International Bottom Trawl Survey Working Group (IBTSWG)

• Main Authors: Alvestad, Anja Helene, Auber, Arnaud, Baldo, Francisco, Baudron, Alan, Beggs, Steven, Bland, Barbara, Börjesson, Patrik, Breddermann, Karsten, Burns, Finlay, Chaves, Corina, Cole, Harriet, Cresson, Pierre, de Boois, Ingeborg J., Denechaud, Côme, Eidset, Elise, Ellis, Jim R., Engås, Arill, Gillespie-Mules, Ruadhán, Griffin, Francis, Hatton, Benjamin, Holdgate, Alex, Huwer, Bastian, Kelly, Eoghan, Kelly, Ruth, Kloppmann, Matthias, Kynoch, Rob, Laffargue, Pascal, Lichtenstein, Uwe, Ludwig, Kim Ellen, Miethe, Tanja, Neumann, Hermann, Reecht, Yves, Rosen, Shale, Schuchert, Pia, Sell, Anne Friederike, Silva, Cristina, Sinclair, Louisa, Stokes, David, van Hal, Ralf, Velasco, Francisco, Villanueva, Ching, Wieland, Kai, Wienerroither, Rupert
• Format: Text
• Language: English
• Published: ICES 2022
• Subjects: Text; ddc:590; ddc:310; ddc:330; International Bottom Trawl Survey > bottom trawl survey data > bottom trawl fishery > Stock assessments > sprat larvae > monitoring surveys > long-term data > fish distribution > relative abundance > standardization efforts > fishing gear > survey coordination > continental shelf > Gulf of Cadiz > Northeast Atlantic > North Sea > groundfish survey > WKFDN > WGNSSK > WGBIE; Northeast Atlantic
• Online Access: https://doi.org/10.17895/ices.pub.20502828; https://www.openagrar.de/receive/openagrar_mods_00085603; https://www.openagrar.de/servlets/MCRFileNodeServlet/openagrar_derivate_00051635/dn065834.pdf

The International Bottom Trawl Survey Working Group (IBTSWG) coordinates fishery-independent bottom trawl surveys in the ICES area in the Northeast Atlantic and the North Sea. These long-term monitoring surveys provide data for stock assessments and facilitate examination of changes in fish distribution and relative abundance. The group also promotes the standardization of fishing gears and methods as well as survey coordination. This report summarizes the national contributions in 2021–2022 and plans for the 2022–2023 surveys coordinated by IBTSWG. In the North Sea, the surveys are performed in quarters (Q) Q1 and Q3, while in the Northeast Atlantic the surveys are conducted in Q1, Q3, and Q4 with a suite of 14 national surveys covering a large area of continental shelf that extends from the north of Scotland to the Gulf of Cádiz. North Sea surveys in 2022-Q1 were affected severely by mechanical and COVID-related issues, as well as the number of storms experienced during the survey period. Some of the ICES rectangles in the survey area could not be sampled and a larger number of the rectangles were only sampled with a single tow. North Sea surveys in 2021-Q3 were broadly complete, with the wider area surveyed and comparable number of hauls. However, some rectangles close to shore or with obstructions may not have had full coverage. Most of the surveys in the Northeast Atlantic were completed successfully. However, the two Spanish groundfish surveys in the Gulf of Cádiz could not be undertaken in 2021. Vessel-related problems also affected the Spanish survey of the Cantabrian Sea, although this survey was completed using two vessels over a more protracted survey window. The IBTSWG welcomed the return of the Portuguese groundfish survey (Q4) after a two-year absence, with the survey being undertaken by the new research vessel, the “Mario Ruivo”. IBTSWG discussed the roadmap for the new survey trawl, following on from the Workshop on the Further Development of the New IBTS Gear (WKFDN). IBTSWG agreed the main ...