Abstract
An artificial tidal flat was created in 2007, to compensate for the loss of a natural tidal flat, at Okinosu, Tokushima City. However, five years after its creation, it was found that the ecological conditions in the artificial habitat of benthic animals differed vastly from those in the natural habitat. In particular, the mud snail Batillaria cumingi, which dominates natural tidal flats, was rarely found in the artificial habitat.
We tested the hypothesis that the “sinking event” was caused due to bioturbation by the ghost shrimp, Nihonotrypaea japonica. The “sinking event” occurred only at the places where N. japonica was abundant. Therefore, it seemed that bioturbation by N. japonica was the cause of the “sinking event”. Although exclusive treatment with N. japonica led to a low-biodiversity assemblage, N. japonica has both positive and negative effects on the tidal flat ecosystem.
