Placement of Floating Net Cages Cultivation System Based on Current Dynamics Model in the Semak Lagoon, Indonesia

This research examines the dynamics of 3-dimensional flow and the placement of floating cages in the Semak Daun Lagoon (SDL). The research was carried out using 3-dimensional current modeling process, which is designed in four tidal conditions model in accordance with the wind and tidal pressure generation. Furthermore, this research used the discretization method to vertically determine the finite volume and sigma coordinates, therefore, the whole domain was 43,575 triangular elements. The acuration of model showed by a MAPE value of 9.9%, its shows model is a very good category. The results of the model showed that the monsoons do not have a significant effect on the current pattern and velocity in SDL, however, the dominant current dynamics are influenced by tides. In addition, the current pattern in SDL waters generally moves from the Southwest to the Northeast at low tides and vice versa. In all tidal conditions, downwelling and upwelling occurred in the middle of the lagoon, with the current pattern and velocity significantly affected by Bathymetry. Surface and vertical current velocities range from 0.002 - 0.600 m/s. However, the current velocities of 0.10 - 0.20 m/s were only found at -2 m depth. Meanwhile, the optimum current velocity for marine cultivation activities is 0.10 - 0.50 m/s, therefore the utilization of SDL waters for floating net cage system cultivation is more optimal at a depth of -2.3 m.