aiding informed management decisions. Fully monitored fisheries enhance collaboration, data accuracy, stock recovery, and reduce impacts on marine wildlife and habitats. However, the full potential of REM may only be achieved when it tracks fishing location and documents catch and bycatch, particularly where vulnerable species and habitats are at risk. As of January 2024, the EU is introducing a Remote Electronic Monitoring (REM) mandate for EU vessels, including CCTV cameras on vessels 18m or more that pose a potential risk of non-compliance, within the next 4 years. Across the UK, different approaches to REM are being taken and legislation is expected to be in place across all 4 countries within the next few years.The Fisheries Act (2020) requires the development of Fisheries Management Plans (FMPs) (replacing EU Multi-Annual Plans) in the UK. 43 FMPs have been proposed and are at various stages of development and implementation, these should all be published by the end of 2028. FMPs have the potential to be very important tools for managing UK fisheries, although data limitations may delay them for some stocks. It is also essential the UK governments define and adopt a standardised approach or model across the four nations to a universally defined FMP design, to ensure the consistence, quality and coherence of all the proposal FMPs.The Marine Conservation Society is keen to see publicly available Fishery Management Plans for all commercially exploited stocks, especially where stocks are depleted, that include:An overview of the fishery including current stock status, spatial coverage, current fishing methods and impactsTargets for fishing pressure and biomass, and additional management when those targets are not being met, based on the best scientific evidenceTimeframes for stock recoveryImproved data collection, transparency, and accountability, supported by technologies such as Remote Electronic Monitoring (REM)Consideration of wider environmental impacts of the fishery, including habitat impacts and minimising bycatchStakeholder engagementKing scallop is included in the King scallop FMP, coordinated by Defra. At the time of writing, it is too soon to know whether proposed management measures will be effective in managing the stock. For more information about this FMP and expected progress and timelines, see [https://www.gov.uk/government/publications/joint-fisheries-statement-jfs/list-of-fisheries-management-plans].

Scallop dredging can be very damaging to seabed habitats and species. However, in this area, vulnerable habitats and species are protected through closed areas, closed seasons, and curfews.Within Lyme Bay, king scallop beds occur both within and beyond 6 nautical miles. This rating focuses on the inshore dredge fishery only (0-6nm).According to MMO landings data in the Lyme Bay area (ICES rectangles 29E6, 29E7, 30E6 and 30E7), dredging accounted for approximately 86.7% of king scallop landings in 2023. This method remains dominant due to its efficiency, but poses significant environmental risks, particularly to sensitive seabed habitats.A standard king scallop dredge (Newhaven dredge) consists of a heavy steel frame and chainmail net, with a toothed bar that flips scallops into the net. Dredges are attached to tow bars dragged along the seabed, with up to 2 dredges per bar. The number of dredges used is limited by vessel engine power and regional legislation.On average, scallop dredging penetrates the seabed by up to 6cm, and can reduce species abundance and richness by 8-12% per pass. Recovery times vary depending on the species and habitat, ranging from months to years. More dynamic environments, such as sandy or wave-exposed areas, support faster-growing species that recover more quickly. In contrast, sheltered habitats like gravel beds or inshore zones, often host slow-growing, long-lived species such as maerl, horse mussels, seagrass, and sea fans, which are more vulnerable to damage and slower to recover.Lyme Bay contains a mixture of less vulnerable sandy, muddy, and mixed substrates, as well as sensitive reef ecosystems. The area is recognised as a biodiversity hotspot, home to over 1300 marine species, including the UK’s largest known colony of pink sea fans, and the rare sunset coral, both classified as Endangered, Threatened, or Protected (ETP) species. Scallop dredging in such areas can have long-term ecosystem consequences, potentially requiring decades for recovery.To safeguard these habitats, a large portion of the bay is protected under the Lyme Bay and Torbay Special Area of Conservation (SAC), where bottom towed gear is prohibited. Since this closure was introduced, species richness in protected areas has increase by 52% between 2008 and 2023. Given the ecological importance of this site, the introduction of inshore Vessel Monitoring Systems (iVMS) in May 2025, alongside standard VMS, will provide a more comprehensive view of fishing effort in Lyme Bay and improve detection of fishing incursions.Bycatch is another key concern. Since 2019, scallop dredgers have been required to land all quota species under the EU Landing Obligation, with the exception of skates and rays. For non-quota species, bycatch must not exceed 5% of total retained catch. In general, bycatch from scallop dredging in the English Channel has a bycatch rate of around 19% of the total catch biomass. Common bycatch species include queen scallop, brown crab, and spider crab. While bycatch levels are not currently thought to threaten theses populations, it is not fully recorded, and some organisms remain on the seabed after the dredge passes, of which can experience high mortality from incurred damage. This raises concerns about unmeasured impacts on vulnerable species and habitats.Discarding, often due to minimum size restrictions, also occurs. While post-release survival is believed to be relatively high, no quantitative assessments of discard rates or survival have been conducted.To support sustainable practices, the Lyme Bay Fisheries and Conservation Reserve developed an Integrated Fisheries Management Plan in 2014. This initiative, focuses on collaborative management, habitat and species risk assessment, and research to improve the long-term sustainability and understanding of fisheries operating in Lyme Bay.

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