Optimal stocking and harvesting of size-structured farmed fish: A multi-period linear programming approach

Abstract

In this paper, a new approach to the production planning problem in fish farms is developed. Production planning problems include: the determination of the optimal number of fry to transfer into the grow-out system, the estimation of population growth and production costs, and the determination of the optimal harvesting schedule in order to maximise profits from the operation. Fish growth has been modelled as a series of transitions through different size-classes. The probability of an individual belonging to a certain size-class at a given future time can then be estimated. Both the growth model and the minimum feed requirements of fish can be determined as linear functions of fish growth. A multi-period linear programming model was then developed to optimise the number of fry and number of harvested individuals from various size-classes, that maximises the net present value of the fish stock.