Spatial Variability of Grain Size and Organic Matter in the Nagura Ampal Ramsar Estuary of Ishigaki Island, Japan: Implications for Tidal Flat and Mangrove Evolution

Dhiva Althaf Pratama1, Wataru Sano2 and Hironobu Kan1, (1)Kyushu University, Graduate School of Integrated Sciences for Global Society, Fukuoka, Japan, (2)Okayama University, Faculty of Education, Okayama, Japan