The proposed Cape Point to Cape Agulhas EBSA is located at the coastal tip of Africa, from Cape Point to Cape Agulhas, within South Africa’s EEZ. It extends from the coast to the inner shelf, and includes key islands, two major bays (False Bay and Walker Bay). This EBSA is of key importance for threatened species and habitats, and for supporting life-history stages, notably for some of the threatened species. The threatened habitats include coastal, inshore and inner shelf ecosystem types. The important life-history stages supported by the area are breeding and/or foraging grounds for a myriad of top predators, including sharks, whales, and seabirds, some of which are threatened species, such as the Endangered African penguin. The EBSA also includes some relatively rare features. For example, it contains one of a few locations where surf diatom accumulations occur in South Africa, that in turn fuel sandy shores with heightened productivity. This EBSA is also the place where the Benguela and Agulhas currents meet, and thus where the Indian and Atlantic Oceans meet.
This is a new, proposed EBSA.
Introduction of the area
Cape Point to Cape Agulhas is a coastal EBSA at the southernmost tip of Africa that includes both benthic and pelagic features, and key links between the terrestrial and marine realms. The proposed EBSA extends from the dune base at the back of the shore to depths that are mostly shallower than 150 m. The Agulhas and Benguela Currents meet offshore of this EBSA, with the sea surface temperature between Cape Point and Cape Agulhas being generally cooler than that further offshore where the warmer Agulhas current has a greater influence. The area is important for many commercially important fish species (e.g., Watermeyer et al., 2016), and forms part of their spawning grounds. Consequently, it provides key foraging habitat for numerous top predators, including sharks, whales, seals and seabirds (e.g., Crawford et al., 2008; Pichegru et al., 2010; Best et al. 2015). The EBSA also contains important breeding and resting sites for these top predators both on the mainland, in bays and on several islands that are contained within the EBSA (e.g., Best 2000; Underhill et al., 2006; Kirkman et al., 2013). Given the close proximity of the EBSA to key research institutions, and the rich diversity of key marine species and features in the area, there are many datasets available for the site. The EBSA also includes areas of high productivity formed by relatively rare surf diatom accumulations.
The reason this site was not part of the original list of EBSAs first proposed in the South Eastern Atlantic EBSA Identification Workshop in 2013 (UNEP/CBD/RW/EBSA/SEA/1/4) is because the value of the area was recognised only afterwards in a gap analysis.
Description of location
The proposed Cape Point to Cape Agulhas EBSA is located at the coastal tip of Africa, within South Africa’s EEZ. It wraps around the tip of Cape Point, extends along the shore to the western end of the terrestrial De Mond Nature Reserve in Struisbaai, just past Cape Agulhas. It extends from the dune base to the inner shelf, roughly 40 km offshore.
Feature description of the area
Cape Point to Cape Agulhas is important for both benthic and pelagic features. The benthic features include ecosystem types comprising mosaics of sand and reef, kelp beds, and several islands (Seal Island, Dyer Island, Geyser Rock, Quoin Rock), and shore habitats including rocky, sandy, mixed and estuarine shores; the pelagic features include important spawning and foraging grounds for a variety of fish and top predators, and areas of high primary productivity. Benthic-pelagic coupling is also a key feature of this EBSA, particularly important in the two important bay systems that are in the EBSA, and for land-sea connectivity among ecosystem types. Overall, the EBSA's most key attributes are that it includes many threatened species and habitats, and supports important life-history stages of many species, including some of the threatened taxa.
Of the 32 ecosystem types represented in Cape Point to Cape Agulhas, two thirds are threatened, including four Critically Endangered and two Endangered types. These are all reef and rocky types, that by implication, support diverse communities that are, in turn, threatened as well. The EBSA forms part of the spawning grounds for many commercially important fish species (e.g., Watermeyer et al., 2016). Consequently, it provides key foraging habitat for numerous top predators, including sharks, whales, seals and seabirds (e.g., Crawford et al., 2008; Pichegru et al., 2010; Best et al. 2013), many of which species are also threatened. It also contains important breeding and resting sites for top predators, in bays, on the islands and the mainland. For example, it contains island-based (Seal Island, Dyer Island, Geyser Rock) and the only mainland-based (Boulders Beach, Stony Point) colonies of breeding Endangered African penguins (Underhill et al., 2006), and Seal Island, Geyser Rock and Quoin Rock support breeding colonies of Cape fur seals (Kirkman et al., 2013). The EBSA may also include areas where southern right whales give birth to and nurse their calves, and possibly mate (Best 2000).
