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Population identification plays an important role in the assessment of Atlantic herring (Clupea harengus). Several morphological/traditional methods have been applied in the past to split catches (both within survey and commercial samples) and to identify herring populations. However, in recent years advances in genomics have provided a robust and precise method to genetically identify herring populations. WKSIDAC2 reviewed the current status of genetic population identification for herring and outstanding issues affecting identification accuracy/success. The genetic methods using single nucleotide polymorphism (SNP) as genetic markers to identify herring population are considered appropriate. Depending on the region of interest, different sets of markers are used to identify herring populations. The differences in the set of markers have only minor influence on the population identification and can be negligible. However, it is recommended to choose sets of markers which will allow a direct comparison between institutes undertaking the classification. Furthermore, the review concluded that 26 different herring spawning populations can be currently identified using genetic methods in the northeastern Atlantic. However, future genetic studies may increase the number of identified populations and also provide a greater resolution for the spatial distributions. For example, from the genetic markers presented during WKSIDAC2, we are not able to genetically differentiate between Icelandic summer spawners, Faroese autumn spawners, and Norwegian autumn spawners. These three populations are currently combined as a single genetic unit. Future work incorporating whole genome sequencing data, is recommended to investigate this issue in more detail. In addition, of the 26 identified genetic populations only some can directly and uniquely be assinged to a particular stock (management unit) and for this reason WKSIDAC2 refrained from establishing such correspondence which

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. 2024 catch advice was drafted for all eight stocks. Benchmark assessments are proposed for 2025 for mackerel, herring, and striped red mullet while both horse mackerel stocks and boarfish are scheduled to be benchmarked in 2024. Northeast Atlantic mackerel. This migratory stock is widely distributed throughout the Northeast Atlantic with significant fisheries in several ICES subareas. The assessment conducted in 2023 is an update assessment, based on the configuration agreed during the 2019 interbenchmark and incorporates updates to the commercial catch, tagging, swept-area, egg survey, and recruitment index dataseries. Advice is given based on stock reference points which were updated during a management strategy evaluation carried out in 2020. SSB has been declining since 2014 but is above MSY Btrigger in 2023. 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 sampling data along with the acoustic survey data from the current year. The 2023 update assessment indicates that SSB is increasing following strong recent recruitment and is well above MSY Btrigger. 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 2023 update assessment is based on an implementation of the XSAM assessment mode

WGIPS met in January 2023 to combine and review the results of the annual pelagic ecosystem surveys and provide indices for the stocks of herring, sprat, mackerel, boarfish, and blue whiting in the Northeast Atlantic, Norwegian Sea, North Sea, and Western Baltic. Timing, coverage and methodologies were assessed and coordinated for the upcoming 2023 surveys. Progression on the update of the WGIPS survey manual (SISP 9) in the TIMES format continued, with an expected first draft to be submitted in spring 2023 and the completion planned within the present WGIPS reporting cycle. The group discussed the future and development of databases used by the group (the ICES DB and the PGNAPES database). The use of StoX and progress on TAF were reviewed during a joint session with the ICES Data Centre and the StoX development team. The biological sampling strategies in WGIPS surveys continue to be discussed and progress is being made on documenting the sampling strategies used in all WGIPS surveys in the new format of the sampling manual. The planned workshop on sampling strategies in the HERAS survey has been postponed until further progress is made on data availability for analysis. WGIPS reviewed progress in using genetic stock separation methods for splitting survey results to component herring stocks and assessed ways forward for the development of these methods whilst maintaining the integrity of the survey indices. The group encourages continued close collaboration of the ICES survey and assessment groups and institutes carrying out the genetic analysis work. WGIPS continues to follow progress on mesopelagic fish sampling in the International Blue Whiting Spawning Survey (IBWSS) through updates from the Ecologically and Economically Sustainable Mesopelagic Fisheries EU project (MEESO) and other developments within this area of relevance to the WGIPS surveys.

