Social net benefits from aquaculture production: A comparison of net cage cultivation and recirculating aquaculture systems

This paper applies cost-benefit analysis to assess social and private net benefits from rainbow trout and European whitefish aquaculture under recirculating aquaculture system (RAS) and marine net cage technologies. In addition to private investment and operational costs, we include eutrophication damage from nutrients and value the fish produced by its producer price. The assessment is made in terms of annualized present value of net benefits. We find that net cage production outperforms RAS by a wide margin for rainbow trout production. For the European whitefish, RAS narrows this gap considerably, but net cage production still receives higher net benefits. We extend our discussion to the specific challenge of the Weser ruling of the EU's Water Framework Directive, which effectively hinders expansion of aquaculture production, and examine whether one-time offsets would provide aquaculture the possibility to expand production. We find that one-time offsetting provides higher net benefits compared to not offsetting with both technologies but is easier to execute for RAS.