Currents of contrast
The Agulhas current, transporting about 73 billion liters of water per second, is one of the most powerful ocean currents in the world. This warm water current runs down the east coast of southern Africa, before retroflecting back eastwards into the Indian Ocean.
Contrastingly, the cold Benguela current is a slower wind-driven current that runs up the west coast of southern Africa. The surface waters in this current are driven offshore by a combination of the prevailing south-easterly wind and the rotation of the earth. This movement of water creates the pulsing upwelling systems that bring cold, nutrient rich waters to the surface, and create some of the most productive waters in the world.
These contrasting ocean currents are responsible for two major biological patterns in the area. High-biomass aggregations of single species in the west, and diverse, species-rich ecosystems in the east. No where else in the world are two contrastingly different ecosystems found in such close proximity, and here in the Cape we get a taste of both, separated by a mere 7kms of land. It is no wonder Sir Francis Drake dubbed it “a most stately thing and the fairest cape we saw in the whole circumference of the earth.”