Analysis of the contribution of the Netherlands commercial CPUE data to ICES stock assessments in the years 1995 - 2000

The contribution of the Dutch commercial CPUE data to the stock assessments of North Sea plaice and sole in the years 1995-2000 has been analysed. The CPUE series are based on the total landings at age in the Dutch beam trawl fishery and the total effort (in HP days at sea) of this fishery. It is shown that the contribution of the sole CPUE data to the final XSA assessments is higher that the contribution of the plaice CPUE data. It is discussed what the general role is of commercial CPUE data in the calibration process of a stock assessment model. The reason for the higher contribution of the sole CPUE data is explained. It is further discussed what the potential caveats are for the use of commercial CPUE data and how that applies to e.g. North Sea plaice.