WHITING Merlangius merlangus
Publication of Advice: 6 June 2025. Published by Marine and Freshwater Research Institute.
Advice
MFRI advises in accordance with the MSY approach that catches in the fishing year 2025/2026 should be no more than 1 100 tonnes.
Stock development
Stock size is above Itrigger and the fishing pressure is below FMSY proxy.
Whiting. Catches by gear type, IS-SMB juvenile index (≤20 cm), fishing pressure proxy (FMSYproxy) and IS-SMB biomass (≥40 cm) index. Shaded area and bars represent 95% CI.
Basis of the assessment and reference points
Basis of the advice | MSY approach |
Management plan | There is no management plan for this stock |
Assessment type | Trends in biomass indicators |
Input data | Commercial catch and survey biomass indices (IS-SMB) |
Approach | Reference point | Value | Basis |
|---|---|---|---|
MSY approach | Itrigger | 1.81 | Iloss defined as the mean IS-SMB survey index 1985–1999 |
FMSY proxy | 0.17 | Average of the ratio of catch to biomass index for the years for which the fishing pressure proxy relative to MSY proxy (f) > 1, where f = Lmean/LF=γM,K=ϴM is based on Lc (length at 50% of modal abundance), which varies each year. |
Prospects
The ICES framework for category 3 stocks, for which analytical assessment is not possible but trends in biomass indicators are assumed to reflect changes in stock dynamics, was applied. (ICES, 2025). The IS-SMB survey index for whiting ≥40 cm is multiplied by an FMSY,proxy, a biomass safeguard (b), and a precautionary multiplier (m). The stability clause was applied since the increase from the previous advice is greater than 20%.
Whiting. Advice calculation.
Ay: Catch advice for 2024/2025 | 1 571 |
Biomass index | |
Latest index value (I2025) | 11 543 |
Fishing pressure proxy | |
FMSY proxy: MSY proxy harvest rate (average of the ratio of catch to biomass index for the years for which f>1, where f = Lmean/ LF = γM,K = ϴM ) | 0.173 |
Biomass safeguard | |
Index trigger value (Itrigger=Iloss*1.4) | 1 812 |
b: Index relative to trigger value, min{I2025/Itrigger, 1} | 1 |
Precautionary multiplier to maintain biomass above Blim with 95% probability | |
m: Multiplier (generic multiplier based on life history) | 0.5 |
Advice calculation1) | 999 |
Stability clause (+20% / -30% compared to Ay, only applied if b>1)2) | 1 |
Catch advice for 2025/2026 | 1 100 |
% advice change3) | -30 |
1) A~y+1~ = I~y~ × F~MSY proxy~ × b × m, limited by stability clause | |
2) min{max(0.7Ay, Ay+1), 1.2Ay} | |
3) The figures in the table are rounded. Calculations were done with unrounded inputs, and compared values may not match exactly when calculated using the rounded figures in the table. | |
The advice for this fishing year is lower than the advice for last year because the biomass index has decreased.
Quality of Assessment
IS-SMB covers the geographical distribution of the fisheries.
Other information
Recruitment was low in 2009–2014 but has increased since then.
Advice, TAC and Catch
Whiting. Recommended TAC, national TAC, and catches (tonnes).
Fishing year | Recommended TAC | National TAC | Total catch |
|---|---|---|---|
2019/2020 | 836 | 607 | |
2020/2021 | 1 003 | 844 | |
2021/2022 | 1 137 | 826 | |
2022/2023 | 1 091 | 1 252 | |
2023/2024 | 1 309 | 720 | |
2024/2025 | 1 571 | ||
2025/2026 | 1 100 |
References and further reading
ICES. 2025. ICES Guidelines - Advice rules for stocks in category 2 and 3. Version 3. ICES Guidelines and Policies - Advice Technical Guidelines. 31 pp. https://doi.org/10.17895/ices.pub.28506179
MFRI Assessment Reports 2025. Whiting. Marine and Freshwater Research Institute, 6 June 2025.