Manila Bay (; ) is a natural harbor that serves the Port of Manila (on Luzon), in the Philippines. Strategically located around the capital city of the Philippines, Manila Bay facilitated commerce and trade between the Philippines and its neighboring countries,Jacinto, G.S., Azanza, R.V., Velasquez, I.B. and Siringan, F.P.(2006)."Manila Bay:Environmental Challenges and Opportunities" in Wolanski, E.(ed.) The Environment in Asia Pacific Harbours. Springer: Dordrecht, Netherlands. p309-328. becoming the gateway for socio-economic development even prior to the Spanish period. With an area of , and a coastline of , Manila Bay is situated in the western part of Luzon and is bounded by Cavite and Metro Manila on the east, Bulacan and Pampanga on the north, and Bataan on the west and northwest.Jacinto, G.S., Velasquez, I.B., San Diego-McGlone, M.L., Villanoy, C.L. and Siringan, F.B.(2006)."Biophysical Environment of Manila Bay - Then and Now", in Wolanski, E.(ed.)The Environment in Asia Pacific Harbours. Springer: Dordrecht, Netherlands. p. 293-307. Manila Bay drains approximately of watershed area, with the Pampanga River contributing about 49% of the freshwater influx. With an average depth of , it is estimated to have a total volume of . Entrance to the bay is wide and expands to a width of . However, the width of the bay varies from at its mouth and expanding to at its widest point.
The islands of Corregidor and Caballo divide the entrance into two channels, about towards the North and wide on the South side. Mariveles, in the province of Bataan, is an anchorage just inside the northern entrance and Sangley Point is the former location of Cavite Naval Base. On either side of the bay are volcanic peaks topped with tropical foliage: 40 km to the north is the Bataan Peninsula and to the south is the province of Cavite.
Across the entrance to Manila Bay are several islands, the largest of which is Corregidor, located 3 kilometers from Bataan and, along with the island of Caballo, separates the mouth of the bay into the North and South Channels. In the south channel is El Fraile Island and outside the entrance, and to the south, is Carabao Island. El Fraile, a rocky island some in area, supports the massive concrete and steel ruins of Fort Drum, an island fortress constructed by the United States Army to defend the southern entrance of the bay. To the immediate north and south are additional harbors, upon which both local and international ports are situated. Large numbers of ships at the North and South harbors facilitate maritime activities in the bay. Being smaller of the two harbors, the North Harbor is used for inter-island shipping while the South Harbor is used for large ocean-going vessels.
History
Manila Bay was connected to Laguna de Bay (pronounced "bai") approximately 3,000 years ago. Recurring episodic uplifts along the West Marikina Valley FaultJaraula, C.B., Siringan, F.P. (2004). Multi-proxy reconstruction of Late Quaternary evolution of Laguna de Bai, Philippines. (Submitted to Palaeogeography, Palaeoclimatology, Palaeoecology). caused the two to break up. Interaction between Manila Bay and Laguna de Bay today occurs only through the Pasig River. The bay was the setting for the Battle of Manila Bay in 1898, in which American troops led by Commodore George Dewey seized the area. This battle showcased the United States' naval strength. All major Spanish ships were destroyed and captured.de Castro, J.A.I. (2010). "Cleaning Up Manila Bay: Mandamus as a Tool for Environmental Protection". Ecology Law Quarterly. (37) pp 797-804 With its proud historic past and abundant marine life,MMDA-Metro Manila Development Authority versus Concerned Residents of Manila Bay. (2008) in de Castro, J.A.I. "Cleaning Up Manila Bay: Mandamus as a Tool for Environmental Protection." G.R. Nos. 171947-48, 574 SCRA 661, 665 Philippines. Manila Bay became the ocean portal and Filipino epicenter for government, economy and industry. During the Russo-Japanese War at the close of the Battle of Tsushima in 1905, three surviving Russian protected cruisers (the Aurora, Zhemchug, and Oleg) managed to make port in then-United States-controlled Manila for repairs. However, because the US was neutral in this conflict, the trio of warships and their crews remained interned by the U.S. until the war officially came to an end in September 1905. During the World War II, Corregidor Island was captured by the Japanese forces based in Manila Bay. Much earlier, various other battles were fought from this naval base, including the Battles of La Naval de Manila in 1646, which finally ended Dutch attempts to seize the Philippines.
The bay remains important for commerce and industry, including fishing, although rapid urban growth and industrialization are contributing to a decline in water quality and deteriorating marine habitats. It also serves a focus for recreation for Metro Manila and is a popular destination for walks and for viewing the sunset. Much of the land fronting the bay along Metro Manila is reclaimed land which now includes important sites such as the Philippine Senate and the Mall of Asia.
On September 27, 2011, the sea walls of Manila Bay were destroyed by the storm surge caused by Typhoon Pedring. Even the United States Embassy, Museo Pambata and Sofitel Philippine Plaza were submerged by the flooding. It was estimated that the damage would cost P30 million to repair. In April 2012, the sea walls were once again opened to the public, having been redesigned to withstand a strong storm surge.
Ecosystem Coastal and marine habitats in the area include upland forests, mangroves, mudflats, sandy beaches, sea grass and coral reefs.
