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].

Gillnets in this area can encounter bycatch of non-target fish, mammals and birds. This includes the harbour porpoise which is vulnerable in Europe.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%).Gillnets and fixed nets can be very size selective, but can bycatch species such as sharks, cetaceans and other marine mammals. In particular, there is concern about bycatch of harbour porpoise. The IUCN lists harbour porpoise as being of least concern globally, but vulnerable in Europe. OSPAR has included the species on its List of Threatened and / or Declining Species and Habitats for the Greater North Sea and Celtic Seas, owing to evidence of a decline in populations, their sensitivity and the threat of incidental capture and drowning in fishing nets. They are also classified as a priority species in UK and EU law, under which there are explicit bycatch requirements. To comply with this, the UK recently designated five Special Areas for Conservation for harbour porpoises, but these areas are not yet managed. The UK Dolphin and Porpoise Conservation Strategy lists harbour porpoise as having 'medium' vulnerability to gillnetting for the UK as a whole. This is based on the species having a high sensitivity to gillnetting and medium exposure.The area of most concern is in the Celtic Seas, southwest of the UK, where most of the UK's gillnetting activity takes place. Exposure to gillnetting is high. A review of activities in the Bristol Channel Approaches Harbour Porpoise SAC lists "commercial fisheries with bycatch (predominantly static nets)" as a high risk, and a strandings report by Cornwall Wildlife Trust also shows that common dolphin bycatch is very high in this area.There is also bycatch of elasmobranch species which may be threatened or endangered. Porbeagle sharks are being caught as bycatch in gillnets but as they are a prohibited species, there is no official data on the numbers being caught and discarded. Spurdog bycatch is also thought to be of concern. The National Evaluation of Populations of Threatened and Uncertain Elasmobranchs (NEPTUNE) highlighted continued problems of spurdog bycatch and despite a supposed real time avoidance programme being implemented, 50 tonnes were still landed in Cornish ports in 2019.There is a relative lack of knowledge on the overall impact of fishing on seabird populations in Europe. Increasing evidence over the last decade has shown that seabirds are suffering mortality from bycatch, particularly in gillnets. Bycatch of seabirds in gillnet fisheries alone is estimated to kill around 400,000 birds globally each year. Diving seabirds, such as guillemots and cormorants, are generally more vulnerable to bycatch in gillnets than surface feeding seabirds. Most of the UK’s gillnetting takes place in the Celtic Seas, southwest of the UK and therefore there is concern for seabird populations here. In particular, species of concern include the razorbill (listed as Near Threatened in Europe by IUCN), puffin (listed as Endangered in Europe by IUCN) and the herring gull, arctic skua and roseate tern which are all classified in the UK as Red under the Birds of Conservation Concern 4: the Red List for Birds (2015).Some pilot projects are underway to improve reporting of bycatch and find ways to reduce it. This includes trialling various types of 'pingers' that would discourage cetaceans from approaching the nets. Pingers have been very effective at reducing porpoise and dolphin bycatch in some fisheries, but haven't been adopted on a large enough scale to significantly tackle the issue. Testing and trials are crucial and may need to be supported by other measures such as seasonal closures.Because of gillnets' durability (they are made of nylon), if lost, they can continue to fish for several weeks before becoming tangled and bundled up, a phenomenon known as 'ghost fishing'. However, static nets, as with all gear, represent an investment by fishermen, and therefore there are incentives to avoid losing or damaging gear.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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