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African Notes: Environmental Information |
 Where the sea meets the land
The climate and way of life in coastal zones is influenced by the adjacent oceans and currents.
On the east coast of southern Africa, all the way up to northern Mozambique, the warm, relatively nutrient poor Agulhas Current creates a sub-tropical climate on land. The landscape includes lush coastal forests and mangroves teeming with life. As the temperature is relatively constant and benign, this current sustains a large diversity of marine life.
By contrast, on the west coasts of South Africa, Namibia and Angola the cold Benguela Current creates a hot, dry, arid climate on land. Yet while the land on the west coast may be arid, the sea is not. Strong, seasonal off-shore winds blow the warmer surface waters out to sea, allowing cold nutrient-rich water to rise to the surface in a process known as upwelling.
The Benguela Current
The Benguela Current Large Marine Ecosystem (BCLME) is one of the most productive ecosystems on Earth. It extends from northern Angola to just east of Port Elizabeth in South Africa. Here, the sea is rich in fish stocks such as hake, sardines, horse mackerel, tuna and rock lobster, while under the sea bed, the shelf hides rich deposits of oil, gas and diamonds.
This wealth carries with it the responsibility of nurturing these resources on behalf of the present and the future inhabitants of southern Africa.
 Precious wetlands
Along both coasts, as elsewhere in the world, wetlands are a precious source of life. A marsh, bog, swamp or vlei is an example of a wetland. Some are constantly underwater, while others dry up at certain times of the year.
Wetlands are productive ecosystems and provide important breeding, nursery and feeding areas for many species. They also help store water, reduce flood damage and erosion, and purify water.
They are vital habitats, yet most of our wetlands are under threat. Langebaan, the Orange River mouth, Walvis Bay Lagoon and St Lucia are examples of major wetlands that we need to protect for future generations.
Find out more about wetlands and marine ecosystems:
Wetlands International
http://www.wetlands.org/
SANBI and DEAT– Working for Wetlands Programme
http://www.sanbi.org/research/wetlandprog.htm
Benguela Current Large Marine Ecosystem Programme
www.bclme.org
DLIST Hotspots
http://www.dlist-benguela.org/Hotspots/Hotspots/
The East African Coastal Databse
http://hq.unep.org/easternafrica/index.cfm
The Greater St Lucia Wetlands Park – a World Heritage Site
http://www.stlucia.org.za
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