This paper describes an experimental large-scale, high-rise artificial reef designed by the authors with the intention of developing an offshore fishing ground in deeper waters and a large-scale, high-rise reef for practical use based on application of the results obtained from the experiments. The experimental reef, the world's largest artificial reef with a height of 35m and 4,000m3 in volume, is located 20km off Nezugaseki, Yamagata Prefecture, in the northem part of the Sea of Japan, in the neighborhood of a natural reef (Ohse Reef) known as an excellent fishing ground for red sea bream (Pagrus major). Observation by diving and trial fishing have shown that a large number of fish of various species gathered and stayed around this artificial reef. The reef is now being used in practical operation, and similar artificial reefs are being built in many other fishing grounds.
