King scallop

Isle of Man king scallops appear to be generally increasing in abundance. However, there is still some uncertainty about the impact of fishing on the stock, so there remains concern for fishing pressure.This rating covers the stock within Isle of Man waters (0-12 nautical miles). Landings of king scallops from around the Isle of Man (ICES rectangles 36E5, 37E5, and 38E5) increased from 705 tonnes in 1992, to a peak of 5714 tonnes in 2016. Since then, landings have declined to 2901 tonnes in 2023.The most recent stock assessment was carried out by Bangor University in 2024 using data up to 2024. Route 2 scoring has been applied to this rating as there are no reference points to indicate a healthy biomass or fishing pressure. King scallops are considered to have high resilience to fishing pressure.Assessments of biomass are based on an abundance index, using data from annual spring research surveys. Biomass fluctuates annually. Therefore, a 3 over 2 rule is applied in which the average of the last two year’s indices - Index A (2024 and 2023) - are compared to the average of the three preceding years - Index B (2022-2020). Based on this measure, Index A (258.5) shows a 42% increase from Index B (181.7), indicating a general increase in abundance. Therefore, we consider there to be no concern for biomass. It should be noted that for Index B (2022-2020), an average of 2019 and 2021 were used as a proxy for 2020 abundance as there was no data available.Scallop abundance (density) within 12 nautical miles of the Isle of Man varies spatially across survey stations. Between 2023 and 2024, scallop density increased at 24 stations and decreased at 11. This pattern may reflect localised impacts of fishing pressure, with the assessment suggesting some levels may be too high. Despite this concern, landings have declined since the introduction of Total Allowable Catches (TACs) in 2017. For the 2024/2025 season, the TAC has increased to 2352 tonnes, reflecting the increased abundance index. However, reduced landings may reflect external factors, such as Brexit or the Covid-19 pandemic, and without an official assessment of fishing pressure against reference points, there remains uncertainty and caution about the impacts of fishing on the stock. Therefore, there remains concern for fishing pressure.The Isle of Man scallop stocks are closely linked to those in the broader Irish Sea. Research suggests it may be more appropriate to manage scallops in the northern Irish Sea as a single stock, as fishing pressure in surrounding areas can influence the reproductive capacity of Isle of Man stocks. Therefore, for effective management, a regional-scale approach may be more suitable.

