Jukuri, open repository of the Natural Resources Institute Finland (Luke) All material supplied via Jukuri is protected by copyright and other intellectual property rights. Duplication or sale, in electronic or print form, of any part of the repository collections is prohibited. Making electronic or print copies of the material is permitted only for your own personal use or for educational purposes. For other purposes, this article may be used in accordance with the publisher’s terms. There may be differences between this version and the publisher’s version. You are advised to cite the publisher’s version. This is an electronic reprint of the original article. This reprint may differ from the original in pagination and typographic detail. Author(s): Elena Aleksejeva, Patrik Börjesson, Jose Antonio Canseco Rodriguez, Nicolas Goñi, Stefanie Haase, Olavi Kaljuste, Niklas Larson, Juha Lilja, Olof Lövgren, Hjalte Parner, Jukka Pönni, Krzysztof Radtke, Beata Schmidt, Elor Sepp, Ivo Sics, Vaishav Soni, Marijus Spegys, Marie Storr-Paulsen, Guntars Strods, Anders Svenson, Andrés Velasco & Adriana Villamor Title: Baltic International Fish Survey Working Group (WGBIFS) Year: 2023 Version: Published version Copyright: The Author(s) 2023 Rights: CC BY 4.0 Rights url: http://creativecommons.org/licenses/by/4.0/ Please cite the original version: ICES. 2023. Baltic International Fish Survey Working Group (WGBIFS). ICES Scientific Reports. 5:70. 90 pp. https://doi.org/10.17895/ices.pub.23675049 ICES SCIENTIFIC REPORTS RAPPORTS SCIENTIFIQUES DU CIEM ICES INTERNATIONAL COUNCIL FOR THE EXPLORATION OF THE SEA CIEM CONSEIL INTERNATIONAL POUR L’EXPLORATION DE LA MER BALTIC INTERNATIONAL FISH SURVEY WORKING GROUP (WGBIFS) VOLUME 5 | ISSUE 70 International Council for the Exploration of the Sea Conseil International pour l’Exploration de la Mer H.C. Andersens Boulevard 44-46 DK-1553 Copenhagen V Denmark Telephone (+45) 33 38 67 00 Telefax (+45) 33 93 42 15 www.ices.dk info@ices.dk ISSN number: 2618-1371 This document has been produced under the auspices of an ICES Expert Group or Committee. The contents therein do not necessarily represent the view of the Council. © 2023 International Council for the Exploration of the Sea This work is licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0). For citation of datasets or conditions for use of data to be included in other databases, please refer to ICES data policy. mailto:info@ices.dk ICES Scientific Reports Volume 5 | Issue 70 BALTIC INTERNATIONAL FISH SURVEY WORKING GROUP (WGBIFS) Recommended format for purpose of citation: ICES. 2023. Baltic International Fish Survey Working Group (WGBIFS). ICES Scientific Reports. 5:70. 90 pp. https://doi.org/10.17895/ices.pub.23675049 Editors Olavi Kaljuste • Elor Sepp Authors Elena Aleksejeva • Patrik Börjesson • Jose Antonio Canseco Rodriguez • Nicolas Goñi • Stefanie Haase Olavi Kaljuste • Niklas Larson • Juha Lilja • Olof Lövgren • Hjalte Parner • Jukka Pönni Krzysztof Radtke • Beata Schmidt • Elor Sepp • Ivo Sics • Vaishav Soni • Marijus Spegys Marie Storr-Paulsen • Guntars Strods • Anders Svenson • Andrés Velasco • Adriana Villamor ICES | WGBIFS 2023 | i Contents i Executive summary .......................................................................................................................iii ii Expert group information .............................................................................................................. iv 1 Terms of Reference ....................................................................................................................... 1 2 Summary of the Work Plan for Year 3 ........................................................................................... 3 3 Summary of outcomes and achievements of the WG during 3-year term ................................... 4 4 Final report on ToRs and Work Plan .............................................................................................. 6 4.1 ToR a) Combine and analyse the results of acoustic surveys and experiments .............. 6 4.1.1 Combined results of the Baltic International Acoustic Survey (BIAS) .............................. 6 4.1.1.1 Area under investigation and overlapping areas ............................................................. 6 4.1.1.2 Total results ..................................................................................................................... 8 4.1.1.3 Area-corrected data ....................................................................................................... 27 4.1.1.4 Tuning fleets for WGBFAS .............................................................................................. 30 4.1.2 Combined results of the Baltic Acoustic Spring Survey (BASS) ...................................... 37 4.1.2.1 Area under investigation and overlapping areas ........................................................... 37 4.1.2.2 Combined results and area corrected data ................................................................... 39 4.1.3 Combined results of the Gulf of Riga Herring Survey (GRAHS) ...................................... 46 4.2 ToR b) Update the BIAS, BASS and GRAHS hydroacoustic databases and ICES database for acoustic-trawl surveys .............................................................................. 51 4.3 ToR c) Coordinate and plan acoustic surveys including any experiments to be conducted ...................................................................................................................... 52 4.4 ToR d) Review the results from BITS surveys and evaluate the characteristics of TVL and TVS standard gears used in BITS ...................................................................... 55 4.4.1 4th quarter 2022 BITS. .................................................................................................... 55 4.4.2 1st quarter 2023 BITS. ..................................................................................................... 56 4.4.3 CPUE in 4th quarter 2022 and 1st quarter 2023 BITS. ..................................................... 57 4.4.4 Standard fishing-gear checking. ..................................................................................... 64 4.5 ToR e) Coordinate and plan demersal trawl surveys and experiments to be conducted, and update, and correct the Tow-Database ............................................... 64 4.6 ToR f) Conduct the analyses related to the improvement of quality of acoustic indices and estimation of the uncertainty in the acoustic surveys coordinated by WGBIFS .......................................................................................................................... 65 4.7 ToR g) Update on progress in development of the StoX software and implementation of it for the calculation of WGBIFS acoustic stock estimates .............. 66 4.8 ToR h) Coordinate the marine litter-sampling programme within the Baltic International Trawl Survey and registering the data in the ICES database .................... 67 4.9 ToR i) Agree a standard pelagic trawl gear used in acoustic surveys ............................ 70 4.10 ToR j) Review and update the manual for International Baltic Acoustic Surveys (IBAS; former SISP 8) and address methodological question raised at the last review of the SISP .......................................................................................................... 71 4.11 ToR k) Review and update the manual for Baltic International Trawl Survey (BITS; former SISP 7) and address methodological question raised at the last review of the SISP .......................................................................................................... 72 4.12 ToR l) Conduct analyses related to the uncertainties in the Gulf of Riga Acoustic Herring Survey (GRAHS) in order to improve the quality of the GRAHS and subsequent indices ........................................................................................................ 72 4.13 ToR m) Evaluate if there are methodological and/or environmental reasons for different survey catchabilities in different ICES Sub-divisions and what may be magnitude of these differences ..................................................................................... 72 5 Inquiries Besides of the Fixed ToRs ............................................................................................. 75 ii | ICES SCIENTIFIC REPORTS 5: 70 | ICES 5.1 Establish quality control checks for door- and wingspread during the upload process to DATRAS (organize a workshop under responsibility of IBTSWG and WGBIFS). (Rec. by WKSAE-DATRAS) ............................................................................... 75 5.2 Ensure that all hydrographic data, collected during the surveys, are uploaded to the ICES Oceanographic Database at the same time as the fish data are uploaded to DATRAS and the Acoustics survey database. (Rec. by WGBFAS) .............. 76 5.3 Review and Enhancement of DATRAS Data Product Descriptions. (Req. by ICES Data Centre) ................................................................................................................... 76 6 Revisions to the work plan and justification ............................................................................... 78 7 Next meeting and election of a new Chair .................................................................................. 79 List of participants.......................................................................................................... 80 Draft resolutions for the next meeting .......................................................................... 81 Agenda of WGBIFS 2023 ................................................................................................ 83 Action List ...................................................................................................................... 85 List of presentations made at the WGBIFS 2023 meetings............................................ 87 Supplementary Document 1: Standard and Cruise Reports of BITS surveys at the WGBIFS 2023 annual meeting ......................................................................................................................................... 89 Supplementary Document 2: Cruise reports of BASS and BIAS surveys at the WGBIFS 2023 meeting ..................................................................................................................................................... 