0023-6152

AA00697606

26159

査読無

0023-6152

AA00697606

To understand seasonal drifts and growth characteristics of anchovy (Engraulis japornicus) larvae in the South Sea of Korea, residual flows were estimated, and then two cases, without and with biological activity, were implemented into numerical simulations. Residual flows were closely related to local wind speeds and directions at surface or in shallow water. Residual flows appeared the strongest in the autumn and weakest in the winter. The patterns of residual flows offshore showed to be similar to that of the Tsushima Warm Currents. During the spring and summer, there was a tendency for larvae to be transferred westward when the southeasterly or southerly winds were dominant. Most larvae were drifted eastward via the currents and converged at the boundary between coastal water and offshore water. Summer had the highest biomass increase, affected by high temperature and high concentration of nutrients being transported from land due to high rainfall. On the other hand, winter had the lowest biomass increase due to low temperature. Spatially, the northern group showed much higher biomass increase than did the Jeju group due to the high concentration of nutrients distribution. The maximum biomass increase for larvae was 187 times after 30 days comparing to initial release, which is comparable to actual value. This study was performed as a preliminary experiment using numerical model to understand the movement and growth of anchovy larvae. The effectiveness of numerical model adaption was well verified by the results. Understanding the movement and growth of larvae for a target species is very important since it is closely related to the productivity of adult. In this respect, this experiment will be contributed as one of tools to study time and spatial movement and growth of larvae for a target species.