Bush said he drew inspiration from a documentary on the island chain’s biological resources shown at the White House in April by Jean-Michel Cousteau, the marine explorer and filmmaker whose father was the late Jacques Cousteau. Over dinner that night, Bush said he also got “a pretty good lecture about life” from marine biologist Sylvia Earle, an explorer-in-residence at the National Geographic Society.

The decision immediately sets aside 139,000 square miles of largely uninhabited islands, atolls, coral reef colonies and underwater peaks known as seamounts to be managed by federal and state agencies.

Conrad Lautenbacher, head of the National Oceanic and Atmospheric Administration, which will manage nearly all of it, said the new protected area would dwarf all others.

“It’s the single-largest act of ocean conservation in history. It’s a large milestone,” Lautenbacher said. “It is a place to maintain biodiversity and to maintain basically the nurseries of the Pacific. It spawns a lot of the life that permeates the middle of the Pacific Ocean.”

‘Unprecedented win’
Conservationists, who have clashed with the Bush administration on most other environmental issues, were just as pleased.

“This an unprecedented win for endangered Hawaiian monk seals, green sea turtles, black-footed albatrosses, tiger sharks, the incredible reef corals in these waters, the people of Hawaii and all Americans, now and in generations to come,” Elliott Norse, president of the Marine Conservation Biology Institute, said in a statement ahead of the announcement. “It’s the start of a new era of protecting places in the sea before they’re degraded beyond recognition. In my opinion, this is the best thing President Bush has done for the environment.”

NBC VIDEO America's Galapagos June 15: MSNBC.com’s Miguel Llanos explains what's supposed to happen with President Bush's plan to create the world's largest marine protected area off Hawaii. MSNBC

The national monument, about the size of California, is larger even than Australia’s Great Barrier Reef Marine Park.

Roger Rufe, president of The Ocean Conservancy, agreed the area was on par with Yellowstone and the Grand Canyon. “Teddy Roosevelt is largely considered the father of our national park system,” he added. With this national monument, “President Bush may be securing a similar legacy in our oceans.”

Clinton designation
Past presidents have taken steps to protect the region, including in 2000 when then President Clinton declared it an ecosystem reserve.

National monument status would provide much stronger, and nearly permanent, protection. Unlike the area’s current ecosystem reserve status, monument status comes with permanent funding and cannot be easily changed or revoked by a new president.

The president had planned as late as Wednesday to use instead the National Marine Sanctuary Act, a law that would allow challenges from Congress and others to the decision, said a senior administration official, speaking earlier on condition of anonymity so as not to upstage Bush.

“This means the area will get immediate protection rather than having to wait another year,” the official said, adding that Bush opted at the last minute to create a national monument after realizing the process had gone on for five years and elicited thousands of comments.

Starting 160 miles west of Kauai, the remote 1,400-mile long string of islands are blanketed with 14 million seabirds that nest there. Beneath the surface of the surrounding waters, fish crowd into pristine coral reefs, some 80-feet tall.

“This refuge that spans 1,400 miles is America’s Galapagos, and Americans don’t know it,” Jim Connaughton, chairman of the White House Council on Environmental Quality, said last year during a trip to the islands.

Midway Atoll, one of the outermost points of the new monument, will retain an emergency landing strip for commercial and military trans-Pacific flights.