90 ICES | WGBIFS 2023 | iii i Executive summary The Baltic International Fish Survey Working Group (WGBIFS) plans, coordinates, and imple- ments demersal trawl surveys and hydroacoustic surveys in the Baltic Sea including the Baltic International Acoustic Survey (BIAS), the Baltic Acoustic Spring Survey (BASS), and the Baltic International Trawl Surveys (BITS) in the 1st and 4th quarter on an annual basis. The group com- piles results from these surveys and provides the herring, sprat, cod and flatfish abundance in- dices for the Baltic Fisheries Assessment Working Group (WGBFAS) to use as tuning fleets. In 2023, WGBIFS completed the following tasks: (1) compiled survey results from 2022 and the first half of 2023, (2) planned and coordinated all Baltic fish stocks assessment relevant surveys for the second half of 2023 and the first half of 2024, (3) updated the common survey manuals according to decisions made during the annual WGBIFS meeting. Data from the recent BITS was added to the ICES Database of Trawl Surveys (DATRAS). The Tow-Database was corrected and updated. The Access-databases for aggregated acoustic data and the ICES database of acoustic- trawl surveys for disaggregated data were updated. All countries registered collected litter ma- terials to DATRAS. The area coverage and the number of control hauls in the BASS, BIAS and GRAHS in 2022 were considered to be appropriate to the calculation of tuning indices and the data can be used for the assessment of Baltic herring and sprat stocks. The number of valid hauls accomplished during the 4th quarter 2022 and 1st quarter 2023 BITS were considered by the group as appropriate to tuning series and the data can be used for the assessment of Baltic and Kattegat cod and flatfish stocks. BIAS and BASS survey sampling variance calculation questions were discussed and standard deviation for Central Baltic herring acoustic index series calculated. In comparison exercises between the StoX survey computational method and traditional IBAS calculation methods it was found that the StoX project, developed for the WGBIFS, has small methodological differences compared to the standard calculation method used by the group, as specified in the Manual for the International Baltic Acoustic Surveys (IBAS), and is thereby caus- ing a small difference in the total number of herring and sprat., The work with transition to a more transparent calculation software (e.g. StoX) will continue during the next period with more thorough analysis of calculation methodologies. A further comparison exercise between the StoX method and traditional Gulf of Riga Herring Survey calculation method was performed using data from 11 last years. It showed no major differences in herring total abundance estimates for most of the years. However, notable differ- ences were in the age compositions of those two methods. Some errors and differences in input data (uploaded into the ICES database) were found and therefore the further analysis was post- poned until these issues are fixed. WGBIFS is planning to continue with analogical comparison exercises in the coming years before the final transition to a transparent reproducible pathway into the ICES Transparent Assessment Framework (TAF) can be done. Work towards transitioning to TAF will continue during the next 3-year period until all methodological and database differences are resolved. Inquiries from other ICES expert groups were discussed and addressed. iv | ICES SCIENTIFIC REPORTS 5:70 | ICES ii Expert group information Expert group name Baltic International Fish Survey Working Group (WGBIFS) Expert group cycle Multiannual fixed term Year cycle started 2021 Reporting year in cycle 3/3 Chair(s) Elor Sepp, Estonia Olavi Kaljuste, Sweden Meeting venue(s) and dates 20-24 March 2023, Cadiz, Spain (22 participants) ICES | WGBIFS 2023 | 1 1 Terms of Reference TOR Description Background Science plan codes Dura- tion Expected deliver- ables a Combine and analyse the results of spring and au- tumn acoustic surveys and experiments Acoustic surveys provide important fish- ery-independent stock estimates for Baltic herring and sprat stocks 3.1 Annu- ally Year 1, 2 and 3 Updated acoustic tuning index for WGBFAS b Update the BIAS, BASS and GRAHS hydroacoustic databases and ICES data- base for acoustic-trawl surveys The aim of BIAS, BASS and GRAHS data- bases is to store the aggregated data. The aim of ICES database is to ensure that the standardized and quality-controlled scruti- nized data from the acoustic-trawl surveys will be stored centrally in a safe way and enables easy access to the data, which will facilitate usage for many different analyses by a wider range of users. 3.1 Annu- ally Year 1, 2 and 3 Updated data- bases with acous- tic and biotic data for WGBIFS c Coordinate and plan acoustic surveys including any experiments to be conducted Acoustic surveys provide important fish- ery-independent stock estimates for Baltic herring and sprat stocks 3.1 Annu- ally Year 1, 2 and 3 Finalized planning for the surveys for WGBIFS d Review the results of BITS surveys and evaluate the characteristics of TVL and TVS standard gears used in BITS Demersal trawl surveys provide important fishery-independent stock estimates for Baltic cod and flatfish stocks 3.1 Annu- ally Year 1, 2 and 3 Updated BITS data in DATRAS data- base for ICES Data Centre and WGBFAS e Coordinate and plan de- mersal trawl surveys and experiments to be con- ducted, and update and correct the Tow Database Demersal trawl surveys provide important fishery-independent stock estimates for Baltic cod and flatfish stocks 3.1 Annu- ally Year 1, 2 and 3 Finalized planning for the surveys for WGBIFS, updated and corrected Tow Database f Conduct the analyses re- lated to the improvement of quality of acoustic indi- ces and estimation of the uncertainty in the acous- tic surveys coordinated by WGBIFS Acoustic surveys provide important fish- ery-independent stock estimates for Baltic herring and sprat stocks 3.1, 3.2, 3.3 Year 1-3 Improved quality of acoustic indices with estimates of the uncertainty for WGBFAS g Update on progress in de- velopment of the StoX software and implementa- tion of it for the calcula- tion of WGBIFS acoustic stock estimates. StoX software produces fish abundance estimations in a transparent and repro- ducible way. Planned development of the StoX post-processing program should al- low implication this software by WGBIFS using the acoustic and biotic data from ICES database for acoustic-trawl surveys. Comparisons will be performed to vali- date whether the StoX software provides us similar results as the current IBAS cal- culation method in order to allow WGBIFS to use it as a new standard tool for the calculation of annual acoustic survey esti- mates. 3.1, 3.2 Year 1-3 Improved trans- parency and re- producibility of acoustic indices, improved pace of work on the level of national data compilation and verification 2 | ICES SCIENTIFIC REPORTS 5:70 | ICES h Coordinate the marine lit- ter-sampling programme within the Baltic Interna- tional Trawl Survey and registering the data in the ICES database. Collected and registered information about the marine litter (mostly anthropo- genic origin), occasionally appeared in the ground trawl fish control-catches, are ad- ditional source of data about present eco- logical status of marine seabed in investi- gated areas of the Baltic. 3.1 Annu- ally Year 1, 2 and 3 Coordinated the marine litter sam- pling programme in the Baltic Inter- national Trawl Sur- vey (BITS). i Agree a standard pelagic trawl gear used the acous- tic surveys Acoustic surveys provide important fish- ery-independent estimates for Baltic her- ring and sprat stocks size and possible un- certainties, which result from, e.g. differ- ent type of fishing gears applied for fish control-catches, should be eliminated. 3.1, 3.2 Year 1-3 Agreement on the standard pelagic fishing gear which will be used in the BIAS and BASS sur- veys j Review and update the manual for International Baltic Acoustic Surveys (IBAS; former SISP 8) and address methodological question raised at the last review of the SISP Acoustic surveys provide important fish- ery-independent stock estimates for Bal- tic herring and sprat stocks 3.1, 3.2 Year 3 Updated IBAS manual for publi- cation in TIMES k Review and update the manual for Baltic Interna- tional Trawl Survey (BITS; former SISP 7) and ad- dress methodological question raised at the last review of the SISP Demersal trawl surveys provide important fishery-independent stock estimates for Baltic cod and flatfish stocks 3.1, 3.2 Year 3 Updated BITS manual for publi- cation in TIMES l Conduct analyses related to the uncertainties in the Gulf of Riga Acoustic Her- ring Survey (GRAHS) in or- der to improve the quality of the GRAHS and subse- quent indices. Until now, the preparation of the survey data for stock assessment is the responsi- bility of the Latvian and Estonian national laboratories. The methodology and con- sistency of results of this survey should be evaluated by the wider international sci- entific expertise available. 3.1, 3.2 Year 1- 3 Improved quality, transparency and reproducibility of acoustic indices, updated data- bases with acous- tic and biotic data from GRAHS m Evaluate if there are methodological and/or environmental reasons for different survey catchabil- ities in different ICES Sub- divisions and what may be magnitude of these differ- ences Within the INSPIRE project assessments of herring and sprat stocks were con- ducted by former assessment units (AUs) instead of currently used central Baltic herring (CBH) and sprat in the entire Bal- tic. It was dis-covered in these assess- ments that catchabilities (q) (understood as ratio between the acoustically esti- mated and the model assessed stock sizes in given area/AU) of acoustic surveys esti- mated by applied assessment models dif- fered by AUs, and usually q’s were higher in northern than in southern waters. The question is if these differences may to some extent be caused by “environmen- tal” differences, acoustic methodologies, area coverages etc. in the surveyed areas. This information is important to have if ICES is asked to develop/evaluate a spa- tial management plan for sprat and her- ring, as has been suggested for several years in the sprat advice. 3.1, 3.2 Year 1- 3 Improved quality and transparency of acoustic indi- ces ICES | WGBIFS 2023 | 3 2 Summary of the Work Plan for Year 3 • Compilation the survey results from 2022 and the first quarter of 2023 and reporting to WGBFAS. (ToR a and d). • Updated databases with acoustic and biotic data (ToR b). • Finalized coordination and planning for the BASS, BIAS, GRAHS and BITS surveys in 2023 and first half of 2024, updated and corrected Tow Database (ToR c and e). • Questions related to BIAS and BASS survey uncertainties estimates were discussed and standard deviation for Central Baltic herring acoustic index series calculated (ToR f). • Uploading the data from the Gulf of Riga Acoustic Herring Survey into the ICES data- base for acoustic and trawl surveys and screening of the data. Analyses related to the uncertainties in the Gulf of Riga Acoustic Herring Survey. (ToR g and l). • Coordinated marine litter sampling programme in the BITS surveys and registered data in the ICES database (ToR h). • Progress towards an agreement in the standard pelagic fishing gear to be used in the acoustic surveys (ToR i). • Review and update of the IBAS and BITS manuals (ToR j and k). • Possible reasons for different survey catchabilities were listed. (ToR m) 4 | ICES SCIENTIFIC REPORTS 5:70 | ICES 3 Summary of outcomes and achievements of the WG during 3-year term Indices for the pelagic and demersal fish stocks in the Baltic Sea from annual surveys as fishery- independent data for analytical assessment purposes in WGBFAS: • Calculated BASS tuning fleet index for Baltic sprat in SDs 24–26 and 28.2 (abundance per age in the age groups 1-8+). • Calculated BIAS tuning fleet index for Baltic sprat in SDs 22–29 (abundance per age in the age groups 1-8+). • Calculated BIAS tuning fleet index for Baltic sprat recruitment in SDs 22–29 (abundance at age 0). • Calculated BIAS tuning fleet index for Baltic sprat in SDs 22–29 and 32 (abundance per age in the age groups 1-8+). • Calculated BIAS tuning fleet index for Baltic sprat recruitment in SDs 22–29 and 32 (abun- dance at age 0). • Calculated BIAS tuning fleet index for Baltic herring in SDs 25–29 (abundance per age in the age groups 1-8+). • Calculated BIAS tuning fleet index for Baltic herring recruitment in SDs 25–29 (abun- dance at age 0). • Calculated BIAS tuning fleet index for Baltic herring in SDs 25–29 and 32 (abundance per age in the age groups 1-8+). • Calculated BIAS tuning fleet index for Baltic herring recruitment in SDs 25–29 and 32 (abundance at age 0). • Calculated BIAS tuning fleet index (in StoX) for Baltic herring in SD 30 (abundance per age in the age-groups 0-15+). • Calculated standard deviations for the Central Baltic Herring BIAS tuning indices. • Uploaded data from the 1st and 4th quarter BITS surveys to the DATRAS database to be used for the calculation of survey indices for the relevant cod and flatfish stocks. • Updated IBAS and BITS manuals. Other survey-derived products: • Annual maps of BASS and BIAS area coverage. • Annual geographical distribution maps of sprat abundance in the Baltic Sea (May-June; BASS surveys). • Annual geographical distribution maps of sprat, herring and cod abundance in the Baltic Sea (September-October; BIAS surveys). • Geographical CPUE distribution map of cod and different flatfish species in the Baltic Sea based on the recent BITS surveys. • Updated Access-databases for aggregated acoustic data (BASS_DB.mdb, BIAS_DB.mdb, BIAS_HERR_SD30_DB.mdl and GRAHS_DB.mdb). • Updated ICES database of acoustic-trawl surveys for disaggregated data. • Updated and corrected the Tow-Database which allows planning the spatial distribution of hauls in the areas, where the seabed is suitable for safety trawling. • Alternative acoustic index series for the pelagic fish stocks in the Baltic Sea as fishery- independent data for benchmark assessment purposes in WKBALTPEL. ICES | WGBIFS 2023 | 5 Other outcomes and achievements: • Agreed plans (time and spatial coverage by countries) for the next standard acoustic sur- veys. • Agreed plans (time and number of planned stations by countries) for the next standard BITS surveys. • 2 recommendations (Annex 4) were made to other ICES Working Groups. • Updated action list (Annex 5) for WGBIFS members. 