NewAge, an international company that has been granted the rights, announced that seismic surveys would begin early next year in a 12 000km2 block around Algoa Bay.
Ross Wanless of BirdLife International said the prospecting threatened crucial penguin breeding colonies at St Croix island, home to more than 60% of the world's remaining African penguins. "If an exploitable resource is found, there will be hugely increased risks of oil spills from wells and from an increase in ship traffic as well as noise pollution," he said.
Even the seismic surveys, which sound out sub-sea geological structures for hydrocarbons, could have a negative impact on penguins and other marine life, said the head of the Bayworld centre for research and education at the Port Elizabeth Museum, Malcolm Smale.
"We do not fully understand the consequences of these euphemistically termed 'sounds' on marine taxa. Buffer zones are being set up, but the birds are not confined to the islands and travel extensively through the shelf waters to feed," said Smale.
Two weeks before the Seli 1 broke up and deposited an oil slick on Cape Town beaches last weekend, Environment Minister Edna Molewa gazetted a draft management plan to deal with the decline of the African penguin population from about one million breeding pairs in the 1920s to 25 000 pairs in 2009.
One of the suggestions favoured by BirdLife is to set up man-made alternative breeding sites in areas where disturbances and competition for favoured food sources, such as anchovies and sardines, would be reduced. Other proposals include closing fisheries near to breeding sites and reducing access to boats and low-flying aircraft.
Lorien Pichegru, a University of Cape Town scientist researching the penguins at St Croix and nearby Bird Island, said setting up new colonies would be a long-term solution because the birds are slow breeders and difficult to relocate.
"In the meantime, if they find oil in Algoa and set up an oil refinery, as proposed, in Coega, the biggest penguin breeding colonies will be threatened by increased traffic and possible oils spills. There are also about 100 000 gannets on Bird Island that will be affected," she said.
Laws and systems put in place to clean up after oil spills were not always properly applied, Pichegru added.
Shaheen Moola, managing director of Feike Natural Resource Management, said the government was "hopelessly" underinsured for a large oil spill on the coast. "South Africa is [currently] only insured for approximately R185-million, whereas a significant oil spill could result in clean-up costs worth billions of rands," he said.
NewAge spokesperson Henry Camp said the Petroleum Agency of South Africa's approval for the seismic surveys in Algoa had followed consultation with marine experts in the area. A comprehensive environmental impact assessment would need to be conducted before exploration drilling or oil production could begin, he said.