The South African Hotspot comprises the Southern Benguela upwelling ecosystem, the hotspot extends from the Orange River Mouth (29 ⁰S) in the northwest to East London (28 ⁰E) in the east, covering an area of 220 000 km2. The hotspot covers the shelf region to approximately 500 m depth and constitutes 26.94 % of South Africa’s EEZ. The area supports important commercial demersal, handline, invertebrate and pelagic fisheries including an important small-scale sub-sector. Mining, shipping and tourism are also important economic activities in the hotspot region.
The hotspot is influenced by two main current systems: the cool Benguela Current flowing north along the west coast of South Africa and the warm Agulhas Current, which flows south and west along the eastern and southern coasts of the country. The Benguela consists of an offshore oceanic component characterized by a slow and equatorward flow and an inshore component characterised by a dynamic wind-driven upwelling. The Agulhas Current is characterized by tropical, oligotrophic, fast -moving waters. It diverts offshore south of East London, following the edge of the Agulhas Bank, and retroflects along the Subtropical Convergence. Large, anticyclonic eddies, named Agulhas Rings, are transported from the Agulhas Current retroflection to the South Atlantic Ocean, transporting Indian Ocean waters to the Atlantic Ocean.
Economic and social context
The main economic activities of the hotspot region are fishing, mining, offshore oil and gas, shipping and tourism. Mining for diamonds, fossil fuels and phosphate are the most common types in the hotspot. Coastal tourism’s contribution to the South African economy has significantly increased in the last decade, with tourism contributing around 9% to the South Africa’s GDP in 2013.
The commercial fishing industry contributes approximately 0.5 % to the South African GDP, of which aquaculture contributes around 10 % and the remainder comes from the commercial fishing sector. Abalone farming is the most productive and valuable of all aquaculture products, accounting for approximately 40 % and 95 % of the total production and value of South African mariculture. Oyster and mussels farming are the second and third most valuable mariculture activities.
The main species targeted by the commercial fisheries include anchovy, sardine, Cape horse mackerel, shallow and deep water hake, tunnids (yellowfin, bigeye, albacore, swordfish), snoek, yellowtail, silver kabeljou, sharks (shortfin mako and blue shark), chokka squid, and West and South Coast rock lobster. There is also an important fishery for abalone that is currently at serious risk from illegal fishing. The bulk of the catch from the commercial fisheries is taken on the western coast of South Africa.
Recreational fishing is a very important activity along the South African coast, taking place in inshore waters and in many estuaries along the coast. Subsistence fishers mainly harvest fish, estuarine, intertidal rocky-shore and sandy beach invertebrates. The West Coast rock lobster (Jasus lalandii), oysters (mainly Striostrea margaritacea), abalone (Haliotis midae) and mullets (Liza richardsonii) are the most important resources for this group of fishers.
Biodiversity of the region
Estuaries, sandy beaches and rocky shores are the most important coastal habitats in the hotspot, supporting a variety of species of commercial, ecological and recreational importance. Sandy and sandy shelf habitat types are the dominant inshore and offshore ecosystems in the hotspot.
The west coast of South Africa is influenced by strong, wind-driven upwelling, which results in high biological productivity and supports a variety of stocks such as pilchard, anchovy, hake, and rock lobster. The Agulhas Current moves southwards down the east coast of South Africa and diverts along the edge of the Agulhas Bank, which is a very important spawning area for many pelagic fish species. The Good Hope jet current connects the Agulhas bank with the West Coast, which is the major upwelling region. This current transports eggs and larvae spawned on the west Agulhas Bank to the West Coast: an important nursery area for juveniles of sardine, anchovy, round herring and snoek.
A total of 12 914 marine species have been recorded in the South African exclusive economic zone (EEZ) as a whole. Mollusca, arthropoda and pisces are the most diverse groups accounting for ~ 68 % of the total number of species in South African waters. Approximately 33% of the total biota are endemic species (~ 4233 species). A total of 85 introduced and 39 cryptogenic aquatic species have been recorded in South Africa.
Key Climate Concerns
- Changes in the distribution of species of ecological and commercial importance. i.e. eastward shifts in the distribution of rocky shore organisms, West Coast rock lobster, sardine and anchovy.
- Over-fishing of target species causing major declines in the abundance of fish, invertebrate and birds species.
- Distribution changes and over-fishing of commercial species have affected a large number of fishers and communities because they are strongly dependent on these resources for their livelihoods.
- Freshwater flow reduction as a result of changing rainfall patterns.
- Medium and high vulnerability of some of the different fisheries sub-sectors to environmental change and variability due to low ability to adapt to reduced catches and catch rates, in particular West Coast rock lobster, the subsistence and small-scale and small pelagic fisheries.