Recovery of macrobenthic communities in tidal flats following the Great East Japan Earthquake

Abstract

Abstract The Great East Japan Earthquake, with a moment magnitude scale of 9.0M on March 11, 2011, caused huge tsunamis that altered aquatic communities in the nearshore ecosystems along the Pacific coastline of Sendai Bay, Japan. However, to understand the ecological implications of the tsunamis' impact, an assessment of the successive changes of the communities and their fate over time is essential. Therefore, we examined eight tidal flat communities of Sendai Bay with the aid of citizen volunteers over 9 years, and compared the microbenthic compositions to those before the earthquake. The results revealed that the differences in the community compositions caused by the tsunamis decreased from year to year and finally disappeared after 7 years except for one flat where the tsunamis largely changed the environmental conditions. The present study indicates that these tidal flat communities are regulated mainly by environmental conditions and are highly resilient to tsunami disturbance.