WGWIDE reports on the status and considerations for management of the Northeast Atlantic mackerel, blue whiting, Western and North Sea horse mackerel, Northeast Atlantic boarfish, Norwegian spring-spawning herring, striped red mullet (Subareas 6, 8 and Divisions 7.a-c, e-k and 9.a), and red gurnard (Subareas 3, 4, 5, 6, 7, and 8) stocks.
2025 catch advice was drafted for six of the stocks (excluding striped red mullet and red gur-nard). Benchmark is proposed for 2026 for blue whiting while mackerel, herring and striped red mullet is scheduled to be benchmarked in 2025. Boarfish and both horse mackerel stocks were benchmarked in 2024, and new assessment has been approved for all three stocks.
Northeast Atlantic Mackerel. This migratory stock is widely distributed throughout the North-east Atlantic with significant fisheries in several ICES Subareas. The assessment conducted in 2024 is an update assessment, based on the configuration agreed during the 2019 interbenchmark and incorporates updates to the commercial catch, tagging, swept-area, and recruitment index dataseries. Advice is given based on stock reference points which were updated during a man-agement strategy evaluation carried out in 2020. SSB has been declining since 2015 but is above MSY Btrigger in 2024. Fishing mortality has been increasing since 2016 and above FMSY since 2021.
Blue Whiting. This pelagic gadoid is widely distributed in the eastern part of the North Atlantic. The current assessment configuration (interbenchmark in 2016) uses preliminary catch and sam-pling data along with the acoustic survey data from the current year. The 2024 update assessment indicates that SSB has been increasing until 2024 following strong recent recruitment and is well above MSY Btrigger, although a decline in SSB is estimated for 2025. Fishing mortality has been above FMSY since 2014.
Norwegian Spring-spawning Herring. This stock is migratory, spawning along the Norwegian coast and feeding throughout much of the Norwegian Sea. The 2024 update assessment is based on an implementation of the XSAM assessment model, now using the SAM platform, and is consistent with the 2023 assessment. A working group level benchmark was conducted in 2024 for the change to the SAM platform. SSB has been declining since 2008, except for an increase in 2021-2022 which was due to the strong 2016 year class entering the SSB. Fishing mortality has been above FMSY since 2019 (except for 2021). Recruitment in 2016-2020 is estimated to be below average and SSB is below MSY Btrigger in 2024 and decreasing further in 2025. However, recruit-ment in 2021 and 2022 is estimated to be above average, and SSB is forecast to be above MSY Btrigger in 2026 if the management strategy is followed in 2025.
Western Horse Mackerel. The Western stock of horse mackerel is distributed throughout ICES Subareas 4,6,7,8 and 9. Following a benchmark in 2017, the stock is assessed using the Stock Synthesis integrated assessment model and improvements to the assessment were done in the 2024 benchmark. Stock reference points were revised in 2024 and new reference points were es-timated. Following a period of declining SSB, there has been a modest upward trend since 2015, albeit from a low level. The 2024 assessment indicates that SSB is below MSY Btrigger in 2024 but forecast to be above MSY Btrigger in 2025. The assessment has been displaying significant retro-spective bias, but changes made to the assessment in the 2024 benchmark have improved the diagnostic analyses compared to the previous model.
North Sea Horse Mackerel. In the 2024 benchmark, a SAM assessment was set up for the North Sea horse mackerel. The new assessment includes catch data, a commercial CPUE index and a combined SSB index from two groundfish surveys. The change resulted in the stock being moved from a category 3 to a category 1 stock and a new advice for 2025 replaced the advice issued in 2023. New reference points were estimated in the 2024 benchmark, but some of the reference point (FMSY, Fpa) could not be reliably estimated. The SSB is estimated to be below Blim in 2024 and forecast to be below Blim in 2025 and to remain below Blim in 2026 even with zero catch in 2025. Based on the MSY approach the advice for 2025 is therefore for zero catch.
Northeast Atlantic Boarfish. Boarfish is a small, pelagic, planktivorous, shoaling species, found over much of the Northeast Atlantic shelf but primarily in ICES subareas 4,6,7 and 8. The directed fishery occurs primarily in the Celtic Sea and developed during the early 2000s, initially unreg-ulated before the introduction of a TAC in 2011. In the 2024 benchmark a length based analytical assessment in Stock Synthesis 3 was set up including catch data, a combined acoustic survey biomass index, a combined groundfish survey biomass index, and new reference points were estimated. Based on the new assessment, the stock was moved from category 3 to category 1 and a new advice for 2025 replaced the advice issued in 2023. The current assessment indicates that, following a decline from 2012 to 2019, SSB has been increasing sharply in recent years following high recruitment in 2017 and 2019. SSB is estimated to be well above MSY Btrigger in 2024 and forecast to remain above MSY Btrigger in 2025 and 2026.
Northeast-Atlantic Red Gurnard. This stock was first considered by WGWIDE in 2016 with ad-vice issued biennially. The assessment was benchmarked in 2021 and a survey-based relative biomass indicator was developed. The 2023 update assessment continues to show the indicator fluctuating without trend since 2010. However, large uncertainties remain with regard to land-ings data due to poor resolution at the species level and reported discarding levels vary widely.
Striped Red Mullet in Bay of Biscay, Southern Celtic Seas, Atlantic Iberian waters. No assess-ment is available for this stock and information on abundance and exploitation level is limited with advice given triennially on the basis of the precautionary approach. However, there are a number of research projects underway which will inform the planned benchmark and potential upgrade of the assessment category.