The owners of a controversial oyster farm on the Point Reyes National Seashore vowed Tuesday to fight federal efforts to shut down the business.

Drakes Bay Oyster Co. filed a lawsuit seeking to overturn last week's decision by U.S. Interior Secretary Ken Salazar, who refused to grant a 10-year permit extension to the oyster farm and required it to close in 90 days.

"We're not going to walk away," owner Kevin Lunny told reporters Tuesday in a conference call. "We're fighting for our community, our employees and families against a federal bureaucracy that seems to value lies over truth and special interest over the welfare of the whole community."

In a 34-page lawsuit filed Monday in U.S. District Court in San Francisco, Lunny alleged that Salazar failed to follow environmental law and relied on bad science in making his decision.

Also, Lunny contends the three-month deadline violates a state water bottom lease and will force him to destroy up to 10 million immature oysters planted in Drake's Estero.

Lunny will seek a preliminary injunction later this week to halt the closure, said Amber Abbasi, chief counsel for Cause of Action, a Washington, D.C., watchdog group working on the case.

Salazar was named as a defendant along with Jonathan Jarvis, head of the National Park Service, and other government officials. Salazar's spokesman responded Tuesday with a brief statement:

"The secretary made his decision after careful consideration of the applicable law and policy," spokesman Blake Androff said in an e-mail. "The department will carefully review the complaint and any related materials that may be filed."

Local environmentalists urging Salazar to evict the farm and designate the spot a public wilderness area said the lawsuit was off-target.

Neal Desai, director of the National Parks Conservation Association, said Salazar didn't consider the environmental analysis to reach his decision. The expired contract and concerns about land use policy were the main factors he cited, Desai said.

Also, Desai said the state has no jurisdiction over the national park land. He said the Lunnys have flip-flopped from a previous position that Salazar should decide the matter without regard to environmental studies.

"This lawsuit is clearly an attempt to privatize the estero and rob the public of this great gift the secretary has given all Americans," Desai said. "The company should really move on."

Drakes Bay Oyster Co. occupies a spot on the 2,500-acre estuary, which has been home to shellfish farming for about 80 years. The government acquired the oyster farm in 1972 and Congress designated the bay a potential wilderness area in 1976.

Lunny and his wife bought a lease to operate the oyster farm in 2004 with the expectation the lease could be extended when it expired on Nov. 30.

But the Park Service determined the land should be returned to its natural state. It did an environmental study that found the operation was harmful to harbor seals and eelgrass beds.

Those conclusions were questioned in a review by the National Academy of Sciences, which said the Park Service overlooked beneficial aspects of oyster farming.

And California Sen. Diane Feinstein, who wrote the law giving Salazar sole authority to grant or deny the extension, accused the Park Service of relying on false and misleading science.

The criticism is reflected in Lunny's lawsuit. He said the Park Service violated the National Environmental Policy Act by not allowing an adequate public review and by failing to correct mistakes.

Lunny said his farm is an eco-friendly, sustainable food provider that employs 31 people. Closure will increase foreign imports of shellfish while ending a long mariculture tradition that has been backed by the Marin County Board of Supervisors and the local farming community.

"It's hard to believe this decision was made when the community is so overwhelmingly supportive," Lunny said. "Somehow this wasn't heard in Washington."