Dredging the raceway. Dredging area to develop the good ship channel. 2 steps moving soil sediment from the bottom water and dumped sediment. Led to increased sediment and suspended solids in the water. To increase the turbidity of water changes in physical characteristics of bottom water. (if the dumped sediment in the sea change is caused by the accumulation of sediment). Case left sediment on may cause changed the hydrology of the area, such as the ทิศทางการ flow of surface water Changes in the nature ocean coast. The spread of nutrients and toxic substances. The change of the plant and the creatures that live on the water.