6 | ICES SCIENTIFIC REPORTS 5:70 | ICES 4 Final report on ToRs and Work Plan 4.1 ToR a) Combine and analyse the results of acoustic sur- veys and experiments 4.1.1 Combined results of the Baltic International Acoustic Survey (BIAS) In September – November 2022, the following acoustic surveys were conducted in the ICES Sub- divisions 21-32 (excl. ICES Subdivision 31). Some subdivisions were only partly covered. Country Data Vessel ICES SDs Length of acoustic transects [NM] Number of hauls Number of hydrological stations Finland 20.09- 03.10.2022 Aranda 30, parts of 29 and 32 1406 44 44 Poland 12-27.09.2022 Baltica Parts of 25 and 26 774 26 41 Latvia 06-17.11.2022 F/V Albatros 3 Parts of 26 and 28 615 17 17 Estonia-Po- land 11.10- 22.11.2022 Baltica Parts of 28, 29 and 32 623 24 24 Sweden 02-22.10.2022 Svea 27, parts of 25, 26, 28 and 29 1295 53 53 Lithuania 24-25.10.2022 F/V Palanga NZ55 Part of 26 112 7 7 Germany 05-24.10.2022 Solea 22, 23, 24 and parts of 21 1208 49 74 4.1.1.1 Area under investigation and overlapping areas Each of the ICES statistical rectangles of the area under investigation was allocated to one coun- try during the WGBIFS meeting in 2022. Thus, each country has a mandatory responsible area. Each rectangle should be covered by an acoustic transect of about 60 NM per 1000 NM2 area and at least two fishing hauls. Nations can also cover areas outside their mandatory areas but the results from the responsible country are used in these cases. During the BIAS 2022 survey, almost all rectangles were covered as planned during the WGBIFS 2022 meeting (Fig. 4.1). Overall, 121 statistical ICES rectangles were inspected and reported. 120 ICES rectangles were investigated by one country. One ICES rectangle was inspected and re- ported by two countries, namely 48H4 by Estonian and Finland. Also, one ICES rectangle (48H5) was additionally inspected by Finland, however, these data were not considered in the final anal- ysis. ICES statistical rectangle 39H0 in ICES Subdivision 26 was not investigated as Russia did ICES | WGBIFS 2023 | 7 not take part in the BIAS 2022 sampling. Rectangles 38G9, 39G9 and 40G9 were inspected only partly, i.e. inside the Polish and Lithuanian EEZ but included in the final analyses. Investigations in the eastern part of ICES Subdivision 32 (the Russian zone) were not planned. Compared to the BIAS 2021, the survey area was extended to the Gulf of Riga area, however, these data were not included into the final analysis asthe measurements in the Gulf of Riga were realised by Estonia and Latvia in slightly different time periods. The obtained results thus were not classified as representative. In total, 6033 NM of acoustic transects were recorded. Moreover, 220 and 260 catch and hydro- logical stations, respectively, were performed. 8 | ICES SCIENTIFIC REPORTS 5:70 | ICES Figure 4.1. Map of the BIAS survey conducted in September-November 2022. Various colours indicate the responsible countries for that ICES rectangle which finally also delivered data to the BIAS-database. Dots with different colours within a rectangle indicate that the rectangle was partly or completely covered by another country and data are available in the BIAS-database (but not included in the final analysis). 4.1.1.2 Total results Geographical distribution of herring, sprat and cod abundance in the Baltic Sea, accordingly to the ICES rectangles inspected in September-November 2022, is illustrated in Figures 4.2 - 4.6. ICES | WGBIFS 2023 | 9 Figure 4.2. The abundance of herring (age 1+) per ICES rectangle monitored in September-November 2022 (the size of a circle indicates estimated numbers of specimens x10^6 in a given rectangle). 10 | ICES SCIENTIFIC REPORTS 5:70 | ICES Figure 4.3. The abundance of herring (age 0) per ICES rectangle monitored in September-November 2022 (the size of a circle indicates estimated numbers of specimens x10^6 in a given rectangle). ICES | WGBIFS 2023 | 11 Figure 4.4. The abundance of sprat (age 1+) per ICES rectangle monitored in September-November 2022 (the size of a circle indicates estimated numbers of specimens x10^6 in a given rectangle). 12 | ICES SCIENTIFIC REPORTS 5:70 | ICES Figure 4.5. The abundance of sprat (age 0) per ICES rectangle monitored in September-November 2022 (the size of a circle indicates estimated numbers of specimens x10^6 in a given rectangle). ICES | WGBIFS 2023 | 13 Figure 4.6. The abundance of cod (age 1+) per ICES rectangle monitored in September-November 2022 (the size of a circle indicates estimated numbers of specimens x10^6 in a given rectangle). The fish abundance estimates, which are based on the BIAS survey in September-November 2022 are presented per ICES rectangle and age-group and are specified in Tables 4.1, 4.2 and 4.3 for herring, sprat and cod, respectively. In addition, the abundance estimates for herring and sprat aggregated per ICES Subdivisions and fish age-groups are presented in Tables 4.4 and 4.5. The highest herring (age 1+) stock abundance was observed in the south-eastern part of the ICES Subdivision 28, in the ICES rectangle 42H0. A somewhat lower, but still significant abundance of the herring stock was assessed in the ICES Subdivisions 26, 29 and 32. Herring (age 1+) was 14 | ICES SCIENTIFIC REPORTS 5:70 | ICES distributed in all except three ICES rectangles of the inspected area (42G9 and 43H1 in the ICES Subdivision 28 and 48H0 in the ICES Subdivision 28). The highest concentrations of young of the year (YOY) herring (age-group 0, year class 2022) was detected in the northern part of the ICES Subdivision 28, especially in rectangle 44H0. High concentrations of 0-age-group herring were detected in the ICES Subdivision 29. YOY herring occurred also in others inspected waters of the Baltic, however levels were significantly lower (Figure 4.3). The highest sprat (age 1+) stock abundance was observed at the border of the ICES Subdivisions 28 and 29 (the Estonian inshore waters) (Figure 4.4). The highest concentration of YOY sprat (year class 2022) was detected in the northern part of the ICES Subdivision 29. YOY sprat was not observed in significant amounts in ICES Subdivisions 25, 26 and 30 (Figure 4.4). The highest cod stock abundance (age 1+) was detected in the ICES Subdivisions 24 and 25 (Fig- ure 4.5). Cod in lower abundances were detected in others areas of the Baltic, but not in ICES Subdivisions 30 and 32. It should be underlined that the cod stock abundance was several times lower than herring and sprat stocks abundance. Table 4.1. Estimated numbers (millions) of herring in September-November 2022, by ICES rectangle and age-group. YEAR SD RECT TOTAL AGE 0 AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2022 21 41G0 6.0 5.9 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 21 41G1 41.6 35.6 4.2 0.9 0.3 0.2 0.3 0.0 0.0 0.0 2022 21 41G2 50.1 50.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 21 42G1 568.9 561.0 6.4 0.1 0.7 0.3 0.5 0.0 0.0 0.0 2022 21 42G2 357.5 353.8 2.8 0.2 0.4 0.1 0.2 0.0 0.0 0.0 2022 21 43G1 363.8 363.7 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 21 43G2 19.4 19.3 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 22 37G0 52.3 51.9 0.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 22 37G1 37.2 36.6 0.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 22 38G0 185.5 184.3 1.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 22 38G1 83.7 82.6 0.6 0.0 0.0 0.0 0.5 0.0 0.0 0.0 2022 22 39F9 62.3 62.2 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 22 39G0 151.0 150.6 0.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 22 39G1 199.7 195.9 3.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 22 40F9 25.2 25.1 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 22 40G0 190.4 187.1 3.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 22 40G1 22.7 22.0 0.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 22 41G0 4.0 3.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 23 39G2 146.9 88.4 44.8 2.2 4.2 2.6 2.3 0.9 1.1 0.5 ICES | WGBIFS 2023 | 15 YEAR SD RECT TOTAL AGE 0 AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2022 23 40G2 126.1 38.7 13.9 44.0 13.2 8.4 3.2 3.2 1.1 0.3 2022 23 41G2 86.7 0.0 0.5 48.2 18.0 8.0 4.4 5.5 1.7 0.4 2022 24 37G2 64.0 52.0 11.9 0.0 0.1 0.0 0.0 0.0 0.0 0.0 2022 24 37G3 58.2 2.3 10.5 8.3 10.7 8.7 6.7 3.8 3.7 3.6 2022 24 38G2 111.9 101.5 8.4 0.2 0.5 0.4 0.4 0.2 0.3 0.2 2022 24 38G3 63.2 37.5 7.0 3.2 5.4 3.5 2.7 1.5 1.1 1.3 2022 24 38G4 444.1 82.3 79.8 47.6 67.2 55.8 45.5 20.2 26.3 19.5 2022 24 39G2 98.8 59.5 30.1 1.5 2.8 1.8 1.5 0.6 0.8 0.3 2022 24 39G3 153.9 65.0 41.8 5.9 14.0 10.6 8.0 2.3 2.5 3.7 2022 24 39G4 71.8 20.3 13.5 7.0 9.1 7.7 6.2 2.8 2.4 2.8 2022 25 37G5 49.3 19.9 3.5 1.5 12.6 4.7 4.4 1.3 1.1 0.2 2022 25 38G5 227.9 0.8 23.5 15.1 100.0 33.6 35.2 9.7 7.3 2.7 2022 25 38G6 66.4 26.4 4.2 3.9 17.0 5.9 5.6 1.9 1.2 0.3 2022 25 38G7 9.0 0.0 1.2 0.5 4.0 1.3 1.4 0.5 0.3 0.1 2022 25 39G4 118.6 0.6 4.9 31.0 11.5 26.3 23.9 14.9 1.1 4.4 2022 25 39G5 213.2 0.0 8.6 16.6 29.0 84.9 20.4 28.1 14.0 11.7 2022 25 39G6 47.6 1.0 6.2 1.3 24.2 6.6 5.3 1.4 1.7 0.1 2022 25 39G7 246.0 1.1 30.5 12.3 111.4 34.1 36.0 10.6 8.2 1.7 2022 25 40G4 571.6 12.2 43.7 45.6 58.8 136.2 58.5 86.3 69.0 61.3 2022 25 40G5 217.6 7.6 12.7 7.5 83.4 50.0 34.2 13.2 4.0 5.0 2022 25 40G6 941.6 4.8 41.9 72.3 82.2 463.5 85.9 133.4 37.6 20.0 2022 25 40G7 365.1 0.0 13.2 20.2 104.5 137.9 47.0 11.3 13.6 17.5 2022 25 41G6 845.5 9.6 16.9 25.0 61.0 361.8 262.8 13.8 46.9 47.7 2022 25 41G7 6.8 1.7 4.8 0.0 0.0 0.0 0.4 0.0 0.0 0.0 2022 26 37G8 264.2 7.8 16.6 16.5 47.7 45.9 41.4 29.0 26.6 32.6 2022 26 37G9 8.2 0.3 0.8 0.4 1.5 1.3 1.5 0.9 0.6 0.9 2022 26 38G8 209.4 9.4 19.1 11.9 44.7 35.7 37.6 21.5 16.7 12.7 2022 26 38G9 219.2 0.5 6.4 14.8 36.1 41.2 44.0 29.2 22.3 24.6 2022 26 39G8 214.9 0.0 9.9 13.3 46.1 40.9 42.8 25.9 19.8 16.2 16 | ICES SCIENTIFIC REPORTS 5:70 | ICES YEAR SD RECT TOTAL AGE 0 AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2022 26 39G9 23.8 0.0 1.0 1.7 4.5 4.7 4.7 3.0 2.0 2.1 2022 26 40G8 166.1 0.0 14.8 9.8 46.0 30.5 33.4 16.9 11.7 2.9 2022 26 40G9 2 773.8 0.0 26.7 80.0 480.1 560.1 480.1 533.4 346.7 266.7 2022 26 40H0 99.0 0.4 6.1 5.4 21.9 26.1 17.7 9.7 8.5 3.1 2022 26 41G8 263.8 0.0 1.6 18.6 35.1 76.7 56.5 34.1 20.8 20.4 2022 26 41G9 112.0 0.0 1.1 5.6 34.2 35.7 10.6 12.1 10.0 2.7 2022 26 41H0 1 518.3 0.0 14.5 76.2 463.8 484.4 143.7 163.7 135.7 36.3 2022 27 42G6 182.4 1.1 8.6 9.6 1.3 86.9 21.2 23.3 20.8 9.6 2022 27 42G7 252.6 1.3 1.0 8.8 63.1 98.5 29.9 24.2 25.4 0.5 2022 27 43G7 35.6 5.9 4.9 10.4 1.3 9.9 1.4 1.9 0.0 0.0 2022 27 44G7 428.0 139.9 38.8 32.8 115.0 65.3 23.1 1.9 8.5 2.6 2022 27 44G8 171.2 36.9 16.4 16.9 27.4 47.4 17.3 5.0 4.0 0.0 2022 27 45G7 518.8 132.3 33.4 59.3 45.2 119.8 11.7 32.4 84.7 0.0 2022 27 45G8 655.0 113.6 74.2 58.2 104.2 129.4 71.7 54.7 32.8 16.2 2022 27 46G8 597.5 231.6 79.9 38.2 15.6 149.8 24.1 20.9 25.4 11.9 2022 28_2 42G8 88.8 1.6 0.0 3.2 27.1 39.5 11.4 4.1 1.4 0.6 2022 28_2 42G9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 28_2 42H0 3 468.2 0.0 101.6 88.4 795.2 499.2 1 005.1 293.8 377.7 307.1 2022 28_2 43G8 384.4 0.0 0.0 29.1 159.6 65.7 34.0 38.9 34.0 23.2 2022 28_2 43G9 76.2 8.1 0.0 1.0 16.5 12.1 25.8 9.5 3.2 0.0 2022 28_2 43H0 231.2 0.0 0.0 12.2 48.7 48.7 48.7 18.3 36.5 18.3 2022 28_2 43H1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 28_2 44G9 418.7 39.9 1.2 39.2 137.2 108.1 45.0 19.9 16.9 11.2 2022 28_2 44H0 5 940.0 3 757.6 303.7 167.7 846.1 346.4 254.5 87.4 109.5 67.2 2022 28_2 44H1 1 902.5 1 000.8 114.9 98.8 323.4 134.6 105.0 42.7 46.0 36.3 2022 28_2 45G9 1 853.5 1 693.0 13.3 9.9 45.7 39.8 15.9 13.8 12.3 10.0 2022 28_2 45H0 23.1 21.0 1.3 0.2 0.2 0.1 0.0 0.1 0.1 0.0 2022 28_2 45H1 1 393.4 1 232.1 113.0 23.1 16.4 6.5 0.0 0.0 2.4 0.0 2022 29 46G9 1 473.0 418.6 97.1 102.6 438.2 88.7 51.4 75.4 191.8 9.3 ICES | WGBIFS 2023 | 17 YEAR SD RECT TOTAL AGE 0 AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2022 29 46H0 1 600.2 1 229.2 13.8 34.3 55.7 107.7 62.1 34.9 56.9 5.5 2022 29 46H1 669.3 85.8 68.0 124.1 237.7 69.8 39.7 25.3 8.2 10.7 2022 29 46H2 9.0 6.5 2.1 0.3 0.1 0.0 0.0 0.0 0.0 0.0 2022 29 47G9 3 468.4 1 786.2 287.9 340.0 427.4 207.0 153.2 103.3 107.9 55.5 2022 29 47H0 3 547.6 2 853.9 51.5 190.4 229.9 76.3 50.3 22.0 49.7 23.6 2022 29 47H1 355.1 330.0 20.4 1.2 2.2 0.8 0.2 0.3 0.0 0.0 2022 29 47H2 3 299.9 679.6 184.8 696.1 1 270.9 230.9 124.7 85.0 7.3 20.6 2022 29 48G9 2 211.8 1 879.3 68.2 116.4 98.8 25.3 10.8 2.4 4.1 6.5 2022 29 48H0 860.6 860.