The technical development of environmentally sustainable forms of production is progressing rapidly in the field of aquaculture, in terms of both the more traditional open systems and the more recent, semiclosed and closed production systems. Different techniques are appropriate in different habitat types, but a number of techniques may also be appropriate for one and the same habitat. Furthermore, the most appropriate technique also varies depending on the species and size of the fish that are farmed. A number of production systems with potential are still merely at the prototype stage, but many others are undergoing constant development and are being operated on a lesser commercial scale as they undergo technical development.
This report provides a review of existing knowledge and an overview of various farming techniques that are currently in use at commercial fish farms, being tested on a smaller scale or at the prototype stage; but all of them could potentially be used in Sweden. The report also includes a description of the general environmental impact of the various technique types, focusing in particular on aqua feed ingredients currently used in aquaculture, and some potential feed ingredients for the future. The farming techniques are undergoing constant, rapid development in terms of water treatment systems, facility types, water consumption, diversification of species, integration between species, and so forth. These new techniques offer major potential for reduction of environmental impact, but they but may need to be developed through continued research and technical innovations.