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

• Main Author: ICES
• Format: Article in Journal/Newspaper
• Language: English
• Published: ICES 2024
• Subjects: Turbot
• Online Access: https://archimer.ifremer.fr/doc/00902/101346/112030.pdf; https://doi.org/10.17895/ices.pub.25605639; https://archimer.ifremer.fr/doc/00902/101346/

The main terms of reference for the ICES Working Group for the Assessment of Demersal Stocks in the North Sea and Skagerrak (WGNSSK) were to update, quality check, and report relevant data for the working group, to update and audit the assessment and forecasts of the stocks, to produce a first draft of the advice on the fish stocks, and to prepare planning for benchmarks in future years. Ecosystem changes have been analytically considered in the assessments for cod, haddock, and whiting in the form of varying natural mortalities estimated by the ICES Working Group on Multispecies Assessment Methods (WGSAM). Conservation status advice was consid-ered but WGNSSK did not identify any conservation aspects for its stocks. Recent benchmarks Benchmarks that involved WGNSSK stocks were organized in 2023–2024. The WKBFLATFISH benchmark for North Sea sole (sol.27.4) and the WKBGAD benchmark for saithe (pok.27.3a46) were convened to evaluate the appropriateness of data and methods to determine stock status. Nephrops in FU32 (nep.fu.32) joined the WKBMSYSPiCT3 benchmark, which resulted in an ac-cepted SPiCT assessment to produce MSY advice for this stock. State of the stocks 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. Seven stocks with agreed reference points (category 1 stocks) have SSB higher than MSY Btrigger (had-dock in 4, 6.a and 20, plaice in 4 and 20, sole in 4, saithe in 3.a, 4 and 6, turbot in 4, whiting in 4 and 7.d and witch in 3.a, 4 and 7.d). Additionally, Northern Shelf cod (cod in 4, 6.a, 7.d and 20) has two substocks (Northwestern and Viking) with SSB above MSY Btrigger, and one substock (Southern) below Blim. The SSB of sole in 7.d is below Blim, while plaice in 7.d is just above Blim. Several North Sea stocks are exploited at or below FMSY levels (haddock in 4, 6.a and 20, plaice in 4 and 20, plaice in 7.d, saithe in 3.a, 4 and 6, sole in 4, sole in 7.d, turbot in ...