Working Group on the Assessment of Demersal Stocks in the North Sea and Skagerrak (WGNSSK)

• Main Authors: Batsleer, Jurgen, Baudron, Alan, Chen, Chun, Cole, Harriet, De Oliveira, Jose A., Denechaud, Côme, Girardin, Raphael, Halouani, Ghassen, Haslob, Holger, Holdgate, Alexander Neil, Jacobsen, Nis Sand, Kempf, Alexander, Kokkalis, Alexandros, Melis, Eleni, Mesquita, Carlos, Miethe, Tanja, Mosqueira, Iago, Nawri, Nikolai, Needle, Coby L, Nielsen, J. Rasmus, Orio, Alessandro, Reecht, Yves, Skjaeraasen, Jon Egil, Soevik, Guldborg, Sys, Klaas, Taylor, Marc Hollis, Tiano, Justin, Vansteenbrugge, Lies, Villagra Villanueva, Damian, Voak, Bella, Vossen, Kathrin, Walker, Nicola
• Format: Report
• Language: English
• Published: ICES 2023
• Subjects: Text; ddc:630; WGNSSK > brill > cod > dab > flounder > grey gurnard > haddock > lemon sole > striped red mullet > plaice > saithe > sole > turbot > whiting > witch > norway pout; Norway; Turbot
• Online Access: https://doi.org/10.17895/ices.pub.22643143; https://www.openagrar.de/receive/openagrar_mods_00092225; https://www.openagrar.de/servlets/MCRFileNodeServlet/openagrar_derivate_00056576/dn067220.pdf

The main impression in recent years is that fishing pressure has been reduced substantially for many North Sea stocks of roundfish and flatfish compared to the beginning of the century. Five stocks with agreed reference points (Category 1 stocks) have SSB higher than MSY Btrigger (haddock in 4, 6.a, and 20; plaice in 4 and 20; saithe in 3.a, 4, and 6; turbot in 4; whiting in 4 and 7.d), while the SSB of sole in 4, sole in 7.d, plaice in 7.d, and witch in 3.a, 4, and 7.d is just above Blim. Northern shelf cod (cod in 4, 6a, 7d, and 20) has one substock (Northwestern) with SSB above MSY Btrigger, one substock (Viking) between MSY Btrigger and Blim and one substock (Southern) below Blim. Several North Sea stocks are exploited at or below FMSY levels (haddock in 4, 6.a, and 20; plaice in 4 and 20; saithe in 3.a, 4, and 6; sole in 4; sole in 7.d; turbot in 4; whiting in 4 and 7.d); however, two stocks are being fished above FMSY (plaice in 7.d; witch in 3.a, 4, and 7.d). All substocks of Northern shelf cod (cod in 4, 6a, 7d, and 20) are fished above FMSY. An important feature is that recruitment remains poor compared to historic average levels for most gadoids, although there are signs of strong recruitment for haddock and whiting in most recent years. Recruitment in 2022 for flatfish stocks continues on a high level only for witch in 3.a, 4, and 7d, and for plaice in 4 and 20.WGNSSK is also responsible for the assessment of several data-limited species (Category 2+ stocks) that are mainly bycatch in demersal fisheries. The summary of stock status is as follows: Category 1: Cod (cod.27.46a7d20): Spawning-stock biomass of the Northwestern substock has been fluctuating above MSY Btrigger for most of the time-series and is well above it in 2023. Spawning-stock biomass of the Viking substock has been fluctuating between MSY Btrigger and Blim for most of the time-series and is just below MSY Btrigger in 2023. Spawning-stock biomass of the Southern substock has been fluctuating around MSY Btrigger for most of the ...