South Africa is globally recognised for its marine biodiversity and high levels of endemism. South Africa’s wide range of oceanographic, bioclimatic, topographical and geological settings have not only resulted in high species diversity and endemism, but also high ecosystem diversity. The marine realm is defined from the dune base, effectively a decadal scale high water mark, to the outer boundary of South Africa’s Exclusive Economic Zone (EEZ), an ocean area of 1.1 million km2. The Marine Ecosystem Classification of South Africa has 150 marine ecosystem types in six marine ecoregions. The map of marine ecosystem types included very fine-scale shore mapping with alignment between marine, terrestrial and estuarine realms in the coastal zone; the inclusion of kelp forests, bays, fluvial fans and stromatolite shores as distinct ecosystem types and the introduction of finer depth strata across shelves and on the slope.
Rivers and wetlands are among the most highly diverse aquatic ecosystems in South Africa and provide a number of high value provisional and regulatory ecosystem services. The management, and monitoring of these systems is important in South Africa which is a water-stressed country and whose socio-economic development places enormous pressure on its water resources. However, these systems are among the most highly threatened and poorly protected ecosystems in the country. The mapping of hydrological features of South Africa, including rivers, waterbodies and springs, have been done since the 1940s . The South African Inventory of Inland Aquatic Ecosystems (SAIIAE) is an inventory and collection of spatial data and supporting information describing the inland aquatic ecosystems of South Africa which include rivers, wetlands, artificial water bodies, freshwater species as well as an emerging database of associated information. The development of this inventory is supported by legislation, including the National Water Act (No. 36 of 1998) and the National Environmental Management: Biodiversity Act (NEMBA) (No. 10 of 2004).
The National Vegetation Map Project (VEGMAP) is a large collaborative project that was established to classify, map and sample the vegetation of South Africa, Lesotho and Swaziland. In the terrestrial environment, vegetation types provide an excellent way of delineating ecosystems at a relatively fine scale. Vegetation types are based on a range of factors, such as geology, soil types, rainfall, temperature and altitude, which determine the composition and structure of plant communities (Mucina & Rutherford 2006). They provide a good indication of terrestrial biodiversity other than plant species, because many animals, birds, insects and other organisms are associated with particular vegetation types or groups of vegetation types. The vegetation map delineates and describes the historical extent of the vegetation types in South Africa, Lesotho and Swaziland prior to major anthropogenic land conversion (circa 1750). The vegetation map is used as the terrestrial ecosystem map in planning and assessment. The main components of the VEGMAP project include: (i) The classification of ecosystem types, (ii) the map of ecosystem types, (iii) the National Vegetation Database. The National Vegetation map and National Vegetation Database are fundamentally important for environmental planning, conservation management, biodiversity assessment and research in the floristically diverse region of southern Africa.
Estuaries are rich and productive systems that produce a wide range of benefits to society. They derive their richness and productivity from nutrient and sediment inputs received from river and sea water, combined with the relatively sheltered aquatic habitat that they provide. Their characteristic biodiversity assemblages have arisen from the need for biota to cope with their salinity gradients and fluctuations. These unique characteristics make estuaries among the most valuable types of ecosystems on earth. The highly dynamic nature of estuarine ecosystems presents a significant challenge to classifying, mapping and managing estuaries. The upstream boundary of the estuaries is determined as the limits of tidal variation or salinity penetration, whichever penetrates furthest. The estuary mouth is taken as the downstream boundary of an estuary. Estuarine Shore is defined as the area from the base of the foredune, or where this line would be if dunes were present, to the back of the surf zone. In total 290 estuaries and 42 micro-estuaries were delineated and classified into 22 estuary ecosystem types and 9 micro-system types.
The ecologically-determined coastal zone includes all ecosystem types that are recognised to be influenced by both the land and sea, i.e., terrestrial ecosystem types that occur exclusively close to the coast, all estuaries, all marine ecosystem types up to the fair-weather wave base (back of the inner shelf; the point at which waves stop having an influence on the seabed), the full extent of bays, and all marine ecosystem types that are influenced by riverine/estuarine flows (freshwater, nutrients and sediments, particularly muds). This now provides us with a coherent ecological unit within which we can do planning, assessment and decision-making that fully accounts for cross-realm processes and connectivity. By working together in a cross-realm team, defining a seashore “zip” that seamlessly connects the terrestrial, marine and estuarine realms, integrating existing national and provincial maps, and mapping the seashore at a scale that is relevant to the ecosystem types and to management, South Africa now has a seamless map of ecosystem types from land all the way to the edge of the Exclusive Economic Zone.
The Prince Edward Islands are located on a shallow volcanic plateau that rises from 3000 m to breach the surface. Marion and Prince Edward Island reach 1230 m and 672 metres above sea level (m a.s.l.), respectively, and are separated by a 19 km shallow shelf. The islands emerged ~0.45 million years ago (mya) and have since been colonised by a wide range of sub-Antarctic flora and fauna. The dominant easterly-flowing current interacts with the plateau to form large phytoplankton blooms that enrich pelagic communities thousands of kilometres downstream. The Prince Edward Islands (PEIs) terrestrial ecosystem types have been classified and mapped into vegetation units based largely on floristics. The PEIs marine ecosystem types encompass both coastal and deep sea marine ecosystem types ranging from the upper-shore limit of the salt-spray influenced supralittoral zone at the islands to the 200 nautical mile limit of the Exclusive Economic Zone (EEZ).