Study Area

Manila Bay is a semi-enclosed bay located on the southwestern coast of Luzon Island, Philipines between 14°50′N and 120°76’E (Siringan et al., 2008). It encompasses an area of nearly 1800 km^2 and a coastline of approximately 190km (Siringan et al., 2008). Presence of blooms will specifically be observed in the upper region of the bay, focusing on nearshore plume concentrations. The upper region, including provinces Pampanga and Bulacan, is extremely prone to red tide incidences due to the unprecedented level of freshwater incursion from the Pampanga River (Azanza and Miranda, 2001). Of the 800m^3/s of fresh water that is drained into Manila Bay, the Pampanga River alone is responsible for 49% of the input (Siringan et al., 2008). The hydrodynamics of the bay is distinguished by a two-gyred circulation pattern originating from the western and eastern coasts of the bay, which subsequently, feeds the two main sources of bloom formation in the bay (Villanoy et al., 2006).

Figure 1: Map of Manila Bay showing where the Pampanga River and its main tributary drain into the northwest region of the bay. Star represents the specific coordinates from which cursor values were taken.