Secondary attributes of Cape Point to Cape Agulhas support all other EBSA criteria except for Naturalness. The EBSA includes relatively rare surf diatom accumulations that are present at a few sites along the South African south coast, and only several other places, globally (Campbell & Bate., 1988, Campbell 1996). These surf diatom accumulations fuel sandy beach food webs with particularly high productivity. The kelp beds in the adjacent habitat also provide beach-cast kelp wrack, which also creates particularly productive sandy shore systems (e.g., Dugan et al., 2003; Rodil et al., 2018). Cape Point represents a biogeographic break between the warm and cold temperate coastal systems (Sink et al., 2012), and thus diversity at this site is comparatively higher than adjacent sites because it includes representatives from both bioregions. And finally, the reef and hard ground habitats all support fragile species, that are slow growing and sensitive to disturbance.
Feature conditions and future outlook of the proposed area
Although the Cape peninsula is protected in a marine protected area, there are numerous threats to the marine environment in this EBSA, particularly within False Bay and Walker Bay. There are several fisheries operating in the area, including those for West coast rock lobster, squid, linefish, and sharks, as well as subsistence and recreational shore and boat-based fishing, kelp harvesting, and bait collecting (Sink et al., 2012). Given the close proximity to the Cape Town harbour, and the numerous smaller ports within the EBSA, shipping is a relatively high pressure here. The coast is under particular pressure from coastal development (outside the many terrestrial nature reserves in the western half of the EBSA), with associated pressures such as waste water discharge; there are also several invasive invertebrates that are primarily associated with rocky shores that have affected native populations (Sink et al., 2012). Global change pressures are affecting the distribution of local fish stocks, which in turn are affecting some of the top predators, including Endangered African penguins, and Endangered Cape gannets (Crawford et al., 2008; Pichegru et al., 2010).
Assessment of the area against CBD EBSA criteria
Uniqueness or rarity
This area meeting EBSA criteria is the only eastern boundary upwelling system that is bounded by warm water systems in the north and in the south (Shillington et al., 2007, Hutchings et al., 2009). The broader area also includes some unique oxygen minimum zones with unique fauna and flora (Bartholomae & van der Plas 2007).
Special importance for life-history stages of species
Cape Point to Cape Agulhas is an important spawning ground for commercially important fish species (e.g., Watermeyer et al., 2016). Consequently, it provides key foraging habitat for numerous top predators, including sharks, whales, seals and seabirds (e.g., Crawford et al., 2008; Pichegru et al., 2010; Best et al. 2013). It also contains important breeding and resting sites for top predators, in bays, on the islands and the mainland. For example, it contains island-based and the only mainland-based colonies of breeding Endangered African penguins (Underhill et al., 2006), and Seal Island, Geyser Rock and Quoin Rock support breeding colonies of Cape fur seals (Kirkman et al., 2013). The EBSA may also include areas where southern right whales give birth to and nurse their calves, and possibly mate (Best 2000).
Importance for threatened, endangered or declining species and/or habitats
There are a number of threatened species that depend on this EBSA focus area for foraging and/or breeding, including Vulnerable white shark, Endangered Indian Ocean humpback dolphin, Endangered Cape gannet, Endangered African penguin, Endangered Cape cormorant, Endangered bank cormorant, white-breasted cormorant, and Near Threatened crowned cormorant.
The area includes a very high diversity of threatened ecosystem types. According to the data from the South African National Biodiversity Assessment (Sink et al., 2012) the area includes small portions of four Critically Endangered ecosystem types, namely Agulhas Inshore Reef, Agulhas Sheltered Rocky Coast, Southwestern Cape Inshore Reef and Southwestern Cape Very Exposed Rocky Coast. It contains two Endangered types, namely a very large area of Agulhas Hard Inner Shelf and some Southwestern Cape Exposed Rocky Coast. An additional 14 Vulnerable ecosystem types, namely Agulhas Dissipative Sandy Coast, Agulhas Exposed Rocky Coast, Agulhas Hard Outer Shelf (a large area), Agulhas Inner Shelf Reef, Agulhas Inshore Hard Grounds, Agulhas Island, Agulhas Mixed Shore, Agulhas Muddy Outer Shelf, Agulhas Sandy Inner Shelf (a large area), Agulhas Sandy Inshore, Agulhas Very Exposed Rocky Coast, Southern Benguela Hard Outer Shelf, Southwestern Cape Mixed Shore and Southwestern Cape Sandy Inshore. By implication, the communities associated with these ecosystems are also likely to be threatened.
Vulnerability, fragility, sensitivity, or slow recovery
The top predators represented in this EBSA have a slow recovery time following impacts to their respective populations. Further, the reefs and hard grounds contain fragile species that are slow growing, and sensitive to disturbance.