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 29 48H1 1 814.5 1 340.8 117.4 151.9 108.9 33.8 21.1 8.2 20.5 11.8 2022 29 48H2 232.1 218.0 4.5 4.7 3.3 0.6 0.4 0.1 0.4 0.2 2022 29 49G9 865.6 141.3 168.5 224.7 171.3 57.2 33.0 13.8 31.8 23.9 2022 30 50G8 1 092.8 162.6 408.4 260.9 158.8 64.3 22.7 7.6 3.8 3.8 2022 30 50G9 769.5 16.7 92.6 256.0 158.8 87.8 91.4 24.5 22.1 19.7 2022 30 50H0 1 437.1 103.3 145.6 389.8 544.8 140.9 42.3 28.2 9.4 32.9 2022 30 51G7 549.0 0.0 23.6 78.2 272.7 112.7 7.3 14.5 30.9 9.1 2022 30 51G8 1 136.8 0.0 32.5 105.7 469.8 211.9 99.1 92.6 59.5 65.8 2022 30 51G9 555.4 446.1 28.2 39.5 15.0 10.1 3.4 2.6 0.0 10.5 2022 30 51H0 469.5 0.8 4.8 105.0 188.2 78.5 48.3 11.0 7.8 24.9 2022 30 52G8 541.2 16.1 35.8 90.6 198.2 104.8 44.8 17.0 16.1 17.9 2022 30 52G9 393.1 180.6 74.3 75.6 35.6 13.1 8.2 3.1 1.3 1.3 2022 30 52H0 533.3 43.1 24.6 37.0 153.9 126.3 33.3 27.6 26.6 60.9 2022 30 53G8 495.8 0.8 1.7 48.8 178.8 179.7 17.4 51.3 5.8 11.6 2022 30 53G9 472.0 93.0 23.1 41.5 83.8 91.8 100.6 18.4 5.6 14.3 2022 30 53H0 886.7 76.8 12.8 128.0 385.4 135.3 41.4 64.2 14.3 28.5 2022 30 54G8 535.9 0.0 2.0 34.1 154.6 154.6 80.3 52.2 18.1 40.1 2022 30 54G9 762.6 28.8 6.2 25.0 256.5 152.9 117.7 40.2 32.5 102.9 2022 30 54H0 795.3 2.6 4.1 169.2 367.9 114.2 41.0 54.7 12.6 29.0 2022 30 55G9 691.3 10.1 70.9 177.2 250.7 91.2 25.3 35.4 5.1 25.3 18 | ICES SCIENTIFIC REPORTS 5:70 | ICES YEAR SD RECT TOTAL AGE 0 AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2022 30 55H0 480.6 23.4 13.3 133.5 166.9 90.1 6.7 21.7 8.3 16.7 2022 32 47H3 565.2 251.5 39.7 75.1 123.9 42.4 23.7 5.4 2.0 1.6 2022 32 48H3 651.5 328.5 9.5 107.0 53.7 58.2 30.7 6.5 27.9 29.6 2022 32 48H4 1 074.1 277.0 89.4 385.9 116.6 75.8 41.8 9.1 36.7 41.8 2022 32 48H5 2 443.9 427.4 153.6 434.1 741.7 339.3 239.8 62.5 24.8 20.7 2022 32 48H6 1 470.3 381.8 78.5 191.6 417.2 206.5 129.0 41.4 14.4 9.9 2022 32 48H7 505.1 15.5 10.5 32.3 160.6 118.4 99.5 32.1 17.1 19.0 2022 32 49H5 917.9 270.4 61.9 335.3 94.8 62.5 35.9 6.9 27.0 23.1 2022 32 49H6 529.2 250.0 22.6 127.0 43.6 32.5 18.1 3.7 17.4 14.4 Table 4.2. Estimated numbers (millions) of sprat in September-November 2022, by ICES rectangle and age-group. YEAR SD RECT TOTAL AGE 0 AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2022 21 41G0 3.1 0.0 0.4 0.9 1.4 0.2 0.1 0.0 0.0 0.0 2022 21 41G1 3.4 0.1 0.7 1.0 1.2 0.4 0.1 0.0 0.0 0.0 2022 21 41G2 7.5 0.1 1.4 2.3 2.9 0.7 0.1 0.0 0.1 0.0 2022 21 42G1 85.6 2.7 16.0 22.5 33.0 8.9 1.4 0.2 0.9 0.0 2022 21 42G2 46.5 15.4 7.0 8.3 11.7 3.3 0.5 0.0 0.2 0.0 2022 21 43G1 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 21 43G2 0.2 0.0 0.0 0.0 0.1 0.0 0.0 0.0 0.0 0.0 2022 22 37G0 122.2 119.8 1.5 0.3 0.5 0.1 0.0 0.0 0.0 0.0 2022 22 37G1 300.9 300.2 0.4 0.2 0.1 0.0 0.0 0.0 0.0 0.0 2022 22 38G0 715.3 705.8 5.9 1.1 2.1 0.3 0.0 0.0 0.0 0.0 2022 22 38G1 85.8 85.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 22 39F9 154.3 152.1 0.9 0.7 0.6 0.0 0.1 0.0 0.0 0.0 2022 22 39G0 144.0 142.8 0.5 0.2 0.5 0.1 0.0 0.0 0.0 0.0 2022 22 39G1 347.2 344.3 1.1 0.4 1.1 0.1 0.1 0.0 0.0 0.0 2022 22 40F9 45.4 44.1 0.5 0.4 0.3 0.0 0.0 0.0 0.0 0.0 2022 22 40G0 15.7 5.2 1.8 3.6 3.7 0.2 0.3 0.7 0.0 0.0 2022 22 40G1 4.5 2.3 0.0 0.0 0.0 0.0 2.3 0.0 0.0 0.0 2022 22 41G0 2.1 0.0 0.4 0.7 0.8 0.1 0.1 0.0 0.0 0.0 ICES | WGBIFS 2023 | 19 YEAR SD RECT TOTAL AGE 0 AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2022 23 39G2 30.1 2.1 3.1 5.4 7.1 5.8 3.9 1.7 1.1 0.0 2022 23 40G2 57.8 10.2 2.6 10.0 23.5 7.4 2.9 0.7 0.3 0.1 2022 23 41G2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 24 37G2 59.6 57.0 1.1 0.4 0.5 0.3 0.2 0.0 0.0 0.0 2022 24 37G3 292.7 28.9 53.6 62.8 68.4 39.9 24.8 7.4 6.9 0.0 2022 24 38G2 440.6 436.7 0.0 0.2 1.4 1.0 0.6 0.6 0.2 0.0 2022 24 38G3 703.0 343.7 66.1 90.2 93.7 56.4 34.2 9.2 9.5 0.0 2022 24 38G4 552.1 0.0 28.0 86.6 169.5 125.3 80.1 35.8 26.9 0.0 2022 24 39G2 20.2 1.4 2.1 3.6 4.8 3.9 2.6 1.1 0.7 0.0 2022 24 39G3 49.3 2.9 2.5 9.3 12.3 9.8 7.2 3.2 2.2 0.0 2022 24 39G4 54.4 1.3 7.3 9.5 14.0 9.6 7.9 2.6 2.2 0.0 2022 25 37G5 279.3 117.0 2.1 3.1 26.1 40.8 35.6 24.1 21.1 9.3 2022 25 38G5 279.7 0.0 1.9 8.9 49.1 74.5 60.9 40.8 29.1 14.5 2022 25 38G6 419.6 0.0 3.4 13.4 83.9 110.3 93.0 62.8 34.6 18.1 2022 25 38G7 0.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 25 39G4 52.2 0.3 1.9 2.9 12.6 11.9 10.8 6.4 0.3 5.1 2022 25 39G5 250.8 0.0 4.9 0.0 81.4 46.5 32.8 46.4 1.9 37.0 2022 25 39G6 892.7 0.0 12.7 51.6 197.7 240.0 182.5 128.4 50.0 29.8 2022 25 39G7 174.0 0.0 2.0 7.7 35.0 43.6 34.7 25.9 17.5 7.7 2022 25 40G4 502.1 2.6 11.6 30.5 125.8 52.4 128.9 63.7 15.3 71.2 2022 25 40G5 435.5 0.9 5.4 52.8 134.4 94.1 71.9 28.3 1.7 46.0 2022 25 40G6 353.5 0.0 1.7 3.4 41.2 80.6 47.8 19.1 61.7 98.0 2022 25 40G7 587.8 0.0 53.0 89.0 196.2 157.4 22.5 7.7 10.5 51.5 2022 25 41G6 988.4 36.9 280.7 166.9 349.0 40.0 72.8 32.8 2.5 6.7 2022 25 41G7 1 672.8 29.8 157.2 185.4 712.4 183.5 150.1 145.8 7.4 101.2 2022 26 37G8 57.4 1.8 4.1 9.2 13.6 18.6 4.0 3.8 2.0 0.3 2022 26 37G9 554.0 89.4 43.3 61.8 146.6 149.6 19.9 31.4 11.5 0.4 2022 26 38G8 281.9 0.0 10.6 26.1 47.0 101.5 50.2 30.7 14.0 1.7 2022 26 38G9 131.0 1.1 10.8 15.6 38.0 42.6 9.6 10.0 3.3 0.0 20 | ICES SCIENTIFIC REPORTS 5:70 | ICES YEAR SD RECT TOTAL AGE 0 AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2022 26 39G8 30.3 0.0 0.6 2.3 3.5 9.8 7.3 3.8 2.3 0.8 2022 26 39G9 0.3 0.0 0.0 0.0 0.0 0.1 0.1 0.0 0.0 0.0 2022 26 40G8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 26 40G9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 26 40H0 3 768.4 27.0 0.0 13.5 994.8 1 981.2 705.1 41.9 4.8 0.0 2022 26 41G8 200.3 0.0 21.5 51.5 82.1 23.7 10.3 9.6 0.7 0.7 2022 26 41G9 2 324.3 198.9 182.6 409.8 681.8 287.2 274.7 76.6 19.9 192.7 2022 26 41H0 5 213.2 331.6 355.1 590.8 1 536.7 642.9 671.5 285.8 122.7 676.1 2022 27 42G6 607.2 14.0 68.9 147.9 288.6 14.4 44.6 5.3 19.6 3.9 2022 27 42G7 1 205.3 83.5 82.1 158.5 258.6 456.9 28.9 8.7 30.4 97.8 2022 27 43G7 1 605.5 166.7 198.1 590.4 461.9 68.8 94.5 0.0 10.8 14.4 2022 27 44G7 269.9 37.2 66.5 46.4 104.7 3.0 0.0 9.0 1.0 2.1 2022 27 44G8 256.9 10.7 34.8 66.9 45.4 30.2 25.0 15.9 8.6 19.3 2022 27 45G7 185.0 105.0 8.4 27.9 19.6 5.6 2.1 8.8 3.5 4.1 2022 27 45G8 1 615.3 381.0 16.3 608.3 290.5 131.9 150.4 0.0 2.2 34.8 2022 27 46G8 1 207.3 1 064.6 32.7 27.9 63.8 10.0 5.2 0.0 0.0 3.2 2022 28_2 42G8 106.2 3.3 0.2 20.4 30.2 16.6 24.4 2.5 6.1 2.5 2022 28_2 42G9 3 918.5 219.4 1 042.3 1 571.3 305.6 343.5 0.0 41.8 83.6 310.9 2022 28_2 42H0 2 942.2 93.0 249.1 606.2 1 064.2 334.7 262.3 86.0 58.5 188.2 2022 28_2 43G8 30.2 16.5 0.0 4.9 6.0 1.8 0.5 0.0 0.5 0.0 2022 28_2 43G9 3 366.5 1 138.3 169.2 1 120.2 569.7 21.7 124.5 63.5 43.4 116.1 2022 28_2 43H0 6 658.4 191.4 735.5 1 472.5 2 512.3 940.3 379.0 221.8 0.0 205.5 2022 28_2 43H1 1 503.2 44.7 170.6 313.4 594.3 220.5 90.0 51.3 0.0 18.3 2022 28_2 44G9 409.0 46.3 26.8 48.1 211.5 41.7 22.8 7.6 4.3 0.0 2022 28_2 44H0 1 325.7 18.5 76.8 161.2 551.7 183.4 178.6 69.8 0.0 85.8 2022 28_2 44H1 3 190.4 109.6 269.5 555.3 1 340.3 392.9 245.2 92.5 4.8 180.3 2022 28_2 45G9 841.3 401.6 3.3 135.1 166.3 89.8 0.0 30.1 1.7 13.4 2022 28_2 45H0 1 269.9 206.8 13.2 215.6 267.9 210.6 144.9 46.2 60.6 104.2 2022 28_2 45H1 10 752.7 1 496.0 217.3 3 092.0 2 290.7 1 622.1 826.8 279.2 301.1 627.6 ICES | WGBIFS 2023 | 21 YEAR SD RECT TOTAL AGE 0 AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2022 29 46G9 1 170.0 52.3 9.1 474.3 387.7 174.3 9.4 5.5 5.5 51.9 2022 29 46H0 531.6 138.3 39.6 77.6 185.5 42.9 15.5 10.7 0.0 21.5 2022 29 46H1 14 089.1 282.2 316.2 4 391.2 4 593.0 1 936.1 591.8 547.8 453.7 977.0 2022 29 46H2 2 681.3 310.9 120.4 1 089.1 772.1 216.2 32.6 42.2 21.6 76.2 2022 29 47G9 774.8 514.9 71.7 62.8 54.2 45.8 1.9 8.8 12.9 1.9 2022 29 47H0 1 505.1 515.1 102.1 397.4 185.7 99.5 59.3 35.7 29.2 81.1 2022 29 47H1 1 420.2 818.7 36.4 221.5 192.7 71.2 17.2 16.7 14.3 31.3 2022 29 47H2 4 211.7 122.9 146.7 1 565.0 1 389.3 456.4 103.6 119.4 77.3 231.0 2022 29 48G9 2 059.9 989.0 137.3 455.0 191.2 92.9 58.2 34.7 29.6 71.9 2022 29 48H0 4 862.4 2 443.2 267.0 1 058.7 453.5 222.6 129.4 66.1 56.6 165.2 2022 29 48H1 3 502.4 1 305.6 290.6 932.4 398.2 197.9 109.1 61.9 52.7 154.0 2022 29 48H2 6 041.3 1 573.2 553.1 1 903.8 822.1 409.7 238.5 124.6 107.8 308.4 2022 29 49G9 591.0 165.3 37.7 148.2 77.7 46.1 31.1 21.7 17.0 46.3 2022 30 50G8 438.8 203.0 44.9 89.3 25.3 23.1 13.6 8.9 4.4 26.4 2022 30 50G9 55.5 13.3 6.9 13.7 4.3 5.1 3.0 2.2 1.1 5.9 2022 30 50H0 46.7 0.0 4.6 12.6 4.1 5.7 3.6 3.3 1.8 10.9 2022 30 51G7 11.4 0.0 0.3 1.9 0.9 1.6 1.0 1.0 0.6 4.1 2022 30 51G8 16.7 0.0 1.2 3.1 1.4 2.4 1.4 1.4 0.8 5.0 2022 30 51G9 312.9 56.1 43.2 76.1 24.7 30.4 18.0 14.1 7.5 42.9 2022 30 51H0 22.7 0.7 5.3 7.2 2.1 2.1 1.1 0.9 0.5 2.9 2022 30 52G8 41.3 0.4 1.6 6.2 2.6 4.9 3.6 4.0 2.4 15.5 2022 30 52G9 131.2 0.0 29.4 38.2 11.1 12.8 8.2 6.7 3.2 21.6 2022 30 52H0 88.5 0.0 14.7 25.9 8.6 10.6 6.5 5.0 2.5 14.6 2022 30 53G8 32.4 0.0 0.1 2.6 1.8 4.1 2.9 3.5 2.2 15.2 2022 30 53G9 24.7 0.2 2.0 4.3 1.8 2.7 1.8 2.1 1.5 8.3 2022 30 53H0 130.6 0.0 25.9 42.9 12.7 13.6 8.1 5.9 3.0 18.6 2022 30 54G8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2022 30 54G9 16.6 0.0 2.1 5.9 1.8 1.9 1.1 0.8 0.4 2.6 2022 30 54H0 8.3 0.0 1.3 2.1 0.8 1.0 0.6 0.5 0.3 1.8 22 | ICES SCIENTIFIC REPORTS 5:70 | ICES Table 4.3. Estimated numbers (millions) of cod in September-October 2005-2022, by ICES rectangle. SD RECT Area 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 24 37G2 192.4 2.2 0.0 1.8 0.0 0.0 0.0 0.0 0.0 6.0 0.0 0.0 1.3 0.0 0.3 0.0 0.0 0.0 0.3 24 37G3 167.7 0.0 4.1 0.9 1.2 0.7 4.3 0.0 2.0 1.1 0.9 0.2 2.3 11.4 2.5 2.9 1.3 0.8 7.8 24 37G4 875.1 9.5 0.1 4.3 5.2 1.4 2.6 0.0 0.0 19.7 0.3 3.3 0.9 4.6 0.5 0.5 1.2 0.4 - 24 38G2 832.9 10.9 0.0 2.0 0.0 0.0 1.9 1.1 6.0 0.5 0.0 0.0 22.8 0.0 15.9 0.0 0.5 5.8 5.5 24 38G3 865.7 0.3 0.0 1.6 1.1 2.0 3.6 0.4 4.4 0.9 25.8 1.2 2.1 4.5 16.3 3.0 4.5 0.6 2.5 24 38G4 1034.8 6.2 0.5 9.7 13.7 1.0 4.4 0.4 2.1 1.7 0.6 14.1 1.9 20.1 5.6 0.9 0.2 3.4 5.8 24 39G2 406.1 1.5 3.9 1.8 0.4 1.3 3.8 0.1 0.9 0.0 1.7 0.1 2.3 2.5 0.4 0.0 0.4 0.0 0.0 24 39G3 765.0 17.9 3.8 13.9 2.8 0.6 3.8 0.3 2.1 5.1 18.7 2.2 1.1 1.7 9.1 2.8 0.4 2.8 2.9 24 39G4 524.8 2.7 1.8 2.4 1.2 1.6 7.1 0.2 0.4 1.2 4.2 1.1 7.9 3.0 1.4 1.9 1.8 1.3 2.3 25 37G5 642.2 17.8 0.3 1.3 0.0 0.4 0.2 0.0 0.0 0.0 0.0 0.0 0.0 2.0 0.0 0.1 0.2 0.0 1.3 25 38G5 1035.7 57.3 2.1 5.2 0.7 2.9 4.5 18.4 19.9 5.0 3.4 2.9 1.0 1.7 10.0 0.5 0.3 0.9 0.5 25 38G6 940.2 9.5 3.0 17.1 2.5 0.3 0.2 0.0 15.5 0.0 0.0 0.0 0.4 0.0 0.3 0.1 0.2 0.4 0.0 25 38G7 471.7 0.0 0.1 0.0 0.9 0.4 0.8 0.0 0.2 0.0 0.0 0.0 - 0.0 0.0 0.0 0.0 0.0 0.0 25 39G4 287.3 2.7 28.5 0.2 4.4 0.3 0.3 0.2 0.6 0.5 2.9 4.2 0.0 1.2 5.2 2.0 0.0 0.0 18.2 25 39G5 979.0 1.5 3.6 1.8 3.1 2.5 6.2 71.3 8.9 4.1 5.8 0.7 3.4 0.8 2.3 1.6 0.6 1.2 4.4 25 39G6 1026.0 0.9 6.5 0.7 4.1 0.5 16.7 3.5 0.0 0.0 0.2 0.1 0.1 0.9 0.9 0.1 0.1 0.4 0.1 25 39G7 1026.0 47.4 0.5 0.4 5.8 0.3 0.2 2.2 0.0 0.0 0.5 0.1 0.0 0.7 7.6 0.0 0.1 0.1 0.0 