Plaice

Plaice in the Western English Channel is currently fished at sustainable levels, but a new advice method highlights that stock biomass is below sustainable levels.Stock assessments for plaice in the Western English Channel are conducted every two years by the International Council for the Exploration of the Sea (ICES). Following a benchmark in 2024, the advice provided that year was replaced, and a new method – the Control Harvest Rate (chr) rule – was adopted for future advice.The chr rule uses the UK-FSP survey index as an indicator of stock development. Advice is based on the average of the two most recent years of this index (2023-2024), multiplied by a constant harvest rate, a biomass safeguard, and a precautionary multiplier. A stability clause – which limits changes in advice to +20% or -30% - can be applied when the index is above the biomass trigger (Itrigger), but was not used in the 2025 advice because the index was below Itrigger.As the chr rule relies on biomass indices rather than absolute reference points, Route 2 scoring is applied. Plaice is considered to have medium resilience to fishing pressure.Under the new advice method, biomass values and thresholds have changed compared to earlier assessments. The updated biomass index indicates that plaice biomass increased from 0.28 in 2007 to a peak of 2.1 in 2014, but declined to 0.8 by 2024. With the trigger level (Itrigger, a proxy for MSY Btrigger) set at 1.04, it is apparent that the stock has been below this threshold since 2019, raising concerns for plaice biomass in the Western English Channel.In contrast, fishing pressure has recently improved. A Harvest Rate (HR) of 1,424 tonnes is used as an MSY proxy. Fishing pressure has exceeded HR since 2003, except for a brief period between 2013 and 2015, when catches fell as low as 1,051 tonnes. After 2015, fishing pressure exceeded HR again, but has declined in recent years, falling below HR once more in 2024 at 1,291 tonnes. This recent reduction suggests that, although the stock has been overexploited in the past, the current fishing pressure is not a concern.Based on the new chr method, ICES advises that catches should be no more than 872 tonnes in both 2026 and 2027. This represents a 5.9% decrease from previous advice, reflecting the decline in biomass and the index now falling below Itrigger.

There is no management plan in place for this fishery, but there are some measures in place.Management of this stock is mainly by Total Allowable Catch (TAC). Until 2023, there was a combined TAC in place for divisions 7.d and 7.e, which hampered effective management of plaice in the English Channel. This stock (7.e) is the smaller of the two plaice stocks. In 2025, plaice in 7.e. has a TAC of 806 tonnes, this is in line with scientific advice for 2025 of ≤ 809 tonnes. In this area, there is a mixed fishery for sole and plaice and the two stocks are dominant commercially caught species. There can be contrasting changes in catch advice which can lead to higher discards of plaice. In 7e, the average discard rate for plaice between 2012 and 2024 was 34%, with discard survival at 50%.Technical measures in place for this fishery are:Minimum Conservation reference Size (MCRS): 270 mmOtter Trawls: minimum 100mm codend with 100mm square mesh (mesh not required east of 5°W)Beam Trawls: minimum 80mm codend with 180mm mesh headline panel.Static Nets: minimum 100mm mesh.Survival exemptions to Landing Obligation (LO)The EU and UK both have fishery management measures, which can include catch limits, population targets, and gear restrictions. However, compliance in the EU and UK has been inconsistent, with ongoing challenges in implementing some regulations. The goal of reaching Maximum Sustainable Yield (MSY) by 2020 was missed, with less than half of UK TACs in 2024 following ICES advice. In 2024, the EU and UK reaffirmed their commitment to sustainable fisheries by aligning management with scientific advice to gradually approach MSY. However, no new target date has been set for achieving MSY across all fisheries. The Landing Obligation (LO), an EU law retained by the UK post-Brexit, requires all quota fish to be landed, even if unwanted (over-quota or below minimum size). It aims to encourage more selective fishing methods, reduce bycatch, and improve catch reporting. However, compliance is poor, and accurate discard levels are hard to quantify with current monitoring programmes. The UK is in the process of replacing the LO with country-specific Catching Policies.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 engagementPlaice is included in the Celtic Sea and Western Channel demersal 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].

Beam trawls have significant impacts on the seabed, including damage to benthic communities and vulnerable marine habitats. They can also have high bycatch, potentially of vulnerable species.In 2024, 71% of the landings were taken by beam trawls, 19% by otter trawls, 3% by fixed nets and 7% by other gear types. Of a total catch of 1122 tonnes, 439 tonnes were also discarded (39.5%).Plaice is mainly caught as bycatch in the sole fishery, which uses 80 mm mesh size. This leads to a large number of plaice being discarded because this mesh size is not matched to the minimum conservation reference size (MCRS) of 27cm. The approximate size at which 50% of females mature or first spawn is around 30-34cm.Beam trawls have the potential to take relatively high quantities of bycatch (more than 50% of catch weight), including those of conservation concern. In the North East Atlantic there are reported catches of demersal elasmobranchs and endangered, threatened and protected (ETP) species, such as sharks, rays and marine mammals. Bycatch data is limited in many UK and EU fisheries as they are generally not well monitored.Demersal trawls have contact with the seabed resulting in penetration and abrasion of habitat features. The impact of trawling on the seabed depends on the location and scale in which trawling occurs. For example, areas that are used to natural disturbance through tides and waves, are less sensitive to habitat impacts. Areas not used to mobile towed gears are typically more sensitive to trawling. Trawl gears are known to have some of the greatest impacts on Vulnerable Marine Ecosystems (VMEs).Beam trawling, especially using chain-mat gear, is a high impact method of fishing and can have a significant impact on benthic communities. Heavy gear tends to have a higher seabed impact than otter trawling and seabed penetration can vary between 1cm and 8cm, depending on the sediment.In the Celtic Seas region, an estimated 66% of the 0-200m zone, and 59% of the 200-800m zone, has been at least partially trawled. Fishing effort in the area has been decreasing since the early 2000s. This has reduced the spatial fishing footprint and the average number of times the seabed is trawled per year. Most habitats are mud and sand, which are less vulnerable to trawling. However, in the Celtic Seas, 95% of areas where VMEs such as cold-water corals and sponges occur or are likely were found to have been fished between 2009 and 2011.Mitigation measures include a ban on bottom trawling below 800m, and restrictions from 400-600m – the areas where most VMEs are found. There remains some uncertainty about the location of some sensitive seabed habitats, so these remain at risk.There are Marine Protected Areas (MPAs) in this area, some of which are designated to protect seabed features from damaging activities. This fishery overlaps with parts of these MPAs, but the proportion of the catch coming from these areas is expected to be relatively low in relation to the unit of assessment (i.e. less than 20% of the catch or effort), and so these impacts have not been assessed within the scale of this rating. Given the important role that MPAs have in recovering the health and function of our seas, MCS encourages the supply chain to identify if their specific sources are being caught from within MPAs. If sources are suspected of coming from within designated and managed MPAs, MCS advises businesses to establish if the fishing activity is operating legally inside a designated and managed MPA, and request evidence from the fishery or managing authority to demonstrate that the activity is not damaging to protected features or a threat to the conservation objectives of the site(s).To improve monitoring and reporting of fishing activity, MCS would like to see remote electronic monitoring (REM) with cameras implemented, used and enforced.

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