Spatial pattern of coral diversity in Luhuitou fringing reef, Sanya Growth variations of scleratinan corals at Luhuitou, Sanya, Hainan Island, and the impacts from human activities CURRENT SITUATION AND DYNAMICS OF SPECIES DIVERSITY IN HERMATYPIC CORAL COMMUNITY ON LUHUITOU FRINGING REEF STUDY ON THE SPECIES DIVERSITY OF THE SCLERATINAN CORAL COMMUNITY ON LUHUITOU FRINGING REEF