25 40G4 677.2 1.4 5.5 15.9 0.2 19.2 0.3 25.3 15.2 2.1 31.0 38.3 7.4 8.4 10.7 8.8 9.5 1.6 0.0 25 40G5 1012.9 2.4 7.6 4.9 25.1 1.8 0.8 14.0 5.5 1.2 8.0 31.0 3.1 0.3 1.2 56.3 1.8 0.5 1.6 25 40G6 1013.0 1.1 6.5 0.2 5.9 6.5 7.0 30.8 5.7 0.2 53.6 17.0 1.8 4.3 0.2 16.1 0.3 6.4 18.0 25 40G7 1013.0 5.7 5.8 0.0 6.3 3.5 0.5 18.6 42.7 0.3 7.8 0.0 3.1 2.7 0.0 0.0 0.0 0.1 1.3 25 41G6 764.4 2.7 14.8 0.0 2.5 0.6 0.4 0.0 1.0 0.0 0.8 0.2 18.9 0.0 0.2 2.2 3.1 0.1 1.6 25 41G7 1000.0 0.1 1.9 8.7 0.3 4.4 1.1 61.9 29.8 35.3 0.0 0.5 0.7 0.9 0.6 0.0 12.7 0.0 0.0 26 37G8 86.0 0.5 3.2 0.0 0.2 0.0 0.0 0.0 0.1 0.0 0.5 0.0 0.0 0.1 0.0 0.0 0.0 0.0 0.2 26 37G9 151.6 37.6 0.9 1.6 1.0 0.3 0.2 0.5 0.6 0.0 0.2 0.2 0.1 2.5 0.0 0.0 0.0 0.0 0.0 26 38G8 624.6 37.1 5.0 1.7 3.4 2.0 1.4 1.3 7.2 0.0 1.0 7.1 0.1 2.0 15.1 0.0 0.3 1.7 0.1 26 38G9 918.2 0.0 0.0 0.0 0.0 0.5 0.0 2.6 4.5 49.2 6.5 0.3 0.6 0.5 0.1 1.7 1.9 1.0 14.6 26 39G8 1026.0 32.3 22.1 1.6 0.8 4.3 9.4 19.9 5.2 0.0 0.5 0.4 0.2 0.6 1.4 2.5 0.2 0.1 1.6 ICES | WGBIFS 2023 | 23 SD RECT Area 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 26 39G9 1026.0 0.0 0.0 0.0 0.0 0.7 0.0 1.8 0.0 3.1 4.7 7.3 0.3 1.2 0.4 0.2 0.7 0.0 4.1 26 39H0 881.6 - - - - 0.0 0.0 0.0 - - - - 0.3 0.1 - 0.0 - - - 26 40G8 1013.0 17.8 4.6 0.5 0.2 0.5 13.5 4.0 3.2 0.0 0.1 2.7 0.1 0.6 1.5 21.8 1.0 0.0 0.1 26 40G9 1013.0 0.0 - 0.0 0.0 3.0 0.0 0.4 5.9 9.1 0.8 - 0.8 1.4 0.1 0.1 0.0 0.0 0.0 26 40H0 1012.1 5.1 - 0.0 0.7 34.6 51.7 1.1 0.2 0.1 0.1 - 5.1 0.0 107.8 0.0 0.0 0.0 0.0 26 41G8 1000.0 0.0 2.6 - 0.0 2.3 3.2 21.9 19.2 0.9 1.3 0.0 1.5 0.7 1.2 9.1 5.5 2.8 0.3 26 41G9 1000.0 10.0 0.1 3.2 0.2 0.0 1.0 0.0 0.0 0.3 195.8 1.6 0.0 0.0 - 0.0 0.7 0.0 0.0 26 41H0 953.3 54.5 0.2 3.4 1.9 0.0 0.1 0.0 0.0 0.3 0.0 0.0 0.0 0.0 - 0.0 0.0 0.0 0.0 27 42G6 266.0 - 2.2 0.0 0.0 1.1 0.0 0.0 0.3 0.0 0.0 0.0 0.0 0.0 0.0 1.7 0.0 0.0 0.0 27 42G7 986.9 1.0 1.1 0.5 0.0 0.9 0.0 1.6 0.6 0.7 0.9 0.0 2.7 0.0 0.0 4.0 0.0 0.0 0.0 27 43G6 269.8 - - - 0.0 - - - - - - - - - - - - - - 27 43G7 913.8 0.0 22.0 0.0 0.1 0.0 0.5 0.1 0.0 1.9 2.7 0.0 3.2 0.0 0.0 0.0 0.0 0.0 0.0 27 44G7 960.5 0.0 1.2 1.3 0.4 0.0 0.2 0.0 0.0 0.0 0.1 0.0 0.5 0.1 0.2 0.0 0.0 0.0 0.0 27 44G8 456.6 0.0 0.0 0.0 0.0 0.5 0.2 0.1 0.0 0.2 0.0 0.0 0.0 0.5 0.0 0.0 0.0 0.0 0.0 27 45G7 908.7 0.0 0.0 0.0 1.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 7.9 0.0 0.0 0.0 0.0 0.0 0.2 27 45G8 947.2 0.0 2.2 0.2 0.0 0.0 0.0 0.0 0.0 1.1 0.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.5 27 46G8 884.8 0.0 0.2 0.0 0.0 0.0 0.0 0.1 0.0 0.0 0.4 0.0 0.0 0.2 0.1 0.0 0.0 0.0 0.0 24 37G2 192.4 2.2 0.0 1.8 0.0 0.0 0.0 0.0 0.0 6.0 0.0 0.0 1.3 0.0 0.3 0.0 0.0 0.0 0.3 24 37G3 167.7 0.0 4.1 0.9 1.2 0.7 4.3 0.0 2.0 1.1 0.9 0.2 2.3 11.4 2.5 2.9 1.3 0.8 7.8 24 37G4 875.1 9.5 0.1 4.3 5.2 1.4 2.6 0.0 0.0 19.7 0.3 3.3 0.9 4.6 0.5 0.5 1.2 0.4 - 24 38G2 832.9 10.9 0.0 2.0 0.0 0.0 1.9 1.1 6.0 0.5 0.0 0.0 22.8 0.0 15.9 0.0 0.5 5.8 5.5 24 38G3 865.7 0.3 0.0 1.6 1.1 2.0 3.6 0.4 4.4 0.9 25.8 1.2 2.1 4.5 16.3 3.0 4.5 0.6 2.5 24 38G4 1034.8 6.2 0.5 9.7 13.7 1.0 4.4 0.4 2.1 1.7 0.6 14.1 1.9 20.1 5.6 0.9 0.2 3.4 5.8 24 39G2 406.1 1.5 3.9 1.8 0.4 1.3 3.8 0.1 0.9 0.0 1.7 0.1 2.3 2.5 0.4 0.0 0.4 0.0 0.0 24 39G3 765.0 17.9 3.8 13.9 2.8 0.6 3.8 0.3 2.1 5.1 18.7 2.2 1.1 1.7 9.1 2.8 0.4 2.8 2.9 24 39G4 524.8 2.7 1.8 2.4 1.2 1.6 7.1 0.2 0.4 1.2 4.2 1.1 7.9 3.0 1.4 1.9 1.8 1.3 2.3 25 37G5 642.2 17.8 0.3 1.3 0.0 0.4 0.2 0.0 0.0 0.0 0.0 0.0 0.0 2.0 0.0 0.1 0.2 0.0 1.3 25 38G5 1035.7 57.3 2.1 5.2 0.7 2.9 4.5 18.4 19.9 5.0 3.4 2.9 1.0 1.7 10.0 0.5 0.3 0.9 0.5 25 38G6 940.2 9.5 3.0 17.1 2.5 0.3 0.2 0.0 15.5 0.0 0.0 0.0 0.4 0.0 0.3 0.1 0.2 0.4 0.0 24 | ICES SCIENTIFIC REPORTS 5:70 | ICES SD RECT Area 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 25 38G7 471.7 0.0 0.1 0.0 0.9 0.4 0.8 0.0 0.2 0.0 0.0 0.0 - 0.0 0.0 0.0 0.0 0.0 0.0 25 39G4 287.3 2.7 28.5 0.2 4.4 0.3 0.3 0.2 0.6 0.5 2.9 4.2 0.0 1.2 5.2 2.0 0.0 0.0 18.2 25 39G5 979.0 1.5 3.6 1.8 3.1 2.5 6.2 71.3 8.9 4.1 5.8 0.7 3.4 0.8 2.3 1.6 0.6 1.2 4.4 25 39G6 1026.0 0.9 6.5 0.7 4.1 0.5 16.7 3.5 0.0 0.0 0.2 0.1 0.1 0.9 0.9 0.1 0.1 0.4 0.1 25 39G7 1026.0 47.4 0.5 0.4 5.8 0.3 0.2 2.2 0.0 0.0 0.5 0.1 0.0 0.7 7.6 0.0 0.1 0.1 0.0 25 40G4 677.2 1.4 5.5 15.9 0.2 19.2 0.3 25.3 15.2 2.1 31.0 38.3 7.4 8.4 10.7 8.8 9.5 1.6 0.0 25 40G5 1012.9 2.4 7.6 4.9 25.1 1.8 0.8 14.0 5.5 1.2 8.0 31.0 3.1 0.3 1.2 56.3 1.8 0.5 1.6 25 40G6 1013.0 1.1 6.5 0.2 5.9 6.5 7.0 30.8 5.7 0.2 53.6 17.0 1.8 4.3 0.2 16.1 0.3 6.4 18.0 25 40G7 1013.0 5.7 5.8 0.0 6.3 3.5 0.5 18.6 42.7 0.3 7.8 0.0 3.1 2.7 0.0 0.0 0.0 0.1 1.3 25 41G6 764.4 2.7 14.8 0.0 2.5 0.6 0.4 0.0 1.0 0.0 0.8 0.2 18.9 0.0 0.2 2.2 3.1 0.1 1.6 25 41G7 1000.0 0.1 1.9 8.7 0.3 4.4 1.1 61.9 29.8 35.3 0.0 0.5 0.7 0.9 0.6 0.0 12.7 0.0 0.0 26 37G8 86.0 0.5 3.2 0.0 0.2 0.0 0.0 0.0 0.1 0.0 0.5 0.0 0.0 0.1 0.0 0.0 0.0 0.0 0.2 26 37G9 151.6 37.6 0.9 1.6 1.0 0.3 0.2 0.5 0.6 0.0 0.2 0.2 0.1 2.5 0.0 0.0 0.0 0.0 0.0 26 38G8 624.6 37.1 5.0 1.7 3.4 2.0 1.4 1.3 7.2 0.0 1.0 7.1 0.1 2.0 15.1 0.0 0.3 1.7 0.1 26 38G9 918.2 0.0 0.0 0.0 0.0 0.5 0.0 2.6 4.5 49.2 6.5 0.3 0.6 0.5 0.1 1.7 1.9 1.0 14.6 26 39G8 1026.0 32.3 22.1 1.6 0.8 4.3 9.4 19.9 5.2 0.0 0.5 0.4 0.2 0.6 1.4 2.5 0.2 0.1 1.6 26 39G9 1026.0 0.0 0.0 0.0 0.0 0.7 0.0 1.8 0.0 3.1 4.7 7.3 0.3 1.2 0.4 0.2 0.7 0.0 4.1 26 39H0 881.6 - - - - 0.0 0.0 0.0 - - - - 0.3 0.1 - 0.0 - - - 26 40G8 1013.0 17.8 4.6 0.5 0.2 0.5 13.5 4.0 3.2 0.0 0.1 2.7 0.1 0.6 1.5 21.8 1.0 0.0 0.1 26 40G9 1013.0 0.0 - 0.0 0.0 3.0 0.0 0.4 5.9 9.1 0.8 - 0.8 1.4 0.1 0.1 0.0 0.0 0.0 26 40H0 1012.1 5.1 - 0.0 0.7 34.6 51.7 1.1 0.2 0.1 0.1 - 5.1 0.0 107.8 0.0 0.0 0.0 0.0 26 41G8 1000.0 0.0 2.6 - 0.0 2.3 3.2 21.9 19.2 0.9 1.3 0.0 1.5 0.7 1.2 9.1 5.5 2.8 0.3 26 41G9 1000.0 10.0 0.1 3.2 0.2 0.0 1.0 0.0 0.0 0.3 195.8 1.6 0.0 0.0 - 0.0 0.7 0.0 0.0 26 41H0 953.3 54.5 0.2 3.4 1.9 0.0 0.1 0.0 0.0 0.3 0.0 0.0 0.0 0.0 - 0.0 0.0 0.0 0.0 27 42G6 266.0 - 2.2 0.0 0.0 1.1 0.0 0.0 0.3 0.0 0.0 0.0 0.0 0.0 0.0 1.7 0.0 0.0 0.0 27 42G7 986.9 1.0 1.1 0.5 0.0 0.9 0.0 1.6 0.6 0.7 0.9 0.0 2.7 0.0 0.0 4.0 0.0 0.0 0.0 27 43G6 269.8 - - - 0.0 - - - - - - - - - - - - - - 27 43G7 913.8 0.0 22.0 0.0 0.1 0.0 0.5 0.1 0.0 1.9 2.7 0.0 3.2 0.0 0.0 0.0 0.0 0.0 0.0 27 44G7 960.5 0.0 1.2 1.3 0.4 0.0 0.2 0.0 0.0 0.0 0.1 0.0 0.5 0.1 0.2 0.0 0.0 0.0 0.0 ICES | WGBIFS 2023 | 25 SD RECT Area 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 27 44G8 456.6 0.0 0.0 0.0 0.0 0.5 0.2 0.1 0.0 0.2 0.0 0.0 0.0 0.5 0.0 0.0 0.0 0.0 0.0 27 45G7 908.7 0.0 0.0 0.0 1.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 7.9 0.0 0.0 0.0 0.0 0.0 0.2 27 45G8 947.2 0.0 2.2 0.2 0.0 0.0 0.0 0.0 0.0 1.1 0.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.5 27 46G8 884.8 0.0 0.2 0.0 0.0 0.0 0.0 0.1 0.0 0.0 0.4 0.0 0.0 0.2 0.1 0.0 0.0 0.0 0.0 28_2 42G8 945.4 4.7 0.0 3.7 3.3 0.5 1.3 0.0 1.6 4.7 1.8 0.0 0.8 0.5 0.0 0.1 8.4 0.0 0.0 28_2 42G9 986.9 0.0 0.2 0.6 1.3 0.0 0.0 0.0 0.0 4.9 293.8 0.0 0.0 0.2 - 0.0 0.7 0.0 0.0 28_2 42H0 968.5 0.0 0.4 10.4 2.9 0.0 0.1 0.0 0.0 0.3 1.2 0.1 0.0 0.1 - 0.0 0.1 0.0 0.0 28_2 43G8 296.2 0.3 0.0 0.0 0.2 0.0 0.0 0.0 5.6 0.1 0.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.5 28_2 43G9 973.7 0.0 0.2 12.7 2.1 1.4 0.0 0.0 8.2 11.8 0.0 0.0 0.0 3.9 0.0 0.0 11.1 0.0 0.0 28_2 43H0 973.7 0.0 0.1 3.6 0.0 0.0 0.1 0.0 0.0 0.6 3.6 0.3 0.0 0.1 - 0.0 0.2 0.0 0.0 28_2 43H1 412.7 0.0 0.1 0.0 0.0 0.0 0.1 0.0 0.0 0.1 0.0 - 0.0 - - 0.0 0.1 0.0 0.0 28_2 44G9 876.6 0.0 0.0 0.5 0.6 0.0 0.9 2.3 2.6 2.7 2.9 0.0 3.3 0.1 0.1 0.0 0.0 0.0 0.3 28_2 44H0 960.5 0.0 0.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 238.7 11.7 0.0 0.2 - 0.0 0.0 0.0 0.2 28_2 44H1 824.6 0.0 0.0 0.0 0.0 0.0 0.1 0.0 0.0 0.4 0.0 0.0 0.0 - - 0.0 0.0 0.0 0.1 28_2 45G9 924.5 0.3 0.0 0.1 0.0 0.4 0.0 0.0 0.6 0.6 0.0 0.0 0.9 0.1 0.6 0.3 24.9 0.2 0.0 28_2 45H0 947.2 0.0 0.0 0.2 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.3 13.2 0.0 0.1 1.1 0.0 28_2 45H1 827.1 0.0 0.0 0.1 0.0 0.0 0.1 0.0 0.0 0.0 0.0 1.7 0.6 0.0 0.0 0.0 0.0 0.0 0.0 29 46G9 933.8 0.0 0.0 0.5 0.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.7 0.0 0.1 0.3 0.0 0.0 0.2 29 46H0 933.8 0.0 0.0 0.0 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.7 0.2 0.0 0.0 0.0 0.0 0.1 29 46H1 921.5 0.0 0.0 0.0 0.0 0.0 0.4 0.0 0.7 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.9 0.0 29 46H2 258.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 29 47G9 876.2 2.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.1 0.0 0.0 0.0 1.0 0.0 0.0 0.0 0.0 0.0 29 47H0 920.3 0.0 0.0 1.3 0.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.4 0.0 0.0 0.0 0.1 0.0 29 47H1 920.3 0.0 0.0 0.0 0.0 0.0 0.0 8.8 0.0 0.0 0.0 0.0 0.0 1.1 0.0 0.8 0.0 0.0 0.0 29 47H2 793.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.7 0.0 0.0 0.0 0.0 0.1 0.0 0.0 0.0 0.0 29 48G9 772.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 29 48H0 730.3 - - 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.0 0.0 0.0 0.0 0.0 0.0 29 48H1 544.0 - - 0.0 - 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.2 0.0 0.0 2.8 0.0 0.0 29 48H2 597.0 - - 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.2 0.2 0.0 0.0 0.0 0.0 26 | ICES SCIENTIFIC REPORTS 5:70 | ICES SD RECT Area 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 29 49G9 564.2 - - 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.1 ICES | WGBIFS 2023 | 27 Table 4.4. Estimated numbers (millions) of herring in September-November 2022 by ICES Subdivision and age-group. YEAR SD AGE 0 AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2022 21 1 389.3 13.7 1.3 1.4 0.5 1.1 0.0 0.0 0.0 2022 22 1 002.2 11.3 0.0 0.0 0.0 0.5 0.0 0.0 0.0 2022 23 127.2 59.2 94.4 35.4 19.0 9.8 9.6 4.0 1.2 2022 24 420.4 202.9 73.6 109.8 88.4 71.1 31.3 37.0 31.4 2022 25 85.5 215.7 252.7 699.5 1 346.7 621.1 326.3 205.9 172.8 2022 26 18.4 118.6 254.2 1 261.7 1 383.4 914.0 879.6 621.5 421.2 2022 27 662.7 257.2 234.1 373.0 707.0 200.5 164.3 201.6 40.7 2022 28_2 7 754.1 649.0 472.6 2 416.2 1 300.6 1 545.4 528.4 639.9 473.8 2022 29 11 829.6 1 084.1 1 986.8 3 044.5 898.1 547.0 370.8 478.6 167.6 2022 30 1 204.8 1 004.5 2 195.7 4 040.2 1 960.1 831.0 566.8 279.7 515.0 2022 32 2 202.1 465.6 1 688.4 1 752.2 935.5 618.5 167.7 167.3 160.0 Table 4.5. Estimated numbers (millions) of sprat in September-November 2022 by ICES Subdivision and age-group. YEAR SD AGE 0 AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2022 21 18.3 25.5 35.0 50.4 13.5 2.2 0.3 1.2 0.0 2022 22 1 902.3 13.1 7.5 9.9 1.0 2.9 0.8 0.0 0.0 2022 23 12.3 5.7 15.4 30.6 13.2 6.8 2.4 1.4 0.1 2022 24 872.0 160.6 262.7 364.6 246.1 157.6 59.9 48.5 0.0 2022 25 187.6 538.6 615.8 2 044.8 1 175.7 944.2 632.2 253.4 496.2 2022 26 649.9 628.8 1 180.6 3 544.1 3 257.3 1 752.8 493.7 181.2 872.6 2022 27 1 862.6 507.7 1 674.2 1 533.1 720.7 350.6 47.6 76.2 179.6 2022 28_2 3 985.5 2 973.8 9 316.1 9 910.9 4 419.6 2 298.9 992.2 564.4 1 852.8 2022 29 9 231.6 2 128.0 12 777.2 9 702.9 4 011.6 1 397.7 1 096.0 878.3 2 217.6 2022 30 273.5 196.7 348.4 109.6 129.0 78.8 63.9 34.1 208.2 2022 32 1 480.8 1 760.2 8 126.8 4 878.8 2 989.6 1 561.4 954.2 911.2 2 111.1 4.1.1.3 Area-corrected data A correction factor for each ICES Subdivision and year was introduced to account for the differ- ent coverage of investigated areas between years. This factor is the proportion between the total area of the ICES Subdivision that are presented in the IBAS Manual and the area of the ICES 28 | ICES SCIENTIFIC REPORTS 5:70 | ICES rectangles, which was covered during the survey. The Gulf of Riga (ICES Subdivision 28_1) is excluded from the total area. All other ICES Subdivisions kept their areas as specified in the IBAS manual (Table 2.2). The area-corrected abundance estimates for herring and sprat per the ICES Subdivision and age- group are summarized in Tables 4.6 and 4.7, respectively. Biomass for herring and sprat per ICES Subdivision and age-group are summarized in Tables 4.8 and 4.9, respectively. Table 4.6. Area-corrected numbers (millions) of herring by ICES Subdivision and age-group (September-November 2022). YEAR SD AREA CORR FACTOR AGE 0 AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2022 21 1.22 1 690.5 16.7 1.5 1.8 0.7 1.3 0.0 0.0 0.0 2022 22 1.02 1 022.9 11.6 0.0 0.0 0.0 0.5 0.0 0.0 0.0 2022 23 1.00 127.2 59.2 94.4 35.4 19.0 9.8 9.6 4.0 1.2 2022 24 1.18 497.2 