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. 2023 catch advice was drafted for mackerel, Western horse mackerel, blue whiting and herring. For the remainder, multi-annual catch advice was previously published. Benchmark assessments are proposed for 2024 for mackerel, both horse mackerel stocks, herring and striped red mullet with boarfish is scheduled to be benchmarked in 2023. Prior to any benchmark assessment for mackerel, WGWIDE recommends that a workshop to review the latest knowledge with regard to the stock component structure takes place. Northeast Atlantic Mackerel. This migratory stock is widely distributed throughout the Northeast Atlantic with significant fisheries in several ICES subareas. The assessment conducted in 2022 is an update assessment, based on the configuration agreed during the 2019 interbenchmark and incorporates updates to the commercial catch, tagging, swept area and egg survey (preliminary) data series. No recruitment index is available for the 2021 year-class as survey coverage was inadequate. Advice is given based on stock reference points which were updated during a management strategy evaluation carried out in 2020. Following a decline since 2014, SSB has been stable (above MSY Btrigger) since 2019. Fishing mortality has been increasing since 2016 and is above FMSY since 2020. Blue Whiting. This pelagic gadoid is widely distributed in the eastern part of the North Atlantic. The current assessment configuration (inter-benchmark in 2016) uses preliminary catch and sampling data along with the acoustic survey data from the current year. The 2022 update assessment indicates that SSB is increasing following strong recent r

The core objectives of the Working Group on International Pelagic Surveys (WGIPS) are to combine and review the results of annual pelagic ecosystem surveys to provide indices for the stocks of herring, sprat, mackerel, boarfish, and blue whiting in the Northeast Atlantic, Norwegian Sea, North Sea, and Western Baltic; and to coordinate timing, coverage and methodologies for the upcoming 2022 surveys. To support this work, the group is drafting an update to the Series of ICES Survey Protocols 9 - Manual for International Pelagic Surveys (SISP9-IPS). This past year, WGIPS held a number of focal sessions including: (1) a session for presenting auxiliary monitoring of ecosystem components beyond the standard fishery survey results for the target species. This session has been held annually since 2019, with presentations this year on tests with an in-trawl stereo camera system during part of the 2021 International Ecosystem Summer Survey in the Nordic Seas (IESSNS), (2) a session on the future and development of databases used to store data from surveys in WGIPS (ICES Acoustic Database and the “PGNAPES” database), developments and use of the acoustic survey analysis software “StoX” and progress on adopting the ICES Transparent Assessment Framework (TAF) for archiving and documenting acoustic index calculations, and (3) a session on biological sampling strategies in WGIPS surveys. The group is documenting the sampling strategies used in all WGIPS surveys (on request from ICES Working group on Acoustic Trawl Data Portal Governance (WGAcousticGov) and is planning a workshop on sampling strategies in the ICES Coordinated Acoustic Survey in the Skagerrak and Kattegat, the North Sea, West of Scotland and the Malin Shelf area (HERAS). The group also reviewed progress on mesopelagic sampling with an update from the European Union Horizon 2020-programme on Ecologically and Economically Sustainable Mesopelagic Fisheries (MEESO), presentations on new net developmen

The Atlantic herring Clupea harengus L has a vast geographical distribution and a complex population structure with a few very large migratory units and many small local populations. Each population has its own spawning ground and/or time, thereby maintaining their genetic integrity. Several herring populations migrate between common feeding grounds and over-wintering areas resulting in frequent mixing of populations. Thus, many herring fisheries are based on mixed populations of different demographic status. In order to avoid overexploitation of weak populations and to conserve biodiversity, understanding the population structure and population mixing is important for maintaining biologically sustainable herring fisheries. The aim of this study was to investigate the genetic population structure of herring in the Faroese and surrounding waters, and to develop genetic markers for distinguishing between four herring management units (often called stocks), namely the Norwegian spring-spawning herring (NSSH), Icelandic summer-spawning herring (ISSH), North Sea autumn-spawning herring (NSAH), and Faroese autumn-spawning herring (FASH). Herring from the four stocks were sequenced at low coverage, and single nucleotide polymorphisms (SNPs) were called and used for population structure analysis and individual assignment. An ancestry-informative SNP panel with 118 SNPs was developed and tested on 240 individuals. The results showed that all four stocks appeared to be genetically differentiated populations, but at lower levels of differentiation between FASH and ISSH than the other two populations. Overall assignment rate with the SNP panel was 80.7%, and agreement between the genetic and traditional visual assignment was 75.5%. The NSAH and NSSH samples had the highest assignment rate (100% and 98.3%, respectively) and highest agreement between traditional and genetic assignment methods (96.6% and 94.9%, respectively). The FASH and ISSH samples had substantially lowe