Satellite images showed damage from the leak may have been misreported, with the spill appearing to be 400 times larger than initially claimed.
Russian prosecutors have opened a criminal probe into an oil spill that occurred on August 7 near Novorosíisk, one of the main ports on the Black Sea.
Satellite images showed damage from the leak may have been misreported, with the spill appearing to be 400 times larger than initially claimed, covering 80 square kilometres instead of 200 square metres and leaving traces of pollution along the scenic coastline.
The spill occurred over the weekend at the oil terminal that belongs to the Caspian Pipeline Consortium (CPC), during the loading of the Greek Minerva Symphony tanker.
The CPC said the spill was contained and cleaned up on Saturday, with no threat to the local population or flora and fauna of the Black Sea.
Yet Russia's Space Research Institute from the Russian Academy of Sciences (RAN) said a satellite image taken on Sunday showed the size of the oil spill to be almost 80 square kilometres, with a 19-kilometre oil slick stretching from the shore to the open sea.
"Estimates show that it's about 40, 60, 80 tons of oil. It's by all accounts much more than the 12 tons declared by the company. A spill of this magnitude is certainly unprecedented for the Black Sea," Evgeny Lupyan, deputy director of RAN's space research institute, said.
The prosecutor general's office has opened an investigation under charges of environmental pollution and said it would seek damages.
Russian media reported traces of oil spotted along the coast of the Black Sea, including a dolphin aquarium in Bolshoy Utrish, 25 kilometres to the west, where workers urgently put up barriers to protect the mammals.
"We didn't know about the oil spill, we just arrived at work in the morning as usual, started inspecting the pens and saw a bit of a film of oil in the remote pens. We looked over the net and saw that the oil film was almost everywhere," said Russian veterinarian Elena Mikhailova.
Russia's state consumer safety agency has stated that an analysis of water samples along the coast has found that it remained within norms.
But World Wildlife Federation (WWF) Russia experts say the spill caused billions of rubles in damages.
The environmental group warned that the oil has already reached the shores of national parks and other protected areas and that most of the oil had dissolved in the water, posing a threat to living organisms and beaches.
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