Current view: Text account
Site description (2001 baseline):
Site location and context
Liguasan Marsh is in south central Mindanao, and is the largest swamp and marsh area on the island. It is a vast complex of river channels, small freshwater lakes and ponds, extensive freshwater marshes and arable land subject to seasonal flooding in the basin of the Mindanao River. Most of the area is underwater during periods of heavy rainfall, but some 140,000 ha dry out during dry periods and are cultivated. The marsh, although generally known as Liguasan, actually consists of two adjoining marshy basins, Liguasan Marsh and Libungan Marsh, with different water regimes. Liguasan lies at the confluence of the Pulangi, Maganoy, Buluan and Allah Rivers, and Libungan lies at the confluence of Libungan and Mindanao Rivers. There is c.5,000 ha of old growth forest within the marsh.
The marsh is home to 112,000 Maguindanaon families whose primary means of livelihood are fishing when water levels are high and agriculture when they are low. Because of its very rich wildlife, the marsh has considerable potential for nature tourism. However, the area is a stronghold of insurgents, and access is restricted. The Government has recognized the importance both economically and politically of Liguasan Marsh and, in the Cotabato Agusan River Basin Development Project, has initiated the construction of a cut off channel from the Pagulungan sector of the Rio Grande de Mindanao to prevent and control floods.
Several threatened species have been recorded at Liguasan Marsh, including Philippine Eagle, but there is little recent information on their status there. It is likely that the relatively extensive lowland forests in this IBA support populations of more of the threatened and restricted-range birds of the Mindanao and Eastern Visayas Endemic Bird Area. The marsh is an important wetland site and supports resident or non-breeding populations of many waterbird species, including herons and egrets, rails, shorebirds and ducks. These include a Mindanao endemic subspecies of Little Grebe, Tachybaptus ruficollis cotabaco, and Comb crested Jacana Irediparra gallinacea, for which Liguasan is the only locality in the Philippines.
Non-bird biodiversity: The marsh supports a great variety of aquatic wildlife. It is one of the last strongholds for the endangered Philippine crocodile Crocodylus mindorensis, and the estuarine crocodile C. porosus also occurs. The marsh is particularly rich in orchids.
Liguasan Marsh is in south central Mindanao, and is the largest swamp and marsh area on the island. It is a vast complex of river channels, small freshwater lakes and ponds, extensive freshwater marshes and arable land subject to seasonal flooding in the basin of the Mindanao River. Most of the area is underwater during periods of heavy rainfall, but some 140,000 ha dry out during dry periods and are cultivated. The marsh, although generally known as Liguasan, actually consists of two adjoining marshy basins, Liguasan Marsh and Libungan Marsh, with different water regimes. Liguasan lies at the confluence of the Pulangi, Maganoy, Buluan and Allah Rivers, and Libungan lies at the confluence of Libungan and Mindanao Rivers. There is c.5,000 ha of old growth forest within the marsh.
The marsh is home to 112,000 Maguindanaon families whose primary means of livelihood are fishing when water levels are high and agriculture when they are low. Because of its very rich wildlife, the marsh has considerable potential for nature tourism. However, the area is a stronghold of insurgents, and access is restricted. The Government has recognized the importance both economically and politically of Liguasan Marsh and, in the Cotabato Agusan River Basin Development Project, has initiated the construction of a cut off channel from the Pagulungan sector of the Rio Grande de Mindanao to prevent and control floods.
Pressure/threats to key biodiversity
The most serious threat to Liguasan Marsh is deforestation of the watershed due to illegal logging, land conversion and shifting cultivation, which has resulted is soil erosion and siltation in the waterways. In some areas, the marsh has been drained for rice cultivation, conversion into fishponds and drilling activities for oil reserves. A 1973 survey indicated that 4,509 ha had been developed into fishponds.
However, unlike other swampy areas in Mindanao (i.e. Agusan Marsh: PH085, and Pagadian and Panguil Bays), Liguasan Marsh has remained relatively pristine due to the peace and order problems brought about by the presence of insurgents. This has prevented development projects in the area from being completed.
Conservation responses/actions for key biodiversity
The 1994 DENR PASA report recommends the re-delineation of the marsh boundaries since a large area of the marsh, especially around the edges, is already occupied, cultivated or converted into fishponds.
A Liguasan Marsh Development Master Plan has been developed by NEDA Region 12. This is a comprehensive plan encompassing socio-economic enhancement through livelihood opportunities, infrastructure and agricultural development and environmental conservation and management.
Surveys are required in this IBA, to investigate both the extent and quality of the remaining habitats, and to determine which threatened and restricted-range birds and waterbirds have important populations there.
Liguasan Marsh was declared a Game Refuge and Bird Sanctuary by Forestry Administrative Order No. 19 on 19 January 1941.
Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Liguasan marsh (Philippines). Downloaded from
https://datazone.birdlife.org/site/factsheet/liguasan-marsh-iba-philippines on 23/12/2024.
