Dover sole
Solea solea
What to check for
Location
Location
Location refers to two things:
- Where the fish population or stock lives, e.g., North Sea, or South Pacific.
- Who is managing the fishery. If it says “All areas”, this means that our scoring for management covers the same area as the fish stock.
English Channel (East): All areas
Technical location
Technical location
A global system is used to split the ocean into different zones, areas, and subdivisions. Each zone is indicated by a number and/or letter. By law, this must be shown on all unprocessed seafood sold in the EU and UK, alongside the fishing method used to catch it. Look for these details on the packet to match your seafood to our ratings.
7d: English Channel (East)
Caught by
Caught by
Bottom trawl (otter)
Otter trawling involves towing a net over the seabed. The net is held open by two panels, known as otter boards. Fish are herded between the boards and into the net, which is then hauled onto the boat.
Bottom trawl (otter)
Rating summary
Eastern English Channel sole biomass is below safe biological levels and there is no recovery plan in place. Otter trawling is likely to cause some damage to the seabed. Bycatch is moderate and may include vulnerable species.
Rating last updated July 2024.
How we worked out this Rating
Stock status
The size and health of a fish population, or 'stock', that is being targeted by fishermen is a crucial indicator of whether a fishery is sustainable. If the stock is too small to withstand fishing, it is at risk of crashing. We look at how big the stock is, and how much pressure there is from fishing, to assess this. The target level that many fisheries aim for is 'Maximum Sustainable Yield' - the most fish that can be caught year after year whilst keeping the population at a healthy size.
Eastern English Channel sole is a critical fail as biomass is outside safe biological levels.
Stock assessments are carried out annually by the International Council for Exploration of the Sea (ICES). The most recent assessment was published in 2024.
Spawning-stock biomass (SSB) has been on a downward trend since 2014. In 2023 and 2024, it is below Blim (11,181 tonnes) and there is no recovery plan in place. In 2024, SSB is 10,467 tonnes.
Fishing pressure (F) has shown a decreasing trend since 2008 and is now around FMSY (0.23) at 0.22.
ICES advises that when the MSY approach is applied, catches in 2025 should be no more than 1,209 tonnes. This is a 19.6% decrease as a result of a lower stock size at the start of the advice year compared to the previous advice (including a lower recruitment estimated for 2023 than assumed last year), and lower target F for the advice year.
Management
Good management is vital to be sure that fishing doesn't cause fish populations to decline. We look at whether regulations follow the best available scientific advice, how well compliance is monitored and enforced, and whether this is effective in maintaining healthy fish stocks.
There is no management plan in place for Eastern English Channel sole and management measures in place have been inadequate at managing the stock.
The sole fishery in the Eastern English Channel is managed by Total Allowable Catch (TAC) and technical measures. Since 2016, advice has been given by ICES for total catch (landings and discards). In 2024, the TAC was set at 1504 tonnes, which is in line with scientific advice. Both advice and TAC have been in decline since 2021.
Sole in the Eastern English Channel has been under the landing obligation since 2018 (partially since 2016). In this area, there is a mixed fishery for sole and plaice and the two stocks are dominat commercially caught species. There can be contrasting changes in catch advice which can lead to higher discards of plaice. In 7.d., discards of plaice have increased from 18.4% in 2006 to 77% in 2023. In comparison, 15% of sole were discarded in 2023.
There are two exemptions in place which allow for discarding of undersized sole in 7.d:
- A survival exemption for coastal otter trawlers outside nursery areas with cod end mesh size of 80-99 mm
- A de minimis exemption for vessels using trammel and gill nets (max. 3% of annual catches) and using trammel and gill nets (max 3% of annual catches) and using beam trawl gear with a mesh size of 80-119 mm equipped with the Flemish panel (max. 3% of annual catches).
Technical measures in place for this fishery are:
- Minimum conservation reference size (MCRS) of 24cm.
- A minimum mesh size of 80mm for the sole fishery (which generates high discarding of plaice as they have a larger MLS than sole).
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 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 engagement
A Southern North Sea and Eastern Channel mixed flatfish FMP has been proposed, coordinated by Defra that covers the English waters within ICES divisions 4b, 4c and 7d. The FMP covers the following flatfish species (quota and non-quota): sole, dab, plaice, flounder, halibut, lemon sole, witch, turbot, brill. It is too soon to know whether the 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/collections/fisheries-management-plans#published-fmps.
Capture method
Environmental impacts of fishing vary hugely, depending on the method used and where it's happening. We look at whether the fishing gear being used could have an effect on seabed habitats, and if so, how severe might this be. We also review whether it catches any other species by accident (bycatch), and what effect this might have on those species - especially if they're Endangered, Threatened, or Protected.
Otter trawling is likely to cause some damage to the seabed. Bycatch is moderate and may include vulnerable species.
