Interspecific Differences in the Recovery of Rocky Intertidal Zonation after the 2011 Great East Japan Earthquake

Both natural and anthropogenic disturbances have significant impacts on populations in terrestrial and marine habitats. Despite evidence that population recovery after large-scale disturbances in terrestrial habitats varies substantially among species depending on species traits and types of disturbance, little is known about interspecific differences in population recovery in marine habitats. In this study, we evaluated the course and status of recovery of the vertical distribution of nine intertidal sessile species over 6 years following the 2011 Great East Japan Earthquake. First, we characterized temporal changes in the vertical position of zonation as the spatial distribution, and total coverage as the local population size after the 2011 earthquake. Then, we evaluated the differences in successional status that explain interspecific differences in zonation recovery speed. Finally, we revealed that temporal changes in the vertical position and abundance after the earthquake differed according to species. The interspecific differences in the speed of recovery of zonation after 2014 were correlated with successional status, with later successional species having a delayed recovery rate. These results indicated that intertidal sessile assemblages continued to change 6 years after the large earthquake, suggesting that evaluations of the impacts of disturbances on assemblages and the course of community recovery require long periods of time.