The Southern African coast is a diverse region including a number of different habitats
each with a wide variety of fauna and flora and it is estimated that there is over
10 000 species of marine organisms (Branch et al 1994). A number of books, although
small is relationship to those published on the better know terrestrial fauna and
flora of this biologically rich and diverse tip of Africa, are available on the
marine habitats and the organisms found within this unique area (see under more
literature material section for a list).
The diversity of fauna en flora present along the southern African coast is a reflection
of the different water masses that influence the climate, sea temperature and other
factors associated with the different geographical (Branch et al 1994). The narrow
continental shelf on the East Coast North of East London bathes the coastal area
in warm water brought down by the Agulhas current from the subtropics. As the continental
self widens to the south the near shore temperature becomes cooler and more temperate.
The west coast is however chilled by northward drifting cold water from the Benguela
current. This and the added occurrence of up-welling where cold nutrient rich water
from the deep replaces surface water blown off shore set the scene for an coastal
region with a higher productivity but lower diversity that the eastern coast (Branch
et al 1994).
The Southern African coast can thus be divided into three zones. The highly productive
but cold west coast, north of Cape point. The diverse temperate south coast, between
Cape point and just north of East London and the more tropical coastal area to the
north of East London. The area north of Durban is characterized by coral reefs otherwise
not found along the southern African coast.
The southern Cape coast from Cape St. Francis Bay to Woody Cape is a number of half-heart
bays with rocky headlands protruding into the sea. The sand accumulates along the
northern and eastern regions of the bays. In Algoa Bay the deposition of sea-born
sand on its northern shores has formed the largest dune field on the eastern coast
of southern Africa, the Alexandra dune field (Lubke et al. 1988). The climate in
the area is very variable. The area fall between the countries winter and summer
rainfall areas and rain can be expected any time of the year. The area is also considered
as one of the windiest part (predominately westerly) of southern Africa (although
not strictly true). The maximum tidal range on the eastern Cape coast is only 2m
and in Algoa Bay spring low tide falls around 10h00 and 22h00.
Further reading or related literature
Day, J. H. 1974. Guide to Marine Life of South African Shores. A. A, Balkema, Cape
Town, 272 pp.
Branch, G. and Branch, M, 1981. The Living shores of Southern Africa. C. Struik,
Cape Town, 272 pp.
Griffiths, C., Griffiths, R. and Thorpe, D. 1988. Seashore Life. Struik Guide Series,
Struik Publ., Cape Town, 64pp.
Lubke, R.A., Gess, F.W. and Bruton, M.N. 1988 A field Guide to the Eastern Cape
Coast. Wildlife Society of Southern Africa, Grahamstown, 520 pp.
Payne, A.I.L., Crawford, R.J.M. and van Dalsen, A. 1989 Oceans of Life off Southern
Africa. Vlaeberg Publ. Cape Town, 380pp.
The Reader's Digest Association South Africa 1984. Atlas of Southern Africa. Produced
in conjunction with the Directorate of Surveys and Mapping, Department, which prepared
the maps for " Our land in close up'. pp 256.
Branch, G.M., Griffiths, C.L., Branch, M.L. and Beckley, L.E. 1994 Two Oceans. A
Guide to the Marine Life of Southern Africa. David Philip Publ (Pty)Ltd. 360 pp