THE CAUSE AND NEGATIVE EFFECT OF "SINKING EVENT" ON A MUD SNAIL BATILLARIA CUMINGI IN AN ARTIFICIAL TIDAL FLAT

Abstract

An artificial tidal flat was created to compensate for the loss of a natural tidal flat in Okinosu, Tokushima City, Japan; however, the ecological conditions of benthic animals in the artificial habitat differ extensively from those of benthic animals in the natural habitat. In particular, the mud snail Batillaria cumingi, which overwhelmingly dominated the natural tidal flat, was rarely found in the created habitat. We confirmed that a "sinking event" occurred only in the artificial tidal flat. The "sinking event" caused B. cumingii to sink into the sediment and decreased the survival rate. Our study suggested that the sinking event was caused by the lack of silt content in the sediment of the artificial habitat.