Major Environmental Concerns  

[ Land | Forest | Biodiversity | Water | Marine & Coastal Environments | Urban & Industrial Environments ]

Underlying Causes

[ Social | Economic | Institutional | Environmental ]

The African coastline is vast and traces a variety of habitats-from open ocean, near-shore waters, and sandy and rocky islands to beaches, lagoons, sand dunes, mud and sand flats, rocky cliffs, sea grass beds, coral reefs, and mangroves. Some of the waters surrounding Africa , particularly those from the Straits of Gibraltar to Guinea , are among the richest fishing grounds in the world, and the marine areas from Angola south to the Cape also contain great wealth (UNEP, 1985). Fish species diversity is high, including some of the most numerous and economically important fish. For many countries, especially in western Africa , fish is the main source of protein; Nigeria consumes the continent's largest quantities of fish (UNEP, 1994). The east coast of Africa , with the possible exception of Somalia , is not as fortunate; there the resources range from moderate to poor (UNEP, 1985).

Fishing and tourism are the main forms of marine resource use in Africa . Tourism is having an increasing impact, for example, in North Africa [Centre for Environment and Development for the Arab Region and Europe (CEDARE), personal communication, 1996]. Exploitation of mangrove forests is also an important economic and subsistence activity in many countries (SARDC, 1994c), and the cutting of these forests causes serious threats to the habitat. Dynamite fishing, the most environmentally destructive fishing method, is used along the coast. Although it is illegal in many countries, the laws are not actively enforced (UNEP, 1996b).

Several eastern African countries are constructing dams for hydroelectric power (UNEP, 1990) and in western Africa nearly all the main rivers have been dammed in at least one location (UNEP, 1989), blocking sediments and nutrients as well as fresh water. Excessive erosion of river mouths and delta areas (often the site of mangrove forests) and recession of shorelines and even disappearance of islands and towns (such as the town of Keta on the western coast) have occurred because of a reduced supply of sediment. The reduction in sediment and nutrient supply also affects the spawning and growth cycles of marine fish and prawn species as well as fisheries further offshore (UNEP, 1990).

The decrease in freshwater discharge in the estuarine areas alters the extent of salt-water intrusion, with significant effects on the coastal ecosystems. For example, the mangrove swamps and rain- forests of the Niger Delta have been damaged by salt-water intrusion (UNEP, 1990). The possible impact of sea level rise is also a high concern in the coastal and island countries of Africa (UNEP, 1996b).

Marine and coastal pollution problems do exist in Africa , although the scale of industrial activities is relatively limited and the size of population in relation to the length of coastline is also relatively small compared with other regions (UNEP, 1989 and 1990). (See Figure 2.5.) The Mediterranean Sea , however, is one of the most polluted water bodies (CEDARE, personal communications, 1996). In Africa , little sewage is treated, and effluents from growing industries are discharged into city sewage systems, rivers, and the coastal environment (including the sea, estuaries, and lagoons) mainly untreated and unchecked.

Pollution has many impacts on major coastal systems, such as the Niger Delta, where aquatic life and habitats are damaged (World Bank, 1996). In eastern Africa -for example, in Madagascar-soil erosion and consequent siltation as well as agrochemical pollution are increasing as a result of the development of irrigation, rice cultivation, and expanded and intensified agriculture into marginal, often sloping, areas (UNEP, 1990). In countries such as Mozambique and Tanzania, expanded, relocated, and new settlements in coastal areas and river plains, as well as overexploitation of mangroves for timber and fuelwood, are also increasing soil erosion problems and habitat loss for aquatic species, including shrimp and prawns (the largest contributor to the Mozambique's foreign exchange) (UNEP, 1990; Dalal-Clayton, 1995; Dejene and Olivares, 1991).

United Nations Environment Programme