Driving forces affecting marine and coastal systems and resources

4.2.1 Population growth:  

The single greatest driving force for environmental change that poses a threat to resources in the coastal zone is population growth.

The location of the country's gold mines on the Witwatersrand (Gauteng Province) has resulted in the historic development of South Africa's industrial heartland in the interior of the country. However, the South African economy is evolving from a strong dependence on production activities to increased manufacturing and service industries and, as a consequence, is increasingly dependent on port facilities for the export of processed products. As a result coastal cities have developed rapidly and industrial centres have expanded. New industrial centres have also developed at Richards Bay (east coast) and Saldanha (west coast). To some extent, the relocation of business to these and other coastal centres is perceived to improve the quality of life. Coastal resort development has increased rapidly, particularly since the 1994 election following which international tourism to South Africa has boomed.

Thirty per cent of the South African population lives along the coast. The natural population growth of coastal areas is compounded by a net in-migration from job seekers, as well as people retiring to the coast and those seeking a better quality of life. Coastally orientated development policies and initiatives[such as the Rural Development Framework, Growth, Employment and Redistribution Strategy (GEAR) and Spatial Development Initiatives (SDIs) are encouraging migration to coastal areas (Cross & Welsh 1999).

4.2.2 Coastal zone management policy:  

In the past, each province had its own policies regarding coastal development; there was no effective national strategy. Many offices were poorly staffed and under-funded. This resulted in inconsistent and often contradictory approaches to coastal zone management. Losses of experienced personnel from existing institutional structures has made this worse. No exact figures are available but this is evident from the number of former provincial conservation scientists in private consultancy.

A recent Environmental Impact Assessment (EIA) for a marine sewage outfall at East London illustrates the problem: In this case the National Department of Environment Affairs and Tourism's Directorate of Pollution Control: Marine Pollution was satisfied that the EIA met their requirements yet the provincial Department of Economic Affairs, Environment and Tourism held up approval of the EIA because they had objections to the discharge of sewage sludge to sea. The resultant delay in approval severely affected the securement of funding to manage the environmental impacts of the present discharge of untreated sewage at the shoreline.

4.2.3 Sea bed mining:  

Marine diamond mining is being undertaken along the west coast between the Orange River mouth and Lambert's Bay. Operations extend from the shore to water depths of up to 130 m. Sea bed mining disrupts the bottom sediment profile, radically altering the habitat for benthic organisms. Recovery from marine mining activity takes decades and it is unknown whether systems can ever recover fully. Since mining largely takes place in the open sea or along high energy coasts the impact of fine grained suspended sediments on marine ecosystems is thought to be minimal.

Richards Bay Minerals recovers various heavy minerals such as titanium and zirconium on the east coast. Adverse impacts of mining related activities include disturbance of sand dune systems (although rehabilitation has been very successful), disturbance of wetlands and estuaries, creation of odours and air pollution, and daming of the lagoon for water supply (although a fish ladder is being built to reopen access for fish and crustacea to the lake.

Figure 4.3 Minerals extraction

Positive impacts of mining are job creation, environmental education programmes and a substantial contribution to the regional and national economy.

Until recently, hydrocarbon (oil and gas) exploration and extraction has been focussed almost entirely on the Agulhas Bank, about 100 km from Mossel Bay. Current exploration extends from the Namaqualand coast to the Tugela Bank off KwaZulu-Natal (Figure 4.3).

4.2.4 Fishing: 

Fishing is one of South Africa's primary economic activities. Commercial fishing generates approximately R1.7 billion annually and employs 27 000 people (with an additional 60 000 people employed in related industries). Recreational fishing generates approximately R1.3 billion annually and employs 131 000 people in related activities. In addition, at least 3.6 million South Africans depend largely on coastal food sources through subsistence activities estimated to be worth R1.1 billion annually (CMPP 1999).

White steenbras

A variety of fishing methods is employed along the South African coast. These range from industrial methods such as purse-seining, bottom and midwater-trawling, to minor commercial, artisanal and subsistence methods such as hoop-net, fish trapping and beach seining. Improvements in fishing methods results in greater numbers and varieties (sizes and species) of fish being caught. As a consequence fish stocks are shrinking and several species face potential extinction. The fishery for the white steenbras Lithognathus lithognathus is an example where increased angling effort and industrial purse-seining in addition to the traditional beach seining has led to a serious decline in stocks (Bennet, 1993).

4.2.5 Shipping: 

South Africa is situated on one of the world's busiest ship transport routes, particularly for the transport of crude oil from the Middle East to Europe and the Americas. Over 4000 ships pass the Cape of Good Hope every year, and R4.2 billion in revenue is generated every year by transporting cargo through South African ports. An analysis of the shipping traffic around the Cape is presented in Table 4.1 below.

Oil spill from tanker

Shipping which is routed around the Cape is exposed to extremes of weather and sea conditions. This greatly increases the risk of major marine pollution incidents, particularly from oil tankers, but also from those with more lethal cargoes such as nuclear waste, which, should a shipping disaster occur could have devastating consequences for human coastal communities, and not just marine life and the dependent economic activities.

Environmental hazards are particularly severe where ballast discharge occurs in closed bays which are biologically important; e.g. Saldanha Bay (Figure 4.4) .

Figure 4.4 Coastal sensitivity map for the Langebaan area. Environments sensitive to oil pollution are indicated in red. Source, South Africa 1984.

The introduction of alien invasive marine organisms also occurs via marine transport, both those carried in ballast water when the ballast water is discharged by vessels loading cargos at South African ports, as well as attached to ship's hulls. The Mediterranean mussel Mytillus galloprovincialis which is replacing the indigenous black mussel Chloromytillus meridionalis is almost certain to have been introduced by ships. Ironically the Mediterranean mussel has become the mainstay of the mussel mariculture industry in Saldanha Bay.

Figure 4.5 Oil transport activities off the South African coast.

4.2.6 Coastal human settlements: 

Much of the country's coastal development for human settlement is centred around the seven large commercial ports situated at Saldanha Bay, Cape Town, Mossel Bay, Port Elizabeth, East London, Durban and Richards Bay (Figure 4.6). These areas also extensive industrial and urban development and have been identifies for the development through many of the Spatial Development Initiatives (SDIs) actively promoted by government. Such initiatives also include the proposed new Ngqura (Coega) port which is planned for the Eastern Cape . Smaller scale coastal developments centre around the many fishing harbours distributed mainly along the Western Cape coast. The concentration of industrial activities and human populations at such centres places high demands on the environment in terms of land for development, water supply and other resources and on the capacity of the marine environment to receive and assimilate sewage and industrial emissions.

Figure 4.6 South Africa's ports and their hinterlands

Much of the South African coastline is exposed, and there are few areas suitable for development other than existing ports and small harbours. Development tends to be focussed around estuaries and ultimately leads to "ribbon" development along the coastline. This causes loss of natural coastal systems, and loss of aesthetic quality in these areas.

Development activities upstream of estuaries such as construction and cultivation often lead to more rapid rates of soil erosion. The soil is transported downstream in rivers and causes greater build up of sediment in estuaries than would naturally occur. Greater sediment build-up causes more frequent, and in some cases permanenet, closure of the estuary mouth. Fish and invertebrates which depend on access either to the estuary or to the ocean, may suffer as a consequence.

>     Marine and Coastal System: Pressures # 1

There is also information about Terrestrial Ecosystems in the following reports:
Metropolitan reports:
	Cape Metropolitan Council (1998 edition)		Durban Pilot Study
	Greater Johannesburg Metropolitan Council (1999 edition)		Greater Pretoria Metropolitan Council (1999 edition)