Species-diverse coral communities on an artificial substrate at a tuna farm in Amami, Japan

► Bluefin tuna farming and breeding is conducted on coral reefs in Japan. ► In the farm, 6-cm-diameter rope is moored 3-m below the surface in 50-m-deep water. ► Sixty coral species grew on the suspended ropes. ► The coral community on the rope was species-diverse, dominated by massive faviids. ► The tuna-farm provided coral habitat in an area where Acanthaster planci destroys corals.