Natural History of Arniston / Waenhuiskrans
The Indian and Atlantic oceans meet at Cape Agulhas. Along the coast sand dunes cover a wavecut platform which varies in width from 3km to 22km, with an altitude of less than 150. Two distinct types of beaches occur; those of rock outcrop and those of flat beach sand. In all instances the rock outcrops are Table Mountain sandstone (some granite). Where shales of the Bokkeveld or Malmesbury intersect the coast no rock outcrops occur, and the beach is covered with sand. The coastal low areas are covered with dunes with intersections of brack marshes.
The climate is typical of a winter rainfall area with wet cool winters and warm dry summers. The majority of rainfall occurs between May and September and varies between just under 400mm to 600mm per year. South facing hill slopes obtain the highest rainfall. Temperature differences are not great, due to the oceanic influence. Summer winds are predominantly South Eastern winds, often very strong. Autumn is relatively still, before the winter rains.
The area has a great variety of shrubs, bushes and wild flowers. Indigenous trees as and natural grass types are scarce.
With the establishment of the Overberg Test Range in 1986, a marine reserve was proclaimed from Arniston to Infanta (up to 12 km wide). Whales and various fish species returned in large numbers after this reserve was created.
The De Hoop wetland was registered as a Ramsar Wetland of International Importance in 1971. It is a highly productive ecosystem with a variety of crustaceans, insect larvae, tadpoles and aquatic plants serving as food sources for aquatic birds, bats and larger mammals. Approximately 200 bird species can be found here. The wetland is 16 km long with an area of about 6.2 km2.