• European Marine Science
• Book close
• NL close

This paper is chapter 5.2 of the ICES CRR “Structure and dynamics of the North Sea benthos” (ICES 2007) compiled by the ICES Study Group on the North Sea Benthos Project 2000. The North Sea Benthos Project 2000 (NSBP) was initiated as a follow-up to the earlier 1986 ICES North Sea Benthos Survey (NSBS). One major aim of the NSBP 2000 was to compare the outcome with that of the 1986 NSBS, in order to identify any significant changes in the community structure and their likely causes. In general, the spatial distribution of the macrofaunal communities in 2000 was rather similar to that in 1986. But changes were found within communities which were addressed to changes in the hydroclimate caused by changes in the North Atlantic Oscillation influencing changes in currents and sediment structure as well as food availability.

The ICES herring assessment working group (HAWG) met online for nine days in March 2023 to assess the state of six herring (Clupea harengus) and three sprat (Sprattus sprattus) stocks. Additionally, HAWG provided advice for eight Sandeel (Ammodytes spp.) in January 2023. The working group conducted update category 1 assessments for four of the herring stocks and category 3 assessments for 2 herring stocks. An analytical assessment was performed for the combined North Sea and Division 3.a sprat, and data limited assessment (ICES category 3) was conducted for English Channel sprat (spr.27.7de). Biennial advice is given for sprat in the Celtic Seas and West of Scotland with advice provided in 2023. North Sea autumn spawning herring (her.27.3a47d). SSB in 2022 was estimated at 1.65 million tonnes while F2–6 in 2021 was estimated at 0.23, which is below FMSY. Recruitment in 2022 is at its highest since 2014, which is expected to contribute positively to SSB levels from 2024 onwards. ICES considers that the stock is still in a low productivity phase. Western Baltic spring-spawning herring (her.27.20-24). SSB in 2022 was estimated at 75,548 tonnes and is below MSY Btrigger, Bpa, and Blim. Recruitment has been low since 2007 and has been deteriorating further with time. F3-6 has been decreasing since 2018 and is now week below FMSY (0.31) at 0.05. The stock has decreased consistently during the second half of the 2000s and given the continued low recruitments, the stock is not able to recover above Blim unless a drastic reduction in fishing effort is applied for several years. Celtic Sea autumn and winter spawning stock (her.27.irls). SSB in 2022 was estimated at 16,539 tonnes, though is increasing from its lowest level seen in 2018 (6,474 tonnes), but remains below Blim (34,000 tonnes). F(2-5 rings) in 2022 was estimated at 0.028, having decreased from a peak of 1.16 in 2017. Recruitment has been consistently below average since 2013. Irish Sea autumn spawning herring (her.27.nirs). SSB in 2022 was estimated at 25,900 tonnes and is above MSY Btrigger, Bpa, and Blim. Recruitment in 2022 is the highest on record and continues the trend of large incoming year-classes in recent years. F4-6 has been stable between 0.22 and 0.24 since 2006 and is below FMSY (0.266). 6aN autumn spawning herring (her.27.6aN). SSB in 2022 was estimated at 33,283 tonnes using the genetically split, Malin Shelf Herring Acoustic Survey (MSHAS). Whilst SSB has increased since its lowest level in 2019, these numbers of herring are low compared to historical estimates. Indicators show that stock size is above MSY Btrigger proxy and below FMSY proxy. Herring in 6.aS/7.b, c (her.27.6aS7bc). SSB in 2022 was estimated at 147,199 tonnes using the genetically split, Malin Shelf Herring Acoustic Survey (MSHAS) and has been increasing since the lowest point in 2016 (36,707 t). Recent catches are among the lowest in the time series. Fishing pressure on the stock is below FMSY proxy (0.034) and the stock size index is well above MSY Btrigger proxy (51 390 t). Sprat in the North Sea and 3.a (spr.27.3a4). SSB in 2023 was estimated at 206,581 tonnes and is above MSY Bescapement, Bpa, and Blim. F1-2 has been decreasing since 2016, however there are high levels of fluctuation throughout the time series. Low recruitment in