Mackerel Scomber scombrus

Advice 2027

352 938

tonnes

Advice 2026

174 357

tonnes

Advice change

102 %

Publication of Advice: 30 September 2026. Published by Marine and Freshwater Research Institute.

Advice

ICES advises that when the maximum sustainable yield (MSY) approach is applied, catches in 2027 should be no more than 352938 tonnes.

Stock development

Fishing pressure on the stock is above F_MSY and F_PA; spawning-stock size is below MSY B_trigger and B_PA and above B_lim.

Mackerel. Summary of the stock assessment. Catches prior to 2000 have been down-weighted in the assessment because of the considerable underreporting suspected to have taken place in this period.

Basis of assessement and reference points

Basis of the advice	Maximum sustainable yield (MSY) approach
Management plan	There is no internationally agreed long-term management strategy for Northeast Atlantic (NEA) mackerel
Assessment type	Age-based analytical model (SAM)
Input data	Catch data, steel tagging data [L3182] (1998–2006), and three survey indices: SSB index from the triennial egg survey [I4189] (1992–2025), abundance indices for ages 2–11 from RFID tagging data [L5543] (2013–2025), and from the IESSNS survey [A7806] ages 3–11 (2010, 2012–2026) and age 2 (2018–2026). Catches prior to 2000 are given a very low weight in the assessment. Weight-at-age in the stock updated annually from samples from the commercial catches and surveys (tagging, egg survey) corresponding to mature fish at spawning time. Maturity ogive and age-varying natural mortality constant over years.

Approach	Reference point	Value	Basis
MSY	MSY Btrigger	4 119 337	BPA; tonnes
	FMSY	0.191	Stochastic simulations, capped at FPA
Precautionary approach	Blim	3 067 017	Lowest spawning-stock biomass (SSB) level that in the past has resulted in good recruitment (2002, 2004, 2005) (ICES, 2025); tonnes
	BPA	4 119 337	Blim × exp (1.65 × σ), σ = 0.179; tonnes
	FPA	0.191	The F that provides a 95% probability for SSB to be above Blim (FP05 with advice rule)

Prospect

Mackerel. Assumptions made for the interim year and in the forecast.

Variable	Value	Notes
Fages  4–8 (2026)	0.167	From the forecast for 2026, based on assumed catch in 2026
SSB (2026) at spawning time	3 204 507	From the forecast for 2026; tonnes
Rage  2 (2027–2028)	4 787 144	Resampled recruitments from the years 2017–2026 (geometric mean shown); thousands
Total catch (2026)	398 186	Sum of expected landings and discards, accounting for the interannual transfers from 2025; tonnes

Mackerel. Annual catch scenarios. All weights in tonnes.

Basis	Total catch	Fishing mortality	Spawning-stock biomass (SSB)		% change			Probability of SSB2028 < Blim (%)
	2027	2027–2028	2027	2028	SSB1)	Catch2)	Advice3)
FMSY	352 938	0.149	3 135 352	3 345 872	6.7	-11	102	33
SSB2028 = Blim	675 632	0.309	3 069 021	3 068 002	-0.03	70	288	50
F = F2026	392 517	0.167	3 127 869	3 312 345	5.9	-1.4	125	35
1) SSB in 2028 relative to SSB in 2027
2) Catch in 2027 relative to estimated catches in 2026 (352 938 t)
3) Advice value for 2027 relative to advice value for 2026 (174 357 t)

Due to an improved recruitment in 2026 (2024 year class), higher mean weights-at-age in the stock, SSB₂₀₂₆ is estimated to be above B_lim. This allows for a higher advised fishing pressure than last year (0.15 for the 2026 advice compared to 0.07 for the 2025 advice), resulting in an increase in advice by 102%.

Quality of the Assessement

Following the inclusion of a new year of data, the estimated stock size remains consistent with last year’s assessment, but there is a downwards revision of the estimated fishing mortality. This retrospective pattern is expected, as the model is still adjusting to some of the input data series that are short (tag index and IESSNS recruitment index).

The higher recruitment in 2026 is based only on the 2026 IESSNS age 2 index and remains to be confirmed when catch data are available.

The final spawning-stoc biomass (SSB) from the 2025 egg survey is 13% lower than the preliminary estimate used in the previous assessment. The stock assessment output was insensitive to this revision.

Mackerel. Current assessment (red line) compared with previous estimates (2022–2025).

