Report of the Workshop on Sexual Maturity Sampling (WKMAT)

The Data Collection Regulation (DCR) programme covers extensive sampling of maturity stages, but uptodate results are rarely used in the assessment of the Spawning Stock Biomass SSB. In several cases, calculation of the proportion of mature fish is based on information collected far outside the spawning season, or on incomplete coverage of the stock distribution area. Market sampling, fishery independent stock surveys and observer programmes provide information on the timing of the spawning season. Samples shortly preceding, or in the early phase of the spawning season may achieve adequate spatial coverage. Improved sampling programmes, further analyses and consideration of the consequences of interannual variation in maturity on stock assessments, will further eliminate the current problems in the maturity sampling programmes.