Developing a decision support system for sustainable cage aquaculture

A decision support system to assist cage aquaculture managers is presented. The system enables managers to perform four essential tasks: (i) site classification, (ii) site selection, (iii) holding capacity determination, and (iv) economic appraisal of an aquaculture farm at a given site. Based on measurements of water and substrate qualities, hydrometeorology and socioeconomic factors, a cage aquaculture site is classified into three categories – poor, medium, and good. With this information, the AHP (analytical hierarchy process) tool is used to evaluate the best site from several alternatives. A simplified version of the Modelling-On growing-Monitoring (MOM), SMOM, is developed and applied to determine how much fish can be grown on site without harming the environment. The simplified model has been calibrated against MOM, compared with other carrying capacity models and validated with farm data. A break-even point–price and return on investment (ROI) are calculated using cage-holding density and volume, mean fish weight at harvest, feed conversion ratio (FCR), survival rate of seed, costs of feed, seed and cages, the interest rate on borrowed funds and the fish price. All model components are integrated seamlessly into a user-friendly interface implemented in Java® called CADS_TOOL (Cage Aquaculture Decision Support Tool). The program with a user's guide is freely available.