| Stock assessment models generally rely upon catch analysis. Catches are estimated from the sampling of landings. The evaluation of the variance associated to these estimators allows to study the induced uncertainty on models results and hence on stock management decisions. Moreover, the sampling scheme may be improved by analysing the variance components. The results show that the variance is mainly due to the variability of landings between days. In addition, as assessment models show liUle sensitivity to old age groups, sampling effort could be partially transferred from the corresponding market category to those of major economie interesl. |
