1997 Volume 34 Issue 2 Pages 147-154
Transport processes of pelagic eggs and larvae of brown sole (Pleuronectes herzenseini) from the spawning ground near the Sado Strait in Sea of Japan were investigated using an Euler-Lagrangian numerical model. Since coastal currents under the wind influence and the interaction of vertical movement of eggs and larvae with the currents could have significant effects on the transport, numerical simulations using three types of wind conditions (north wind, west wind and west-south-west wind: the wind speed is 4m/s in each case.), two kinds of inflow condition (fast and slow), and two pattems of vertical movement (passive and active) were made to explore their influence on the transport process. The retention rate, which indicates the percentage of eggs and larvae retained in shelf areas shallower than 100m, ws calculated for each case. The retention rates under the westerly winds are appreciably high compared to those under the north wind. However, when the westerly wind speed is over 5m/s, the rates for the cases of passive movement rapidly decrease. On the other hand, the rates for the cases of active one are maintained as 100% even under the strong Winds, because the eggs and larvae tend to be transported along the shore line. This suggests that westerly winds, which are generally dominant during the spawning period of brown sole, could enhance the larval retention in the coastal water in combination with the vertical migration of larvae.