240.0 87.0 129.8 104.6 84.0 37.1 43.7 37.1 2022 25 1.03 88.3 222.6 260.8 721.8 1 389.8 641.0 336.8 212.5 178.3 2022 26 1.10 20.3 130.8 280.2 1 390.8 1 525.0 1 007.5 969.6 685.1 464.3 2022 27 1.23 815.6 316.5 288.1 459.1 870.2 246.8 202.2 248.1 50.1 2022 28_2 1.01 7 855.7 657.5 478.8 2 447.9 1 317.6 1 565.6 535.3 648.3 480.0 2022 29 1.04 12 299.7 1 127.2 2 065.8 3 165.5 933.8 568.7 385.5 497.7 174.3 2022 30 1.15 1 382.9 1 153.0 2 520.2 4 637.3 2 249.8 953.8 650.6 321.0 591.2 2022 32 1.42 3 129.7 661.8 2 399.6 2 490.3 1 329.5 879.1 238.3 237.7 227.4 Table 4.7. Area-corrected numbers (millions) of sprat by ICES Subdivision and age-group (September-November 2022). YEAR SD AREA CORR FACTOR AGE 0 AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2022 21 1.22 22.3 31.0 42.5 61.3 16.4 2.7 0.3 1.5 0.0 2022 22 1.02 1 941.5 13.3 7.6 10.1 1.0 3.0 0.8 0.0 0.0 2022 23 1.00 12.3 5.7 15.4 30.6 13.2 6.8 2.4 1.4 0.1 2022 24 1.18 1 031.3 189.9 310.7 431.2 291.1 186.3 70.8 57.4 0.0 2022 25 1.03 193.6 555.8 635.5 2 110.2 1 213.3 974.4 652.4 261.5 512.1 2022 26 1.10 716.3 693.1 1 301.4 3 906.7 3 590.5 1 932.1 544.2 199.7 961.9 ICES | WGBIFS 2023 | 29 2022 27 1.23 2 292.4 624.8 2 060.5 1 886.8 887.0 431.5 58.6 93.8 221.1 2022 28_2 1.01 4 037.7 3 012.7 9 438.3 10 040.8 4 477.5 2 329.0 1 005.2 571.8 1 877.1 2022 29 1.04 9 598.5 2 212.5 13 284.9 10 088.5 4 171.0 1 453.2 1 139.5 913.2 2 305.8 2022 30 1.15 314.0 225.8 399.9 125.7 148.0 90.4 73.3 39.2 239.0 2022 32 1.42 2 104.5 2 501.7 11 550.1 6 933.9 4 249.0 2 219.2 1 356.2 1 295.1 3 000.3 Table 4.8. Estimated biomass (in tons) of herring in September-November 2022. YEAR SD AREA CORR FACTOR AGE 0 AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2022 21 1.22 37 579 744 93 81 33 56 - - - 2022 22 1.02 9 725 155 - - - 19 - - - 2022 23 1.00 1 994 1 529 11 557 4 490 2 309 1 409 1 506 599 161 2022 24 1.18 6 251 6 470 4 237 5 709 4 923 4 180 1 851 2 388 1 869 2022 25 1.03 1 181 6 792 10 538 26 142 50 784 26 291 15 600 9 745 8 567 2022 26 1.10 229 3 694 9 455 42 442 51 907 41 933 41 803 30 178 23 977 2022 27 1.23 4 943 5 493 6 520 10 622 24 475 7 929 6 770 8 195 1 755 2022 28_2 1.01 48 143 10 639 11 002 62 741 38 139 52 428 18 486 22 123 18 456 2022 29 1.04 67 785 17 646 41 188 69 209 23 741 15 645 11 170 14 333 5 522 2022 30 1.15 6 514 18 067 51 228 103 503 54 695 25 505 18 251 9 894 20 495 2022 32 1.42 17 603 9 683 43 203 52 670 31 148 21 606 6 524 6 005 6 309 Table 4.9. Estimated biomass (in tons) of sprat in September-November 2022. YEAR SD AREA CORR FACTOR AGE 0 AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2022 21 1.22 109 407 687 1 135 346 52 7 29 - 2022 22 1.02 8 785 145 107 148 16 54 15 - - 2022 23 1.00 59 83 273 591 262 133 47 27 3 2022 24 1.18 4 351 2 503 4 523 6 733 4 676 3 010 1 187 945 - 2022 25 1.03 810 4 967 7 167 27 949 17 657 14 636 9 981 4 389 7 794 30 | ICES SCIENTIFIC REPORTS 5:70 | ICES 2022 26 1.10 3 461 7 098 13 982 43 762 42 521 24 068 6 905 2 484 12 100 2022 27 1.23 9 693 5 708 21 539 23 377 11 797 5 932 774 1 339 3 161 2022 28_2 1.01 19 241 31 107 99 021 112 551 51 708 28 407 12 392 7 329 23 649 2022 29 1.04 34 786 19 550 130 371 107 258 47 021 17 357 13 663 11 118 27 088 2022 30 1.15 1 387 2 422 4 808 1 573 1 958 1 213 1 031 566 3 487 2022 32 1.42 8 280 22 448 108 012 69 776 43 804 24 237 15 395 14 494 32 023 4.1.1.4 Tuning fleets for WGBFAS 4.1.1.4.1 Herring in the ICES Subdivisions 25–29 and 32 The tuning fleet for the assessment of the Central Baltic herring (CBH) abundance in the ICES Subdivisions 25-29 and 32 per age-group and for the years 1999-2022 (BIAS) is presented in Fig- ure 4.7. The area-corrected combined results (for age 1+ CBH) of the above-mentioned ICES Sub- divisions are presented in Table 4.10. The recruitment index for herring (age 0) in the ICES Sub- divisions 25-27, 28_2, 29 and 32 is presented in Table 4.11. Figure 4.7. Autumn (BIAS) tuning fleet index (abundance per age-groups and years 1999-2022) for herring in the ICES Subdivisions 25-27, 28_2, 29 and 32. ICES | WGBIFS 2023 | 31 Table 4.10. Whole time-series of tuning indices. Autumn acoustic (BIAS) tuning fleet index (numbers in millions) for the Central Baltic herring (the ICES Subdivisions 25–27, 28_2 ,29 and 32). YEAR TOTAL AGE 1+ AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 1999 21 838 1 797 5 129 3 729 4 469 3 755 1 458 851 650 2000 83 056 36 325 6 175 13 326 8 230 8 309 4 622 3 610 2 460 2001 24 961 4 101 8 453 3 476 4 738 1 598 1 252 872 471 2022 - - - - - - - - - 2003 67 368 27 502 12 483 12 639 7 678 2 913 2 121 762 1 271 2004 35 713 5 270 13 824 6 960 4 735 2 508 1 132 604 680 2005 61 842 2 138 10 933 23 335 14 982 5 203 2 981 1 096 1 175 2006 74 433 10 308 10 385 16 353 23 178 8 094 3 161 1 719 1 234 2007 37 650 7 507 8 773 3 208 4 522 10 112 1 760 925 843 2008 42 084 8 043 7 888 9 323 4 613 5 218 4 716 1 173 1 112 2009 51 018 9 623 17 587 7 738 7 083 2 377 3 080 2 878 652 2010 46 331 8 600 9 595 13 496 5 273 3 879 1 738 1 924 1 827 2011 46 213 2 633 6 274 11 532 13 037 5 606 3 278 1 495 2 357 2012 54 244 16 761 3 839 7 847 9 425 9 275 2 711 2 271 2 115 2013 60 519 10 835 13 216 5 464 9 559 8 053 7 532 2 239 3 620 2014 79 860 6 994 19 549 21 194 9 356 7 370 6 584 4 929 3 885 2015 116 661 51 982 11 236 17 027 17 420 5 774 5 192 3 678 4 352 2016 88 025 9 117 42 808 15 590 8 932 5 681 2 384 1 756 1 756 2017 68 079 9 687 9 173 33 042 6 607 5 037 2 195 764 1 574 2018 91 182 10 512 15 556 15 017 32 380 8 093 6 045 2 268 1 311 2019 43 101 3 669 7 463 10 455 6 825 10 655 1 937 1 294 803 2020 51 466 12 953 5 642 11 333 7 287 5 091 6 948 929 1 283 2021 47 709 5 525 16 464 6 519 7 179 4 625 3 369 2 960 1 068 2022 38 611 3 116 5 773 10 675 7 366 4 909 2 668 2 529 1 574 Note: In the years, 1999, 2001-2005 and 2008 the coverage was very poor. It is recommended that these data should not be used. These values are marked in red. 32 | ICES SCIENTIFIC REPORTS 5:70 | ICES Table 4.11. Autumn acoustic (BIAS) recruitment index (age 0; numbers in millions) for the Central Baltic herring (the ICES Subdivisions 25-27, 28_2, 29 and 32). YEAR AGE 0 1999 2 794 2000 2 841 2001 2 149 2002 - 2003 10 376 2004 1 600 2005 6 989 2006 2 847 2007 13 583 2008 10 748 2009 3 462 2010 1 667 2011 10 575 2012 12 420 2013 3 143 2014 51 138 2015 7 623 2016 8 016 2017 10 004 2018 2 524 2019 35 406 2020 10 346 2021 3 381 2022 24 209 Note: In the years, 1999, 2001-2005 and 2008 the coverage was very poor. It is recommended that these data should not be used. These values are marked in red. 4.1.1.4.2 Sprat in the ICES Subdivisions 22–29 and 32 The tuning fleet for the assessment of sprat abundance in the ICES Subdivisions 22-27, 28_2, 29 and 32 per age-group and for the years 1991-2022 (BIAS) is presented in Figure 4.8. The area- ICES | WGBIFS 2023 | 33 corrected combined results (for age 1+ sprat) of the above-mentioned ICES Subdivisions are pre- sented in Table 4.12. The recruitment index for sprat (age 0) in the ICES Subdivisions 22-29 and 32 is presented in Table 4.13. Figure 4.8. Autumn (BIAS) tuning fleet index (abundance per age-groups and years 1999-2022) for sprat in the ICES Sub- divisions 22-27, 28_2, 29 and 32. Table 4.12. Whole time-series of tuning indices. Autumn acoustic (BIAS) tuning fleet index (numbers in millions) for Baltic sprat (ICES Subdivisions 22-27, 28_2, 29 and 32). YEAR TOTAL AGE 1+ AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 1999 198 805 4 901 91 682 16 654 36 136 39 064 5 275 3 339 1 754 2000 179 117 72 295 8 611 53 087 8 052 16 597 15 982 1 739 2 753 2001 113 000 12 990 38 116 7 766 30 756 4 306 10 175 6 480 2 412 2022 - - - - - - - - - 2003 239 388 116 750 35 764 25 611 24 155 10 042 13 306 5 077 8 684 2004 261 821 170 345 58 120 11 981 8 019 4 887 2 518 2 391 3 560 2005 263 066 12 592 165 847 59 588 10 643 5 471 3 011 2 364 3 550 2006 327 851 83 120 24 175 147 488 52 014 10 143 5 143 2 278 3 491 2007 188 002 75 613 39 491 12 088 40 276 15 871 1 516 768 2 379 2008 180 451 43 600 62 492 25 534 6 913 28 474 8 951 1 383 3 105 2009 261 814 134 253 49 826 39 347 9 935 9 111 13 065 4 102 2 176 2010 137 720 15 367 88 035 14 904 9 019 2 161 2 967 3 707 1 560 2011 155 994 34 095 20 175 68 118 17 115 8 393 3 072 1 838 3 188 34 | ICES SCIENTIFIC REPORTS 5:70 | ICES YEAR TOTAL AGE 1+ AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2012 212 116 108 251 28 703 15 212 43 526 6 640 3 453 2 135 4 196 2013 122 484 38 416 35 889 17 151 8 465 15 537 3 171 1 116 2 739 2014 105 288 19 021 33 428 22 062 11 957 5 857 9 166 1 771 2 026 2015 230 152 162 639 18 894 22 417 12 790 4 198 3 964 3 086 2 164 2016 205 802 33 849 119 884 29 659 11 196 5 441 2 461 1 506 1 805 2017 236 228 48 761 52 739 103 922 15 961 7 473 3 698 1 230 2 445 2018 141 317 41 907 24 557 16 383 39 840 11 997 3 293 1 434 1 905 2019 111 898 17 161 28 807 15 797 12 692 29 391 4 002 1 642 2 404 2020 141 614 62 659 19 408 21 467 9 689 8 402 17 421 1 226 1 343 2021 241 994 100 173 70 693 23 649 19 445 7 632 6 306 12 185 1 910 2022 129 385 9 810 38 604 35 439 18 894 9 536 4 830 3 394 8 878 Note: In the years, 1999, 2001-2005 and 2008 the coverage was very poor. It is recommended that these data should not be used. These values are marked in red. ICES | WGBIFS 2023 | 35 Table 4.13. Autumn acoustic (BIAS) recruitment index (age 0; numbers in millions) for sprat (ICES Subdivisions 22-27, 28_2, 29 and 32). YEAR AGE 0 1999 34 354 2000 6 762 2001 12 157 2002 - 2003 168 681 2004 3 673 2005 42 975 2006 86 431 2007 21 061 2008 131 972 2009 14 528 2010 53 562 2011 49 130 2012 34 941 2013 25 347 2014 182 073 2015 43 534 2016 32 784 2017 126 748 2018 19 371 2019 122 062 2020 111 155 2021 12 442 2022 21 928 Note: In the years, 1999, 2001-2005 and 2008 the coverage was very poor. It is recommended that these data should not be used. These values are marked in red. 36 | ICES SCIENTIFIC REPORTS 5:70 | ICES 4.1.1.4.3 Herring in ICES Subdivision 30 A comparison exercise between the StoX and traditional BIAS calculation methods was per- formed for the SD 30 herring acoustic abundance index during the WGBIFS meeting in 2020. It was found that the StoX project, developed for WGBIFS, has small methodological differences compared to the standard calculation method used by the group, as specified in the Manual for the International Baltic Acoustic Surveys, (IBAS) and is thereby causing a minor difference in the total number of herring. Nevertheless, WGBIFS decided to change to the StoX calculation method and recommended a new herring abundance time-series for the assessment purpose. In 2022, the Finnish BIAS survey was realized on board of the r/v “Aranda”. The distance of the acoustic transects and the numbers of realized fish control-hauls were conducted more or less as planned. Tuning fleet data from October 2007-2022 BIAS surveys for the assessment of the Gulf of Both- nian herring stock (the ICES Subdivisions 30-31) are presented in Table 4.14. Estimates from the StoX calculations for the surveys covering the years 2007-2022 are presented in Figure 4.9. Figure 4.9. Autumn (BIAS) abundance of herring (per age-group for the years 2007-2022) in ICES Subdivision 30. Table 4.14. Correction factor and area corrected numbers (millions) of herring per age-groups in the ICES Subdivision 30 (2007-2022) based on the StoX calculations. YEAR AREA CORR FACTOR AGE 0 AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8 AGE 9 AGE 10 AGE 11 AGE 12 AGE 13 AGE 14 AGE 15 2007 1.04 480 6346 5228 1902 1492 5449 1420 786 536 490 322 253 139 145 75 260 2008 1.21 1069 3074 5105 3478 1649 1707 3285 1235 987 630 396 292 173 155 145 147 2009 1.06 819 4667 5074 5358 2491 1259 1458 3525 1210 544 575 316 336 172 152 221 2010 1.06 712 4465 7189 3611 3424 1669 1055 931 2145 505 519 261 184 128 72 173 2011 1.06 2504 4412 6285 7406 2942 3127 1360 587 497 1949 379 288 202 164 133 149 2012 1.08 1398 11389 3905 3271 2902 1695 1627 962 382 504 817 344 140 104 103 178 2013 1.08 5567 1849 3889 1503 1717 1597 711 884 408 172 260 477 188 92 49 104 ICES | WGBIFS 2023 | 37 2014 1.08 11845 4839 2637 2193 1012 687 554 626 322 180 102 204 237 52 50 81 2015 1.22 3446 8863 3462 1912 1334 763 764 458 472 284 156 121 176 129 109 65 2016 1.08 1502 2003 6118 2778 1544 956 499 540 438 276 263 138 138 223 173 171 2017 1.08 1287 7732 5065 8105 2444 1595 927 449 426 368 294 238 62 82 148 207 2018 1.08 6174 2882 3937 2087 3158 869 767 412 262 275 245 137 161 68 48 190 2019 1.08 2798 3538 3682 3780 1834 2333 838 492 440 261 148 125 50 84 47 94 2020 1.08 5444 9016 8361 3422 2987 1993 1299 483 319 241 92 91 79 46 18 86 2021 1.16 2732 2202 5200 3046 1449 963 811 299 199 181 79 69 49 32 33 75 2022 1.16 1393 1162 2539 4672 2266 961 655 323 185 177 73 62 34 30 7 27 * The abundance indices for age-groups 0 and 1 is underestimated in the survey and should therefore not be used for the assessment. 