福島県環境創造センター
Fukushima Environmant Creation Center

We report on the impacts of the 2011 tsunami disaster on tidal flat ecosystems along the northeastern Japanese coast. Habitat structure was drastically modified by the tsunami, seismic subsidence, and/or liquefaction, resulting in intensive changes of associated biota. Although the biotic community has gradually recovered over the past 5 years, ongoing restoration projects are emergent threats for coastal ecosystems. Surveys revealed that several tidal flats in semi-enclosed bays are distinguished as key habitats for endangered macrozoobenthos, such as Cerithioidea gastropods and the marsh crab Chasmagnathus convexus. We also found that an estuarine system (the Samegawa River) in southern Fukushima Prefecture maintained a high diversity of endangered macrozoobenthos even after the tsunami. These key areas should be preserved as habitats for source populations in the meta-population network, for future conservation of biodiversity in tidal flats.