Does selectivity matter? A fisheries management perspective

The authors’ experiences in relation to the estimation of selectivity and its impact on the formulation of management advice are summarised for 14 different resources. These include instances where advice (generally in the form of a catch limit) is based on an assessment, as well as cases where a Management Procedure is developed (applying MSE) for this purpose. Relative paucity of older fish in either or both of catches or surveys is a frequent occurrence which has a number of alternative explanations, including doming in selectivity, and estimates of many biological reference points are not robust to this uncertainty. However, when the impacts of uncertainties in estimating selectivities are considered relative to those of the other uncertainties which also influence the calculation of catch limits, the former usually (although not always) seem to be of somewhat lesser importance.