Traditionally, the approach used in the assessment of new fisheries has been based on research surveys, making it possible to estimate the standing stock and potential yield of a resource by coarse methods. The main aim of such surveys is to monitor fishing operations in order to develop a comprehensive sampling design which will provide data in line with assessment procedures that are quite similar to those commonly used in the statistical sampling theory. These procedures are, to a certain extent, limited by the complex fishing strategies of the operators and by the movements of fish stocks, which seriously affect model assumptions. This paper demonstrates that for the new fishery, analyses using catch-at-age data derived from research cruises may provide an alternative to other methods of estimating the parameters of fish stocks. This alternative method is applied to the new fishery of Dissostichus eleginoides off the south of Chile which is being conducted in accordance with CCAMLR regulations.