The area incorporates the most intensive wind-induced upwelling cell in the world – located just off Lüderitz (Bakun 1996), and seven other upwelling cells (Hutchings et al., 2009). This is reflected in the very high productivity of the system (Bakun 1996), the abundance of fish stocks and higher trophic level species (van der Lingen et al., 2006), and the numerous commercial, artisanal and recreational fisheries it supports. The key highly productive fisheries include pelagic fisheries, demersal fisheries (including 2 species of hake Merluccius spp.), midwater purse-sein and demersal crustacean fisheries.
The kelp beds and surf diatom accumulations contribute to elevated productivity for coastal ecosystems, notably the sandy shores (Campbell and Bate, 1988, Rodil et al., 2018). As a spawning area for commercially important fish species, productivity across the shelf is also relatively high.
The Agulhas and Benguela currents also meet in the broader area surrounding the EBSA. Consequently, Cape Point is a biogeographic break between the warm and cold temperate bioregions, and thus biodiversity in the area is expected to relatively higher here compared to that of surrounding areas. This is additionally true because the conditions range from fully sheltered within the bays, to fully exposed on the open coast, and because it contains 32 different ecosystem types, each likely supporting their own biological communities. The EBSA is also known to support diverse assemblages of key species (e.g., Best et al., 2013).
Best, L.N., Attwood, C.G., da Silva, C., and Lamberth, S.J. 2013. Chondrichthyan occurrence and abundance trends in False Bay, South Africa, spanning a century of catch and survey records. African Zoology, 48: 201-227.
Best, P.B. 2000. Coastal distribution, movements and site fidelity of right whales Eubalaena australis off South Africa, 1969–1998. South African Journal of Marine Science, 22: 43-55.
Campbell, E.E. 1996. The global distribution of surf diatom accumulations. Revista Chilena Historia Natural, 69: 495-501.
Campbell, E.E., Bate, G.C. 1988. The estimation of annual primary production in a high energy surf-zone. Botanica Marina, 31: 337-343.
Crawford, R.J.M., Underhill, L.G., Coetzee, J.C., Fairweather, T., Shannon, L.J., Wolfaardt, A.C. 2008. Influences of the abundance and distribution of prey on African penguins Spheniscus demersus off western South Africa. African Journal of Marine Science, 30: 167-175.
Dugan, J., Hubbard, D.M., McCrary, M.D., Pierson, M.O. 2003. The response of macrofauna communities and shorebirds to macrophyte wrack subsidies on exposed sandy beaches of southern California. Estuarine, Coastal and Shelf Science, 58S: 25-40.
Johnson, D.E., Barrio Froján, C., Turner, P.J., Weaver, P., Gunn, V., Dunn, D.C., Halpin, P., Bax, N.J., Dunstan, P.K., 2018. Reviewing the EBSA process: Improving on success. Marine Policy 88, 75-85.
Kirkman, S.P., Yemane, D., Oosthuizen, W.H., Meÿer, M.A., Kotze, P.G.H., Skrypzeck, H., Vaz Velho, F., Underhill, L.G. 2013. Spatio-temporal shifts of the dynamic Cape fur seal population in southern Africa, based on aerial censuses (1972–2009). Marine Mammal Science, 29: 497–524.
Pichegru, L., Ryan, P.G., Crawford, R.J.M., van der Lingen, C.D., Grémillet, D. 2010. Behavioural inertia places a top marine predator at risk from environmental change in the Benguela upwelling system. Marine Biology, 157: 537-544.
Rodil, I.F., Lastra, M., López, J., Mucha, A.P., Fernandes, J.P., Fernandes, S.V., Olabarria, C. 2018. Sandy Beaches as Biogeochemical Hotspots: The Metabolic Role of Macroalgal Wrack on Low-productive Shores. Ecosystems, in press.
Sink, K., Holness, S., Harris, L., Majiedt, P., Atkinson, L., Robinson, T., Kirkman, S., Hutchings, L., Leslie, R., Lamberth, S., Kerwath, S., von der Heyden, S., Lombard, A., Attwood, C., Branch, G., Fairweather, T., Taljaard, S., Weerts, S., Cowley, P., Awad, A., Halpern, B., Grantham, H., Wolf, T. 2012. National Biodiversity Assessment 2011: Technical Report. Volume 4: Marine and Coastal Component. South African National Biodiversity Institute, Pretoria.
Underhill, L.G., Crawford, R.J.M., Wolfaardt, A.C., Whittington, P.A., Dyer, B.M., Leshoro, T.M., Ruthenberg, M., Upfold, L., Visagie, J. 2006. Regionally coherent trends in colonies of African penguins Spheniscus demersus in the Western Cape, South Africa, 1987–2005. African Journal of Marine Science, 28: 697-704.