Plaice

Pleuronectes platessa

Method of production — Caught at sea
Capture method — Demersal otter trawl
Capture area — North East Atlantic (FAO 27)
Stock area — English Channel: West
Stock detail — 7e
Picture of Plaice

Sustainability rating three info

Sustainability overview

Updated: July 2019.

The plaice stock in the Western English Channel is in a good state, but fishing pressure is significantly above sustainable limits. A single catch limit covers both eastern and western English Channel plaice, and while total catches of eastern Channel plaice seem to be in line with advice, catches of western Channel plaice seem to exceed advice, indicating that the current management measures are allowing overfishing. Plaice is caught in a mixed fishery targeting sole, with 80 mm mesh size. This leads to a large number of plaice being discarded because this mesh size is not matched to the lower size limit for plaice. There are a number of Protected, Endangered and Threatened species found in the Celtic Seas, including the Western Channel, that could be impacted by bottom trawling and gillnetting, including sharks and cetaceans. Look for fish sold by vessels involved in the “Seafish Responsible Fishing Scheme” for assurance of scientific co-operation, better environmental practices and experimentation with Benthic Release Panels to reduce impact to bottom dwelling species.

Biology

Plaice is a bottom-dwelling flatfish. It spawns in the early months of the year (January to March) and sometimes makes long spawning migrations. North Sea plaice reach between 35 and 45 cm in their 6th year. It is a long-lived species, becoming sexually mature at 3-7 years (females) 2-6 (males) and living 30 years or more. Maximum reported age 50 years.

Stock information

Criterion score: 0.5 info

Stock Area

English Channel: West

Stock information

The plaice stock in the Western English Channel is in a good state, but fishing pressure is significantly above sustainable limits.

Fishing mortality (F) declined substantially after 2007, but has increased again since 2015 and in 2018 it was 0.61 - above the proxy for FMSY (0.48). The spawning-stock biomass (SSB) has increased substantially since 2008, and in 2018 was 1.99, well above the proxy for MSY Btrigger (0.66). However, it has been decreasing since 2016 and is projected to be 1.87 in 2019. Recruitment in the last three years has been below the long-term average.

ICES advises that when the precautionary approach is applied, catches of the western Channel plaice stock in 2020 should be no more than 2721 tonnes. This is a 25% decrease on last year’s advice, owing to a decline in the stock and the application of the precautionary buffer to account for uncertainty in the assessment. The assessment is considered only indicative of trends because it is based on landings data only and because discarding is considered to be substantial in this stock. Exploratory assessments using discard information indicate that the recent fishing mortality is likely to be higher, and recent Spawning stock biomass lower than in the current landings only assessment. There is also uncertainty about the landing statistics of the western Channel plaice stock because of migration between this area and the eastern English Channel during the spawning period. Assuming the same proportion of the western Channel plaice stock is taken in the eastern Channel as during 2003-2018, this will correspond to catches of plaice in the western Channel in 2020 of no more than 2,456 tonnes.

Management

Criterion score: 0.5 info

This stock is covered by the EU’s Western Waters Multi Annual management Plan (MAP). With data limited stocks, such as western Channel plaice, best available scientific advice should be used for setting Total Allowable Catches.

A single TAC covers both eastern and western English Channel plaice, so management should ensure that fishing opportunities are in line with the stock status for each of the stocks in the combined area, to ensure that both are exploited sustainably. Total catches of eastern Channel plaice stock seem to be in line with advice. However, catches of western Channel plaice stock seem to exceed advice, indicating that the combined TAC is allowing overfishing.


