Numerical simulation of environmental effect on the transport of Japanese sand eel larvae by the seabed sand picking

Abstract

The Bisan Strait Sea in The Seto Inland Sea becomes one of the main spawning grounds of the sand eel. The sand eel catch lowers over 80% in spite of the decrease of the direct sand bank area by seabed sand picking in this sea area being about 13% in comparison with 1977 ages in 1998. Then, it was made that the effect of the change of water depth by the seabed sand picking on the transportation to growth field of Japanese sand eel larvae was evaluated according to the numerical model to be a purpose for the Japanese sand eel larvae in the time in which self swimming force in the Bisan Strait sea is scarce. As the result, it was indicated that Japanese sand eel larvae transported to the growth field in the Bisan Strait west sea decreased about 17% according to the numerical model.