Venice, Louisiana (CNN) -- Frustrated Louisiana officials Sunday demanded the federal government approve their plans to dredge up walls of sand to protect delicate inland estuaries from the Gulf of Mexico oil spill.

"Either the Coast Guard has to side with its American citizens and protect its communities, or it has to side with a major world corporation named BP and betray American citizens in that process," St. Bernard Parish President Craig Taffaro told reporters.

With oil sloshing ashore along the state's barrier islands and seeping into marshes around the mouth of the Mississippi River, state and parish leaders want to use dredges to close channels between the Gulf and the coastal estuaries.

They said those plans have been held up by the Army Corps of Engineers and the agencies in charge of the spill response, including the Coast Guard and BP, the company responsible for the spill.

Coast Guard Rear Adm. Mary Landry, the federal on-scene coordinator for the response effort, told reporters the barrier island project was still under review. Environmental and wildlife officials "are weighing in on the impact to endangered and threatened species and other impacts this large-scale project could have," she said.

But Plaquemines Parish President Billy Nungesser pointed to pictures of an oil-covered pelican nesting ground and asked reporters, "Is it affected now?"

Thousands of barrels of oil a day have been spewing into the Gulf since late April, when the BP-contracted drilling rig Deepwater Horizon blew up and sank about 45 miles off Louisiana. Beyond the state's barrier islands lie a filigree of marshlands, bayous and islands that are rich in wildlife and fisheries that represent the source of about a third of the U.S. seafood industry.

Tim Kerner, mayor of the town of Jean Lafitte, said the dredging plan is "the only plan that'll possibly work" to save those estuaries.

"It's the plan that will save the wildlife, save the marine life and also the way of life for the town of Jean Lafitte and all the coastal communities," Kerner said.

Nungesser, Taffaro and other representatives of the state's coastal parishes toured the threatened region with Gov. Bobby Jindal on Sunday.

Jindal said his state needs "a greater sense of urgency" from those in charge of the cleanup, or for them to delegate authority to regional officials. He said the state is already doing preparatory work for dredging and could begin operations immediately on receiving approval.

"Ten days later, you'll see land being built. You'll literally see sand being built along these critical passes," he said.

Mayors and parish presidents were critical of both the government and BP's handling of the cleanup, recounting stories of misdirected protective booms or skimmers that sat on trucks ashore. And a visibly angry Taffaro said the delays threatened his parish's ecosystem and the livelihoods of his people.

"I don't have a crystal ball," he said. "But if I were a betting man, I would be betting that the plan is to let us die, then come back and do $75 million worth of cleanup and close the book."

He said some officials had even suggested setting oil-soaked marshes ablaze, a step he called "not an option for us."

"That kills our hurricane protection. It wipes out our species, our ecosystem and everything we've been fighting to protect," he said.

