A Brazilian petrochemical company wants to drill exploratory oil wells in the ocean near the mouth of the Amazon. Brazil environmental protection agency rejected the firm’s request and researchers worry over the plan may one day be approved, encouraging more offshore drilling in the area.
Carlos Rezende, a marine biologist at State University says “If activities continue there is an appreciable risk of an oil spill the fact that this is an exploratory well to study the region’s deep sea oil potential does not make it accident free”.
In May, Brazil’s Institute for the Environment and Renewable Natural Resources (Ibama) rejected an application by oil company Petrobras to drill in what is known as block FZA-M-59, a section of seabed about 175 kilometers off the coast of northern Brazil, near the border with French Guiana and about 540 kilometers from the mouth of the Amazon River (see “The Search for Oil”).
The agency said the company’s environmental impact assessment and its emergency plan in the event of a spill were inadequate. Petrobras, which is based in Rio de Janeiro, has since appealed and filed a new application.
The company defended itself to Nature, saying that the planned drilling site “has no record of any nearby conservation units nor is it near any rivers, lakes, floodplains or reef systems”. But Rezende says the Great Amazon Reef system is only about 50 kilometers from the site, and that oil in the water could travel that distance.
The threats to the reef system, which lies 70-220 meters below the ocean surface, are of great concern to some scientists. It has been difficult to survey the area due to turbulent waters, but studies estimate the reef to be 9,500 to 56,000 square kilometers across the mouth of the Amazon12. When it was first described by scientists in the 1970s, researchers did not observe the rich biodiversity. However, studies in 20162 and 20193 discovered a thriving ecosystem that is home to coral, sponge and fish communities.
Ronaldo Francini-Filho, a marine ecosystem researcher at the University of São Paulo in Brazil says “It’s huge and sensitive”. Rodrigo de Moura, a marine ecologist at the Federal University of Rio De Janeiro who has mapped reefs at the mouth of the Amazon, agrees and says “There are a lot of known unknowns”.
If approved, the project could set a precedent that allows drilling at 15 other deep-sea sites nearby that have been flagged for exploration, says Suely Araújo, senior policy specialist at Climate Observatory, a civil society organization based in Rio de Janeiro. a coalition focused on climate change policy.
So far, 95 exploratory wells have been drilled in the region without a major oil spill; some natural gas deposits have been found, but none large enough for commercial use. All of those wells were in shallow water, but FZA-M-59 is at a depth of 2,800 meters, in a part of the ocean that some researchers believe is more promising.
Egberto Pereira, an organic geochemist at the State University of Rio de Janeiro, says it is possible that oil lies beneath FZA-M-59 because the landscape and rock composition in the area are similar to the landscape and rock composition of the oil-rich region off Guyana , where the oil company ExxonMobil has been operating since 2015.
Researchers think it is premature to make such estimates when oil has not yet been found. And they are not convinced that Petrobras has correctly assessed the impact of drilling. The company says its oil spill modeling meets Ibama requirements.
But modeling has shown that oil could reach French Guiana, Guyana, Suriname and the Caribbean, Rezende points out. He also says that the models used by Petrobras “do not take into account wind-generated waves, which are quite intense in the region and would certainly draw oil to the coast”.
Scientists fear that if the oil were to reach the coast, it could damage the mangroves at the mouth of the Amazon. “The region has the second largest continuous mangrove area in the world,” says Francini-Filho. “Because it is highly sensitive, oil contamination would be catastrophic.”
Petrobras tells Nature that it has drilled nearly 3,000 wells in deepwater locations without any complications, and that these “added to the technical expertise and experience accumulated over 70 years allow the company to open new frontiers with complete safety towards the Equatorial Range environment.”
Brazilian President Luiz Inácio Lula da Silva campaigned as an environmental crusader who would protect the country’s biodiversity and health. Allowing drilling in FZA-M-59 could question its sincerity.
“Is this what we want as a country?” Araújo asks. If approved, the project won’t begin producing oil until 2030. “How much will a barrel cost by then, assuming nations switch to renewable energy?” she asks. “We should think about a development plan for the 21st century.”
Reference: https://www.nature.com/articles/d41586-023-02187-3
