Lepidorhombus whiffiagonis

Method of production — Caught at sea
Capture method — Demersal otter trawl
Capture area — North East Atlantic (FAO 27)
Stock area — Northern North Sea, West of Scotland
Stock detail — 4a, 6a
Picture of Megrim

Sustainability rating two info

Sustainability overview

Updated: July 2019.

Megrim in the Northern North Sea and West of Scotland is in a very healthy state and is being harvested sustainably. Megrim are mainly caught as part of the targeted fishery for monkfish or anglerfish, and as bycatch in fisheries for demersal species such as cod and haddock. While fishing is within sustainable limits, management measures (Total Allowable Catches) do not match up to the stock areas, which could in theory allow overfishing to take place. Demersal trawling can have habitat and bycatch impacts, but discard rates of unwanted fish by demersal otter trawls in this area are lower than in other parts of the north-east Atlantic.


A common flatfish found in shelf seas throughout the northeast Atlantic. Megrim spawns in spring in deep water off Iceland, and between January and April along the edge of the continental shelf to the southwest and west of the British Isles. It is found at depths ranging from 50-800 m, but with the highest abundance around 100-300 m. For both sexes combined, 50% of individuals mature at about 20 cm at 2.5 years old. Males reach first maturity at a lower length and age than females. Megrim can attain a length of about 60 cm, although more usually 35-45 cm, and a maximum age of 14-15 years.

Stock information

Criterion score: 0 info

Stock Area

Northern North Sea, West of Scotland

Stock information

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

Fishing pressure (F) has declined since the mid-1990s and has been below FMSY since 2002. In 2018 the ratio of F:FMSY was 0.4. Biomass (B) has increased since the mid-2000s and been above MSY Btrigger for the entire time-series. In 2018, the ratio of B:BMSY was 1.68. MSY BTrigger is 0.5.

ICES advises that when the EU multiannual plan (MAP) for Western waters and adjacent waters is applied, catches in 2020 that correspond to the F ranges in the MAP are between 6,450 and 8,350 tonnes. ICES considers that the FMSY range for this stock used in the MAP is precautionary. The upper limit is equivalent to fishing at FMSY. This is close to the previous year’s advice, as the stock is in a similar state.

The estimates of relative B and relative F have large uncertainty, but there is a low probability that B is below MSY Btrigger and a high probability that F is below FMSY.

The advice is given for two species of megrim combined, as they are caught together: Lepidorhombus whiffiagonis and L. boscii. Available information indicates that L. boscii are a negligible proportion of catches, based on historical sampling of the Scottish and Irish megrim catch.


Criterion score: 0.5 info

This stock is covered by the EU Western Waters Multi Annual management Plan (MAP). Since 2013, landings in 4a and 6a have been between 1/3 and 1/2 of advised limits. However, the Total Allowable Catch (TAC) does not match the assessment area and it is recommended that this be corrected. There are two TACs, covering a very wide area: one is for areas: 6 (West of Scotland), 5b (Faroes), 12 (N of Azores) and 14 (E of Greenland). It includes Division 6b (SE Greenland), which is assessed separately. The uptake of this TAC in 2018 was 33%. The other TAC is for areas 4 (North Sea) and 2a (Norwegian Sea); in 2018, uptake was 113%.

The average discard rate between 2016 and 2018 was 8% of the total weight of catch.

Megrim is a bycatch species in the mixed demersal trawl fishery in divisions 4.a and 6.a. Management measures for other species have constrained the fishery, and the reduction in effort and fishing mortality on megrim since the early 2000s may have contributed to the increase in biomass.

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

Finfish trawls (i.e. demersal otter trawls) accounted for 97% of the megrim catch and discards in 2018. Most of the catches are by Scotland, with some from Ireland, Spain and France. They are mainly caught as part of the targeted fishery for monkfish or anglerfish, and as bycatch in fisheries for demersal species such as cod and haddock. Male megrim grow to a smaller maximum size than females, and as a consequence the majority of males in the catch are discarded and the bulk of fish landed is comprised of females (around 90%). The minimum conservation reference size for megrim in EU waters is 20cm (25cm in Skagerrak/Kattegat). Increased mesh sizes (120mm) brought in to protect cod since 2010 have also benefitted the megrim population by reducing the bycatch of juveniles.

Demersal otter trawling can catch a number of unwanted species, including commercial species, and vulnerable species such as sharks and rays. However, in the North Sea and West of Scotland, discard rates of unwanted species are lower than the average (which in general is 30-40% of total catch by weight), at around 16% for commercial species. Cod in West of Scotland waters, however, has a very high discard rate owing to low quotas.

Demersal otter trawls use doors to hold nets open that penetrate the seabed, resulting in the abrasion of habitat features. The ground ropes, sweeps and bridles of the trawl can have similar abrasive impact. Various closures are in place in the area of this stock, including UK and European Marine Protected Areas. Some MPAs are designated to protect benthic features. If those MPAs were found to be subjected to bottom trawling, MCS would consider it a default red rating unless there is evidence (e.g. environmental impact assessment) indicating the activity does not damage the integrity of the site.


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.

Halibut, Atlantic (Farmed)
Sole, Dover sole, Common sole
Turbot (Caught at sea)
Turbot (Farmed)


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 [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/ Available at [Accessed on 17.07.2019].

ICES. 2019. Megrim (Lepidorhombus spp.) in divisions 4.a and 6.a (northern North Sea, West of Scotland). In Report of the ICES Advisory Committee, 2019. ICES Advice 2019, lez.27.4a6a, Available at [Accessed on 19.07.2019].

Seafish, 2016. RASS Profile: Megrim in northern North Sea and West of Scotland. Available at [Accessed on 19.07.2019]