Chapter 3 The Environmental Resources of the Nile Basin 12.3% cities/ 1.0% 1.4% forests built-up areas grasslands water bodies shrublands bare soils agricultural –1.3% & woodlands land –4.7% –10.1% –17.9% 57 KEY MESSAGES • The Nile Basin has many unique aquatic and to conserve the basin’s unique ecosystems, with terrestrial ecosystems, and is home to thousands mixed conservation success. of species of plants and animals, many of them • The root causes of the rapid degradation of the endemic to the basin. basin’s environmental resources are population • The basin’s water and related environmental growth, poverty, civil insecurity, and weak policy, resources provide a wide range of societal goods legal, and institutional frameworks in the Nile and services, contributing between 40 and 60 per riparian countries. cent of the gross domestic product of the Nile • The Lake Victoria Basin Commission (LVBC), the riparian countries. Intergovernmental Authority on Development • The Nile’s system of waterways and wetlands (IGAD), and the Nile Basin Initiative (NBI) are constitutes an important flight path for migratory examples of a growing number of regional birds and also a destination for migratory birds frameworks established in recent years to address from other regions of Africa. Seventeen aquatic environmental degradation within the Nile Basin. and wetland ecosystems within the basin have been designated as international Ramsar sites. • Key recommendations for regional-level actions by the Nile riparian countries include the • Natural resources of the Nile Basin are under restoration of degraded water catchments critical increasing pressure from a multiplicity of sources, for sustaining the flow of the major Nile tributaries, mainly agriculture, livestock, invasive species, restoring badly degraded lands that export large bushfires, mining, urbanization, climate change, quantities of sediments and cause serious siltation and natural disasters. of reservoirs, and establishing a regional network • Many protected areas (national parks and game, for monitoring changes in water quality and land- wildlife, and forest reserves) have been established use within the basin. Clearing water hyacinth, an invasive species that has had an adverse impact on many parts of the Nile Basin, including parts of Lake Victoria. 58 STATE OF THE RIVER NILE BASIN 2012 ENVIRONMENTAL RESOURCES THE NILE – A BASIN RICHLY ENDOWED ENDEMIC SPECIES Number of endemic The Nile Basin is richly endowed by nature. Its water resources mammals, birds, and amphibians are an integral part of a complex and highly varied landscape that in each of the Nile riparian countries includes small and large lakes; massive riverine floodplains; a broad 2010 Mediterranean delta; forests, woodlands, and extensive savannah (Source of data: IUCN Red List Ver. 2010.4) plains; semi-arid drylands and deserts; low-lying plains; and snow- N capped mountains. The basin has a rich bird life, some of the world’s 0 250 500 km largest congregations of large mammals, and several centres of endemism (i.e. areas with a high occurrence of endemic species such as the Ethiopian Highlands, the Sudd, Mts Elgon and Rwenzori, and Lake Victoria). A number of habitats, such as the Albertine Rift and Ethiopian Highlands, are part of the globally significant Eastern Afromontane biodiversity hotspot. The great biological diversity of the Nile Basin arises from the 6 remarkable variability of its geophysical features and the vast expanse Egypt of its watershed, which spans 35 degrees of latitude. The considerable environmental resources provide the riparian communities with diverse goods and services, and support the livelihoods of a large proportion of the basin population. 1 A good understanding of the environment, of which water is a vital Eritrea 10 component, is essential for its proper management. Wise use and rational utilization of environmental resources are, in turn, critical Sudan for sustaining water resources – crucial for sustaining Nile flows. This chapter builds upon the preceding chapter on water 71 resources by providing an overview of the state of the basin’s biophysical resources, their economic importance, the various threats they are facing, the root causes of the threats, and the measures needed to slow down or reverse the decline Ethiopia of the environmental assets. More detailed descriptions of 79 the Nile ecosystem can be found in publications such as 2 Rzóska (1976) and Dumont (2009). Only brief accounts of Uganda the environmental systems are presented below. 