Abstract
Field observations were performed to know the characteristics of flow and transport of materials in a mangrove area located in Ishigaki Island, in which geographical features, vegetation, water qualities, characteristics of soils and flow were measured by using various devices. At spring tide, organic materials and nutrients which have been provided by the mangrove forests are exported to the coastal area during low tide. On the contrary, the seawater which contains a large amount of dissolved oxygen moves toward the mangrove swamp during high tide. These results suggest that these transports of organic materials, nutrients and dissolved oxygen support biological activity in the mangrove and the coastal areas.
