The reef was discovered in 2016, but is now known to extend further than thought, right into areas where Total is seeking to drill, 75 miles (120 km) off the Brazilian coast, the group said.
The finding, made during a research expedition, invalidates Total’s environmental impact assessment, which is based on the reefs being located at least five miles (eight km) from drilling, Greenpeace said.
“Now that we know the Amazon Reef extension overlaps with the perimeter of Total’s oil blocks, there is no other option for the Brazilian government but to deny the company’s license to drill for oil in the region,” said Thiago Almeida, Greenpeace Brazil campaigner in a statement.
Contacted by AFP, Total declined to comment.
Greenpeace described the newly found reef extension as an area of rhodoliths, a calcareous algae that form a habitat for reef creatures.
“To learn the Amazon Reef extends beyond our expectations was one of the most exciting moments of my research about this ecosystem,” said Fabiano Thompson, an oceanographer at Rio de Janeiro Federal University.
“The more we research about the Amazon Reef, the more we find. We still know so little about this fascinating new ecosystem and the knowledge obtained so far indicates any oil drilling activity could seriously harm this unique system,” he said.
In 2013, Total joined BP and Brazil’s Petrobras to buy the exploration blocks in the mouth of the Amazon. But they have yet to secure the go-ahead from Brazilian environmental authorities to start drilling.
In August, the regulator Ibama told Total it would have to provide additional information.