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 dive-caught king scallops in Lyme Bay, including minimum sizes, catch limits, and time restrictions. However, due to limited information on the dive fishery and the fact that scallop stocks in the area are overfished, it remains unclear whether these measures are sufficient to ensure the fishery’s long-term sustainability. 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 dive fishery (hand-gathering) for scallops in Lyme Bay (ICES area 7e), which is estimated to contribute less than 5% of total scallop landings in the area. Some scallop beds lie 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.Diving is a highly selective and low-impact method of harvesting scallops, posing significantly less risk to habitats and non-target species compared to dredging. However, appropriate regulation is still necessary to ensure that dive fisheries operate sustainable and do not compromise long-term stock health.Devon & Severn IFCA measures:Category 1 (commercial) or category 2 (recreational) permit requiredTime restrictions: Category 1: prohibited July, August, September unless compliant with gear (iVMS/VMS) and spatial restrictions.Category 2: No restrictions Minimum Conservation Reference Size (MCRS):Category 1: 100mm (110mm July, August, September)Category 2: 100mmCatch Limits:Category 1: 2400 scallops per day in July, August, SeptemberCategory 2: 25 scallops per dayFishing curfew: 1900-0700Southern IFCA measures:Fishing for sale permit requiredMaximum vessel length: 12mMinimum Conservation Reference Size (MCRS): 100mm in 7e, 110mm in 7dFishing curfew: 1900-0700The Lyme Bay Reserve, covering 90 square nautical miles across both IFCA districts operates under the above regulations. It also promotes a voluntary code of conduct aimed at improving environmental and economic outcomes for the inshore fleet. However, this code does not currently cover scallop diving. There is also an integrated fisheries management approach, which encourages collaboration to enhance sustainability and support healthier marine ecosystems in the region.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 impacts Targets for fishing pressure and biomass, and additional management when those targets are not being met, based on the best scientific evidence Timeframes for stock recovery Improved 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 bycatch Stakeholder 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].

Hand-diving for scallops is a very low impact fishing method, with no unwanted bycatch of any other animals and very little impact on habitats.Dive-caught scallops are a more environmentally responsible alternative to dredged scallops. It involves collecting scallops from the seabed by hand, one at a time. This may include the use of boats and scuba equipment also. This method produces no bycatch and causes minimal disturbance to marine habitats.In the Lyme Bay area, dive caught scallops have a very low activity level and account for less than 5% of landings. The main environmental risks come from poor practices. Such as, contact with fragile or sensitive seabed ecosystems by divers or through anchoring. However, such impacts are limited due to the small scale of the fishery and the care generally taken by divers.Consumers should be aware of potential toxins within shellfish. Hand-dived scallops should only be purchased from processors who routinely test for toxins, as eating shellfish from areas with high levels of toxins, bacteria or chemical contamination can be dangerous.