In the European Union (EU), EU fishing vessels can fish up to 12 nautical miles of any Member State coast, and closer by agreement. There is overarching fisheries legislation for all Member States, but implementation varies between fisheries, Member States and sea basins.
The EU Common Fisheries Policy (CFP) is the primary overarching policy. Its key environmental objectives are to restore and maintain harvested species at healthy levels (above BMSY), and apply the precautionary and ecosystem-based approaches to fisheries management. To achieve the MSY objective, the MSY exploitation rate is supposed to be achieved by 2020, but this seems unlikely to happen.
The CFP also introduced a Landing Obligation (LO) which bans the discarding at sea of species which are subject to catch limits. Some exemptions apply to species with high post-capture survival, and where avoiding unwanted catches is very difficult. These exemptions are outlined in regional discard plans. Despite quota ‘uplift’ being granted to fleets under the LO, available evidence suggests there has been widespread non-compliance with the policy, and illegal and unreported discarding is likely occurring.
Multi-Annual Plans (MAPs) are a tool for implementing the CFP regionally, with one in place or being developed for each sea basin. They specify fishing mortality targets and ranges for the main targeted species, as well as lower biomass reference points. If populations drop below these points it should trigger a management response. The MAPs also empower Member States to jointly apply measures such as closures, gear or capacity limits, and bycatch limits. There is concern however that the MAPs do not provide adequate safeguards to maintain all stocks at healthy levels.
The EU Technical Measures regulation addresses how, where and when fishing can take place in order to limit unwanted catches and ecosystem impacts. There are common measures that apply to all EU sea basins, and regional measures that vary between sea basins. Measures include Minimum Conservation Reference Sizes (MCRS, previously Minimum Landing Sizes, MLS), gear specifications, mesh sizes, closed areas, and bycatch limits.
The Control Regulation, which is being revised in 2019, addresses application of and compliance with the above, e.g. keeping catches within limits, recording and sharing data, and satellite tracking of vessels over 12 metres (VMS).

Capture Information

Criterion score: 0.5 info

In 2018, 70% of the landings were taken by beam trawls, 23% by otter trawls, and 4.9% by gillnets.

Plaice is mainly caught as bycatch in the sole fishery, which uses 80 mm mesh size. This 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. The approximate size at which 50% of females mature or first spawn is around 30-34cm. The discard rate was estimated to be 25% in 2018, but there is uncertainty in this estimate. The landing obligation is being phased in between 2019 and 2021 for plaice in the western Channel, with a discard plan to allow some discarding to take place. Plaice can be discarded from trammel nets and otter trawls owing to high rates of survival when caught by these gears.

There are a number of Protected, Endangered and Threatened species found in the Celtic Seas, including the Western Channel, including basking sharks, commons skates and spurdog. These can be vulnerable to demersal trawling. Other potentially impacted species and habitats in the Southwest UK include the pink sea fan Eunicella verrucosa, which is listed as ‘vulnerable’ by the IUCN. Reduced feeding success and growth rates of benthivorous fish are potential secondary effects of trawling impacts, which has been observed for European plaice in gravel substrates in the Celtic Sea. Trawling in the Celtic Sea has also been associated with declining length-weight ratios for lemon sole, megrim and cod, implying that reduced prey availability imposed by trawling may lead to reduced carrying capacity, and these effects may compromise recovery of threatened stocks and ecosystems.

Alternatives

Based on method of production, fish type, and consumer rating: only fish rated 2 and below are included as an alternative in the list below. Click on a name to show the sustainable options available.

Dab
Halibut, Atlantic (Farmed)
Halibut, Pacific
Megrim
Plaice
Sole, Dover sole, Common sole
Sole, Lemon
Turbot (Caught at sea)
Turbot (Farmed)

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 12.07.2019].

ICES. 2019. Working Group for the Celtic Seas Ecoregion (WGCSE). ICES Scientific Reports. 1:29. 1078 pp. doi: 10.17895/ices.pub.4982. Available at http://www.ices.dk/sites/pub/Publication%20Reports/Expert%20Group%20Report/Fisheries%20Resources%20Steering%20Group/2019/WGCSE/01_WGCSE_2019.pdf [Accessed on 12.07.2019].

ICES. 2019. Plaice (Pleuronectes platessa) in Division 7.e (western English Channel). In Report of the ICES Advisory Committee, 2019. ICES Advice 2019, ple.27.7e, doi: 10.17895/ices.advice.4799. Available at http://ices.dk/sites/pub/Publication%20Reports/Advice/2019/2019/ple.27.7e.pdf [Accessed on 12.07.2019].

Sustainable Fisheries Partnership (SFP). FishSource profile: European plaice Western English Channel. https://www.fishsource.org/stock_page/1755. [Accessed on 12.07.2019]