4.1.2 Combined results of the Baltic Acoustic Spring Survey (BASS) In May 2022, the following acoustic surveys were conducted: Country Data Vessel ICES SDs Length of acous- tic transects [NM] Number of hauls Number of hydro- logical stations Latvia-Poland 20-27.05.2022 Baltica Parts of 26 and 28 604 17 19 Estonia-Po- land 28.05- 02.06.2022 Baltica Parts of 28, 29, 32 370 11 11 Poland 03-15.05.2022 Baltica Parts of 25 and 26 772 26 37 Germany 02-27.05.2022 Walther Herwig III 24 and parts of 25, 26, 28 and 29 1053 48 105 Sweden 10-16.05.2022 Svea Parts of 27 and 28 432 17 17 4.1.2.1 Area under investigation and overlapping areas The BASS surveys were realized in May 2022 by the above-mentioned five countries in the ICES Subdivisions 24-32 (excl. ICES Subdivisions 28_1, 30, 31), however, some ICES Subdivisions were not fully covered (Figure 4.10). The two rectangles in the ICES Subdivision 28_2, (45H0 and 45H1) was not investigated due to survey planning problems in Latvia, and two rectangles in the ICES Subdivision 26 (40G9 and 40H0) was not monitored as Lithuania did not take part in the BASS 2022 cruise. Also ICES statistical rectangle 39H0 in ICES Subdivision 26 was not inves- tigated as Russia did not take part in the BASS 2022 sampling. Compared to the previous BASS survey, in 2022 the investigated area was extended to the northern part of Subdivision 29, i.e. rectangles 48G9 - 48H0. Only two ICES rectangles (47H3 and 48H3) were inspected in the ICES Subdivision 32. In May 2022, a total of 63 ICES rectangles were covered with acoustic and biotic monitoring. 62 ICES rectangles were investigated by one country. One ICES rectangle was 38 | ICES SCIENTIFIC REPORTS 5:70 | ICES inspected and reported by two countries, namely 42G7 by Sweden and Germany. Also, six ICES rectangles were additionally inspected by another country (i.e. 42G9, 43G9 and 44G9 by Latvia and 38G5, 39G6 and 40G8 by Germany), however, these data were not considered in the final analysis. Echo-integration was recorded at a total linear distance of 3231 NM, moreover, 119 and 189 catch and hydrological stations, respectively, were inspected. The BASS surveys design only covers the sprat distribution area representatively hence only a sprat abundance index is calcu- lated. Figure 4.10. Map of the BASS survey conducted in May 2022. Various colours indicate the responsible countries for that ICES rectangle which finally also delivered data to the BIAS-database. Dots with different colours within a rectangle indi- cate that the rectangle was partly or completely covered by another country and data are available in the BASS-database (but not included in the final analysis). ICES | WGBIFS 2023 | 39 4.1.2.2 Combined results and area corrected data The geographical distribution of the sprat abundance per ICES rectangles monitored in May 2022 is demonstrated in Figure 4.11. The Baltic sprat stock abundance estimates per ICES rectangles and ICES Subdivisions according to age-groups are presented in Tables 4.15 and 4.16. A correc- tion factor for each ICES Subdivision and year is used to account for the difference in coverage between years. This factor is the proportion to the total area of the ICES Subdivision (see the IBAS Manual) and the area of rectangles covered during the survey. The correction factors, cal- culated by covered ICES Subdivisions for 2022 was applied. In May 2022 sprat was very widely distributed in the Baltic Sea and occurred in each monitored ICES rectangle (Figure 4.11). The highest sprat (age 1+) stock abundance was observed in the central part of the Baltic Sea (the ICES Subdivisions 25, 26 and 28). 40 | ICES SCIENTIFIC REPORTS 5:70 | ICES Figure 4.11. The abundance of sprat per ICES rectangles monitored in May 2022 (the size of the circle indicates the esti- mated numbers of specimens x10^6 in the given rectangle). ICES | WGBIFS 2023 | 41 Table 4.15. Estimated abundance (millions) of sprat in May 2022 per age-group and ICES-rectangle in the given ICES Subdivisions. YEAR SD RECT TOTAL AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2022 24 37G3 53.25 19.25 5.91 7.46 5.84 4.07 5.33 4.58 0.81 2022 24 37G4 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2022 24 38G2 12.50 4.52 1.39 1.75 1.37 0.96 1.25 1.07 0.19 2022 24 38G3 342.70 123.91 38.01 48.00 37.60 26.21 34.31 29.45 5.21 2022 24 38G4 85.90 0.04 14.70 19.72 15.17 11.12 12.77 11.05 1.33 2022 24 39G2 0.63 0.00 0.06 0.19 0.16 0.06 0.10 0.06 0.00 2022 24 39G3 36.73 1.60 4.58 7.50 7.80 3.95 5.02 5.64 0.64 2022 24 39G4 474.18 37.18 151.19 131.67 51.59 50.68 26.08 24.45 1.34 2022 25 37G5 309.48 10.71 39.25 47.62 56.88 58.31 37.07 48.09 11.54 2022 25 38G5 2 246.76 13.06 399.17 632.15 387.31 390.50 188.54 204.71 31.32 2022 25 38G6 1 112.97 0.80 152.51 245.80 220.79 224.77 116.24 131.68 20.38 2022 25 38G7 23.30 0.16 5.31 7.25 3.69 3.32 1.72 1.63 0.22 2022 25 39G4 1 093.93 0.33 177.02 388.40 166.45 154.76 156.34 45.10 5.53 2022 25 39G5 7 008.74 85.46 2 414.58 2 489.95 904.24 658.94 331.18 124.39 0.00 2022 25 39G6 4 515.74 77.75 1 230.01 1 532.11 624.02 557.79 261.94 212.32 19.81 2022 25 39G7 4 929.43 237.74 1 808.00 1 826.97 485.14 309.81 174.90 82.69 4.18 2022 25 40G4 5 680.94 28.25 1 869.25 2 046.86 821.01 524.13 290.76 95.41 5.27 2022 25 40G5 4 193.18 149.26 1 709.88 1 369.15 501.98 288.70 115.28 57.26 1.67 2022 25 40G6 2 208.32 49.14 897.14 738.84 264.26 173.17 64.35 20.62 0.80 2022 25 40G7 1 314.07 3.67 416.23 505.89 194.32 122.48 51.26 20.22 0.00 2022 25 41G6 1 698.22 236.93 657.47 438.73 150.89 107.73 74.45 29.00 3.02 2022 25 41G7 1 232.59 73.50 542.73 378.76 124.23 73.82 27.07 12.19 0.29 2022 26 37G8 84.99 3.22 34.89 26.57 11.37 4.83 2.64 1.33 0.14 2022 26 37G9 551.00 12.07 159.11 162.45 101.66 59.09 23.50 26.22 6.89 2022 26 38G8 2 235.37 5.80 489.76 665.01 513.18 292.30 90.06 149.10 30.16 2022 26 38G9 2 704.83 7.58 518.73 782.45 636.91 387.17 140.74 186.76 44.48 2022 26 39G8 6 710.02 23.01 1 528.39 1 970.64 1 489.86 882.84 337.15 383.78 94.36 2022 26 39G9 3 686.07 1.45 573.79 987.46 899.02 599.25 248.76 275.61 100.73 42 | ICES SCIENTIFIC REPORTS 5:70 | ICES YEAR SD RECT TOTAL AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2022 26 40G8 9 018.47 193.73 2 994.64 2 711.68 1 563.28 825.61 329.90 330.55 69.07 2022 26 41G8 4 740.46 117.73 2 178.60 1 336.81 432.61 205.77 138.43 265.11 65.40 2022 26 41G9 4 788.34 339.17 2 346.36 1 039.44 255.41 187.50 133.41 67.03 420.03 2022 26 41H0 3 587.45 419.56 2 146.36 501.21 147.44 92.86 74.17 11.83 194.02 2022 27 42G6 1 062.18 59.69 809.36 158.01 17.56 8.78 0.00 8.78 0.00 2022 27 42G7 2 160.35 43.96 743.29 924.56 112.42 67.43 33.77 146.15 88.77 2022 27 43G7 562.16 5.12 270.70 178.74 13.35 24.38 28.21 13.35 28.32 2022 27 44G7 2 982.20 322.02 1 803.32 383.63 117.61 260.42 30.80 16.80 47.60 2022 27 44G8 1 698.52 97.46 902.17 242.25 370.33 27.84 30.63 0.00 27.84 2022 27 45G7 2 353.28 461.26 1 239.94 561.41 51.21 0.00 20.67 11.16 7.63 2022 27 45G8 3 205.09 363.74 1 912.70 578.70 72.75 115.44 9.50 64.29 87.98 2022 27 46G8 2 076.41 228.58 1 132.25 358.89 181.21 45.49 25.65 104.33 0.00 2022 28_2 42G8 3 621.08 98.04 1 684.57 1 215.08 296.87 224.32 64.59 6.36 31.23 2022 28_2 42G9 6 321.78 348.93 3 090.11 2 296.37 326.19 115.08 94.12 11.36 39.62 2022 28_2 42H0 1 746.55 61.54 585.72 476.17 125.51 97.54 95.73 30.37 273.97 2022 28_2 43G8 884.13 7.82 323.92 303.58 184.65 0.00 18.78 0.00 45.38 2022 28_2 43G9 6 024.28 219.13 3 044.24 2 080.76 322.26 159.74 131.48 18.22 48.45 2022 28_2 43H0 2 685.73 70.21 1 118.03 760.71 171.85 258.76 86.58 44.98 174.63 2022 28_2 43H1 128.43 2.09 37.87 39.18 10.92 15.43 5.26 4.42 13.25 2022 28_2 44G9 2 338.54 52.79 885.41 982.43 155.88 117.15 96.99 13.85 34.04 2022 28_2 44H0 4 337.47 98.96 1 792.67 1 446.75 192.94 317.33 71.84 70.61 346.37 2022 28_2 44H1 1 289.20 36.12 542.76 397.85 90.83 110.41 21.03 25.21 64.99 2022 28_2 45G9 4 823.66 346.62 2 475.20 1 646.87 240.06 51.19 41.84 5.59 16.29 2022 29 46G9 5 702.92 482.67 3 455.81 1 332.25 190.79 160.59 64.60 2.30 13.91 2022 29 46H0 3 565.58 252.85 2 089.84 936.62 124.19 113.71 42.17 1.01 5.18 2022 29 46H1 3 257.29 208.59 1 257.60 983.72 179.87 183.92 122.60 195.49 125.50 2022 29 47G9 2 897.86 236.27 1 804.51 633.79 98.55 81.79 34.37 1.12 7.46 2022 29 47H0 2 289.34 170.86 1 149.86 633.26 142.44 110.29 62.11 3.68 16.84 2022 29 47H1 4 162.34 387.07 1 584.50 1 202.38 228.64 223.32 139.67 246.70 150.07 ICES | WGBIFS 2023 | 43 YEAR SD RECT TOTAL AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2022 29 47H2 3 022.58 291.08 856.03 953.12 210.44 207.67 125.29 235.40 143.54 2022 29 48G9 945.19 19.98 475.91 200.26 134.65 59.61 29.47 0.11 25.20 2022 29 48H0 845.55 17.88 425.74 179.15 120.46 53.32 26.36 0.10 22.54 2022 29 48H1 472.36 11.43 117.12 159.99 37.05 43.57 29.81 45.27 28.13 2022 29 48H2 425.53 10.30 105.51 144.13 33.37 39.25 26.85 40.78 25.34 2022 32 47H3 1 323.46 58.56 430.16 386.70 134.60 87.10 61.08 94.18 71.08 2022 32 48H3 963.15 28.54 294.68 252.82 100.47 77.24 61.09 76.34 71.97 Table 4.16. Estimated numbers of sprat (millions) by ICES Subdivision and age-group (May 2022). YEAR SD AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2022 24 186.50 215.84 216.29 119.53 97.05 84.86 76.30 9.52 2022 25 966.76 12 318.55 12 648.48 4 905.20 3 648.24 1 891.09 1 085.29 104.04 2022 26 1 123.32 12 970.63 10 183.73 6 050.74 3 537.22 1 518.77 1 697.32 1 025.26 2022 27 1 581.83 8 813.74 3 386.19 936.43 549.78 179.24 364.85 288.15 2022 28_2 1 342.25 15 580.50 11 645.74 2 117.96 1 466.96 728.24 230.97 1 088.22 2022 29 2 088.98 13 322.43 7 358.68 1 500.45 1 277.04 703.30 771.97 563.70 2022 32 87.10 724.84 639.52 235.08 164.34 122.17 170.51 143.04 4.1.2.2.1 Sprat in the ICES Subdivisions 24 – 28 Tuning Fleets for WGBFAS The area-corrected abundance estimates for sprat per ICES Subdivision are summarized in Table 4.17. The corresponding biomass estimates of sprat are given in the Table 4.18. The complete time-series (2001 - 2022) of the area-corrected sprat abundance of the ICES Subdivisions 24, 25 26 and 28_2 is given in the Table 4.19. 