ASEAN Protected Areas

Tasek Merimbun Wildife Sanctuary

ASEAN Heritage Park, Brunei Darussalam

Location

The 7,800 ha park was established in 1984 and lies in northeast Borneo within the Sultanate of Brunei Darussalam in the district of Tutong, about 60 km (one hour drive) south east of Bandar Seri Begawan in Tutong District in the floodplain of the Tutong River.

Habitats

The site consists of a complex of shallow, freshwater lakes and grassy marshes surrounded by a large area of seasonally flooded peat swamp forest, to the west of the Tutong River. The lakes are fed by three streams and overflow from the Tutong River during the rainy season (August to December). The maximum depth of water in the lakes is about 4 m; the pH is low. Dryobalanops rappa and Dactylocladus stenostachys are the dominant trees in the peat swamp forest.

These also have important stands of ramin Gonostylus maingayi, the elegant sealing wax palm Cyrtostachys renda and fan palms Licuala paludrosa and Borassodendron borneense. Clusters of the pitcher plant Nepenthes ampullaria crouch on the peaty soil whilst N. bicalcarata, N. gracilis and N. mirabilis climb among small trees. There are also large areas of lowland dipterocarp forest at the south end of the park. The site constitutes the largest peat swamp reserve in northern Borneo and has a tropical monsoonal climate with an average annual rainfall of about 3,000 mm.

Wildlife

The lakes support a rich fish fauna, including eels which form the basis of a small local fishery. The most obvious wildlife of Tasek Merimbun are the waterbirds. Nesting colonies of purple heron and egrets occur and the brahminy kite and lesser fishing eagle are common raptors circling over the lakes. Up to 30 darters are resident on the lakes. Many other species of waterfowl occur as visitors.

Monitor lizards, reticulated python and many frogs occur in the park. The estuarine crocodile Crocodylus porosus was formerly common in the area, but is now rare.

There are many fascinating insects to be seen such as great leaf insects, giant beetles and gorgeous bufferflies including the beautiful Rajah Brooke’s birdswing.

To the south of the park, less accessible swamp forests and lowland dipterocarp forests stretch for any miles. These forests are populated by the full range of lowland forest fauna of NE Borneo including pheasants, bears, many types of monkeys including the pretty red-leaf monkeys, spooky-eyed tarsiers, slow loris and flying lizards. The only obvious absence is the lack of orangutans in these forests. These were probably present a few hundred years ago, for collections of skulls in the nearby Niah caves indicate that orang-utan was a major food item in prehistoric times and it is likely that this great ape was hunted out of this part of Borneo.

Other Interests

Due to its accessibility, the site is used extensively for day trip picnic groups, but visitors can enjoy boat trips, bird viewing from high towers and huts on boardwalks.

Visiting

Access is by road using private transport (no public transport is available). Leave Bandar Seri Begawan by Jalan Tutong, then turn left to Lamunin and then onto Tasek Merimbun. The route is well sign posted from Jalan Tutong. Some sections of the road are in poor condition and some near the Tutong river are liable to flooding during the months of November and December. No permits or entrance fee payable, though there may be a small fee for the visitor’s centre.

Conservation Programmes

The reserve had suffered a period of neglect and some facitlities had deteriorated but most have been repaired and the museum staff use the site for research and training.

Threats

The park has suffered damage in the north as a result of forest fires. Some adjacent lands have been planted with rubber. There are minor threats from indigenous hunters and fishermen in the remoter parts and but otherwise, the site faces little pressure.