King scallop

King scallops from offshore in the western English Channel appear to be declining in abundance but are not subject to overfishing. Therefore, there is concern for biomass but not 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 offshore part of the western English Channel. Between 2017 and 2023, international landings average around 3,200 tonnes per year.Scoring 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 8600 and 35,500 tonnes from 2017 to 2024. A gradual decline has been observed in recent years – from 32,813 tonnes in 2022 to 15,153 tonnes in 2024. Without reference points, it remains unclear whether this represents an unhealthy stock level. However, as this latest figure (15,153 tonnes) is below the average from 2021 to 2023 (26,129 tonnes), there is 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 26.5% corresponds to MSY, which would maintain the stock at 35% unfished levels. In 2023, the estimated HR was the highest since 2017 at 21.63%. However, as HR remains below the MSY proxy (26.5%), there is no 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.

Few appropriate management measures are in place to control king scallop fishing in the western English Channel. There are currently no catch limits, and fishing effort is not responsive to stock size.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.Scallop beds in the western English Channel region straddle both UK and French waters. This rating largely focuses on the offshore dredge fishery for king scallops within the UK portion of the western English Channel.In offshore English waters, the main regulatory framework for scallop dredging is the Scallop Fishing (England) Order 2012, which applies beyond 6nm. Key measures include:UK scallop licence required for vessels over 10m.Maximum of 16 dredges permitted (0-12nm)Minimum Conservation Reference Size (MCRS): 100mm in ICES area 7eBycatch limit: 10% of total catch under shellfish permitGear specifications and restrictionsEffort limit under the Western waters regime: vessels 15m and above are restricted to 70 days at sea in ICES area 7 between January 1 and March 31.The 100mm MCRS helps to protect juvenile scallops (which mature around 80mm), but may not fully support long-term stock stability as reproductive output increases with size.Importantly, there is no Total Allowable Catch (TAC) for scallops, meaning there are no binding catch limits to prevent overfishing. While seasonal closures have been implemented in ICES area 7d and the Lyme Bay area of 7e to reduce fishing pressure during the scallop spawning season (May to October), these do not cover the full spawning period and may displace effort into adjacent areas, including the offshore western English Channel.Although fishing pressure remains below the MSY proxy, biomass is declining, and no formal reference points have been established to assess stock status. Given the likely connectivity between scallop populations, high fishing pressure in neighbouring regions may still negatively impact the western English Channel stock.EU vessels (mostly French) also operate in these waters under a separate management regime, as no joint framework exists. French regulations include a limited number of scallop licences, gear specifications (though no dredge limit), a closed season from May 15 to 30 September, and weekly catch limits based on vessel size and time of year. However, these catch limits are not based on stock status, and overfishing may still occur.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. There is yet to be restrictions on where dredging can occur, so vulnerable habitats and species may be at risk.According to MMO landings data in the offshore area of the western English Channel, dredging accounted for approximately 97.2% 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.The seabed in this area is primarily composed of coarse sediments, such as gravel, pebbles, shingle, and cobbles. However, it also includes highly diverse and vulnerable habitats, including rocky reefs and maerl beds – particularly around Guernsey and Jersey. Scallop dredging in these sensitive areas can cause long-lasting ecological damage, with recovery potentially taking decades.Some of these ecosystems have been designated as Marine Protected Areas (MPAs). In offshore waters, the Western Channel Marine Conservation Zone (MCZ) is currently undergoing consultation under the proposed Western Channel and South West Marine Protected Areas Fishing Gear Byelaw 2025. This byelaw would prohibit scallop dredging within the MPA, but until it is implemented, vulnerable seabed habitats remain exposed to potential damage.Jersey and Guernsey, which are situated within the Western English Channel region, are also developing MPAs and Marine Spatial Plans. These initiatives aim to safeguard vulnerable seabed features, such as maerl beds, reefs and seagrass, through proposed no-take zones and gear prohibitions.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.