44 | ICES SCIENTIFIC REPORTS 5:70 | ICES Figure 4.12. Spring (BASS) tuning fleet index (abundance per age-group and year 2001-2022) for sprat in the ICES Subdi- visions 24, 25, 26 and 28_2. Table 4.17. Area-corrected numbers (millions) of sprat by ICES Subdivision and age-group (May 2022). YEAR SD AREA CORR FACTOR AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2022 24 1.04 193.06 223.43 223.90 123.73 100.46 87.84 78.98 9.85 2022 25 1.03 997.68 12 712.61 13 053.09 5 062.11 3 764.94 1 951.58 1 120.01 107.37 2022 26 1.39 1 559.79 18 010.39 14 140.64 8 401.77 4 911.61 2 108.90 2 356.82 1 423.63 2022 27 1.23 1 946.82 10 847.40 4 167.51 1 152.50 676.63 220.59 449.03 354.64 2022 28_2 1.21 1 623.73 18 847.82 14 087.92 2 562.11 1 774.59 880.96 279.41 1 316.43 2022 29 1.14 2 371.66 15 125.24 8 354.46 1 703.50 1 449.85 798.47 876.43 639.98 2022 32 6.51 566.90 4 717.67 4 162.33 1 530.01 1 069.58 795.17 1 109.80 931.00 Table 4.18. Area-corrected sprat biomass (in tonnes) according to ICES Subdivision and age-group (May 2022). YEAR SD AREA CORR FACTOR AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2022 24 1.04 1782.0 3441.0 3726.9 2351.7 1839.0 1831.4 1648.7 233.3 2022 25 1.03 6505.6 122730.4 146755.0 61715.1 49024.4 28649.0 16627.4 1845.1 2022 26 1.39 8469.1 147728.6 139261.0 89082.7 54980.8 23848.3 27593.3 17122.7 2022 27 1.23 7944.5 74454.3 38769.6 11879.3 6524.3 2367.5 4910.3 3826.5 ICES | WGBIFS 2023 | 45 2022 28_2 1.21 8062.1 146728.9 133593.5 25827.7 19388.5 10067.7 3118.8 14503.6 2022 29 1.14 10578.5 114957.0 74893.8 18125.6 14906.5 8467.6 8913.3 6660.2 2022 32 6.51 2194.3 33863.7 35723.7 14423.3 10692.4 8191.3 10827.8 9971.5 Table 4.19. Whole time-series of tuning indices. Spring acoustic (BASS) tuning fleet index (numbers in millions) for Baltic sprat (ICES Subdivisions 24, 25, 26 and 28_2). YEAR TOTAL AGE 1-8 AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2001 109 404 8 225 35 735 12 971 37 328 5 384 4 635 4 526 600 2002 125 783 27 412 18 982 36 814 19 045 14 759 2 517 3 670 2 585 2003 84 987 26 469 16 471 8 423 15 533 5 653 7 170 1 660 3 607 2004 258 607 136 162 65 566 15 784 11 042 12 655 3 271 7 806 6 321 2005 134 374 4 359 88 830 23 557 7 258 3 517 2 781 1 830 2 243 2006 130 287 13 417 7 980 76 703 21 046 5 702 1 970 1 526 1 943 2007 132 637 51 569 28 713 6 377 36 006 7 481 1 261 533 698 2008 102 723 9 029 40 270 20 164 5 627 21 188 4 210 757 1 477 2009 139 641 39 412 26 701 36 255 10 549 6 312 14 106 5 341 964 2010 112 785 9 387 58 680 15 199 15 963 5 062 1 654 5 566 1 273 2011 128 154 18 092 6 791 66 160 16 689 10 565 4 077 2 399 3 382 2012 107 661 22 700 22 080 11 274 35 541 7 515 5 025 1 367 2 158 2013 111 419 24 877 35 333 18 393 11 358 14 959 3 385 2 164 950 2014 76 549 10 145 26 907 19 857 7 458 6 098 3 810 1 217 1 058 2015 160 549 70 752 24 660 29 744 18 935 8 081 4 074 2 581 1 721 2016 108 392 15 555 75 824 9 121 3 990 1 895 791 514 703 2017 233 353 32 701 36 292 132 939 20 630 6 790 2 250 809 942 2018 171 723 27 209 25 642 38 632 69 259 7 251 2 086 1 025 619 2019 161 411 15 958 28 778 32 532 49 495 30 131 3 384 487 647 2020 144 015 38 096 26 252 29 054 19 630 18 377 11 756 473 376 2021 128 876 23 212 45 545 20 134 18 028 8 525 7 160 5 361 911 2022 134 097 4 374 49 794 41 506 16 150 10 552 5 029 3 835 2 857 Note: In year 2016, the coverage was very poor. It is recommended that these data should not be used. 46 | ICES SCIENTIFIC REPORTS 5:70 | ICES 4.1.3 Combined results of the Gulf of Riga Herring Survey (GRAHS) In July - August 2022, the joined Latvian-Estonian survey in the Gulf of was conducted. The total area of the Gulf of Riga was covered with acoustic transect (area corrected factor=1). Country Data Vessel ICES SDs Length of acoustic transects [NM] Number of hauls Number of hydro- logical stations Latvia-Esto- nia 27.07- 01.08.2022 F/V Urga 28_1 484 17 17 The geographical distribution of the Gulf of Riga herring abundance per ICES rectangles moni- tored in July-August 2022 is demonstrated in Figures 4.13-4.14. The Gulf of Riga herring abun- dance and biomass per ICES rectangles according to age-groups are presented in Tables 4.20 and 4.21. The highest herring (age 1+) stock abundance was observed in the central part of the ICES Subdivision 28_1, in the ICES rectangle 44H3, whereas the highest concentrations of young of the year (YOY) herring (age-group 0, year class 2022) was detected in the northern part of the Gulf of Riga, in rectangle 45H3. ICES | WGBIFS 2023 | 47 Figure 4.13. The abundance of the Gulf of Riga herring (age 1+) per ICES rectangle monitored in July-August 2022 (the size of a circle indicates estimated numbers of specimens x10^6 in a given rectangle). 48 | ICES SCIENTIFIC REPORTS 5:70 | ICES Figure 4.14. The abundance of the Gulf of Riga herring (age 0) per ICES rectangle monitored in July-August 2022 (the size of a circle indicates estimated numbers of specimens x10^6 in a given rectangle). ICES | WGBIFS 2023 | 49 Table 4.20. Numbers (millions) of Gulf of Riga herring stock in July-August 2022. YEAR RECT AGE 0 AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2022 43H3 337.40 744.38 314.43 430.82 173.28 125.81 50.90 30.79 22.45 2022 43H4 5.85 134.81 42.90 39.57 16.84 22.46 5.67 4.28 4.64 2022 44H2 985.29 1 265.26 345.10 230.55 50.47 22.54 4.39 7.89 7.67 2022 44H3 787.68 1 285.26 625.90 947.00 438.02 305.85 124.53 36.34 41.69 2022 44H4 59.25 498.44 179.79 265.44 209.95 159.08 58.01 13.75 26.69 2022 45H2 370.84 566.37 115.75 84.84 14.05 5.62 0.00 0.00 11.24 2022 45H3 5 281.44 752.20 218.43 261.01 119.80 92.15 54.31 8.87 16.31 Table 4.21. Biomass (in tonnes) of Gulf of Riga herring stock in July-August 2021. YEAR RECT AGE 0 AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 2022 43H3 1067.89 12419.76 6442.11 9817.96 4367.53 3254.51 1410.85 861.03 650.65 2022 43H4 30.90 2230.66 845.59 915.97 415.59 581.09 150.65 117.45 132.88 2022 44H2 3649.13 19635.94 7080.15 5222.83 1032.46 570.51 104.02 226.34 205.84 2022 44H3 2670.16 20474.69 12761.33 21298.25 10610.22 7602.55 3218.72 1035.42 1301.41 2022 44H4 316.04 7732.15 3403.48 5811.65 4907.15 3904.95 1451.35 380.36 807.55 2022 45H2 1491.79 8613.61 2382.37 1764.30 286.56 126.42 - - 306.22 2022 45H3 17094.73 11312.26 4279.34 6001.83 2880.58 2288.71 1420.38 276.19 546.26 Tuning Fleets for WGBFAS The tuning fleet for the assessment of the Gulf of Riga herring (CBH) abundance in the ICES Subdivisions 28_1 per age-group and for the years 1999-2022 is presented in Figure 4.15. The combined results (for age 1+ GoR herring) of the above-mentioned ICES Subdivision are pre- sented in Table 4.22. 50 | ICES SCIENTIFIC REPORTS 5:70 | ICES Figure 4.15. Gulf of Riga tuning fleet index (abundance per age-group and year 1999-2022) for herring in the ICES Subdi- vision 28_1. Table 4.22. Whole time-series of tuning indices. Gulf of Riga Acoustic Herring Survey (GRAHS) index (numbers in mil- lions) for the Gulf of Riga herring (the ICES Subdivision 28_1). YEAR TOTAL AGE 1+ AGE 1 AGE 2 AGE 3 AGE 4 AGE 5 AGE 6 AGE 7 AGE 8+ 1999 13 245 5 292 4 363 1 343 1 165 457 319 208 98 2000 12 310 4 486 4 012 1 791 609 682 336 151 243 2001 12 516 7 567 2 004 1 447 767 206 296 56 173 2022 12 187 3 998 5 994 1 068 526 221 87 165 128 2003 17 495 12 441 1 621 2 251 411 263 269 46 193 2004 16 542 3 177 10 694 675 1 352 218 195 94 137 2005 15 564 8 190 1 564 4 532 337 691 92 75 83 2006 15 638 12 082 1 986 213 937 112 223 36 49 2007 7 774 1 478 3 662 1 265 143 968 116 103 39 2008 17 070 9 231 2 109 4 398 816 134 353 6 23 2009 14 287 6 422 4 703 870 1 713 284 28 223 44 2010 10 124 5 077 2 311 1 730 244 593 107 12 50 2011 15 690 3 162 5 289 2 503 2 949 597 865 163 162 2012 10 936 5 957 758 1 537 774 1 035 374 308 193 2013 18 739 9 435 5 552 592 1 240 479 827 187 427 ICES | WGBIFS 2023 | 51 2014 9 303 1 109 3 832 2 237 276 570 443 466 370 2015 7 876 3 221 539 1 899 1 110 255 346 181 325 2016 8 560 4 542 1 081 504 1 375 690 152 113 103 2017 11 452 3 231 3 442 874 402 1 632 982 137 752 2018 23 041 11 216 4 529 3 607 776 338 1 439 755 381 2019 17 141 4912 7007 2237 1335 475 228 681 265 2020 19 664 9947 2637 3571 1189 985 344 186 805 2021 16 256 6171 4885 990 2085 793 670 257 405 2022 11 635 5247 1842 2259 1022 734 298 102 131 4.2 ToR b) Update the BIAS, BASS and GRAHS hydroacous- tic databases and ICES database for acoustic-trawl sur- veys After validation, the data from the Baltic International Acoustic Survey (BIAS), the Baltic Acous- tic Spring Survey (BASS) and the Gulf od Riga Acoustic Herring Survey (GRAHS) carried out in 2022 were added to the BIAS_DB.mdb, the BIAS_HERR_SD30_DB.mdl, the BASS_DB.mdb, and the GRAHS_DB.mdb access-databases, respectively. The specification of these databases is as following: 1. BIAS_DB is based on the country level made calculations according to IBAS methodol- ogy (fish up to 8+ age group), note: in SD30 the StoX calculation has been used for herring since 2020. 2. BIAS_HERR_SD30_DB for herring based on StoX calcualtions (using StoX project for IBAS calculations, fish up to 15+ age group) 3. BASS_DB for sprat based on the country made calculations according to IBAS method- ology (fish up to 8+ age group). 4. GRAHS_DB for the Gulf of Riga herring based on the country level made calculations using the nearest haul method (fish up to 8+ age group). All these databases also include queries with the used algorithms for the creation of report tables and the calculation of the different tuning fleets. The updated versions of the databases are lo- cated in the folder “Data” of the ICES WGBIFS 2023 SharePoint. The results of the next international acoustic surveys (BIAS, BASS, GRAHS) should be summa- rized in table format according the IBAS Manual and latest one month before the next year meet- ing uploaded to the ICES WGBIFS-SharePoint. O. Kaljuste from Sweden and B Schmidt from Poland were assigned as the above-mentioned (BAD1) acoustic-trawl data coordinators, respon- sible to control that the acoustic survey results are uploaded in the right format to the SharePoint of WGBIFS. Moreover, B. Schmidt was assigned as the manager of the BIAS, BASS and GRAHS databases for aggregated data (BIAS_DB.mdb, BIAS_HERR_SD30_DB.mdb, BASS_DB.mdb and GRAHS_DB.mdb). B. Schmidt will in cooperation with the national data submitters check the 52 | ICES SCIENTIFIC REPORTS 5:70 | ICES provided data for errors and preliminary analysis will be performed in order to present the data to the WGBIFS meeting for further evaluations and discussion. If the countries do not submit the data to the database manager in the agreed time, this work cannot be done during the WGBIFS annual meeting with the required quality. 4.3 ToR c) Coordinate and plan acoustic surveys including any experiments to be conducted All the Baltic Sea countries intend to take part in the BASS and BIAS (except Russia, for which no information is available) acoustic surveys and experiments in 2023 (Figures 4.16 – 4.17). There is also an intention to conduct a Latvian/Estonian survey in the Gulf of Riga (GRAHS) in July- August 2023. The list of participating research vessels and initially planned periods of particular surveys are given in the following tables: ICES | WGBIFS 2023 | 53 BASS/2023 surveys Vessel Country Area of Investigation (ICES Subdivisions) Period of Investigations Duration (Days) Svea Sweden 27, partly 28 16-24.05.2023 9 Baltica Estonia/Poland 28.2, 29 partly 32 30.05-04.06.2023 6 Walther Herwig III Germany 24, 25, 26, 27, 28, 29 (for all SD: only part moni- tored) 2-27.05.2023 26 Baltica Latvia/Poland 26 partly, 28 partly 22-29.05. 2023 8 Commercial Vessel Lithuania Part of 26 08-09.05.2023 2 Baltica Poland 25 and 26 04-17.05.2023 14 GRAHS/2023 survey Vessel Country Area of Investigation (ICES Subdivisions) (Preliminary) Period of Investigations Duration (Days) Ulrika Latvia/ Estonia 28.1 July/August 2023 7 BIAS/2023 surveys Vessel Country Area of Investigation (ICES Subdivisions) (Preliminary) Period of Investigations Duration (Days) Svea Sweden 27 and parts of 25,26,28,29 2 – 16.10 2023 15 Baltica Estonia/Poland 28,29,32 22.10-03.11.2023 13 Aranda Finland 29N, 30 and 32N 20.9.-4.10.2023 16 Baltica Latvia/Poland 26 partly, 28 partly 9-21.10 2023 13 Commercial Vessel Lithuania Part of 26 15-17.10.2023 2 Baltica Poland Parts of 25 and 26 20.09-05.10.2023 16 54 | ICES SCIENTIFIC REPORTS 5:70 | ICES ICES | WGBIFS 2023 | 55 Figures 4.16.–4.17. The planned coverage of the Baltic Sea and the assignment of the national/joint acoustic surveys to the ICES rectangles during the May 2023 and September/October 2023. Base colours of rectangles indicate the country or joint survey, which is responsible for given ICES-rectangle. Coloured dots indicate overlapping coverage by other coun- tries (sometimes only parts of rectangle are covered). 4.4 ToR d) Review the results from BITS surveys and evalu- ate the characteristics of TVL and TVS standard gears used in BITS 4.4.1 4th quarter 2022 BITS. During Autumn 2022, the level of realized valid hauls represented 99.4 % of the total planned stations (Fig. 4.18). Unfortunately, data from Russian EEZ was not available. 56 | ICES SCIENTIFIC REPORTS 5:70 | ICES The coverage by depth stratum is as follows (depth stratum, coverage in %): 1, 97; 2, 97; 3, 100; 4, 115; 5, 86 and 6, 100). The number of valid hauls was considered by WGBIFS as appropriate for tuning series, and it is recommended that the data are used for the assessment of the Baltic and Kattegat cod and flatfish stocks. Figure 4.18. Comparison of the planned and