PH010
Manila Bay


Year of compilation: 2001

Site description
This IBA includes the extensive intertidal areas from the Municipality of Balanga in Bataan Province round the north and east shores of Manila Bay to Cavite City, south of Metro Manila. This large, enclosed sea bay is fringed by shallow intertidal mudflats and sand flats. Relicts of mangrove swamp survive, particularly in the Bataan area, but most have been converted to large areas of aquaculture ponds and salt pans. Plant communities in adjacent areas include coconut plantations and denuded hill vegetation. The city and port of Metro Manila is situated on the eastern side of the Bay. The site is very important for its fisheries production that supports a large urban population along the periphery of the Bay. There are high concentrations of fish traps and extensive mariculture within the open sea area, and aquaculture schemes cover about 70 km of the coastline. There is a salt pan industry at Cavite in the southeast, and several areas of shantytown development on the shores of the Bay.

Key biodiversity
Large numbers of migratory shorebirds uses the intertidal mudflats, fishponds and salt pans in Manila Bay in winter and during the migration seasons. Monthly counts at a high tide roost in Metro Manila in 1979-1982 revealed a maximum of about 32,000 shorebirds in January 1980, and in early April 1987, about 8,000 shorebirds of 20 species were recorded at seven sites, mainly drained fish ponds and areas of intertidal mudflat. It has consistently registered the highest numbers of waterbirds at any site in the Philippines during the Asian Wetland Counts in 1990-1994. There have been records of several threatened waterbirds there, but it is unclear whether this IBA is of significance for the conservation of any of these species.

Pressure/threats to key biodiversity
The many threats to Manila Bay include the destruction of the remaining patches of mangroves for aquaculture, reclamation of intertidal areas for housing development, road construction and salt pans, continuous dredging and pollution (solid waste, domestic sewerage, industrial waste, and oil spills). There is continued denudation of the natural vegetation in the water catchment area. The heavily polluted and silted Pasig River drains into the bay. Shooting of shorebirds at fishponds and dynamite fishing are additional threats to the bay’s biodiversity. Construction along the shoreline, especially in the Roxas Boulevard area, has disturbed the roosting areas of shorebirds, which have been forced to use alternative roosting places, such as the NAIA Complex.

Conservation responses/actions for key biodiversity
A considerable amount of research has been carried out by the National Pollution Control Commission in its Manila Bay Monitoring Project, which launched an anti pollution campaign jointly with the Haribon Foundation. Manila Bay is an ideal area for research on fisheries, wildlife, biomass and marine pollution because of its close proximity to major research agencies. The Bureau of Fisheries and Aquatic Resources has carried out some studies, and the Forest Research Institute and Asian Wetland Bureau (now Wetlands International) have conducted shorebird studies. The small pockets of mangrove swamp remaining in Pampanga Bay are of considerable value for research and conservation education. A Presidental Task Force for the rehabilitation of Manila Bay was created in October 1993 to provide a mechanism for the management of the bay. A comprehensive management plan was submitted to the Office of the President in 1994.

Protected areas
Not officially protected.

Habitat and land use
This IBA includes the extensive intertidal areas from the Municipality of Balanga in Bataan Province round the north and east shores of Manila Bay to Cavite City, south of Metro Manila. This large, enclosed sea bay is fringed by shallow intertidal mudflats and sand flats. Relicts of mangrove swamp survive, particularly in the Bataan area, but most have been converted to large areas of aquaculture ponds and salt pans. Plant communities in adjacent areas include coconut plantations and denuded hill vegetation. The city and port of Metro Manila is situated on the eastern side of the Bay. The site is very important for its fisheries production that supports a large urban population along the periphery of the Bay. There are high concentrations of fish traps and extensive mariculture within the open sea area, and aquaculture schemes cover about 70 km of the coastline. There is a salt pan industry at Cavite in the southeast, and several areas of shantytown development on the shores of the Bay.


Recommended citation
BirdLife International (2022) Important Bird Areas factsheet: Manila Bay. Downloaded from http://www.birdlife.org on 20/08/2022.