DURBAN – The South African Association for Marine Biological Research (Saambr) has shared some facts on the proposed seismic surveys off the Wild Coast.
Saambr’s conservation strategist Dr Judy Mann said: “Seismic surveys are used by mining companies to find and estimate the size of offshore oil and gas reserves.
A ship tows multiple airgun arrays that emit thousands of high-decibel explosive impulses to map the sea floor and rock strata. Hydrophones attached to long cables pick up the signal reflected off the sea floor. Based on the return time of the reflected or refracted impulses to the hydrophones, the underlying structure of the ocean floor can be mapped in 3D.
“Seismic surveying works a little bit like the echolocation that dolphins and whales use to navigate and find their prey. An energy source (airgun) sends pulses of sound outwards, this then travels through the water column right into the sea floor. Some of the sound waves refract (bend) or reflect off surfaces, and a receiver (hydrophone) detects the returning sound. The patterns in the returned sound (echos) help scientists to work out what is under the sea floor.”
She said the areas wanted to be surveyed are Morgans Bay, north of East London, to Port St Johns off the Eastern Cape coast. The proposed survey area is about 20km offshore in water depths ranging from 700m to 3 000m. The area covers over 6 000km² of ocean surface. This is part of the so-called Transkei Block – Exploration Right 12/3/252.
The surveying is expected to take between four to five months, depending on the weather and sea conditions.
“We know that many of the marine and coastal habitats off the South African east coast are unique and support a high ecological diversity, much of which is not found elsewhere (ie endemic). Deep-water habitats (of 500m) in particular, are largely unexplored ecologically, so we do not know exactly what occurs or what ecological processes take place there,” Mann said.
“We have serious concerns about the risks of drilling for oil offshore of the Wild Coast, given that this region is influenced by one of the fastest-flowing and most powerful oceanic currents in the world – the Agulhas Current. This current is not static – it meanders up to 100km in width, and while it generally flows from north to south, current reversals are not uncommon, particularly in deeper water. Large-scale eddies peeling off the current complicate the flow, with offshore water frequently reaching our coast. The power of the current is such that attempts to contain any accidental spillage or normal operational spillage would likely be unsuccessful.
“We saw clear evidence of this when plastic nurdles spilled in Durban Harbour, spread along the entire coast of KwaZulu-Natal and the Eastern Cape within days of the disaster. While internationally, the risk of a catastrophic blow-out (large-scale oil spill) is rated as very low by environmental-impact assessments, this does not consider the increased risks posed by the harsh, unique, physical environment found off the Wild Coast. Importantly, the potential impacts of developing and running shore-based facilities for the processing and transport of oil and gas, should they be found in viable quantities, have not yet even been considered.”
Mann said it was their opinion that the best way forward for environmental sustainability and local job creation is to expand technology that makes use of renewable energy.
On Thursday, the South Durban Community Environmental Alliance held a peaceful protest calling on Sasol to move away from fossil fuels to renewable energy. The protest action took place in Richards Bay, Umkomaas, the South Coast and Isipingo on Thursday.
Earlier this month, the Democratic Alliance spokesperson on environment, forestry and fisheries Dave Bryant called on the Minister of Environment, Forestry and Fisheries Barbara Creecy to re-evaluate her consent for the seismic blasting in the ocean along the Wild Coast.
Bryant said they shared the grave concerns of civil society and residents regarding the proposed plans for blasting in the area, which is due to start on December 1, 2021.
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