Biodiversity
A total of 19,139 birds belonging to 330 families and 99 species were observed at various monitoring sites along the bay area. The endangered Chinese Egret (Egretta eulophotes) and Black-winged cuckoo-shrike were sighted in the area. A large number of migratory birds, catfish and mackerelsMartinez-Goss, M.L. (1999). Estimation of fish biomas in Laguna de Bay based on primary productivity- A special study of the National Statistical Coordination Board. were once abundant in these waters. Their decline ushered in the appearance of squid, shrimp, and small pelagic species such as herrings and anchovies.
Mangroves
The mangrove ecosystem around Manila Bay has both ecological and socioeconomic uses with its association of unique plant and animal species. Of the original of mangroves existing at the turn of the 20th century, only are remaining as recorded in 1995.Bureau of Fisheries and Aquatic Resources – BFAR. (1995). Fisheries Sector Program – Resources and Ecological Assessment of Manila Bay. Final Report. BFAR- Department of Agriculture, Quezon City, Philippines. A few of the mangrove swamps remaining in Pampanga Bay are of considerable value for research and conservation education.National Water Resources Council - NWRC. (1983). Framework Plan: Pampanga River Basins. Report No. 24-3A. As natural habitats, mangroves considerably help in acting as a protective buffer against cyclones and storms.
Predominant in the bay area are Avicennia marina (gray or white mangrove) together with 15 species of mangroves belonging to 9 families that grow there. In the Bataan area, species of mangrove swamps that are found thriving include: Rhizophora apiculata (bakhaw lalaki in Filipino) Rhizophora mucronata (Asiatic mangrove) Avicennia marina (gray or white mangrove) Nypa fruticans (nipa palm) Sonneratia alba (no common name) Scyphiphora hydrophyllacea (nilad in Filipino) Sonneratia acida (pagatpat in Filipino) Acanthus ilicifolius (holly-leaved acanthus) Excoecaria agallocha (milky mangrove)
Plantations of Cocos nucifera (coconut palm) co-exists with the mangroves found in these areas.
Wetlands Covering about , wetlands around Manila Bay are useful in:Alonzo-Pasicolan, S. (1987). Status of Wetlands in Luzon. Paper presented at the Conference on Wetland and Waterfowl Conservation in Asia, Malacca, Malaysia, February 23–28, 1987. IWRB & Interwater. providing food and habitat for fish, shorebirds and wildlife; maintaining and improving the water quality of rivers, lakes and estuaries, acting as reservoirs for watersheds, and protecting adjacent and downstream properties of the area from potential flood damage
Mudflats, sand flats, swamps, beaches and rocky shores form part of the wetlands in Manila Bay. Found mostly along the coast of Bataan and Pampanga, mudflats are suitable habitats for shellfish.
Coral reefs Contributing to the balanced functioning of the ecosystem around Manila Bay, coral reefs in the area provide sanctuary for fishes. Consequently, its decline through the years has directly affected fish yield.International Centre for Living Aquatic Resources Management - ICLARM (1996). Resource and Ecological Assessment of Manila Bay Philippines: Results of Monitoring Activities (1995-1996).
Seagrass beds As a diverse ecosystem, seagrass beds provide shelter for fishes and other marine life forms. Like the coral reefs, most of the seagrass beds in Manila Bay are found near its mouth, most notably in the areas of Malolos, Orion, Mariveles, and Corregidor Island.
Upland forests Within the watershed of Manila Bay upland forests abound which are sources of food, timber, fuel wood and other products, as well as habitats for wildlife. These forests provide protection from soil erosion and help maintain the water levels and water quality in rivers and streams. Mount Makiling, Angat Dam watershed, La Mesa Dam watershed, Mounts Palay-Palay / Mataas na Gulod, Mount Arayat and other portions of national parks located in Bataan, Bulacan, Rizal and Tarlac form part of these upland forest ecosystem.
Key developments
Land reclamation
Largely intended for use in human settlement and industrial development, land reclamation projects contributed to the reduction of mangroves around the area, as well as significant reduction in Metro Manila's shoreline. From 1944 to 1991, approximately of shoreline have been reclaimed in the northern part. In 2009, the Pambansang Lakas ng Kilusang Mamamalakaya ng Pilipinas (Pamalakaya) said that there are of foreshore areas in Cavite and of shallow coastal waters to expand Sangley Point naval base as part of reclamation projects, which are mostly funded by foreign investors.World Justice Project. (2009). "Eco-lawyer Presses Manila Bay Clean Up". Inquirer Company, Philippines accessed at
Land conversion Conversion of mangrove and mudflat areas into fishponds have impacted the physical features of the bay whereby what used to be irregular shoreline in 1944 has become more linear by 1977. Shoreline retreat continued as man-made structures such as fish pens occupied coastal areas, with progradation dominant from 1977 to 1991. Most areas of the bay, except those near the ports, are largely used as a major fishing ground, with fisheries and aquaculture as the dominant source of livelihood for the inhabitants in the coastal areas.
From 1990, approximately 1,200 hectares of mangroves were cleared, with the land converted for aquaculture or used as salt beds.<ref name="PEMSEA">PEMSEA. (2004) Manila Bay: Refined Risk Assessment. PEMSEA Technical Information Report No. 2004/01. Global Environment Facility / United Nations Development Programme / International Maritime Organization Regional Programme on Building Partnerships in Environmental Management for the Seas of East Asia (PEMSEA). Quezon City, Philippines.</ref> In 1993 much of the fisheries resources steadily declined due to overfishing and overharvesting.
Waterfront development