Lake Lanao (9797)
Philippines, Asia
Site overview
KBA status: confirmed
Global KBA criteria: B2
Year of last assessment: 2006
National site name: Lake Lanao
Central coordinates: Latitude: 7.8833, Longitude: 124.2500
System: freshwater, terrestrial
Elevation (m): 710 to 710
Area of KBA (km2): 643.13966
Protected area coverage (%): 95.52
KBA classification: Global
Legacy site: Yes
Site details
Site description: Lake Lanao is the second largest lake in the Philippines and the largest in Mindanao. It is a large, oligotrophic, freshwater lake, formed by the tectonic volcanic damming of a basin between two mountain ranges and the collapse of a large volcano. This IBA includes the lake itself and some extensive forest cover on its south and southeast shorelines. Some of the higher altitude forests of the Lake Lanao Watershed are included in the Butig Mountains (PH099) and Mt Piagayungan (PH098). There are extensive reed beds around the edges of the lake, and large areas of Eichhornia crassipes and other aquatic vegetation on the lake surface. Most of the surrounding areas have been cleared for agriculture but there is still some primary lowland dipterocarp forest on the nearby Sacred Mountain, and there are patches of secondary dipterocarp forest at Wao. The lake serves as a reservoir for the generation of hydroelectric power on the Agus River, which generates 70% of the electricity used by the people of Mindanao. It supports a major fishery, and is important for recreational activities including boating, swimming and sport fishing. There are several towns and many villages around it, and a Mindanao State University campus is situated there.
Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance that meets the thresholds for at least one criterion described in the Global Standard for the Identification of KBAs. KBA identified in the CI/CEPF Conservation Outcomes booklet for the Philippines Hotspot (2006). Taxonomy, nomenclature and threat category follow the 2004 IUCN Red List.
Additional biodiversity: Several of the threatened and restricted-range species of the Mindanao and Eastern Visayas Endemic Bird Area have been recorded around Lake Lanao, all forest birds apart from Spot-billed Pelican and Philippine Duck. The pelican is extinct there, but Philippine Duck probably still occurs, as the lake is reported to support large numbers of waterfowl. It is likely that some of the old bird records from ‘near Lake Lanao’ were actually collected in, for example, the nearby Mt. Piagayungan (PH098) or the Butig Mountains (PH099). However, the limited area of lowland forest near the lake could still support some forest birds. Non-bird biodiversity: Lake Lanao is of great limnological interest. The fauna includes many species of fishes and invertebrates that are endemic to the lake, and presents an outstanding opportunity for research on evolution in the Cyprinids. There are about twenty species of Cyprinidae endemic to the lake, but many of the other fishes occurring in the lake have been introduced.. Mammals occurring in the area include wild pig (probably Sus philippensis) and deer Cervus mariannus and many endemic small mammals.
Habitats
Summary of habitats in KBA: Lake Lanao is the second largest lake in the Philippines and the largest in Mindanao. It is a large, oligotrophic, freshwater lake, formed by the tectonic volcanic damming of a basin between two mountain ranges and the collapse of a large volcano. This IBA includes the lake itself and some extensive forest cover on its south and southeast shorelines. Some of the higher altitude forests of the Lake Lanao Watershed are included in the Butig Mountains (PH099) and Mt Piagayungan (PH098). There are extensive reed beds around the edges of the lake, and large areas of Eichhornia crassipes and other aquatic vegetation on the lake surface. Most of the surrounding areas have been cleared for agriculture but there is still some primary lowland dipterocarp forest on the nearby Sacred Mountain, and there are patches of secondary dipterocarp forest at Wao. The lake serves as a reservoir for the generation of hydroelectric power on the Agus River, which generates 70% of the electricity used by the people of Mindanao. It supports a major fishery, and is important for recreational activities including boating, swimming and sport fishing. There are several towns and many villages around it, and a Mindanao State University campus is situated there.
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Wetlands(Inland) | 33 | |
| Forest | 33 | |
| Artificial - Terrestrial | 33 |
Threats
Summary of threats to biodiversity at KBA: There are some major problems within the Lake Lanao Watershed, including land claims by migrants, cattle ranchers and rebel returnees. Other problems include illegal logging, small-scale mining and quarrying activities, and soil erosion leading to siltation and increased turbidity of the waterways and lake. Indigenous fishes in Lake Lanao are threatened by the introduction of exotic fish species, overfishing, domestic pollution and an increase in fertilizer use. The operation of the Maria Cristina hydroelectric dam (which is controlled by NAPOCOR) causes seasonal fluctuations in the water level of the lake and displacement of the fish and their breeding grounds. The construction of additional spillways for the hydro electric power station involves more dredging of river banks and destruction of riparian habitat.
Additional information
References: Davies et al. (1990); Scott (1989).