Bamboo reefs were set on a tidal flat in the western part of the Seto Inland Sea on May 27, 2006. To examine the propagation effect, various experiments were carried out. From inside the bamboo reef, animals were monitored using an underwater CCD camera during spring tides in August, September, November 2006, January, April, and May 2007. A total of 5,640 individuals were observed (22 fish species and 2 cephalopod species). And fishes are feeding plankton inside bamboo reefs, sessile organisms on the bamboo branches and epifauna, infauna in sand bottom. A total of 3,731 individuals were observed by SCUBA diving around the bamboo reefs (26 fish species, 2 mollusk species, 2 arthropod species, and 4 cephalopod species). Also Sepia lycidas eggs on branches of bamboo in June 2006. Previously Apostichopus japonicus had not existed in the study area. These are observed on March 2007 and collected 457 individuals (95% interval estimation is 1,763 to 2,560 individuals) on May 2007. Mean standard body length of Apostichopus japonicus of green type was 59.3 mm and black type was 57.5 mm.