Report of the Workshop on Optimization of Biological Sampling at Sample Level (WKBIOPTIM)

The Workshop on Optimization of Biological Sampling at Sample Level (WKBIOP-TIM), chaired by Ana Cláudia Fernandes (Portugal) and Julie Coad Davies (Denmark) was held in Lisbon, Portugal, 20–22 June 2017. Twenty-two participants from 12 coun-tries within the ICES and Mediterranean communities were representedThe workshop focused on practical aspects of optimization of sampling. Prior to the workshop, two sets of R-scripts were developed that used the current exchange format of the Regional Database (RDB) as input. The first set of scripts is useful for cases where there is considerable a priori evidence of oversampling (e.g. several hundreds of meas-urements per sample over a relatively short size/age-class range). The script imple-ments simulations of several types of sampling strategies (user defined) and produces a set of graphical and numerical outputs that allow the visualization of the conse-quences of measuring different number of individuals per sample. The second set of scripts can be used to determine the number of fish, hauls and trips that should be taken without significant loss of precision in the final estimates. In both cases scripts were prepared to use “lengths” as the biological parameter to be analysed but can be extended to other biological parameters, like age distribution or discards.