Russian independent oil producer Rosneft said Wednesday it's working to set an environmental baseline to review as it readies for work in arctic reserves.

Rosneft and U.S. energy company Exxon Mobil signed a cooperation agreement in 2011 to develop three reserve areas in the Kara Sea, located within the Arctic Circle.

The company said Wednesday it was studying the marine ecosystem to get a better understanding of the potential impact of offshore exploration.

"The objective of the said studies is collection of data on marine fauna in Rosneft license areas with a view to building a complete and detailed picture of the baseline environment state and developing a set of environmental controls to be applied during hydrocarbons exploration and production," it said.

Advocacy groups like Greenpeace have expressed concern about oil operations in the pristine arctic environment, saying the remote and extreme location may present obstacles to responding to any potential spill.

Rosneft in 2012 started seismic surveys of the Kara Sea to get a better understanding of the reserve potential.

The U.S. Geological Survey estimates the arctic holds 13 percent of the world's undiscovered oil reserves and about 30 percent of the world's undiscovered natural gas.