Numerous impacts are generic in nature, synonymous with virtually any shipping activity. These include waste disposal, sewage, paints, hydrocarbons, bunkering, freshwater, etc. Legislation is in place to deal with many of these impacts, and consequently these are not dealt with here.
Table 4. Summary of Socio-economic and biophysical impacts of marine diamond mining operations in the BCLME.
Creation of Employment and Revenue
Marine diamond mining industry provides considerable employment and tax revenue in RSA and Namibia.
Human resource development and social betterment
Some of the larger companies diamond companies in RSA and Namibia have started programs to develop skills and improve living conditions for low skilled workers (e.g. trust funds for training, sponsorship of community needs, development of alternative land uses).
Namibian companies are required to preferentially employ Namibian citizens and purchase Namibian goods and services. Some companies have taken initiatives with small contractors to expand shallow water operations.
Shifting emphasis from Onshore to Offshore Mining
An ongoing shift in emphasis from onshore to offshore mining is leading to escalating unemployment in coastal towns in RSA and Namibia because of reduced low-skilled labour requirements.
Revenue from offshore mining reaching local areas is much reduced compared with onshore mining as the larger vessels are supplied and serviced from a few large urban centres (e.g. Cape Town and Lüderitz).
Alternative land-use options and training initiatives are being promoted and/or investigated.
Involvement of small scale miners
Opportunities for involvement of small scale miners in the diamond industry has been very limited owing to limited access to finance, technical skills and poor security.
Mechanisms are being introduced to facilitate entry by small-scale miners (e.g. improved access to funding and technology).
Allocation of mining revenue to mining areas
Tax revenue from mining concerns in RSA and Namibia is generally fed into a central revenue fund and is not necessarily re-invested in local districts. This has resulted in diamond mining areas exhibiting retarded growth and poor infrastructure.
Financial and service inputs are being redirected by government and industry to upgrade facilities and capacities of affected towns.
Terrestrial mining in the coastal zone has numerous impacts including scarring of the landscape, and the production of sediment plumes which can impact terrestrial and aquatic communities.
Mitigation is principally through rehabilitation of prospected and mined areas and through discharging fine tailings into slimes dams.
Beach mining activities
Seawalls, constructed to permit ‘terrestrial’ access to diamond deposits in the subtidal, result in physically altered shorelines and severe impacts on sandy and rocky shore fauna.
Using material for seawall construction that is equivalent to that which is stripped from the shore allows for a more rapid recovery of affected communities.
Shallow water (<30 m) mining
Access to the shore by shore-based operators requires roads, camps and often rock cuts.
Nearshore pumping has numerous impacts on benthic communities including the creation of sediment plumes, smothering of reef with discharged tailings, destabilising gravel beds, physical disturbance by pipes, moving of boulders and kelp cutting by divers to provide unencumbered access to mining sites.
In-water mining needs to be limited to boat based operations only.
Tailings must be dumped away from rocky reef areas and boulder movements need to be kept to a minimum. Restrictions have been placed on the width of lanes cut, clear-cutting and/or repeated cutting.
Mid-Water and Deep-Water Mining (>30 m)
Fine tailings material remains in suspension for long periods and can impact phytoplankton, fish and marine mammals through light reduction, nutrient enrichment, remobilization of contaminants, clogging of fish gills and reducing oxygen levels.
Mining process impacts benthic fauna by disturbing sediments, smothering and aggravating oligoxic conditions on the sea floor.
Suggested mitigation includes leaving lanes of undisturbed sediments between mining areas.
The Integrated Environmental Management philosophy, encompassing scoping, impact assessments and environmental management plans, is a large step toward the integrated environmental management of activities affecting the BCLME. Environmental concern, however, has had a recent birth, and the processes and mechanisms of environmental management are still evolving. The current model is good, but a few criticisms are warranted to take the environmental management of diamond mining in the BCLME into the future. Criticisms of socio-economic, biophysical and environmental management as a whole are discussed below.