In 2023, catch was 1,517 tonnes, most of this (1,288 tonnes) was landed. Beam trawl accounts for around 45% of landings, with otter trawl accounting for 24%, trammel and gillnets, 29%, and other gear types, 2%.
Plaice is taken as bycatch in this fishery, and therefore management advice for sole must also take into account the advice for plaice. The minimum mesh size of 80mm in place 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 for plaice. The use of larger mesh sizes would reduce the catch of undersized plaice and sole, but would also result in a loss of marketable sole in the short term. Anglerfish, cuttlefish, and lemon sole are also important bycatches in this fishery.
Demersal otter trawls have the potential to take relatively high quantities of bycatch. In the Northeast Atlantic there are reported catches of demersal elasmobranchs and endangered, threatened and protected (ETP) species (e.g. 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).In the Eastern English Channel, scars related to bottom trawling are difficult to identify due to predominantly sandy sediments.
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.
To reduce the impacts of fishing on the marine environment we would like to see a just transition to the complete removal of bottom towed gear from offshore Marine Protected Areas designated to protect the seabed. We also want to see reduction and mitigation of environmental impacts including emissions and blue carbon habitat damage.
References
Burt, G. J., Readdy, L., Benedet, R., and Forster, R. 2021. Programme 40; Western Channel sole and plaice. Fisheries Science Partnership 2020/2021. Final Report. Centre for Environment, Fisheries and Aquaculture Science (Cefas), Lowestoft, UK, 47 pp.
Cook, R., Gaudian, G., des Clers, S. and Seip- Markensteijn, C.M., 2022. Marine Stewardship Council (MSC) Public Certification Report: Scottish Fisheries Sustainable Accreditation Group (SFSAG) Northern Demersal Stocks. Prepared by Control Union (UK) Limited on behalf of Scottish Fisheries Sustainable Accreditation Group (SFSAG). May 2022. Available at https://cert.msc.org/FileLoader/FileLinkDownload.asmx/GetFile?encryptedKey=BdxOJoY7Sf4DmNJEB/m47M6xx0rRfgP/niGx3vj5Ud8hadYI3XCNrnlSFL/jlTgK [Accessed on 12.07.2024].
Department of Agriculture, Environment and Rural Affairs. Cod Conservation measures in the Irish Sea. Available at https://www.daera-ni.gov.uk/articles/cod-conservation-measures [Accessed on 12.07.2024].
Eigaard, O.R., Bastardie, F., Breen, M., Dinesen, G.E., Hintzen, N.T., Laffargue, P., Mortensen, L.O., Nielsen, J.R., Nilsson, H.C., O'Neill, F.G., Polet, H., Reid, D.G., Sala, A., SkOld, M., Smith, C., Sorensen, T.K., Tully, O., Zengin, M., Rijnsdorp, A.D., 2016. Estimating seabed pressure from demersal trawls, seines, and dredges based on gear design and dimensions. ICES Journal of Marine Science, Volume 73, Issue suppl 1. Pages i27-i43. Available at https://academic.oup.com/icesjms/article/73/suppl_1/i27/2573989 [Accessed on 12.07.2024].
Hiddink, J., Jennings, S., Sciberras, M., Szostek, C.L., Hughes, K.M., Ellis, N., Rijnsdorp, A.D., McConnaughey, R.A., Mazor, T., Hilborn, R., Collie, J.S., Pitcher, C.R., Amoroso, R.O., Parma, A.M., Suuronen, P. and Kaiser, M.J. 2017. Global analysis of depletion and recovery of seabed biota after bottom trawling disturbance. PNAS. 114:31, pp. 8301-8306. https://doi.org/10.1073/pnas.1618858114.
ICES. 2024. Sole (Solea solea) in Division 7.d (eastern English Channel). In Report of the ICES Advisory Committee, 2024. ICES Advice 2024, sol.27.7d. Available at https://doi.org/10.17895/ices.advice.25019675. [Accessed on 12.07.2024].
Kennelly, S. J. & Broadhurst, M. K., 2021. A review of bycatch reduction in demersal fish trawls. Rev Fish Biol Fisheries 31, 289–318. https://doi.org/10.1007/s11160-021-09644-0.
Kynoch, R., Fryer, R. & Neat, F., 2015. A simple technical measure to reduce bycatch and discard of skates and sharks in mixed-species bottom-trawl fisheries. ICES J Mar Sci,72(6):1861.
Silva, F., Ellis, J. & Catchpole, T., 2012. Species composition of skates (Rajidae) in commercial fisheries around the British Isles and their discarding patterns. J Fish Biol., 80:1678–1703.
van Denderen, P. Bolam, S., Hiddink, J.G., Jennings, S., Kenny, A., Rijnsdorp, A., and van Kooten, T., 2015. Similar effects of bottom trawling and natural disturbance on composition and function of benthic communities across habitats. Mar Ecol Prog Ser. 2015;541:31–43.
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