The domestic and foreign trends of offshore aquaculture were reviewed based on the results of interviews and internet survey to overview its future directions. Regarding large-scale offshore aquaculture, there are two strategies; (1) the conventional aquaculture system that combines multiple cages and feeding platforms is enlarged and expanded, and (2) a super-large aquaculture system with a production capacity of 10,000 tons per year is newly developed. In addition, semi-closed or closed Recirculating Aquaculture Systems (RAS) on the sea is becoming conspicuous. On the other hand, regulatory uncertainty such as a permitting issue to use sea area has been identified as one of the main barriers to offshore aquaculture development. Technological development and systemization are also required to promote offshore aquaculture. Prospects include collaboration between offshore aquaculture and renewable energy industries such as offshore wind power generation. Including the permitting issue, Marine Spatial Planning (MSP) is expected to utilize the marine space in versatile and effective way. From a view of aquaculture in harmony with the surrounding environment, Integrated Multi Trophic Aquaculture (IMTA) is one of the promising measures for offshore aquaculture as well as for aquaculture in protected seas. It will be difficult to secure the feed if the offshore aquaculture develops rapidly. Several researchers are interested in enhancing marine productivity and producing fish oil and meal using deep sea water with rich nutrients upwelled by renewable energy.
