Re-opening Criteria for Flemish Cap Cod: a Survey-based Method by

One of the main difficulties in the assessment of closed fisheries is the lack of catch data needed to perform a VPA; nevertheless, assessment is necessary in order to advise for re-opening in the framework of the Precautionary Approach. In this situation, advise is usually based on survey trends, and the problem of not knowing the true abundance is translated to the advise as an increase of uncertainty. Nevertheless, when there was a calibration by a VPA assessment in the past, those catchability figures can be used to scale the current survey results and obtaining an estimation of the true abundance, more convenient for a precautionary advise. This paper proposes a way to manage survey information, using the Flemish Cap cod stock as an example. A stochastic simulation including estimates of errors in survey abundance and catchability at age is presented. The method, based in a stochastic design, yields a spawning stock biomass cumulative distribution ready to compare with Blim in probabilistic terms