Of estuaries, lagoons and wetlands

Writer: Dr Anina Lee.

Despite the rain we've had over the last few days, South Africa, and especially the Western Cape, is seriously affected by drought brought on by climate change. Fresh water is therefore an extremely precious commodity.

Estuaries and lagoons Estuaries are one of the most important features of the South African coastline; they are tranquil areas of high productivity and play a vital role in the life cycles of many plants and animals – especially as a nursery for fish.

The Klein River in Hermanus has an estuary, as do the Onrus River, the Bot River, the Kleinmond River and the Uilenkraals River. These water bodies are often referred to as ‘lagoons’. This may be fine for visitors, but in fact they are not lagoons, they are estuaries. So what is the difference?

Kleinrivier Estuary

An estuary is where a river meets the sea. Situated at the interface between fresh- and marine waters, estuaries are among the most biologically productive ecosystems in the world and are of great ecological and economic importance.

Estuaries form a transition zone, known as an ecotone, between river environments and maritime environments. Estuaries are subject both to marine influences – such as tides, waves, and the influx of saline water – and to riverine influences – such as flows of fresh water and sediment. The mixing of seawater and fresh water provides high levels of nutrients both in the water column and in sediment, making estuaries among the most productive natural habitats in the world.

Click below to read more. (The full article can be found on page 8)