[A-CG50] [JJ] Coastal Ecosystems -- 2. Coral reefs, seagrass and macroalgal beds, and mangroves

[ACG50-P04] Verification of Seagrass Beds recovery in the inner part of Otsuchi Bay, Iwate prefecture, where the distribution decreased due to the tsunami associated with the 2011 off the Pacific coast of Tohoku Earthquake

*Yoshiyuki TANAKA¹, Hideki FUKUDA², Toshihiro Miyajima³ (1.Center for Liberal Arts and Sciences, Hachinohe Institute of Technology, 2.Coastal Conservation Section, International Coastal Research Center, Atmosphere and Ocean Research Institute, The University of Tokyo, 3.Marine Biogeochemistry Group, Division of Ocean-Earth System Science, Atmosphere and Ocean Research Institute, The University of Tokyo)

Keywords:recovery, Zostera marina

The Sanriku coast of Japan was struck by a massive tsunami associated with the 2011 off the Pacific coast of Tohoku Earthquake on 11 March 2011. The tsunami caused large disturbances in ecosystems along the coasts. Especially, seagrass beds located in inner part of Otsuchi Bay, Iwate prefecture, was seriously damaged.
We have been investigating seagrass beds coverage using CCD camera and have been analyzing temporal changes. We also have been analyzing water qualities such as nutrients and suspended solids.
Two Zostera species, Zostara marina and Z. caulescens were observed at the study sites. After the tsunami attack, seagrass beds coverage was hardly recovering for 5 years. However, recently trend of recovery was detected. We will present the possible cause of this delayed recovery of seagrass bed coverage.