LIFE CYCLE IMPACT OF INDUSTRIAL AQUACULTURE SYSTEMS: A REVIEW

The capture fishery production has overexploited the wild-fish stocks and global demand for aquatic products is still increasing. Industrial aquaculture systems, such as marine net-pen, have a life cycle (LC) impact most of which is due to the energy needed to produce feed, and to the marine biotic resource overexploitation. To this regard, it should be worth calculating the primary production required (PPR) indicator to account for the impact of these production systems. Following the PPR approach, a three times higher value could be estimated respect to the life cycle assessment (LCA) method that underestimates the marine biotic impacts of fishery products. LCA is often referred to as "cradle to grave" analysis. On the contrary, the system boundaries of LCA of aquaculture systems studies are 'from cradle to farm-gate', thus avoiding the analysis of the subsequent processing, wholesaling, retailing, preparation and disposal of the fish. Anyhow, among the aquaculture systems, conventional marine net-pen has the lowest impact, while typical land-based freshwater recirculating system has a much higher impact, due to a large use of materials and energy, at least an order of magnitude higher than those of the net-pen. Nonetheless, the life cycle environmental impacts of a land-based freshwater recirculating system are very sensitive to the primary energy mix used to generate electricity.