Lake Kutubu

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Lake Kutubu
Clouds over Lake Kutubu.jpg
Lake Kutubu
Geographical location Southern Highlands Province in Papua New Guinea
Tributaries Hamua Creek (largest tributary), springs in the lake
Drain Soro River / Digimu River
Location close to the shore Mendi
Data
Coordinates 6 ° 24 ′  S , 143 ° 19 ′  E Coordinates: 6 ° 24 ′  S , 143 ° 19 ′  E
Lake Kutubu (Papua New Guinea)
Lake Kutubu
Altitude above sea level 808  m
surface 49.24 km²
length 19 km
width 4 km
Maximum depth 70 m
PH value 7.6 to 8.1
Catchment area 250 km²
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The Lake Kutubu is a predominantly groundwater-fed lake with high biodiversity in the Southern Highlands Province of Papua New Guinea . It is east of the Kikori River , to whose catchment area it belongs, 50 km southwest of Mendi , the capital of this province.

Location and description

Lake Kutubu is one of several lakes that are located on a high plateau. The lake is the second largest in Papua New Guinea after Lake Murray , lies at 808 m above sea level and is the largest lake in the highlands. The lake is about 19 km long and about 4 km wide at its widest point. The lake area is 49.24 km² and its water catchment area is about 250 km². It is located in a karst area and was originally formed by volcanic rubble and ash that blocked the valley in which it is located today. The lake has several small islands, the largest of which is Lake Kutubu Village . It is fed by small tributaries and springs, most of which are under water.

The alkaline (pH 7.6 to 8.1) and mineral-rich (166 to 203 µS / cm) water of Lake Kutubu is very clear due to the lack of nutrients and the lack of large tributaries. The maximum water depth is 70 m. At a depth of 10 to 25 m there is a temperature jump to 1.6 to 3 ° C. Below this thermocline, the chemical composition of the water is also significantly changed, with a high content of dissolved phosphorus and nitrogen-containing compounds and a very low content of dissolved oxygen below 2 mg / l. Local vertical water circulation occurs only rarely (every 10 to 20 years) and irregularly, which leads to fish deaths. The water level in the lake fluctuates by around 2 m over the course of the year.

Two ethnic groups live in the water catchment area , the Foe in the south and the Fasu in the north, together 33 villages with around 11,000 inhabitants.

climate

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

Flora and fauna

Lake Kutubu is listed (together with Lake Sentani ) as an ecological region of WWF-Global 200 . Aquatic plants grow to a depth of 6 m. It is the most extraordinary habitat of sea fish in the New Guinea and Australia area. Of the 18 species of fish that live here, a dozen are endemic . a .:

The problematic neozoa in Lake Kutubu are the European carp and mosquito fish, which are common to humans .

ecology

Because of its biological and ecological importance, the region is classified as the Wetland of International Significance by the Ramsar Convention . The area is managed by the Lake Kutubu Wildlife Management Area , which covers an area of ​​240.57 km². The area was investigated by WWF and a management plan for the water catchment area developed, which is exemplary for Papua New Guinea. The project was completed in December 2007. Lake Kutubu is located in the area of ​​the planned World Heritage Site Kikori River Basin - Great Papuan Plateau (literally " Kikori basin - great Papuan plateau").

use

The local population uses the lake's fauna as an important source of protein. The preferred fishing methods in 1997 were fishing with hand lines after fishing (30%) and crabs (24%), with spears (17%) and with gill nets (17%). An estimated 1.2 million fish and crustaceans were fished from Lake Kutubu each year. Three species (crayfish (35%), Hephaestus adamsoni (23%) and Oxyeleotris fimbriata (22%)) accounted for 80% of the catch. Up to 40% of the catch consists of five of the endemic fish species.

The lake gave its name to the Kutubu Oil Project , Papua New Guinea's first exploited oil field, operated by Oil Search Limited since 1992. The oil field supports the local economy and has led to the influx of people into the area. Ecological problems result from the growing population and the consequent pollution, forest destruction and overfishing. A planned road gas pipeline under the Papua New Guinea LNG Project is likely to exacerbate these problems, although it is well managed.

Individual evidence

  1. ^ Brian Essai: Papua and New Guinea: A Contemporary Survey . Oxford University Press, Melbourne 1961, p. 21.
  2. ↑ a b Lake Kutubu at www.ramsar.org
  3. ↑ a b c d Pilot and Demonstration Activities: Integrated Catchment Management in Lake Kutubu, Papua New Guinea , Report of the Asian Development Bank
  4. ↑ a b Lake Kutubu and Sentani at www.worldwildlife.org
  5. ^ Lakes Kutubu and Sentani - A Global Ecoregion at www.panda.org
  6. ↑ D. Polhemus, R. Englund, G. Allen (2004). Freshwater Biotas of New Guinea and Nearby Islands: Analysis of Endemism (PDF; 2.3 MB). Bernice Pauahi Bishop Museum, Conservation International
  7. ↑ a b Kikori River Basin - Great Papuan Plateau on whc.unesco.org
  8. ↑ Lake Kutubu Catchment Management Plan: Project Inception Report ( Memento of the original from June 24, 2007 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , P. 3 u. 6 (pdf) @1@ 2Template: Webachiv / IABot / www.adb.org
  9. ↑ Kutubu ( Memento of the original of April 21, 2004 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. on www.oilsearch.com @1@ 2Template: Webachiv / IABot / www.oilsearch.com