The biophysical costs of technology: Assessing the environmental impacts of alternative salmonid culture systems in Canada using life cycle assessment

This study employed Life Cycle Assessment (LCA) to quantify and compare the potential environmental impacts of culturing salmonids in a conventional marine net-pen system with those of three reportedly "green" alternatives; a marine floating bag system; a land-based saltwater flow-through system; and a land-based freshwater recirculating system. Results of the study indicate that while the use of these alternative systems may reduce the local ecological impacts typically associated with net-pen salmon farming, the increased material and energy demands of these closed-containment systems may also result in substantial contributions to several environmental impacts of global concern, including global warming, resource depletion, and acidification. While these systems are currently being promoted as environmentally-friendly alternatives, this study reveals that there may be unintended environmental consequences associated with their use that should be considered in any further evaluation of their environmental performance.