Norway redfish Sebastes viviparus
Publication of Advice: 6. júní 2025. Published by Marine and Freshwater Research Institute.
Advice
MFRI advises that when the MSY approach is applied, catches in each of the fishing years 2025/2026 and 2026/2027 should be no more than 683 tonnes.
Stock development
Stock size is above Itrigger and the fishing pressure is below FMSY proxy.
Norway redfish. Catches, IS-SMB biomass index and fishing pressure proxy. IS-SMB biomass index: the red horizontal lines indicate average biomass indices for 2021–2023 and for 2024–2025 used in the advice calculations; the shaded area shows 95% confidence intervals.
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, 2021). IS-SMB biomass index of Norway redfish is used as an indicator of stock development. As sufficient data on life history in addition to length measurements from catches, the advice is based on the new rfb-rule for ICES category 3 data-limited stocks and is valid for each of the fishing years 2025/2026 and 2026/2027.
Norway redfish. Advice calculation.
Ay: Catch advice for 2024/2025 | 569 |
Stock biomass trend | |
Index A (2024-2025) | 45 575 |
Index B (2021-2023) | 34 697 |
r: Stock biomass trend (index ratio A/B) | 1.314 |
Fishing pressure proxy | |
Mean catch length (Lmean = L2024) | 26 |
MSY proxy length (LF=M) | 24 |
f: Fishing pressure proxy (LF=M/Lmean) | 0.923 |
Biomass safeguard | |
Last index value (I2025) | 33 568 |
Index trigger value (Itrigger=Iloss*1.4) | 9 471 |
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) | 0.95 |
Advice calculation1) | 769 |
Stability clause (+20% / -30% compared to Ay, only applied if b>1)2) | 1 |
Catch advice for 2025/2026 and 2026/2027 | 683 |
% advice change3) | 20 |
1) Ay × r × 1/f × b × m | |
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 is higher because the stock size indicator has increased.
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 | 9 471 | Iloss×1.4; Iloss defined as the lowest survey value |
FMSY_proxy | 1 | Relative value from LBI analysis, assuming M/K = 1.5 | |
Lc | 20 | Length at first capture, 50% modal abundance from catch length data | |
LInf | 36 | Asymptotic length, defined as maximum length from catch length data | |
K | 0.14 | Population growth rate | |
LF=M | 24 | 0.75 x Lc + 0.25 x LInf |
Quality of the assessment
The IS-SMB covers the entire fishing grounds of Norway redfish in Icelandic waters. Due to the aggregating behaviour of the species, survey indices are often dominated by a few large hauls, causing high variance in the survey indices. Little is known about stock productivity and exploitation status.
Other informations
Limited information is available on stock productivity of Norway redfish.
Advice, tac and catch
Norway redfish. Recommended TAC, national TAC, and catches (tonnes)
Fishing year | Recommended TAC | National TAC | Total catch |
|---|---|---|---|
2011/2012 | 1 500 | 1 219 | |
2012/2013 | 1 500 | 605 | |
2013/2014 | 1 500 | 666 | |
2014/2015 | 1 500 | 1 500 | 390 |
2015/2016 | 1 500 | 1 500 | 421 |
2016/2017 | 1 500 | 1 500 | 110 |
2017/2018 | 1 500 | 1 500 | 151 |
2018/2019 | 1 500 | 1 500 | 164 |
2019/2020 | 697 | 697 | 138 |
2020/2021 | 684 | 684 | 96 |
2021/2022 | 609 | 609 | 74 |
2022/2023 | 585 | 585 | 59 |
2023/2024 | 569 | 569 | 110 |
2024/2025 | 569 | 569 | |
2025/2026 | 683 | ||
2026/2027 | 683 |
References and further reading
ICES. 2021. Tenth Workshop on the Development of Quantitative Assessment Methodologies based on LIFE-history traits, exploitation characteristics and other relevant parameters for data-limited stocks (WKLIFE X). ICES Scientific Reports. Report https://doi.org/10.17895/ices.pub.5985
MFRI Assessment Reports 2025. Norway redfish. Marine and Freshwater Research Institute, 6 June 2025.