Lake Kutubu

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The Lake Kutubu is a predominantly groundwater -fed lake with a high biodiversity in the Southern Highlands Province of Papua New Guinea. It is located east of Kikori River, whose catchment area he belongs, 50 km south-west of Mendi, the capital of this province.

Location and description

The Lake Kutubu is one of several lakes located on a high plateau. The lake is the second largest in Papua New Guinea after Lake Murray, located at 808 m above sea level and is the largest lake in the highlands. The lake is about 19 km long and at its widest point, about 4 km wide. The lake area is 49.24 km ² and its catchment area is about 250 square kilometers. It is located in a karst area and was originally created by volcanic debris and ash that blocked the valley in which it lies today. The lake has several small islands, the largest is Lake Kutubu Village. It is fed by small tributaries and springs, most are underwater.

The alkaline (pH 7.6 to 8.1 ) and mineral-rich ( 166-203 ĩS / cm) water of Lake Kutubu is very clear due to lack of nutrients and lack of large inflows. The maximum water depth is 70 m. In a depth of 10 to 25 m, there is a temperature jump layer to 1.6 ° to 3 ° C. Below the thermocline and the chemical composition of the water is significantly altered with a high content of dissolved phosphorus-and nitrogen -containing compounds and a very low content of dissolved oxygen of less than 2 mg / l A local vertical water circulation takes place only rarely ( every 10 to 20 years) and irregular, resulting in fish kills. The water level of the lake fluctuates during the year by about 2 m.

In the water catchment area has two ethnic groups, the Foe in the south and the Fasu in the north, together 33 villages with approximately 11,000 inhabitants.

Climate

The mean daily temperature is 23 ° C. The average annual rainfall in the area of ​​Lake Kutubu is about 4500 mm. The rainiest months are April / May and September / October. The humidity is high throughout the year, with 85 to 90 % in the morning and 70 to 80 % in the afternoon.

Flora and Fauna

The Lake Kutubu is ( together with the Lake Sentani ) managed as an ecological region of the WWF Global 200. Aquatic plants grow up to 6 m water depth. He is the most unique habitat of sea fishing in the room Guinea and Australia. Of the 18 species of fish living here a dozen are endemic, including:

  • Two undescribed goby of the genus Glossogobius
  • A Catfish ( Oloplotosus torobo )
  • Aquamarine Rainbow Fish ( Melanotaenia lacustris )
  • The Kutubu - hard head ( Craterocephalus lacustris )
  • A Grunzbarsch (Hephaestus Adamsonite )
  • Several Schläfergrundeln the genus Mogurnda ( Mogurnda furva, Mogurnda kutubuensis, Mogurnda spilota, Mogurnda variegata, Mogurnda vitta )

In the Lake Kutubu live as problematic invasive species which spread from human European carp and mosquito fish.

Ecology

Because of its biological and ecological significance of the region is classified as a Wetland of International Significance of the Ramsar Convention. The area is managed by the Lake Kutubu Wildlife Management Area, which covers an area of ​​240.57 km ². The area has been studied by the WWF and a management plan for the watershed developed, which is exemplary for Papua New Guinea. The project was completed in December 2007. The Lake Kutubu is in the area of the proposed World Heritage Site Kikori River Basin - Great Papuan Plateau (literally " Kikori Basin - large Papuan Plateau ").

Use

The local population uses the fauna of the lake as an important source of protein. Preferred methods of fishing fishing with handlines for fish ( 30%) and cancers ( 24%), with spears (17 %) and gill nets (17%) in 1997. So 1.2 million fish and crustaceans per year were estimated from the fished Lake Kutubu. Three species ( crayfish ( 35%), Hephaestus Adamsonite ( 23%) and Oxyeleotris fimbriata (22%) ) made ​​by 80 % of the catch from. Up to 40 % of the catches consist of five of the endemic fish species.

The lake gave its name to the Kutubu Oil Project, the first depleted oil field in Papua New Guinea, which is operated by Oil Search Limited since 1992. The oil field supports the local economy and led to the influx of people into the area. Ecological problems arising from the growing population and the consequent pollution, deforestation and overfishing. A planned gas pipeline in the context of Papua Newguinea LNG Project with street will probably aggravate these problems, although it is well managed.

Lake Murray (Papua New Guinea) Endemic (epidemiology) Lake Kutubu rainbowfish Gillnetting
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