Picture: ISTOCK
Picture: ISTOCK

Prospecting rights over huge areas of SA’s continental shelf have been granted to three companies searching for phosphate. It could signal the beginning of a destructive mining process that will grind up the seabed and spew sediment into the water column as liquid "dust". This would pose a threat to ocean ecosystems, fish and fisheries.

The licences cover 150,000km² in SA’s western and southern exclusive economic zone and were awarded to Green Flash Trading 251, Green Flash Trading 257 and Diamond Fields International by the Department of Mineral Resources.

Studies commissioned by the Safeguard our Seabed Coalition (SOSC) of nongovernmental organisations, has warned marine phosphate mining "would have severe and irreversible impacts on marine ecosystems, livelihood and food security benefits sustained by our fishing industry".

Bulk marine sediment mining uses a suction hopper dredge, which gouges the sediment to a depth of 3m. Its dredge head, which is about 11m wide with cutting teeth and high-pressure water jets, is dragged across the sea floor, crushing hard sediment and sucking it — and everything else in the way — up a tube.


Once the phosphate has been filtered out, all excess water and fine particulate is flushed back into the sea in a sediment plume. Mining would take place on the continental shelf in what is known as the benthic zone, the area just above and below the seabed. Apart from anchoring aquatic plants, it is home to sea stars, barnacles, mussels, anemones, crustaceans, molluscs and other organisms that make their home on or in the sea floor. Much of the food supply is in the form of "marine snow", small particles of decaying organic matter that slowly descend and accumulate on the ocean bed.

According to Saul Roux, a legal campaigner at the Centre for Environmental Rights (CER), the effects of mining include:

Destruction of seabed ecosystems, the building blocks of marine ecosystems;

The release of hazardous substances such as radioactive materials, methane, hydrogen sulphide and heavy metals locked in the seabed;

Destruction of spawning, breeding and feeding habitats for fish species, many of which are commercially important;

Reduced light penetration and therefore photosynthesis of marine plants;

Burial and smothering of marine organisms in the mining block and surrounds; and

Habitat destruction and ecosystem changes in mined areas that could be permanent as recovery takes centuries.

The CER has flagged serious gaps in SA’s legal, governance and institutional frameworks able to manage such bulk marine sediment mining. This would mean, says Roux, that the phosphate mining operations would be "unregulated and not subject to state monitoring or enforcement of its compliance with licences and laws". This would bring severe and irreversible damage to marine environments and fisheries.

A report commissioned by the SOSC shows there is no need for marine phosphate mining as there are more socioeconomically and environmentally friendly ways to obtain it. These include the recovery of phosphates from human and animal waste and a more efficient application of phosphate fertiliser to soils.

Despite the environmental and economic risks and after almost three years of advocacy, the government has not responded to calls by the SOSC for an environmental assessment of marine phosphate mining. Nor has it taken any steps towards establishing a moratorium pending a strategic inquiry. This points to a determination to forge ahead at all costs. 

Pinnock writes for the Conservation Action Trust.

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