[A-HW22] Material transportation and cycling at the land-sea interface: from headwaters to the ocean

[AHW22-03] Effects of terrestrial water and material transport on blue carbon ecosystems in a coastal island scale

*Mitsuyo Saito¹, Shin-ichi Onodera¹, Mayuko Hamada², Fujio Hyodo², Takuya Akinaga^3,4, Nhat Hong Nguyen³, Qidi Gao¹, Reiya Matsubara⁵ (1.Graduate School of Advanced Science and Engineering, Hiroshima University, 2.Faculty of Environmental, Life, Natural Science and Technology, Okayama University, 3.Graduate School of Life and Environmental Sciences, Okayama University, 4.NEWJEC Inc., 5.School of Integrated Arts and Sciences, Hiroshima University)

Keywords:Submarine Groundwater Discharge (SGD), Blue carbon, Coastal ecosystems, Watershed

Seagrass-seaweed meadows (hereafter SSM) are regarded as an important coastal ecosystems with several ecosystem services, such as carbon capture (blue carbon). In this research, we aimed to examine the effect of terrestrial water and material transport on the blue carbon ecosystems in an island of Seto Inland Sea, western Japan. We succeeded in mapping the spatial distribution of SSM by the imagery analysis using UAV (Unmanned Aerial Vehicle; drone) including tidal flat areas and the evaluation of fish diversities applying environmental DNA technique. We confirmed that both river and submarine groundwater discharge (SGD) influcence on the spatial and temporal variation in SSM ecosystems as the pathways of water and materials from watersheds.