Cage culture in Japan toward the new millenium

The history of cage culture in Japan dates back to about 200 years ago with the primitive wooden frame net cage for anchovies or sardines as the bait for skipjack pole and line. This type of net cage was employed for yellowtail farming and developed in various areas of Western Japan. Recent development of cage culture in Japan can be summarized with the statistical data of marine species such as yellowtail, red sea bream, coho salmon, horse mackerel, striped jack, flatfish, and puffer. Total production of these fish was about 250,000 tons worth 282 billion yen in 1997. Some technical matters for the cage structure regarding size, materials, and shapes as well as the feeding systems will be illustrated, together with the recent research and development projects on the new concepts of the large-scale cage for tuna farming and the submersible cage for abalone farming. Two projects by the Marino Forum 21 are also introduced; the farming platform and the air bubble curtains and acoustic guiding for behaviour control in marine ranching. For purposes of live fish marketing and price control, highlights are given on the net cage attachment to the large set-net fisahing gear, and on the cage-combined set-net as the latest challenge in the coastal fisheries. Finally, recent developments on the conservation issues or responsible aquaculture are also discussed