Other Information

The sum of the unilateral quotas for mackerel has resulted in catches that have exceeded the scientific advice by, on average, 39% since 2010. The stock is estimated to be above B_lim in 2026 but remains below MSY B_trigger. The advice is based on the MSY approach, which is intended to lead to a medium-term recovery above MSY B_trigger. Failing to adhere to the advised catches as derived from the application of the MSY approach may lead to a lower chance of the stock recovering to above MSY B_trigger in the medium term.

Following analysis of the changes in recruitment between 2004 and 2026 (ICES, 2026b), the years 2017−2026 were selected by ICES as the time period to calculate the recruitment in the forecast to reflect the currently observed low stock productivity.

On request from UK, Norway, Iceland, Greenland, and Faroes, ICES evaluated the performance of a set of rebuilding harvest control rules (HCRa and HCRb) for mackerel (ICES, 2026c). The HCRs were tested using a simulation framework that differs from the short-term forecast method used for the advice, and therefore the results presented in the technical service (ICES, 2026c) may differ from those presented in the catch scenarius table. As the stock is estimated to be above B_lim in 2026, all the HCRs tested lead to an advised fishing mortality for 2027 equal or lower than that from the ICES advice rule.

Based on the recruitment assumptions used in the forecast, SSB in 2028 is predicted to be composed of 41% of age-2 and age-3 fish. Therefore, the forecasted SSB in 2028 and the probability of SSB to be below B_lim in 2028 are sensitive to the forecast assumptions.

Advice, tac and catch

Mackerel. Recommended TAC, national TAC, and catches (tonnes).

Year	Recommended TAC	Iceland national TAC	Catches Iceland	Total national TAC	Total catch
1987			0	442 000	654 992
1988			0	610 000	680 491
1989			0	532 000	585 920
1990			0	562 000	626 107
1991			0	612 000	675 665
1992			0	707 000	760 690
1993			0	767 000	824 568
1994			0	837 000	819 087
1995			0	645 000	756 277
1996			92	452 000	563 472
1997			925	470 000	573 029
1998	498 000		357	549 000	666 316
1999	437 000		0	562 000	640 309
2000	642 000		0	612 000	738 606
2001	665 000		0	670 000	737 463
2002	694 000		53	683 000	771 422
2003	542 000		122	583 000	679 287
2004	545 000		0	532 000	660 491
2005	420 000		363	422 000	549 514
2006	487 000		4 222	444 000	481 181
2007	509 000		36 706	502 000	586 206
2008	456 000		112 286	458 000	623 165
2009	578 000		116 160	605 000	737 969
2010	572 000	130 000	121 008	885 000	877 272
2011	672 000	154 825	159 263	959 000	948 963
2012	639 000	145 227	149 282	927 000	899 551
2013	542 000	123 182	151 235	906 000	938 299
2014	1 011 000	167 826	173 560	1 392 000	1 401 788
2015	906 000	172 964	169 336	1 229 000	1 215 827
2016	773 842	147 824	172 079	1 057 000	1 100 135
2017	857 185	168 464	167 366	1 173 000	1 159 641
2018	550 948	134 772	168 331	998 000	1 023 144
2019	770 358	140 240	128 077	864 000	839 727
2020	922 064	152 141	151 534	1 090 879	1 039 513
2021	852 284	140 627	132 176	1 199 103	1 081 540
2022	794 920	148 242	129 976	1 188 227	1 046 720
2023	782 066	144 039	141 369	1 188 265	1 056 241
2024	739 386	115 533	89 614	990 582	897 701
2025	576 958	125 572	129 628	760 714	809 175
2026	174 357	129 628		398 186
2027	352 938

References and further reading

ICES. 2020. Workshop on Management Strategy Evaluation of Mackerel (WKMSEMAC). ICES Scientific Reports. 2:74. 175 pp. http://doi.org/10.17895/ices.pub.7445

MFRI Assessment Reports 2025. Mackerel. Marine and Freshwater Research Institute, 30 September 2025.

ICES. 2025. Benchmark workshop on Mackerel and Norwegian spring-spawning herring (WKBMACNSSH). ICES Scientific Reports. 7:64. 509 pp.  https://doi.org/10.17895/ices.pub.29279615

ICES. 2026a. Mackerel (Scomber scombrus) in subareas 1-8 and 14 and in divisions 9.a, 12.a, and 12.b (Northeast Atlantic and adjacent waters). In Report of the ICES Advisory Committee, 2026. ICES Advice 2026, mac.27.nea, https://doi.org/10.17895/ices.advice.30932144

ICES. 2026b. Working Group on Widely Distributed Stocks (WGWIDE). ICES Scientific Reports.

ICES. 2026c. Technical service document - advice special request document