Highly Skewed Tidal Circulation Pattern and Water Quality in Puerto Galera Bay, Mindoro Island, Philippines

Abstract

Coastal waters in and around Puerto Galera Bay, Mindoro, Philippines, is drastically contaminated generally due to poorly constructed sanitation and household facilities and runoff from the hillsides associated with the tourism development. In this study, a field survey on tidal currents and water quality in and around Puerto Galera Bay was conducted with hydrodynamic numerical simulations of tidal currents, in which a nesting technique was employed for properly incorporating the effects of complicated tidal fluctuation outside the bay. The results reveal the existence of a highly asymmetrical pattern of tidal flow fluctuation having strong tidal residual flow and the vulnerability of the flow field to water quality deterioration within the semi-enclosed innermost bay area. The highly asymmetrical tidal flow fluctuation is attributed to the asymmetrical generation of detached eddying motion around Puerto Galera as a highly nonlinear phenomenon producing strong tidal residual currents. These results are useful in understanding the physical conditions of the bay, which are needed for consideration in the local government's coastal management plan.