Dover sole
Solea solea
What to check for
Location
Irish Sea
Technical location
Atlantic, Northeast, Irish Sea
Caught by
Bottom trawl (otter)
Rating summary
Sole in this area is in a good state and fishing pressure is within sustainable limits. There is no management plan in place for Irish Sea Dover sole but some measures are in place and have been effective in recovering the stock. In 2024, TAC has been set in line with ICES advice. There is also a minimum conservation reference size and mesh size restrictions in place. Otter trawling is likely to cause some damage to the seabed. In the Irish Sea, there is concern over levels of bycatch of the vulnerable cod and whiting stocks in the Irish sea.Rating last updated July 2024.
Technical consultation summary
Sole in this area is in a good state and fishing pressure is within sustainable limits. Previously, spawning stock biomass (SSB) was just above Blim and was predicted to drop to below Blim. However, perception of the stock has now changed and SSB in 2024 is above MSY Btigger (3129 tonnes) at 4665 tonnes and in 2025 is predicted to be 4647 tonnes. Fishing pressure was previously thought to be above Flim and now is below FMSY (0.164) at 0.098 in 2023. There is no management plan in place for Irish Sea Dover sole but some measures are in place and have been effective in recovering the stock. In 2024, TAC has been set in line with ICES advice. There is also a minimum conservation reference size and mesh size restrictions in place. Otter trawling is likely to cause some damage to the seabed. In the Irish Sea, there is concern over levels of bycatch of the vulnerable cod and whiting stocks in the Irish sea.
How we worked out this Rating
Sole in this area is in a good state and fishing pressure is within sustainable limits.Stock assessments are carried out annually by the International Council for the 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.This stock was benchmarked in 2024 and has updated reference points. Previously, spawning stock biomass (SSB) was just above Blim and was predicted to drop to below Blim. However, perception of the stock has now changed and SSB in 2024 is above MSY Btigger (3129 tonnes) at 4665 tonnes and in 2025 is predicted to be 4647 tonnes. Fishing pressure was previously thought to be above Flim and now is below FMSY (0.164) at 0.098 in 2023.ICES advises that when the MSY approach is applied, catches in 2025 should be no more than 609 tonnes.
There is no management plan in place for Irish Sea Dover sole but some measures are in place and have been effective in recovering the stock.In most years between 2007 and 2018, scientific advice was for zero catch. Total Allowable Catch (TAC) during that time slowly reduced from 820 tonnes in 2007 to 40 tonnes from 2016-2018. Catches were reduced, in line with TAC, and fishing pressure was considered to be at a sustainable level. The TAC has since increased and in 2024 was set at 625 tonnes. This is in line with advice given by ICES (revised in May 2024). This suggests that measures have been effective in recovering the stock.Sole is caught in a mixed fishery with other flatfish as well as gadoids. Discards of sole have increased recently from 3.5% (average 2016-2018) to 10% (average 2018-2020) to 12.8% (2023).Since 2000, a spawning closure for cod has been in force in the Irish Sea. No direct impact on the sole stock is expected from this closure.Technical measures in place for this fishery are:Minimum mesh sizes and minimum conservation reference size (MCRS) of 24cm.Beam trawlers, fishing with mesh sizes equal to or greater than 80 mm, are obliged to have 180 mm mesh sizes in the entire upper half of the anterior part of their net.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 engagement
Otter trawling is likely to cause some damage to the seabed. In the Irish Sea, there is concern over levels of bycatch of the vulnerable cod and whiting stocks in the Irish sea.Sole are predominantly caught by beam trawlers (85% of 2023 catch) and otter trawls (24% of 2023 catch) in the Irish Sea. Whilst discards of sole are increasing, there can also often be high amounts of discarding of other species.Of greatest concern is the bycatch of the vulnerable cod and whiting stocks in this area. Cod in the Irish Sea is managed as a by-catch only species and it cannot be directly targeted. There are technical measures in place for the Irish Sea nephrops fishery where a number of highly selective gears are mandatory. There are also gear requirements for vessels targeting haddock and this requires bottom trawls or seines to use either a 120mm cod end or an eliminator trawl (with 600mm large mesh panels and 100mm cod-end mesh panel). For vessels where the catch contains less than 10% of haddock, cod, skates and rays (combined), vessels must have a 100mm cod-end mesh and 100mm square mesh panel.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).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
AFBI. The assessment of fish stocks in the Irish Sea. Available at https://eservices.afbini.gov.uk/fisheriesandaquaticecosystems/fish-stock-assessment.html [Accessed on 10.09.2023].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 13.07.2023].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 13.07.2023].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 12.07.2023].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.a (Irish Sea). In Report of the ICES Advisory Committee, 2024. ICES Advice 2024, sol.27.7a. Available at https://doi.org/10.17895/ices.advice.25019672 [Accessed on 20.07.2024].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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