Plaice

Pleuronectes platessa

Method of production — Caught at sea
Capture method — Beam trawl
Capture area — North East Atlantic (FAO 27)
Stock area — Irish Sea
Stock detail — 7a
Picture of Plaice

Sustainability rating three info

Sustainability overview

Updated: July 2020.

The Irish Sea plaice stock is in a very healthy state and fishing pressure is low, although the amount of fish discarded at sea is high. This stock is covered by the EU’s Western Waters Multi Annual management Plan (MAP), in which it is considered bycatch. The total allowable catch (TAC) in recent years have been set in line with advice, and catches are usually below TACs, owing to limited market demand. ICES suggests that spatial management of fleets in the Irish Sea may reduce the discarding of plaice. Trawling can have impacts on the seabed, and there is concern over levels of bycatch of the vulnerable cod and whiting stocks in the Irish sea.

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 info

This stock is in a healthy state and fishing pressure is within sustainable limits.

Spawning-stock biomass (SSB) in 2020 is estimated to be 16,505 tonnes. It has been increasing since 2012 and has been well above MSY Btrigger (8,757 tonnes) since 2013. Recruitment is fluctuating without an overall trend but is estimated to be at its lowest in 2017-2019, which could lead to a stock decline. Fishing mortality (F) was 0.073 in 2019. It has generally been declining since 1992 and has been below FMSY (0.196) since 2011.

ICES advises that when the MSY approach is applied, catches in 2021 should be no more than 2846 tonnes. The advice for 2021 represents a decrease compared to the advice for 2020. This is due primarily to the change in the advice basis from the precautionary approach to the MSY approach.

Management

Criterion score: 0.5 info

This stock is covered by the EU’s Western Waters Multi Annual management Plan (MAP), in which it is considered bycatch. The total allowable catch (TAC) in recent years have been set in line with advice, and catches are usually below TACs, owing to limited market demand. A combination of this and a mismatch between the minimum landing size (27cm) and mesh size of the gear has resulted in the majority of the catch being discarded since 2004 (61% average discard by weight). Despite this excessive level of discarding, total fishing pressure on the stock is currently within sustainable levels. However, more must be done to reduce discarding. Any measures that effect a reduction in discards will result in increased future yield. However, the market demand for plaice is poor and small plaice are particularly undesirable. ICES suggests that spatial management of fleets in the Irish Sea may reduce the discarding of plaice. The landings obligation does not currently apply to this stock.


The UK is due to leave the EU on 31st December 2020, and new UK Fisheries legislation is being developed during 2020. MCS will update ratings with new management information when new legislation comes into force.

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: 0.75 info

Of the plaice that was landed in 2018, 33% was caught by beam trawl and 64% by otter trawl. Of the plaice that was discarded, which 40% survived, beam trawl accounted for 54% and otter trawl, 41%. This data has not been made available for 2019. The beam trawl fleet is generally targeting sole. Plaice is primarily caught by Irish, UK and Belgian fleets. High levels of discarding are known to occur in all fisheries that catch plaice in the Irish Sea, which indicates a mismatch between the minimum conservation reference size (27cm) and the mesh size of the gear being used. The approximate size at which 50% of females mature or first spawn is around 30-34cm. Spatial management of fleets in the Irish Sea may reduce the discarding of plaice.

Of greater concern is the bycatch of the vulnerable cod and whiting stocks in this area. Technical measures to reduce bycatch levels in this fishery include minimum mesh sizes, and 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 to allow escapes.

Beam and otter trawling can have impacts on the seabed. Beam trawlers often use tickler chains to disturb fish from the seabed. Beam trawling is not a well targeted fishing activity, with poor selectivity and the potential to catch a wide variety of non-target species, including benthic invertebrates disturbed from the seabed. A seasonal closure of the spawning grounds for cod restricts the footprint of trawling on the seabed at certain times of the year.

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)
Megrim
Plaice
Sole, Dover sole, Common sole
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 17.07.2020].

ICES. 2020. Plaice (Pleuronectes platessa) in Division 7.a (Irish Sea). In Report of the ICES Advisory Committee, 2020. ICES Advice 2020, ple.27.7a. Available at https://doi.org/10.17895/ices.advice.5918. [Accessed on 17.07.2020].

ICES. 2020a. Working Group for the Celtic Seas Ecoregion (WGCSE). Draft report. ICES Scientific Reports. 2:40. Xx pp. Available at http://doi.org/10.17895/ices.pub.5978. Publication of the full report is expected end of 2020. [Accessed on 17.07.2020].

ICES, 2019. Plaice (Pleuronectes platessa) in Division 7.a (Irish Sea). In Report of the ICES Advisory Committee, 2019. ICES Advice 2019, ple.27.7a, https://doi.org/10.17895/ices.advice.4798. Available at http://ices.dk/sites/pub/Publication%20Reports/Advice/2019/2019/ple.27.7a.pdf [Accessed on 12.07.2019].

Seafish, 2018. RASS Profile: Irish Sea plaice, beam trawl. Available at https://www.seafish.org/risk-assessment-for-sourcing-seafood/profile/irish-sea-plaice-beam-trawl [Accessed on 17.07.2020].