Influence of wave energy on Holocene coral reef development: an example from Ishigaki Island, Ryukyu Islands, Japan

Wave energy induced by ocean swell and local winds is an important factor controlling the coral reef development. Here we compare and contrast facies, ages, and accretion rates of reefs that developed independently along windward and leeward margins of the same island. As both reefs face the open ocean, swells provide a background of low- to medium-energy condition with additional energy along windward margins due to prevailing winds. This similarity of the wave-energy regimes (medium to high energy) produced a similar framework facies that was constructed by robust-branching Acropora. However, much greater lateral accretion rates were observed in the high-energy reef than in the medium-energy reef. Also, coral cobble facies were only found in the medium-energy reef, indicating that the reef framework was more susceptible to storm breakage than that in the high-energy reef. These differences are attributable to the differing biological and ecological responses of corals to wave energy and water motion.