Brazil's push into a new oil frontier off the state of Amapa moved forward with the discovery of hydrocarbons at the Morpho well, about 175 kilometers from the coast, and with the authorization by Ibama, the federal environmental agency, for Petrobras to drill three more wells in block FZA-M-59, in the Foz do Amazonas Basin, off Brazil's northern coast. The frontier sits in front of one of the world's most sensitive shorelines, home to the planet's largest continuous mangrove belt and the Great Amazon Reef System, and the licensing is already being challenged by federal prosecutors.
Petrobras announced the find on August 14. The well was drilled in deep waters, at a point where the sea is 2,886 meters deep. According to Ibama, the licensed campaign covers four wells, Morpho as the main well plus three contingency wells, with activities between 2025 and 2029. News site G1 reports that the state-controlled company plans to invest US$2.5 billion in 15 wells along the Equatorial Margin, the offshore strip that runs from Amapa toward the country's northeast, by 2030. Petrobras is testing the commercial potential of the reservoir and sent a sample of the light crude to Rio de Janeiro for analysis.
What prosecutors and the regulator say
The Federal Prosecution Office (MPF) again demanded explanations from Ibama in a request confirmed on September 2. According to prosecutors, the agency told a federal court hearing in April 2025 that the drilling would be short, lasting about six months, while the licensing documents describe a four-well campaign running to 2029. The MPF says the contradiction undermines transparency and makes it harder to weigh risks, because a multi-year offshore operation can pile up impacts on marine fauna, artisanal fishing and the way of life of traditional communities. The request went from the prosecutors' socio-environmental support group to Ibama president Jair Schmitt. In a statement, Ibama said it runs the licensing with technical rigor, that the environmental impact study and the individual emergency plan cover every phase of the operations, and that the prosecutors' recommendations are already part of the process.
Mangroves, corals and poorly mapped currents
From Amapa to Maranhao, the coast forms the longest unbroken mangrove belt on Earth, built by species such as the red mangrove (Rhizophora mangle). The ecosystem works as a nursery for the fisheries that sustain local communities, holds back erosion and stores large volumes of carbon. Between 70 and 220 meters below the surface lies the Great Amazon Reef System, documented in 2016: a rare mesophotic reef, with more than 40 coral species and 60 sponge species, that thrives under the murky water discharged by the Amazon River.
"If we have an environmental problem, cleanup is much harder, because most of our coast is mangrove and floodplain forest," Valdenira dos Santos, who holds a doctorate in marine geology and geophysics, told Rede Amazonica, the local TV affiliate that first aired her assessment. She said the Amapa coast has unique hydrodynamics, maximum environmental sensitivity (index 10), currents that reach 2 meters per second, tides that hit the shore head-on and an almost total lack of data on coastal currents. She also points to a daily risk that predates the oil push: tankers pass every day through the North Channel, the entrance to the Amazon waterway, and the state has no regional contingency plan. "In Amapa we depend directly on surface water to supply our cities," she said.
Greenpeace Brasil said in a note to G1 that economic viability "does not erase the environmental, climate and social risks" of the Equatorial Margin. The group noted that in the 2025 auction run by ANP, the national oil regulator, 19 blocks were taken in the Foz do Amazonas and await licensing, while another 36 remain under study, raising the cumulative risk of simultaneous operations. For the NGO, defending a just energy transition abroad while opening new fossil fuel fronts at home are incompatible paths. While Petrobras tests the reservoir's potential, Santos points to another bottleneck: Amapa has minimal installed capacity for marine research and a shortage of qualified workers to produce the coastal data the coming years will demand.