ANCHORAGE, Alaska - Native Alaskan groups who depend on whaling and a coalition of environmental groups sued the federal government Tuesday, seeking to block a Shell Oil subsidiary from drilling next year in the Beaufort Sea.

The Alaska Eskimo Whaling Commission and the Inupiat Community of the Arctic Slope, a federally recognized tribal government representing Alaska North Slope communities, asked the 9th U.S. Circuit Court of Appeals to overturn a drilling plan the Minerals Management Service approved in October.

Hours later, a coalition of 10 environmental groups and Arctic communities filed a second action with the San Francisco court, claiming the MMS did not properly evaluate the effects of the proposed drilling, including the risk of a major spill.

Lily Tuzroyluke, executive director of the Native Village of Point Hope, an Inupiat Eskimo community on the shore of the Chukchi Sea, said the ocean is her people's garden.

"We rely on it for our food and our culture," she said in a statement. "MMS' decision to allow Shell to drill for oil in the Arctic Ocean next summer recklessly endangers the traditional subsistence way of life we have sustained for thousands of years.

MMS spokesman Nicholas Pardi said the agency could not comment on pending lawsuits.

Shell Alaska spokesman Curtis Smith said MMS was thorough in its technical and environmental evaluation.

"Shell has demonstrated its ability to operate in the Arctic in an environmentally responsible manner," he said in an e-mail. "We fully expect MMS to be successful in defending its approval."

He said Shell has gone to great lengths to minimize the impact of its drilling program, including a voluntary shutdown during the fall subsistence whaling harvest by the villages of Nuiqsut and Kaktovik, installing best available discharge technology and reducing the number of wells.

"These steps were taken after considering direct feedback from North Slope stakeholders," he said.

MMS in October approved Shell's Beaufort plan for two wells. The agency last week conditionally approved a Shell drilling plan for up to three exploratory wells in the Chukchi Sea. For both projects, Shell proposes exploratory drilling in open water using a 500-foot (152-meter) drill ship, an ice management vessel, an ice class anchor handling vessel and oil spill response vessels.

Representatives of Inupiat whalers said they were not satisfied.

"Shell wants to drill wells and drive its fleet of vessels straight through the bowhead whale migration," said George Edwardson, president of ICAS, in a prepared statement. "What happens if there is a major oil spill? We have an obligation to protect our people."

Harry Brower, chairman of the whaling commission, said he understands that people want oil and gas.

"But the government and the offshore operators need to understand that development has to be done in a way that does not threaten our subsistence livelihood and culture," he said. "We depend on the bowhead whale for food."

The environmental groups said Shell Beaufort drilling would occur as close as 20 miles from the Arctic National Wildlife Refuge. They claim MMS approved the plan based only on a short internal review of how industrial drilling, including significant underwater noise, could deflect bowhead whales from their usual migration routes.

Shell's Beaufort offshore drilling has been challenged before.

In 2007, MMS approved Shell's drilling program, but the 9th Circuit stopped it, ruling that MMS failed to disclose potential impacts to the bowhead whale and subsistence communities. Shell eventually withdrew the plan.

Brower acknowledged Shell's agreement to halt operations during the bowhead whale subsistence hunt by two villages, Nuiqsut and Kaktovik.

"Even though this proposal has some protection for our hunting, it would allow Shell to dump thousands of barrels of drilling muds, cuttings, and other waste into Camden Bay, including cooling water full of biocides. Our whales feed and rest in Camden Bay, and care for their young there. We are very concerned that these discharges will harm the whales."

The whaling groups are represented by Chris Winter of Crag Law Center in Portland, Ore.

Earthjustice filed the second lawsuit on behalf of Point Hope, the group Resisting Environmental Destruction on Indigenous Lands, the Alaska Wilderness League, the Center for Biological Diversity, Defenders of Wildlife, Natural Resources Defense Council, Northern Alaska Environmental Center, Oceana, Pacific Environment and the Sierra Club.