Apart from having several hundreds of kilometres of coastline, the marine environment around the CMA is unique in that it lies at the juncture of two biogeographic provinces. The area east of Cape Point at the tip of the Cape Peninsula lies within the warm Agulhas Province and supports a relatively diverse array of marine species. The marine biota inhabiting this rocky intertidal zone are not evenly distributed along the shore. While the cold West Coast supports a high biomass of organisms, it is relatively poor in terms of species richness relative to the warmer False Bay coast. Species richness on these beaches is far lower than on the adjacent rocky shores, primarily due to the reduced habitat diversity.
Dunes occur at the landward extreme of sandy beaches.
In water of less than five metres depth, rocky reef areas are dominated by seaweeds, with the kelp Ecklonia maxima forming the bulk of the algal biomass. A large proportion of the larger fish species, primarily those belonging to the Family Sparidae, is also endemic to southern Africa. The pelagic zone Back to top The pelagic zone includes the water above the reefs and sandflats. Here plankton form the basis of the foodwebs. The pelagic zone is also used by whales and dolphins.