To understand spatio-temporal distributions of jellyfish in Masan bay, a three-dimensional hydrodynamic model, POM, was applied in coupling with Lagrangian particle tracking model.
The hydrodynamic model considered tides, wind temperature and salinity. First, the tidal currents was northwestward at flood tides and southeastward at ebb tides. Wind are applied with average velocity and frequent direction. Temperature and salinity are reproduced from field data and marine environment measurement data. The result of residual flows that considered tides, wind, temperature and salinity appeared rotation and multi-direction flows.
For particle tracking model, 100 particles are released separately at Masan port, Heavy industry and Gapo new port which exist concrete structures. The sea areas are divided A, B, C and D. A is located north of Dot-island which flows slowly, B is located between Dot-island and Machang-bridge, C is located between Machang-bridge and entrance of Masan bay, and D is located outside of bay. Spatial distribution of jellyfish is higher than other sea areas according to time. It seemed to be affected residual flow and depth of Machang-bridge. Vertically, distributions of surface and middle layer are higher than bottom layer. Compared with Masan port and Heavy industry which are located on same latitude, jellyfishes are much flowed in Masan port because of seawater movement. About 38% Particles that considered residual flow are flowed to outside of bay after 15 days. We tried numerical experiments considering only the respective physical factors of tidal residual currents, drift currents, density currents, and residual currents in sea area that residual currents are dominant. Consequently, we confirmed that the effect of the wind is superior components to agglomerate jellyfish.