Effects of Infilling a Sea Caldron on Tidal Currents and Seaweed and Seagrass Bed Habitats

Abstract

  To investigate changes in tidal current arising from infilling a sea caldron and their influence on seaweed and seagrass bed habitats, numerical simulations of tidal current before and after infilling the sea caldron were carried out using a multi-level flow model. Separate simulations were conducted for stages of infilling to clarify stepwise changes in flow field, and changes in horizontal and vertical velocity distributions at the sea caldron were examined. Effects of changes in flow field on the seaweed and seagrass bed habitats around the sea caldron were also investigated. The results indicated that velocity distributions at both ends of the sea caldron changed in the final stage of infilling, while those at the center gradually changed as the filling progressed. The changes in flow field at the seaweed and seagrass beds were found to remain within the inhabitable range for the species present.