Wetlands are important ecologically, because they moderate water flow and regulate water quality. They act as sponges during wet periods, therefore controlling the extent and impacts of flooding and droughts. They slow down the flow of water, causing suspended matter to settle out or to be absorbed by wetland plants. Wetland plants are specifically adapted to flourish in areas of higher than average concentrations of certain elements.
Wetlands are among the most threatened aquatic habitats in
South Africa, and it is estimated that up to 50% of wetlands
may have been lost country-wide. Threats to wetlands include
human activities, such as channelisation, drainage, crop
production, effluent disposal and water abstraction. Loss of
wetlands leads to a reduction or loss in biodiversity, as the
plants and animals that are adapted to wetland habitats are
often unable to adapt to new environmental conditions, or to
move to more suitable ones. Loss of harvestable resources
also occurs when wetlands are lost. For example reeds and
grasses are important materials in traditional construction,
and reduction in these resources creates a dependence on
other materials such as wood, plastics, and metals, which
have negative environmental impacts. Loss of water quality
and flow regulation is a further consequence of loss of
wetlands, and may result in greater extent or severity of
flooding.
Of the more than 800 naturally-occurring freshwater
wetlands in South Africa, 14% have full protection within a
national park, provincial nature reserve or wildlife sanctuary
and 4% are partly protected. South Africa currently has
16 wetlands designated as wetlands of international
importance in accordance with the Ramsar Convention.
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