Lake Chilwa

The Chilwa Lake is located in southeastern Malawi on the border with Mozambique.

Geography

It is the second largest lake in Malawi and extends approximately 60 km north-south and 40 kilometers east-west. The lake lies at an altitude of 627 meters. He has seven tributaries but no outlet, but it is suspected that takes place over the marshes or some underground water exchange with the northern and depending on the season about 100 to 300 square kilometers Chiuta Lake. The two lakes are separated by a 15 to 25 meters high, resulting probably 10,000 years ago sand barrier.

Near the western shore of the lake is the hilly Chisi Iceland, in the middle of the lake is the smaller island Thongwe.

Hydrology

The Chiuta Lake may turn merges into the Amaramba Lake in Mozambique, which is drained by the Lugenda. The Chilwa lake is very shallow, the water depth is 1 to 2 meters. The area of ​​the entire water area is about 2250 square kilometers, but is highly dependent on the amount of inflow. Differences are of open water, marsh land and seasonally flooded area. Their size was at the end of the dry season in October 2006 as measured by satellite imagery, 828, 303 or 687 square kilometers. After prolonged dry season the surrounding marshland and parts of the lake may dry out. 1995 was even the entire Chilwa Lake dry after it had rained for two consecutive years only 775 or 748 millimeters. At low tide, the salinity is increased. The shore regions consist mainly of reeds ( Typha domingensis, a cattail - type ), are linked from the ropes can be attached to fishing nets.

Use

The Chilwa Lake is rich in fish, in the long-term average each year 15,000 tons are fished, which are (on average 16-43 percent), 22 percent of the fishing Trages the country. The productivity is 8o to 160 kg / ha. Three species of fish together provide 85 percent of the yield: Oreochromis shiranus chilwae, local name " Makumba ", belong to the tribe of Tilapiini; African catfish, local name " Mlamba "; and the small Barbus paludinosus, belonging to the genus Barbus, local name " Matemba ". All three species are able to regenerate even with different high water levels.

The Chilwa Basin is an early settlement area for the ethnic groups of the Nyanja, Yao, Lomwe Nguni and who, presumably, but before, operated according to written sources from the 19th century on the flood plains agriculture. The British colonial authorities tried with little success to push through the marshes as a protection zone. Since the 1950s, parts of the area were established in the local context as irrigated agriculture. Studies of the FAO do not suggest a waiver of agriculture, but a partial agricultural use and involvement of the population in measures for the protection of wetlands.

Until the early 1970s, six irrigation programs for intensive agricultural use were established, which have an average size of 500 acres for each 1300 to 1500 farmers. Some villages have been relocated to this within the area, new settlers from outside however, there were hardly any. The projects were supported by a Taiwanese charity and IFAD. Main crops are rice, corn, peanuts and tobacco, for their own use varieties of vegetables are grown. Overall, lived according to an estimate from 2000 in about 300 settlements and 77,000 people in large part on the wetlands of the Chilwa Lake. The region has 162 inhabitants per square kilometer, one of the highest population densities in Malawi. By increasing land use biodiversity has since declined measurably.

Flora and Fauna

To the Chilwa Lake is home to around 160 species of water birds including 41 species of migratory birds. With traps, snares or nets case with rice or millet as bait waterfowl are caught for their own consumption and for sale in markets. A Danish project has been working since 2003 to regulate the fishing quotas. Birds are an important protein source in times of little fishing. An estimated 1.2 million birds are caught per year. These include moorhen, Whistling Ducks and Hottentottenenten. Breeding season is from January to July, hunting season is the rainy season in the months of December to February. 2001 29 bird sanctuaries have been set up, where hunting is prohibited throughout the year. At the establishment of a statutory hunting management was still working in 2006.

The fish fauna of Lake Chilwa 27 species. For fishing on the most important are the small, about 12 cm long carp fish Barbus paludinosus, the catfish Clarias gariepinus and both 25 and 45 cm long Tilapiaarten Oreochromis shiranus chilwae and Coptodon during alli. Other types are the cichlid Haplochromis callipterus and the tetras Hemigrammopetersius barnardi. In the crustacean zooplankton Diaphanosoma excisum, Tropodiatomus kraepelini, Daphnia barbata, micrura Moina, Ceriodaphnia cornuta and Mesocyclops leukarti were found. The benthic invertebrate fauna includes Nilodrum brevibucca, N. brevipalpis, Ecnomus sp., Dipseudopsis sp., The apple snail Lanistes ovum, the plates snail Bulinus globosus and Biomphalaria sp horn snail ..

Since 2006 the area has been designated a UNESCO Biosphere Reserve.