TUSK Brosme brosme
Publication of Advice: 6 June 2025. Published by Marine and Freshwater Research Institute.
Advice
MFRI and ICES advise that when the Icelandic management plan is applied, catches in the fishing year 2025/2026 should be no more than 7 451 tonnes. In addition, continued closure of nursery areas off the southeast and southern coast should be maintained (Regulation No. 961/2019).
Stock development
Fishing pressure is below FMGT, Fpa, and Flim. Spawning-stock size is above MGT Btrigger, Bpa and Blim.
Tusk. Catches in Icelandic waters (by Icelandic and other nations). Shaded areas and error bars show 95% confidence intervals.
Basis of the assessment and reference points
Basis of the advice | Management plan |
Management plan | TAC set using the ICES advice rule with a fishing mortality FMGT = 0.23 applied to ages 7 to 10, modified by the ratio SSBy / MGT Btrigger when SSBy < MGT Btrigger. The expected range of realized fishing mortalities (F) following the management plan (FMGT) is between 0.15 and 0.31. |
Assessment type | Statistical catch at age model (SAM) |
Input data | Age and length data from commercial catches and surveys (IS-SMB, IS-SMH and IS-SMN) and total catches. |
Approach | Reference point | Value | Basis |
|---|---|---|---|
MSY approach | MSY Btrigger | 4 800 | Based on Bpa |
FMSY | 0.23 | Leads to long-term MSY, based on stochastic simulations (EqSim). | |
Management plan | MGT Btrigger | 4 800 | From the management plan |
FMGT | 0.23 | From the management plan | |
Precautionary approach | Blim | 3 400 | Lowest SSB (2016) where large recruitment was observed |
Bpa | 4 800 | Blim x e^1.645 * 0.2^ | |
Fpa | 0.23 | Fp05, maximum F at which the probability of SSB falling below Blim is <5% |
Prospects
The Icelandic Ministry of Industries has a fisheries management plan for Icelandic tusk which was evaluated by ICES (ICES, 2022). It is considered to be precautionary and conforms to ICES MSY approach. According to the management plan, FY/Y+1, i.e. the advice fishing mortality that is applied from 1 September in year Y to 31 August in year Y+1, is calculated from the harvest control rule (HCR) as:\[ \text{F}_{Y⁄Y+1}=\text{min}\left(\frac{\text{SSB}_Y}{\text{MGT B}_{trigger}} ,1\right) \text{F}_{mgt} \]
To calculate the catch in the last four months of the year Y (September through December), the following F is used in the year Y:
\[ \text{F}_Y=\frac{2}{3}\text{F}_{SQ} + \frac{1}{3}\text{F}_{MBT} \]
In year Y+1, F(Y⁄Y+1) is used. Finally, the catch advice for the year Y/Y+1 is calculated using the following formula:
\[ C_{Y⁄Y+1}=\frac{1}{3}C[\text{F}_Y]+ \frac{2}{3} C[\text{F}_{Y/Y+1}] \]
where the catch C[.] is calculated using the Baranov catch equation with the corresponding biomass, natural mortality, and fishing mortality values in each year.
Tusk. Assumptions made for the interim year and in the forecast.
Variable | Value | Notes |
|---|---|---|
Fages7-10 (2025) | 0.18 | Assuming status quo F (average over the last three years) for 1 January–31 August 2025 and FMGT for 1 September–31 December 2025; tonnes |
SSB (2026) | 11 620 | Short-term forecast; in tonnes |
Recruitment age 1 (2026) | 32 507 | Averaged from the past 10 years of the assessment; in thousands |
Recruitment age 1 (2027) | 32 507 | Averaged from the past 10 years of the assessment; in thousands |
Catch (2025) | 5 045 | Results from Fages–7-10 (2025); in tonnes. |
Tusk. Projection of SSB (tonnes) on catch according to management plans.
