No abstract

To promote utilization of Okinotorishima island and its surrounding areas mainly in the fishery field, fishery resources and environmental conditions were surveyed in and around the coral reef of the island. Corals were widely distributed in the lagoon. Some useful fishery species were caught through the wide range from the surface to the deep water around the reef. Their preys such as eggs, juveniles and young of some small sized fish species were also observed there. Therefore, it may be possible to utilize the island as a good fishing ground with an artificially increased primary production. To develop this potential, some ideas and their issues to be solved in the future were discussed in this study.

No abstract

This report introduces the outline of the technical development about coral propagation.

We confirmed that high coral community cover in top-shell snail (Tectus niloticus) aquaculture structure installed in the northern part of Miyako-jima Island, Okinawa prefecture. The purpose of this study is to grasp the reason why the structure has been functioning recruitment and growth of coral. As the results, it was suggested that the lattice structure in top-shell snail aquaculture structure functioned effectively recruitment of a coral larva. In addition, it was suggested that the measure-shaped structure functioned as to damp current speed at the time of the high surge and it has contributed to the growth of coral.