Lake Naujan (9740)
Philippines, Asia
Site overview
KBA status: confirmed
Global KBA criteria: B2
Year of last assessment: 2006
National site name: Lake Naujan
Central coordinates: Latitude: 13.1667, Longitude: 121.1833
System: freshwater, terrestrial
Elevation (m): 20 to 20
Area of KBA (km2): 289.15908
Protected area coverage (%): 53.19
KBA classification: Global
Legacy site: Yes
Site details
Site description: Naujan Lake lies near to the north-east coast of Mindoro, approximately 8 km from Pinagsabangan. It is a large freshwater lake probably of volcanic origin, extending for about 14 km from north to south, and 7 km from east to west. The eastern shore is precipitous, but to the west the land rises gradually and there are large areas of shallow water with an abundant growth of aquatic vegetation. There are several hot springs along the eastern shore and the maximum depth of the lake is 45 m. The surrounding areas are covered in a mixture of forest, scrub and grassland with some orchards and coconut plantations. The MUFRC ( Multiple-use Forest Research Center) Experimental Forest lies to the south of the lake, on very steep and broken topography at 200-1,200m. It is in an old logging concession, which in 1980 was mostly covered by secondary growth of predominantly dipterocarp forest and a few patches of grassland and scrubland. However, no forest could be seen in this area in 1991 when viewed from Ilong Peak on Mt Halcon. The main sources of livelihood of the local people are fishing and farming. The species caught include milkfish, mullet, goby, mudfish, tilapia, carp, freshwater prawns and freshwater snails. Where the marshes permit cultivation, the land has been drained, cleared and planted with rice. Important agricultural crops include citruses, coconuts, rambutans and coffee. A very profitable duck raising industry thrives in the surrounding area.
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: Naujan Lake supports large numbers of ducks and other waterfowl, several of which may occur in internationally important numbers. Resident species include the threatened Philippine Duck, which formerly occurred here in substantial numbers but now appears to have declined. The area surrounding the lake used to have extensive lowland dipterocarp forests, notably the MUFRC Experimental Forest, and significant populations of several of Mindoro's restricted-range endemic species, including all of the lowland specialists characteristic of the Mindoro Endemic Bird Area. However, most if not all of this forest appears to have been cleared or degraded, and these species may be locally extinct. Non-bird biodiversity: Naujan Lake has a rich fish fauna including several protected species. The Philippine crocodile Crocodylus mindorensis, an endangered species endemic to the Philippines, formerly occurred in the area, but may now be extinct on Mindoro. The estuarine crocodile Crocodylus porosus still occurs in the restricted zone of the National Park.
Habitats
Summary of habitats in KBA: Naujan Lake lies near to the north-east coast of Mindoro, approximately 8 km from Pinagsabangan. It is a large freshwater lake probably of volcanic origin, extending for about 14 km from north to south, and 7 km from east to west. The eastern shore is precipitous, but to the west the land rises gradually and there are large areas of shallow water with an abundant growth of aquatic vegetation. There are several hot springs along the eastern shore and the maximum depth of the lake is 45 m. The surrounding areas are covered in a mixture of forest, scrub and grassland with some orchards and coconut plantations. The MUFRC ( Multiple-use Forest Research Center) Experimental Forest lies to the south of the lake, on very steep and broken topography at 200-1,200m. It is in an old logging concession, which in 1980 was mostly covered by secondary growth of predominantly dipterocarp forest and a few patches of grassland and scrubland. However, no forest could be seen in this area in 1991 when viewed from Ilong Peak on Mt Halcon. The main sources of livelihood of the local people are fishing and farming. The species caught include milkfish, mullet, goby, mudfish, tilapia, carp, freshwater prawns and freshwater snails. Where the marshes permit cultivation, the land has been drained, cleared and planted with rice. Important agricultural crops include citruses, coconuts, rambutans and coffee. A very profitable duck raising industry thrives in the surrounding area.
| IUCN Habitat | Coverage % | Habitat detail |
|---|---|---|
| Forest | 5 | |
| Wetlands(Inland) | 48 | |
| Artificial - Terrestrial | 48 |
Threats
Summary of threats to biodiversity at KBA: The lake is open to commercial fishing subject to certain limitations, but the enforcement of these regulations and other park regulations is reported to be poor. The Department of Environment and Natural Resources (DENR) has expressed the desire to establish a crocodile farm and crocodile sanctuary at the lake. The lake is rich in nutrients and supports a major fishery of both demersal and pelagic species. Most of the inhabitants of the region depend on the lake for their livelihood. Because of the increase in the human population in the area, the demand on the lake's natural resources has grown rapidly. Fishing is intensive and there is continuing conflict between preserving the National Park for wildlife and development of the area for commercial and subsistence level activities by the local residents. The privately owned fish corral built at the mouth of the Butas River with Government approval constitutes a major threat. Its massive door is opened during high tide and then closed, blocking the exit of marine species in their migration to the sea to breed. The small population of crocodiles, although protected by law, continues to be persecuted; fishermen catch young crocodiles on fishing lines and large animals are killed in nets.
| Threat level 1 | Threat level 2 | Threat level 3 | Timing |
|---|---|---|---|
| Biological resource use | Fishing & harvesting aquatic resources | Unintentional effects: large scale (species being assessed is not the target) [harvest] | Ongoing |
Additional information
References: Catibog-Sinha (1982); Davies et al. (1990); Diesmos and Pedregosa (1995); Scott (1989).