Dover sole
Solea solea
What to check for
Location
Celtic Sea, Bristol Channel
Technical location
Atlantic, Northeast, Bristol Channel, Celtic Sea (North)
Caught by
Bottom trawl (beam)
Rating summary
Sole biomass in this area is in a good state and fishing pressure is within precautionary limits. There is no management plan for Celtic Sea Dover sole, but some measures are in place which are largely effective, including the Celtic Sea Protection Zone. While sole discards are generally low, plaice is also caught here, and discards of that stock are significant. 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.Rating last updated July 2024.
Technical consultation summary
Sole biomass in this area is in a good state and fishing pressure is within precautionary limits. Spawning-stock biomass (SSB) has been above MSY Btrigger (3,057 tonnes) since 2009; it shows an increasing trend in recent years and is 5,415 tonnes in 2024. Fishing pressure (F) is above FMSY (0.251) at 0.29 in 2023. However, it is below Fpa (0.402) and Flim (0.543). There is no management plan for Celtic Sea Dover sole, but some measures are in place which are largely effective, including the Celtic Sea Protection Zone. While sole discards are generally low, plaice is also caught here, and discards of that stock are significant. 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.
How we worked out this Rating
Sole biomass in this area is in a good state and fishing pressure is within precautionary limits.Stock assessments are carried out annually by the International Council for Exploration of the Sea (ICES). The most recent assessment was published in 2024.The stock assessment defines reference points for fishing pressure (F) and biomass (B). For fishing pressure, there is a target to keep F at or below Maximum Sustainable Yield (MSY). For biomass, there is no target. However, there is a trigger point (MSY BTrigger). Below this level, F should be reduced to allow the stock to increase. Because BMSY is not defined, the Good Fish Guide applies its own definition of 1.4 x MSY BTrigger.Spawning-stock biomass (SSB) has been above MSY Btrigger (3,057 tonnes) since 2009; it shows an increasing trend in recent years and is 5,415 tonnes in 2024. Recruitment has been variable, fluctuating around 5 million recruits with occasional strong year classes. Low recuitment is predicted for 2024 which may lead to a decrease in SSB in future assessments.Fishing pressure (F) is above FMSY (0.251) at 0.29 in 2023. However, it is below Fpa (0.402) and Flim (0.543). ICES advises that when the MSY approach is applied, catches in 2025 should be no more than 1,149 tonnes.
There is no management plan for Celtic Sea Dover sole, but some measures are in place which are largely effective, including the Celtic Sea Protection Zone.The sole fisheries in the Celtic Sea are managed by Total Allowable Catch (TAC) and technical measures. TAC has been set in line with scientific advice in recent years and catches have been in line with the TAC.The Landings Obligation is in force for this stock, however, there is a North-Western Waters Discard Plan detailing some exemptions for unavoidable bycatch by some gears.Technical measures in place for this fishery are:Minimum mesh sizes and minimum conservation reference size (MCRS) of 24cm for UK vessels (25cm for Belgian vessels from 11th March 2017, except vessels with engine power <221 kW and/or volume <70 GT).National regulations restrict areas for certain types of vessels.A number of areas are closed to fishing at certain times of the year, e.g. the Trevose box, an area of sea around 11,400 square miles extending from Trevose head in Cornwall to the Gower peninsular in South Wales from January - March. This is the spawning period for a number of demersal stocks, so while it is primarily intended to reduce catches of spawning cod, other stocks are likely to benefit. However, beam trawlers have been allowed to fish there since 2005.The Celtic Sea Protection Zone (CSPZ) also has restrictions on fishing gearFor vessels fishing with demersal trawls and seines operating in the inner CSPZ within UK waters, the baseline mesh size is 110mm codend with a 120mm square mesh panel (there are derogations in place).The Celtic Sea is an area without days-at-sea limitations for demersal fisheries. In this context and given that many demersal vessels are very mobile, changes in effort measures in areas other than the Celtic Sea, can influence the effort regime in the Celtic Sea (increased effort in Celtic Sea for Belgian beamers during 2004–2005 when days-at-sea limitations were in place for the Eastern English Channel).For more information about this fishery in Cornwall, see: https://www.cornwallgoodseafoodguide.org.uk/fish-guide/sole-dover-sole.phpThe 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 engagement
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.Sole are predominantly caught by beam trawlers (87% of 2023 catch) and otter trawls (13% of 2023 catch) in this area. Whilst discards of sole are increasing, there can also often be high amounts of discarding of other species.The sole fishery catches significant amounts of plaice, most of which is undersized and discarded. This is because the minimum mesh size of this fishery is 80mm: selective for sole (MCRS of 24cm) but not plaice (27cm). Therefore, better selectivity is needed.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.An estimated 45% of the Celtic Sea region was trawled in 2018. 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. 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
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 divisions 7.f and 7.g (Bristol Channel, Celtic Sea). In Report of the ICES Advisory Committee, 2024. ICES Advice 2024, sol.27.7fg. Available at https:/doi.org/10.17895/ices.advice.25019681 [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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