Human activity has been impacting marine ecosystems for millennia, and fishing is most often seen as the cause of overexploitation and depletion of marine biological resources (Myers and Worm 2003, Salomon 2009). There is a wealth of recent studies illustrating how our perception of pristine conditions in the seas and oceans has shifted over generations. This is referred to as ‘Shifting Baselines’. A wide range of evidence about (pre) historical reference conditions and early baselines has increased the awareness on the limitations associated with the current scientific methods to determine appropriate reference conditions against which current targets for conservation and management are set, in particular for fisheries (Pinnegar and Engelhard 2008). It is acknowledged that environmental reference conditions and targets must strive to integrate all available and relevant data and information for improved assessments, including incorporating historical data into conservation and management frameworks (Pinnegar and Engelhard 2008, McClenachan et al. 2012). Historical data can contribute in explaining underlying cause-effect relations in changes in the ecosystems, potentially reveal information and knowledge from past conditions (Jackson et al. 2001), and help defining reference conditions and achievable targets for environmental management today. The present thesis focuses on quantitative data to extend the timeframe of current analyses on fisheries (landings, fleet dynamics, spatial dynamics, indexes of productivity of the fleet and impact of fishing) and on the reconstruction of historical timeseries to expand our knowledge on historical references for the Belgian sea fisheries. In achieving this, it intends to counter the concept of 'Shifting Baselines' applied to the Belgian Sea fisheries. The ‘Historical Fisheries Database’ (HiFiDatabase) is a product of this thesis. It is the result of a thorough search, rescue, inventory, standardization and integration of data for Belgium’s sea fisheries that were not ...