Candaba Swamp
Location:	l5°05'N, 120°53'E; near the towns of Candaba, San Miguel and San Ildefonso, 50 km NNW of Metro Manila, Pampanga and Bulacan Provinces, central Luzon.
Area:	32,000 ha.
Altitude:	1 lm.
Biogeographical Province:	4.26.12.
Wetland type:	11, 15, 17, 18, 19 & 20.
Description of site:	A complex of freshwater ponds, swamps and marshes with surrounding areas of seasonally flooded grassland, arable land and palm savanna on a vast alluvial flood plain. The entire area is usually flooded in the wet season, but most of it dries out during the dry season (late November to April) and is converted into rice fields and plantations of water melons. The main area for waterfowl is an impoundment of about 300 ha, with a mixture of open shallow water, small islands, and rafts of floating vegetation, adjacent to the Pampanga River about nine km north of Baliuag. The impoundment is used as a fish pond during the rainy season, and then drained in January or February to be used for agriculture. Candaba Swamp acts as a natural flood retention basin holding wet season overflow from the Maasim, San Miguel, Garlang, Bulu and Penaranda Rivers, and draining into the Pampanga River. The natural retention capacity is estimated at approximately 1.5 billion cubic metres. The average depth of water is l-2m, and the maximum about 5m.
Climatic conditions:	Tropical climate with a pronounced dry season from November to May and a pronounced wet season from June to October (Type I).
Principal vegetation:	No information is available on the aquatic vegetation; most of the flood plain is under cultivation for rice and other crops, and there are some patches of Nypa fruticans and mangroves in surrounding areas.
Land tenure:	A small part of the swamp is state owned and has been classified as "alienable and disposable"; the remainder is privately owned by many individuals.
Conservation measures taken:	None.
Conservation measures proposed:	A proposal has been made by the local government of Pampanga to delineate some 500 ha of the swamp as a waterfowl sanctuary. The Haribon Foundation has proposed the establishment of a multiple use sanctuary which would protect migratory waterfowl populations, provide an educational and recreational facility for the general public, and act as a water storage reservoir for the local fisheries and for emergency irrigation of surrounding farmland.
Land use:	Aquaculture (fish ponds) and agriculture (mainly rice and water melons); fish ponds and cultivation of rice and sugar cane in surrounding areas. The swamp was a traditional waterfowl hunting area in the past, and some hunting of ducks and rails, although now illegal, still occurs.
Possible changes in land use:	The swamp may be converted into a retention basin for routing peak discharges.
Disturbances and threats:	Some siltation is occurring, but this is unlikely to be very serious in the short term unless drastic erosion takes place in the Sierra Madre Range. However, some portions of the marsh have been converted into fishponds while other areas have been drained for agricultural purposes. Large areas are planted with water melons during the dry season, and there is a possibility that water levels may be controlled so that crops can be grown all year round. There is some illegal hunting of birds for recreational purposes.
Economic and social values:	The swamp is important for agricultural and fisheries production (mainly Chanos chanos), for flood control, and as a source of water for irrigation. It is a favourite spot for local and visiting bird-watchers and naturalists, and has great potential for nature-oriented outdoor recreation and conservation education as there are few other places so close to the metropolitan area of Manila that support so much wildlife.
Fauna:	An extremely important staging and wintering area for ducks, especially in October and November when the swamp regularly supports between 5,000 and 10,000 birds. In 1982, about 100,000 ducks were observed in a single day. No other site in the Philippines is known to support such large concentrations of Anatidae. The two most abundant species are Anas luzonica and A. querquedula; A. acuta is common, and Dendrocygna arcuata, Anas penelope, A. clypeata, Aythya ferina and A. fuligula occur in significant numbers. Anas strepera and Aythya baeri were recorded in 1978 and 1979 respectively, the first observations of these species in the Philippines. The area is also very important for wintering egrets; about 3,000-5,000 Egretta alba were observed in January 1987. The reed-beds at Candaba and in the surrounding areas are one of the few known wintering areas of the Speckled Reed Warbler Acrocephalus sorghophilus, a very local species which breeds in northeastern China. The marshes support breeding populations of several Rallidae, notably Rallus zorquatus and Porphyrio porphyrio, and some ducks may breed. In all, about 60 species of birds use the marsh for feeding and roosting.
Special floral values:	No information.
Research and facilities:	Preliminary faunal and floral surveys have been carried out.
References:	Alonzo-Pasicolan (1987); Alvarez (1984); Glass et al. (1979); Karpowicz (1985); Kennedy & Dickinson (1980); Tahal Consulting Engineers (1978).
Criteria for inclusion:	lb. le, 2a, 2b, 3a.
Source:	Haribon Foundation and Robert S. Kennedy.