In October 1999, Greenpeace and six native Alaskan Inupiat Eskimos filed a petition against the development by BP Exploration (Alaska) Inc. of the Northstar oil field in the Beaufort Sea, the first offshore oil project in the Alaskan Arctic. The petitioners sought to challenge the US Secretary of the Interiors 1999 approval of the Development and Production Plan (DPP) of the Northstar oil and gas development project. The Inupiats alleged that approval would harm their subsistence lifestyle because it threatened their ability to continue hunting, fishing, and gathering traditional subsistence resources. The plaintiffs claimed that the final Environmental Impact Statement (EIS) was inadequate; they argued that it failed to sufficiently analyse the impact of the Northstar project on the Inupiats lifestyle. The plaintiffs also claimed that the oil discharge prevention and contingency plan did not comply with the requirements of the Oil Pollution Act of 1990.