Endogenous fisheries management in a stochastic modelwhy do fishery agencies use TACs along with fishing periods?

Résumé

The aim of this paper is to explain under which circumstances using TACs as instrument to manage a .shery along with .shing periods may be interesting from a regulatory point of view. In order to do this, the deterministic analysis of Homans and Wilen (1997) and Anderson (2000) is extended to a stochastic scenario where the resource cannot be measured accurately. The resulting endogenous stochastic model is numerically solved for .nding the optimal control rules in the Iberian sardine stock. Three relevant conclusions can be highligted from simulations. First, the higher the uncer- tainty about the state of the stock is, the lower the probability of closing the .shery is. Second, the use of TACs as management instrument in .sheries already regulated with .shing periods leads to: i) An increase of the optimal season length and harvests, especially for medium and high number of licences, ii) An improvement of the biological and economic variables when the size of the .eet is large; and iii) Eliminate the extinction risk for the resource. And thir