recent years had contributed to the stock being below MSY Bescapement, though this has been alleviated by the 2023 year-class. Sprat in the English Channel (spr.27.7de). SSB in 2022 was estimated at 28,439 tonnes using the Pelagic Ecosystem Survey in the Western Channel and Celtic Sea (PELTIC). The catch advice applies a constant harvest rate (CHR) of 8.57% to the survey biomass. Fishing pressure is below FMSY proxy with stock size above MSY Btrigger (Istat). Sprat in the Celtic Seas and West of Scotland (spr.27.67a-cf-k). Catch advice was given for 2024 and 2025 using the ICES Category 5 method where only landings data are available. The precautionary buffer (20% reduction) was applied in 2021, and thus was not applied in this advice year. Sandeel in Divisions 4b–c (Sandeel area 1r). SSB in 2022 was estimated at 134,266 tonnes and is above MSY Bescapement, Bpa, and Blim. Although recruitment has been below average between 2020–2022, the low fishing mortality in 2021 and 2022 has allowed a sufficient rebuild to the stock to allow a fishery in 2023. F1-2 is currently at its lowest level since 2012. Sandeel in Divisions 4b–c (Sandeel area 2r). SSB in 2022 was estimated at 63,831 tonnes and is below MSY Bescapement and between Bpa and Blim. Recruitment in 2022 is lower than that in 2021. F1-2 has decreased since the previous year. Sandeel in Divisions 4a–b and Subdivision 20 (Sandeel area 3r). SSB in 2022 was estimated at 405,550 tonnes and is above MSY Bescapement, Bpa, and Blim. Recruitment in 2022 is lower than that in 2021. F1-2 has increased since the previous year. Sandeel in Divisions 4a–b (Sandeel area 4). SSB in 2022 was estimated at 85,477 tonnes and is below MSY Bescapement and between Bpa and Blim. Recruitment in 2022 is higher than that in 2021. F1-2 has decreased since the previous year. Sandeel in Division 4a (Sandeel area 5r). Catch advice was given for 2023 and 2024 using the ICES Category 5 method where only catch data are available. The precautionary buffer (20% reduction) was applied in 2021, and thus was not applied in this advice year. Sandeel in Subdivisions 20–22 (Sandeel area 6). Catch advice was given for 2023 and 2024 using the ICES Category 5 method where only catch data are available. The precautionary buffer (20% reduction) was applied in 2021, and thus was not applied in this advice year. Sandeel in Division 4a (Sandeel area 7r). Catch advice was given for 2023 and 2024 using the ICES Category 5 method where only catch data are available. The precautionary buffer (20% reduction) was applied in 2021, and thus was not applied in this advice year. Sandeel in Division 6a. Catch advice was last given in 2021 following the ICES Category 6 method. This advice is not due for update until 2024. Standard issues such as benchmark planning, the quality and availability of data, availability of data through industry surveys and scientific advances particularly with respect to the use of genetics for stock discrimination were discussed. All data and scripts used to perform the assessments and the forecast calculations are available at https://github.com/ICES-dk/wg_HAWG and accessible to anyone.

The work was supported by the Copernicus Marine Environment Monitoring Service (CMEMS) LATEMAR project. CMEMS is implemented by Mercator Ocean in the framework of a delegation agreement with the European Union. This work has also been conducted as part of the bilateral project EOLO-1 (“Extreme Oceanic waves during tropical, tropical-like, and bomb cyclones”) between CNR-ISMAR and the University of Tokyo (Japan; Prof. Takuji Waseda). Antonio Ricchi funding have been provided via the PON “AIM” - Attraction and international mobility program AIM1858058. Joanna Staneva acknowledges H2020 IMMERSE Project, Arno Behrens was supported by CMEMS Waveflow project and G. Gayer by ESA Black Sea and Danube Regional Initiative (EO4BS). Issue sup1: Copernicus Marine Service Ocean State Report, Issue 5 Supplement.-- Karina von Schuckmann (Editor), Pierre-Yves Le Traon (Editor), Neville Smith (Chair) (Review Editor), Ananda Pascual (Review Editor), Samuel Djavidnia (Review Editor), Jean-Pierre Gattuso (Review Editor), Marilaure Grégoire (Review Editor),