Tagging Baltic Cod - TABACOD : Eastern Baltic cod: Solving the ageing and stock assessment problems with combined state-of-the-art tagging methods

Historical tagging data - The objective of WP1 was to collate data from previous tagging experiments in the Baltic Sea to provide the empirical information for the development of statistical growth models and the estimation of historical growth for stock assessment purposes. Data from cod tagging experiments (using conventional tags) performed between the 1950s and 1990s by Sweden, Poland, Latvia, Finland, Denmark and Germany in the Baltic Sea have been collected from the respective national archives, digitized, quality-checked and combined in a common database. The database contains information about ~ 86200 cod releases. Data for a total of 10143 recaptured cod are available covering a release period between 1955 and 1993. The records in the compiled database of all recaptured cod includes information on release and recapture date, location (geographical coordinates or ICES Subdivisions) and total length, as well as occasional information on total weight, sex and maturity stage. The length of recaptured cod ranged between 140-1100 mm and the time between release and recapture ranged between 0-3928 days. In addition, tagging data for a more recent project CODYSSEY (446 fish tagged with Data Storage Tags between 2002 and 2006), covering the southern Baltic Sea, were also combined with the historical database adding 234 cod recaptured between 2003 and 2006. The length of recaptured CODYSSEY cod ranged between 450-985 mm and time between release and recapture ranged between 1-607 days. These data provided key information to estimate the historical baselines of eastern Baltic cod growth and therefore contributed substantially to the re-establishment of an analytical stock assessment for the eastern Baltic cod in 2019 (WP3). In addition, these data provides detailed information that can be used to estimate horizontal movements of the population between different areas of the Baltic Sea (WP3)...