34 DR Congo 2 Kenya Rwanda 2 Burundi 118 Tanzania 59 KEY ENVIRONMENTAL RESOURCES ! Alexandria N Rivers ! ! Suez 0 250 500 km The Nile drainage network, which Cairo is described in Chapter 2, comprises M a many rivers, small and large. Among the in N bigger rivers are the Kagera, Nzoia, Victoria ile Nile, Semliki, Albert Nile, Bahr el Jabal, Bahr el Ghazal, Sobat, Blue Nile (Abay), R e Atbara (Tekezze) and Main Nile. The rivers d ! EGYPT Aswan S are commonly fringed by gallery forests e and herbaceous littoral vegetation. The a latter is dominated by papyrus, common ! reed (Phragmites australis), water lily, Nile Wadi Halfa cabbage (Pistia stratiotes), and occasionally water hyacinth. The rivers are inhabited by ! ile numerous species of vertebrates, including N Bur Sudan n ai the hippopotamus, Nile crocodile, Nile M monitor, rock python, spotted-necked otter, A tb a ra and numerous cobras. They also support (T e k e z ERITREA z many species of birds, amphibians, and fish. e THE SUDAN ! ) Fish species of greatest economic importance Khartoum ! Asmara include the cichlids (mainly Oreochromis, R a h a Tilapia, and Haplochromis species), cyprinids d (mainly Barbus and Labeo species), catfish ! El Obeid B l D u in e d (Bagrus sp.), lungfish (Protopterus sp.), and e N r e l i i le N freshwater eels (Anguilla sp.). (A e b it a hr el A h y) Ba rab W So ba Bahr el f t a ! ga Ghazal r a e R o Baro Z Addis Ababa p l o e S SOUTH ru r Ak u r h ob K Ju a SUDAN o B B a P ETHIOPIA LAND COVER IN THE NILE BASIN h ib r o r e l 2009 N J e u b m e a l t i irrigated croplands n S n u ! a o Juba bare areas grassland A s e w il a mosaic croplands and vegetation N t r e b l UGANDA rainfed croplands A evergreen broadleaf forest DR CONGO Kampala KENYA mosaic forest-shrubland/grassland ! shrubland Lake M ig ori sparse vegetation Victoria ! Nairobi Kigali R ! uwana wetland RWANDA M ! o urban areas Bujumbura am ! e water bodies BURUNDI The NBI is not an authority TANZANIA (Map prepared by the NBI; source of data ESA on international boundaries. Kigoma ! Globcover Project 2009) 60 STATE OF THE RIVER NILE BASIN 2012 ENVIRONMENTAL RESOURCES Many species of molluscs (freshwater snails and slugs), oligochaetes (worms), and insects are associated with the Nile and its tributaries. Lake Victoria The groups of aquatic insects include odonates (dragonflies and damselflies), mayflies, stoneflies, caddisflies, blackflies, midge has a surface area of flies, water beetles, and water scorpions. There are also decapods 2 (freshwater crabs, shrimps, and prawn) that make up an important 68,000 km part of the food chain. Lakes and drainage area of An estimated 3 per cent (95,926 km2) of the Nile’s open water is in 2 the form of lakes. Notable large lakes include Victoria, Kyoga, Albert, 184,000 km George, Edward, and Tana. The lakes are primarily located in the Equatorial Lakes Plateau region. The only major lake in the desert biome is Lake Nasser/Nubia, which resulted from the damming of the Nile at Aswan. The lakes in the basin have various functions, including acting as a habitat for aquatic plant and animal species, buffering the discharge of outflowing rivers against seasonal extremes, and acting as a trap for sediments from the headwater areas. The lakes in the equatorial region are at different stages of eutrophication, and experience frequent algal blooms, low transparency, hypolimnetic anoxia (i.e. oxygen limitation in bottom waters), and occasional fish kills. Lake Victoria is the world’s second-largest freshwater lake by surface area, and acts as a natural reservoir for the White Nile. It has a convoluted shoreline dotted with large papyrus, Loudetia, and Phragmites wetlands. The lake contains over 500 fish species, and supports the largest inland fisheries in the world, with annual fish catches in the region of 500,000 metric tonnes. Commercial catches are dominated by: the Nile perch, Nile tilapia, and silver cyprinid. The lake is also used for hydropower generation, recreation, drinking water, and as a recipient of municipal and industrial wastewater. Daybreak over the Victoria Nile at Jinja, Uganda. 61 Lake Tana, the source of the Blue Nile (Abay), is located at the top of the eastern Nile watershed, and has alkaline water due to intensive evaporation. Its shores are mainly rocky but at the mouth of affluent rivers there are clusters of papyrus-dominated littoral vegetation. The lake has a significant commercial fishery based on tilapia, barbels, and catfish. Its endemic fish are prevented from spreading downstream by the Blue Nile (Tis Issat) Falls. Perhaps more important is the lake’s cultural value. Some of its many islands hold monasteries dating from the 14th century that house remains of ancient Ethiopian emperors and treasures of the Man fishing on Lake Tana. Ethiopian church. Water birds are quite abundant and otters have been recorded in the lake. Of the smaller lakes in the basin, the most notable are the Rweru, Cyohoha, Mugesera, Ihema, Ruhondo, and Bulera in Kagera sub- basin; lakes No, Shambe, Dapiu, and Ambadi in the Sudd region; Lake Nasser/Nubia at The Sudan–Egypt border, and Lake Manzala in the Nile Delta.