Fisheries and Resources Monitoring System

Yellowtail flounder - Grand Bank
Fact Sheet Title  Fact Sheet
Stocks management recommendations 2023
Yellowtail flounder - Grand Bank
Fact Sheet Citation  
Yellowtail flounder in Div. 3LNO
Owned byNorthwest Atlantic Fisheries Organization (NAFO) – ownership
ident Blockident Blockdisplay tree map
Species List:
Species Ref: en - Yellowtail flounder, fr - Limande à queue jaune, es - Limanda, ru - Камбала желтохвостая (=лиманда желтохвостая)
ident Block Yellowtail flounder - Grand Bank
Aq Res
Biological Stock: Yes         Value: Regional
Management unit: Yes        Reference year: 2022
Aq Res State Trend
Aq Res State Trend
Aq Res State Trend Aq Res State Trend
Aq Res State TrendNone- Low Fishing MortalityNo or low fishing mortalityGreen
Aq Res State TrendVirgin-Large stock sizePre-exploitation biomass or high abundance

The stock size has decreased since 2012, but remains above Bmsy with a probability of 0.61. There is very low risk (<1%) of the stock being below Blim and a very low risk of F being above Flim=Fmsy (7%). Recent recruitment is unknown.
Habitat Bio
Climatic Zone: Temperate.   Bottom Type: Unspecified.   Depth Zone: Slope - Deepslope (500 m - 1000 m).   Horizontal Dist: Neritic.   Vertical Dist: Demersal/Benthic.  

Geo Dist
Geo Dist: Straddling between High Seas and EEZ

Water Area Overview
Spatial Scale: Regional

Water Area Overview
Aq Res Struct
Biological Stock: Yes

Yellowtail flounder is caught in a directed trawl fishery and as by-catch in other trawl fisheries. The fishery is regulated by quota and minimum size restrictions. Catches in several years were low due to industry-related factors, but in recent years catches were higher, and in 2021 and 2022 were 86% and 53% of the TAC respectively. American plaice and cod are taken as by-catch in the yellowtail fishery. There is a 15% by-catch restriction on American plaice and a 4% limit on cod.

Ecosystem sustainability of catches

Fishing intensity on yellowtail flounder has impacts on Div. 3NO cod and Div. 3LNO American plaice through by-catch. General impacts of fishing gears on the ecosystem should also be considered. Areas within Divs. 3LNO have been closed to bottom fishing to protect sponge and coral species.

Yellowtail flounder is included in the benthivore guild of the Grand Bank (3LNO) Ecosystem Production Unit (EPU). Other NAFO managed stocks in this guild within the EPU include 3LNOPs thorny skate, 3NO witch flounder, 3LNO American plaice, and 3LNO shrimp. The Catch/TCI is below the 2TCI ecosystem reference point (3LNO Benthivore Catch2022/TCI=0.80) indicating a low risk of ecosystem overfishing.
Bio Assess
Ref Point

Blim is 30% Bmsy and Flim is Fmsy (STACFIS 2004 p. 133).

Medium-term projections were carried forward to the year 2026 for Catch2023=TAC=20 000 t. Constant fishing mortality was applied from 2023-2026 at several levels of F (F=0, Fstatus quo, 75% Fmsy, 85% Fmsy, and Fmsy). At the end of the projection period, the risk of biomass being below Blim is 6% or less in all cases.

For the Fstatus quo projections, probability that F > Flim=Fmsy in 2025-2026 was from 0.11 to 0.12 and at 75% Fmsy, that probability was between 0.27 and 0.28. Projected at the level of 85% Flim, the probability that F > Flim was 0.36 and for Fmsy projections, this probability increased to 0.50. For biomass projections, in all scenarios for 2024-2026, the probability of biomass being below Blim was 0.06 or less. The probability that biomass in 2026 is greater than B2023 is 0.60, 0.49, 0.44 and 0.38 for projections of Fstatus quo, 75% Fmsy, 85% Fmsy, and Fmsy respectively.
Assess Models
Analytical assessment

A Schaefer surplus production model in a Bayesian framework was used for the assessment of this stock. The results were comparable to the previous assessment. Input data comes from research surveys and the fishery. The last available survey that covered the complete stock area was in autumn 2020. New vessels are being used to conduct the Canadian surveys and information from 2022 onwards are being examined for comparability to the previous survey indices used in this assessment.

The next assessment is planned for 2025.

Fishing Mortality



Human impact

Mainly fishery related mortality has been documented. Other sources (e.g. pollution, shipping, oil-industry) are undocumented.

Biological and environmental interactions

The Grand Bank (3LNO) Ecosystem Production Unit (EPU) is currently experiencing low productivity conditions, with EPU biomass well below pre-collapse levels (pre-1990s). While some rebuilding was observed since the 1990s, biomass declined across multiple trophic levels and stocks after 2014, and has not yet returned to the early-mid 2010s level.

Sci Advice

Special comments

Management of yellowtail flounder should take into consideration impacts on other stocks. By-catch in the yellowtail flounder fishery may be impeding recovery of Div. 3NO cod and American plaice in Div. 3LNO, which have both been below Blim for many years. Measures to reduce by-catch of American plaice in the yellowtail flounder fishery, in particular, which currently has a 15% limit, could reduce the impact of fishing on the recovery of that stock.
Management unit: Yes


Recommendation for 2024 to 2025

Scientific Council advises that fishing mortality up to 75% Fmsy, corresponding to catches of 15 560 t and 15 810 t in 2024 and 2025, respectively, have risk of no more than 30% of exceeding Flim, and are projected to maintain the stock around Bmsy with a low risk of being below Blim.

No explicit management plan or management objectives are defined by the Commission. Convention General Principles are applied.

Stock definition for management purposes

The management unit is NAFO Divisions 3LNO. The stock is mainly concentrated on the southern Grand Bank and is recruited from the Southeast Shoal area nursery ground.
Northwest Atlantic Fisheries Organization (NAFO) Scientific Council Documents SCR Doc. 22/018, 23/002, 23/016, 21/19 and SCS Doc. 21/05, 21/06, 21/09, 21/13. Click to open
Northwest Atlantic Fisheries Organization (NAFO). 2023. Report of the Scientific Council Meeting, 2 – 15 June, 2023. NAFO SCS Doc. 23/18. Click to open
Northwest Atlantic Fisheries Organization (NAFO). 2008. Resolution on the Interpretation and Implementation of the Convention on the Future Multilateral Cooperation in the Northwest Atlantic Fisheries. 30th Annual Meeting – September 2008. NAFO/GC Doc. 08/3. Click to open
Northwest Atlantic Fisheries Organization (NAFO). 2004. NAFO Precautionary Approach Framework. Annual Meeting, September 2004. NAFO FC Doc. 04/18. Click to open
powered by FIGIS  © FAO, 2024
Powered by FIGIS