We assume shared responsibility for maintaining the health, diversity and productivity of our own coastal environment.
The western coast of South Africa is dominated by coastal upwelling . This upwelling is driven by south-easterly and southerly winds which, in combination with coriolis forces, leads to offshore drift of surface waters, thus allowing colder bottom water into the surface layer. Upwelling results in the introduction of cold, nutrient-rich waters to the west coast. Cape Columbine is one of the major upwelling sites . St. Helena Bay, although adjacent to the Cape Columbine upwelling site is, due to its orientation and shallow bathymetry, protected from direct upwelling effects.
Along the South African coast, low-oxygen waters are a feature of the Benguela system. Two local zones of formation of oxygen-deficient water have been identified on the South African west coast, one in the vicinity of the Orange River mouth and the other in St Helena Bay. Water can advect southwards as compensation flow for the surface north-westerly drift.
Biological ccommunities along the west coast generally exhibit low species richness, with high biomass values being achieved by a few species, including kelps, limpets, black mussels, white mussels, abalone, rock lobsters and a number of fish and bird species.
The marine environment in St. Helena Bay supports an array of important marine aquatic ecosystems as well as other beneficial uses.
The area includes a rock lobster reserve; No rock lobster may be caught between Stompneus Point and beacons SHBE/DR at Wilde Varkens Valley (near Doctor’s Reef), extending six nautical miles seawards from the high-water mark.
No rock lobster may be caught between Shell Bay Point and Stompneus Point, extending three nautical miles seawards from the high-water mark.
The beaches within the Water Quality Trust's study area are some of the most popular recreation and tourist areas in St. Helena Bay and support activities such as bathing, surfing, kite- and windsurfing, yachting, diving, beach sports and walking.
The coastline along the study area is also popular for recreational fishing, and mussels (for human consumption) are sometimes collected from rocky shores, e.g. near Cape St Martin, Britannia Bay, Laaiplek and Dwarskersbos.