In recent years, a number of management measures have been brought in to control scallop fishing around the Isle of Man, including the UK's first long term management plan for inshore scallop fishing. The fishery is now closely monitored, and management is responsive to scientific information. However, it is not yet clear if measures have resulted in sustainable levels of fishing.Scallop beds in the northern Irish Sea are likely to be genetically connected, suggesting that a coordinated, regional management approach may be more appropriate. However, no joint management framework currently exists. This assessment applies only to the Isle of Man territorial waters (0-12 nautical miles).The Isle of Man scallop fishery is managed by the Department for environment, Food and Agriculture (DEFA) in collaboration with the Joint Scallop Management Board (SMB) for queen and king scallops. In June 2022, the Long-Term Management Plan (LTMP) for king scallop dredging was formally adopted – the first strategic, long-term approach to inshore scallop management in the British Isles. It aims to achieve Good Environmental Status through an ecosystem-based approach and an optimised Harvest Control Strategy. A key initial focus was to reduce excess fleet capacity by revoking unused licenses and updating regulations on vessel power and dredge numbers through the Capacity Reduction Programme. The plan is subject to review every five years, with the next in June 2027.In the 2023/2024 season, 53 vessels from the Isle of Man, Wales, Scotland, England, and Northern Ireland were licensed to fish within Isle of Man waters. Management of this fishery differs by area, with stricter regulations in the 0-3nm zone, than the 3-12nm zone. For the 2023/2024 season, measures included:Total Allowable Catch (TAC): 2179 tonnesDaily catch limits: 800-900kg per vessel (varies within the season)Closed season: 1 June – 31 OctoberFishing curfew: 1800 – 0600Christmas break: 21 December – 2 January (inclusive)Minimum Landing Size (MLS): 110mmBycatch limit: queen scallops permitted up to 10% of trip weightClosed areas: both temporary and permanent closures to protect stocks.Gear restrictions and vessel controls (see Bloor et al. 2024).Monitoring and compliance: use of Vessel Monitoring Systems (VMS) and submission of logbooks for daily catch returns.TACs were first introduced in 2017 in response to increasing fishing pressure and declining stock abundance. From 2017 to 2020, TACs were reduced by 20% annually. In 2020, Covid-19 restrictions prevented surveys, and the 2019/2020 TAC (2049 tonnes) remained in place through to 2021/2022.Since 2020, catches have remained below seasonal TAC limits, suggesting good compliance. In 2023/2024, the TAC was set at 2179 tonnes, with approximately 90% landed (1960 tonnes). Following a 42% increase in the abundance index, the 2024/2025 TAC rose by the maximum allowable annual adjustment of 20%, reaching 2352 tonnes. Approximately 97% of this was landed (2286 tonnes).DEFA highlights that strong compliance with TAC limits is more likely due to management measures and market fluctuations than to declining stock abundance. That said, some areas may be experiencing disproportionate levels of fishing effort, as between 2023 and 2024, 11 out of 35 survey stations exhibited a decline in scallop density. However, there is no formal assessment of fishing pressure against biological reference points, so it remains unclear whether current measures are achieving sustainable harvest levels.This fishery is also covered by the Western Waters Effort regime, which limits the number of days vessels over 15m can dredge in ICES area 7. However, it has had no limiting effect on the Isle of Man fishery to date.Nonetheless, high fishing effort elsewhere in the Irish Sea may still affect the stability of Isle of Man stocks. This highlights the need for further research and the development of collaborative, pan-Irish Sea management measures to safeguard scallop sustainability across connected populations in 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.There are several scallop beds in the northern Irish Sea that may be ecologically or genetically connected. However, no joint management framework currently exists. This assessment applies only to Isle of Man territorial waters (0-12 nautical miles).MMO landings data from the Isle of Man and adjacent waters show that king scallop are predominantly caught by dredging (95.1%), with a small proportion taken by otter trawling (4.8%) and pots/traps (0.1%). Dredging remains the primary method due to efficiency, but can have significant environmental impacts, especially on the seabed.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 Isle of Man supports sensitive habitats, including horse mussels and maerl reefs, which provide shelter for juvenile fish and other marine life. Scallop dredging in these areas can have broader ecosystem consequences and may take decades to recover. To protect these areas, 10 Marine Nature Reserves (MNRs) have been designated in inshore waters (0-3nm), covering 51.8% of this zone, and 10.8% of the Isle of Man’s total territorial waters. Towed gear, including dredges, is banned in all MNRs, except Ramsey Bay, where limited dredging is allowed under strict conditions.In open areas of the 0-3nm zone, Fisheries Zones have tailored management plans regulating vessel access and gear use. Outside this zone, other management measures are in place and temporary closures may be used to protect areas with high scallop densities.Bycatch is another concern. A long-term dataset (1992-2021) exists from 12 survey stations around the Isle of Man, although it is not publicly available. Common commercial bycatch includes queen scallops, whelk, flatfish, skates and rays, monkfish, plaice, and brown crab. Non-commercial bycatch species include starfish sea urchins, snails and octopus. Some endangered, threatened, or protected (ETP) species, such as the common skate complex and angel shark, are also at risk.Not all bycatch is recorded and some organisms remain on the seabed. These may suffer high mortality from dredge damage, raising concerns about unmeasured impacts on vulnerable species. To reduce bycatch, recommendations include using more durable belly rings, enhanced monitoring, and real-time closures.The Isle of Man’s Long-Term Management Plan for king scallops identifies key research areas to improve understanding, management, and sustainability of dredging, including bycatch data, habitat sensitivity, and cumulative seabed impacts.

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