Dover sole
Solea solea
What to check for
Location
Celtic Sea South, southwest of Ireland
Technical location
Atlantic, Northeast, Celtic Sea (South), Southwest of Ireland (East), Southwest of Ireland (West)
Caught by
Bottom trawl (otter)
Rating summary
Updated: July 2021.This stock is data limited. There is concern for the biomass and no concern for fishing pressure. The state of the stock is unknown and ICES cannot assess the stock and exploitation status relative to maximum sustainable yield (MSY) and precautionary approach (PA) reference points, as the reference points are undefined. Catches have been stable since 2006. There is no management plan in place for this stock, but some measures are in place. As this stock is data limited, this limits the effectiveness of management. Sole is a small (but valuable) component (up to 5%) of the landings in this mixed fishery, which also has a bycatch of the highly vulnerable plaice stock. Otter trawlers interact with the seabed and can modify bottom topography and cause damage and removal of some biogenic features including vulnerable marine habitats and benthic communities.
How we worked out this Rating
This stock is data limited. There is concern for the biomass and no concern for fishing pressure.The state of the stock is unknown and ICES cannot assess the stock and exploitation status relative to maximum sustainable yield (MSY) and precautionary approach (PA) reference points, as the reference points are undefined. Catches have been stable since 2006 and sole has a medium resilience to fishing pressure.For stocks without information on abundance or exploitation, ICES considers that a precautionary reduction of catches should be implemented when it is not clear that the current level of exploitation is appropriate for the stock. The precautionary buffer was applied in 2019 and has been applied again in 2020, therefore it's application ahs not been considered in 2021. ICES advises that catches in 2022 should be no more than 213 tonnes.This stock was benchmarked in 2020 to address the inclusion of available new landings-at-age data for the Division 7.h. component, fishery-independent indices, and to consider stock identity. The benchmark concluded that there was no appropriate method for evaluating stock status and trends, as the sampling only covers a small part of the total fishery, which is not considered to be representative of the whole area. Misreporting is also considered to be an issue for this stock, however, it remains difficult to fully quantify.
There is no management plan in place for this stock, but some measures are in place. As this stock is data limited, this limits the effectiveness of management.Catches in this area are taken in a mixed fishery and according to ICES, should be managed as such. Constraining the landings by TAC will not constrain the catches. As sole are caught in spatially distinct areas, restricting effort in these areas will be more effective than limiting landings. The TAC is currently not restrictive, but for some countries, the quota appears to have become restrictive. In 2020, landings (284 tonnes) were 86% of the TAC (329 tonnes).Misreporting is also considered to be an issue for this stock but remains difficult to quantify. From 2016 the landings obligation was phased in for this stock, and discards are considered to be negligible.Technical measures in place for this fishery are:Minimum Conservation Reference Size (MCRS) of 24cmThe Celtic Sea Protection Zone (CSPZ) also has restrictions on fishing gearFor vessels fishing with demersal trawls and seines operating in the outer CSPZ within UK waters, the baseline mesh size is 100mm codend with a 100mm square mesh panel (not required within UK waters east of 5 degrees west).For vessels fishing with demersal trawls and seines in the outer EU CSPZ (outside UK waters), demersal trawlers and seines must operate using a 100mm codend within ICES divisions 7f-k and in the area west if longitude 5 degrees west in 7e.The geographical separation between where the landings in 7h and 7j are taken, suggests that there are two discrete fisheries occurring in the stock area. This perception is further supported by the clear variation in the gears used to catch sole within the two ICES divisions. Within 7j, sole is predominantly landed by otter trawls, whereas the 7h fishery is mainly targeted by beam trawls. ICES suggests that two separate assessments are required to effectively manage the fishery.Both the EU and UK have fishery management measures in place, which can include catch limits, targets for population sizes and fishing mortality, and controls on what fishing gear can be used and where. In the