Basis | Catch (2025/2026) | Fishing mortality (2025/2026) | SSB (2027) | % SSB change1) | Advice change2) |
|---|---|---|---|---|---|
Management plan | 7 451 | 0.23 | 12 550 | 8 | 26 |
1) SSB in 2027 relative to SSB in 2026 | |||||
2) Advice value for 2025/2026 relative to advice value for 2024/2025 (5914 t) | |||||
The advice for 2025/2026 is higher than the advice for 2024/2025 because of the increase in the stock size.
Quality of the assessment
For F and SSB, the results of the assessment in 2025 are consistent with those from 2024.
Tusk. Current assessment (red line) compared with previous estimates 2021–2024. The stock was benchmarked in 2022 and only lines from 2022 onwards should be compared to the reference points. Prior to the benchmark, recruitment was estimated at age 3 and is not shown.
Other information
A higher proportion of catches in Subarea 14 have been reported since 2015. If these catches continue, they should be sampled to ensure that data are representative of the full stock. The Greenlandic deep sea survey has shown that an unknown proportion of the stock extends from the Icelandic exclusive economic zone (EEZ) and along the east Greenland continental shelf edge down to 62°N.
Advice, tac and catch
Tusk. Recommended TAC, national TAC, and catches (tonnes). Note that catch and TAC in Icelandic waters is by fishing year whereas catch in other areas is by calendar year.
Fishing year | Recommended TAC | National TAC | Landings of Iceland in Icelandic waters | Landings of other nations in Icelandic waters | Total landings in Icelandic waters | Landings in East Greenland waters3) | TAC in East Greenland3) |
|---|---|---|---|---|---|---|---|
2010/2011 | 6 000 | 6 000 | 6 235 | 1 898 | 6 235 | 175 | |
2011/2012 | 6 900 | 6 900 | 5 983 | 1 606 | 5 983 | 253 | |
2012/2013 | 6 700 | 6 700 | 5 555 | 1 336 | 5 569 | 427 | |
2013/2014 | 6 300 | 6 300 | 4 850 | 1 360 | 5 438 | 254 | |
2014/2015 | 4 000 | 4 000 | 4 136 | 1 304 | 5 440 | 1 599 | 1 500 |
2015/2016 | 3 440 | 3 440 | 3 221 | 900 | 4 121 | 606 | 1 500 |
2016/2017 | 3 780 | 3 780 | 1 689 | 729 | 2 418 | 781 | 1 500 |
2017/2018 | 4 3701) | 4 370 | 2 200 | 885 | 3 085 | 681 | 1 500 |
2018/2019 | 3 7761) | 3 776 | 2 453 | 778 | 3 231 | 565 | 1 500 |
2019/2020 | 3 8561) | 3 856 | 2 460 | 781 | 3 241 | 225 | 1 500 |
2020/2021 | 2 2891) | 2 289 | 2 192 | 757 | 2 949 | 702 | 1 500 |
2021/2022 | 2 1721) | 2 172 | 1 918 | 503 | 2 421 | 681 | 1 500 |
2022/2023 | 4 4642) | 4 464 | 2 421 | 640 | 3 061 | 765 | 1 500 |
2023/2024 | 5 1392) | 5 139 | 1 592 | 784 | 2 376 | 940 | 1 500 |
2024/2025 | 5 9142) | 5 914 | |||||
2025/2026 | 7 4512) | ||||||
1) 13 % harvest control rule | |||||||
2) FMGT = 0.23 | |||||||
3)Calendar year (latter year in the fishing year column) | |||||||
References and further reading
ICES. 2022. Workshop on the evaluation of assessments and management plans for ling, tusk, plaice and Atlantic wolffish in Icelandic waters (WKICEMP). ICES Scientific Reports. 4:37. 271 pp. http://doi.org/10.17895/ices.pub.19663971
Regulation No. 961/2019 on limitations to longline fishing in deep-sea areas (2019). Issued by the Ministry of Fisheries and Agriculture. Retrieved May 08, 2025, from https://www.stjornartidindi.is
MFRI Assessment Reports 2025. Tusk. Marine and Freshwater Research Institute, 6 June 2025.