Aquatic Biomes of Southern Africa
Biomes are regions that display similar climatic and geographic characteristics, climate is determined by precipitation (rainfall) and average temperature. Geography comprises the terrain, the location and any barriers such as mountains, rivers etc. Specific conditions determine the flora and fauna within the biome, the fauna, flora and soil organisms within a biome make up an ecosystem.
Biomes are either aquatic or terrestrial. We will first touch on aquatic biomes. Water covers a large portion of the earth’s surface and is richly diverse in plants and animals, we get freshwater and marine biomes.
These generally have a low salt concentration (less than 1%) and include, rivers, streams, ponds, lakes and wetlands. Man made dams will have an impact on the free flow of a river and the character of the biome.
Here we have a higher salt content (3,5%) around 35 grams of dissolved salt per litre of water. Consists of our oceans, estuaries and coral reefs.
- Marine biome vegetation consists of various types of algae one the major sources of oxygen in the world, green algae also assists in the removal of carbon dioxide from the atmosphere.
Our oceans are large marine bodies that cover large portions of the earth’s surface (nearly three quarters) as such they hold the largest diverse ecosystems. Examples are the plethora of fish, sharks, whales, octopuses, shellfish, perlemoen etc.
- Coral Reefs are formed underwater from Calcium Carbonate deposits produced by living coral, in our case they are found mainly along the warm east coast in the greater St Lucia area as well as Kozi Bay, Sodwana Bay and Leadsman Shoal. Lesser deposits are found at Aliwal Shoal near Umkomaas.
- Estuaries are coastal bodies of water permanently or periodically open to the sea. Salinity varies according mix of fresh (river or stream) and sea water. Biologically they are extremely diverse and provide a habitat for many plants, birds and animals.
Our coastline extends over 3 000 kilometres, from Namibia to Mozambique. It is rugged, with rocky shores exposed to high wave and wind activity. Numerous estuaries are found along the coast, most of which are found on the East Coast between Cape Padrone in the Eastern Cape and Mtunzini in KwaZulu Natal. The Eastern area receives the highest rainfall, mainly in the summer months. South Africa’s east coast has relatively warm waters whilst the west is much colder. The Benguela current on the South-West coast supports large numbers of marine animals, whilst the Agulhas current off the East Coast has a lesser quantity of fish but more diverse species. The coastline offers numerous economic opportunities for tourism, fishing and recreation. The main harbours being Richards Bay, Durban,Port Elizabeth and Cape Town.