[A-CG33] Land-Ocean Interaction -Water and material cycle for coastal ecosystems-

[ACG33-06] The influence of groundwater discharge on primary production in a shallow coastal sea, Obama bay,Japan

*Shiho KOBAYASHI¹, Ryo SUGIMOTO², Youji MIYATA¹, Hisami HONDA³, Makoto YAMADA³, Osamu TOMINAGA², Daisuke TAHARA², Jun SHOJI⁴, Makoto TANIGUCHI³ (1.Kyoto University, 2.Fukui Prefectural University, 3.Research Institute for Humanity and Nature, 4.Hiroshima University)

Keywords:land-ocean interaction, submarine groundwater discharge, costal ecosystem, primary production

Submarine groundwater discharge (SGD) often influences on biogeochemical properties in coastal seas. We observed spatial and temporal variations in SGD using ²²²Rn and seepage meter along the shoreline of Obama bay, Japan. The results showed SGD exists even in the shallow sea adjacent to the small water catchment area (~ 1 km²), where the range of the tide is relatively small (10 ~ 30 cm). The spatial and temporal variations in chlorophyll observed at the same time suggest that the SGD influences on primary production.