Optimal Harvest Schedule for Maricultured Shrimp: a Stochiastic Sequential Decision Model

Abstract

Successful introduction of advanced intensive technology in shrimp mariculture requires the appropriate management tools. This report presents a management model for determining the optimal stocking and harvesting schedules for a shrimp pond of a mariculture shrimp operation. The developed model is an extension of the classical growing inventory model. It provides a set of simple intra- and interseasonal decision rules expressed as cutoff revenue when both price and weight are assumed random, and as cutoff price or cutoff weight when either price or weight is assumed random. If current realized revenue is less than the cutoff revenue, the decision is to keep the crop and delay the decision to sell for another period; otherwise, the decision is to sell. Application of this model to a hypothetical shrimp farm in Hawaii with 24 0.2-ha round ponds indicates that net return can be increased three times by applying the derived optimal policies, compared with a conventional fixed scheduling scheme. The economics of controlled environment is also evaluated using the model.