Environment

Lake Chad - Lakes of the World

This endorheic lake shared by Cameroon, Chad, Niger, and Nigeria has shrunk significantly in recent decades.

5. Description

Lake Chad is a diminishing freshwater lake that is shared by Chad, Niger, Nigeria, and Cameroon. Prior to 1973, the size of the lake was 25,000 square kilometers. Today, it’s less than 2,000 square kilometers having dried up considerably, according to Lake Chad Basin Commission studies (LCBC). The size of Lake Chad’s basin is 2,300,000 square kilometers. According to the Food and Agriculture Organization (FAO), the basin occupies parts of Nigeria, Niger, Algeria, Sudan, Central Africa, Chad, and Cameroon, and covers 8 percent of the African continent. Lake Chad is also endorheic with no outflow rivers, and water escapes it through evaporation or natural seepage. It’s shallow, with an estimated maximum depth of around 15 meters. Chari River and its main tributary Logone River provide about 90 percent of Lake Chad’s waters, with most of the rest coming from Yobe River which flows from northeastern Nigeria into Chad. Water levels in Lake Chad are reducing, thereby causing a major ecosystem imbalance in the four countries sharing it. Various factors have caused this to occur in Africa's fourth largest lake, according to the World Wide Fund for Nature (WWF).

4. Historical Role

Research by UNEP reports that Lake Chad’s basin was formed during the Cretaceous Period around 65 million years ago. Extensional tectonic forces caused the formation to happen. Lake Chad served as a trade hub for people living in the Northern, Central, and South Sahara regions centuries ago. Trading was carried out between the Sokoto Barguirmi, Kanem-Bornu, Wadai, and Mandara kingdoms in the 1500s and 1600s. When the French, German, and British planned to take over the Lake Chad region in the 1890s, they encountered Rabih az Zubayr, a warlord who repulsed their advances at first. Eventually, however, the Europeans prevailed, and shared Lake Chad among them, and opened it for navigation, according to LCBC. At the end of the First World War, France and Britain pushed out the Germans from the lake and shared it among themselves, thereby beginning the initial colonial development of the territory. When the four countries now sharing it achieved independence in the 1960s, they set up LCBC to oversee Lake Chad’s natural resource management.

3. Modern Significance

An estimated 20 million people depend on Lake Chad economically, and it’s estimated that by 2020 that figure will increase to 35 million per World Wide Fund for Nature (WWF) reports. Communities from some of the poorest countries live around the Lake Chad basin. Populations in the upper catchment area of the lake make their livelihoods from fishing, agriculture, and pastoralism. There are over 150,000 fishermen living by Lake Chad’s shores and on its islands. Yearly, the lake produces between 60,000 to 70,000 metric tons of fish catches, according to WWF. But, as the waters recede, locals are shifting from fishing to farming traditional crops like maize, rice, and cowpeas on Lake Chad’s floor. Women have also taken to growing the protein-, iron-, and beta carotene-rich blue algae spirulina on the shallow water pools by the lake, according to FAO. Lake Chad also regulates water supplies, recharges the aquifers, and controls flooding in regions around it according to WWF.

2. Habitat and Biodiversity

There are three climatic zones around Lake Chad. These are the Sahara desert climate in the north, the wet and dry season region of the Sahel in Central Chad, and the hot, wet-to-dry tropical climates in Sudan’s south. This climate sustains diverse biodiversity in Lake Chad, including the 176 native fish species according to LCBC. The lake’s water surface is dotted with reed beds and clear waters. The North and South basins of Lake Chad are separated by a swamp belt. Wetland plants which grow in the south basin include cyperus papyrus and hippo and Phragimites reed grasses. In the saline northern basin, the common reed and the flowering typha plant grow there. In the clear waters, at times the Nile Lettuce sprouts as well. Lake Chad’s southern shore is made up of dark Pleistocene clay. During flooding, grasses sprout and replace the trees destroyed by waters. Acacia dominates the woodlands by the lake, but there are also baobabs, desert date palms, African myrrh, and Indian jujube deciduous trees here as well according to WWF. Around a million birds, many migrating between Palearctic and Afro-tropical ecological zones, also take refuge around the lake.

1. Environmental Threats and Territorial Disputes

Since 1960, Lake Chad has shrunk by 50 percent according to a UNEP report. Unregulated human use of its water, climate change, droughts, overgrazing, deforestation around the lake, and vegetation losses are some of the factors that have contributed to the reduced water levels. The four countries sharing Lake Chad also have unsustainable irrigation and dam projects which have rerouted waters from the lake’s main source rivers, the Chari and Logone. The low water levels are interfering with the nesting areas for birds like the endangered black crowned crane, and such migratory species as the ruff, according to WWF. Fish are no longer migrating here, and populations of species like the Chiracins have also been reduced, while Nile perch catches have significantly decreased in volume. Populations of crocodiles and hippopotamuses, which help maintain ecological balance and regulate fish populations, have also suffered as Lake Chad’s waters have diminished.

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