This data contains monitoring data of the RV ALKOR cruise AL549 conducted in January 2021 (January 25th – February 1st) in the Western Baltic Sea by the University of Hamburg. The cruise was part of the 5-year monitoring programme Winter cod 2021-25 (Monitoring winter spawning activity of Western Baltic cod (Gadus morhua) (2021-25)) of the University of Hamburg aiming at investigating the early-winter spawning activity of Western Baltic cod to identify potential climate-induced shifts in spawning phenology. The data set includes station data (i.e. action log) of the cruise.

The station data was obtained from the DSHIP action log available at the BSH (Bundesamt für Seeschifffahrt und Hydrographie), Germany.