EU, compliance with regulations has been variable, and there are ongoing challenges with implementing some of them. There was a target for fishing to be at Maximum Sustainable Yield by 2020, but this was not achieved. The Landing Obligation (LO), an EU law that the UK has kept after Brexit, requires all fish and shellfish to be landed, even if they are unwanted (over-quota or below minimum size). It aims to promote more selective fishing methods, reduce bycatch, and improve recording of everything that is caught, not just what is wanted. Compliance with the LO is generally poor and actual levels of discards are difficult to quantify using the current fisheries observer programme.In the UK, it is too early to tell how effective management is, as the Fisheries Act only came into force in January 2021. The Act requires the development of Fisheries Management Plans (FMPs) (replacing EU Multi-Annual Plans) but there are no details yet on how and when these will be developed. FMPs have the potential to be very important tools for managing UK fisheries, although data limitations may delay them for some stocks. MCS is keen to see FMPs for all commercially exploited stocks, especially where stocks are depleted, that include:Targets for fishing pressure and biomass, and additional management when those targets are not being metTimeframes for stock recoveryTechnologies such as Remote Electronic Monitoring (REM) to support data collection and improve transparency and accountabilityConsideration of wider environmental impacts of the fishery
Otter trawlers interact with the seabed and can modify bottom topography and cause damage and removal of some biogenic features including vulnerable marine habitats and benthic communities. They can also be bycatch of vulnerable species.In 2020, 299 tonnes of sole were landed. Of this, otter trawl accounted for 52%, and beam trawl accounted for 47%. Other gear types made up 1% of the catch. The assessed part of the fishery focusses mainly on division 7j, where Irish vessels operate close to the shore on sandy grounds off the southwest of Ireland. Sole is a small (but valuable) component (up to 5%) of the landings in this mixed fishery. The minimum conservation reference size is 24cm for sole, and the minimum mesh size is 80 mm for trawl gears. This leads to bycatch of plaice, which has an MCRS of 27cm.Whilst discards of sole are considered negligible in the fishery, there is discarding of non-commercial species and commercial species of unmarketable size. Some beam trawlers are experimenting with benthic drop-out panels that release about 75% of benthic invertebrates from the catches. Full square mesh codends are being tested in order to reduce the capture of benthos further and improve selectivity of gadoids (cod and whiting etc.).Demersal otter trawls have the potential to take relatively high quantities of bycatch (> 40% of catch weight). There are also reported catches of demersal elasmobranchs and endangered, protected and threatened (ETP) species (e.g. sharks and rays) in certain circumstances.Although otter trawls are considered to have a potential to cause significant habitat damage, damage to vulnerable and sensitive marine habitats is likely to be minimised given that the footprint of the fishery is within core areas, typically historically fished ground. In the Eastern English Channel, scars related to bottom trawling are difficult to identify due to predominantly sandy sediments.
References
EU, 2019. Regulation (EU) 2019/472 of the European Parliament and of the Council of 19 March 2019 establishing a multiannual plan for stocks fished in the Western Waters and adjacent waters, and for fisheries exploiting those stocks. Available at https://eur-lex.europa.eu/legal-content/EN/TXT/?qid=1554387217276&uri=CELEX:32019R0472 [Accessed on 19.07.2021].Froese R. and Pauly D. (Editors), 2019. Solea solea, Common sole. Available at: https://www.fishbase.de/Summary/SpeciesSummary.php?ID=525&AT=sole [Accessed on 16.07.2021].ICES. 2019. Report of the Working Group for the Celtic Seas Ecoregion. ICES Scientific Reports, 1:29. 1604 pp. Available at http://doi.org/10.17895/ices.pub.4982 [Accessed on 19.07.2021].ICES. 2020. Benchmark Workshop for Flatfish stocks in the North Sea and Celtic Sea (WKFlatNSCS). ICES Scientific Reports, 2:23. 966 pp. Available at http://doi.org/10.17895/ices.pub.5976. [Accessed on 16.07.2021].ICES. 2021. Sole (Solea solea) in Divisions 7.h-k (Celtic Sea South, southwest of Ireland). In Report of the ICES Advisory Committee, 2021. ICES Advice 2021, sol.27.7h-k. https://doi.org/10.17895/ices.advice.7864 [Accessed on 16.07.2021].
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