President Bush last week announced his intention to create the largest marine reserve on Earth in the Northwestern Hawaiian Islands. The president's decision caps a century of protection efforts by both Republican and Democratic presidents beginning with Theodore Roosevelt and including Lyndon Johnson, Ronald Reagan and Bill Clinton. But none ever proposed the sweeping level of protection that is being recommended by the Bush administration.

While we and others in the conservation community have not always agreed with President Bush's environmental policies, we believe it is important to acknowledge a significant policy achievement when it occurs — and this is one of them.

Beginning 160 miles northwest of Kaua'i, and extending roughly 1,200 miles into the Pacific Ocean, the uninhabited islands, reefs, shoals and atolls of this archipelago make up one of the most remote and relatively undisturbed coral reef systems in the world. The area proposed for protection covers roughly 140,000 square miles of ocean, larger than all of America's national parks combined.

Almost 70 percent of the tropical, shallow-water coral reefs in American waters are in this one place, together with 7,000 species of marine and terrestrial life, a quarter of which aren't found anywhere else. More than 14 million seabirds make these islands their home for at least a part of the year, along with the last population of the endangered Hawaiian monk seal.

The president's plan for the sanctuary has the distinction of receiving broad support from the Hawaiian people and from Hawai'i's Republican governor, Linda Lingle, who recently closed state waters in the Northwestern Hawaiian Islands — everything up to three miles from shore — to commercial activities, including fishing. Many Native Hawaiians, who consider these islands an important part of their cultural and religious heritage, would also like to see commercial fishing ended in federal waters, which stretch three to 50 miles from shore.

In the preliminary management plan announced by the White House, the president did just that, recommending that commercial fishing be phased out over five years. What's more, the president's proposal will spur efforts to compensate the few remaining fishermen who still hold commercial permits in the area for surrendering their permits to the government, which would then permanently retire them. While it is still too early to know whether these efforts will be successful, such a buyout package would provide for an early end to fishing in the archipelago and offer reasonable compensation to the fishermen who have earned part of their livelihood there.

Just as we have protected spectacular areas on land from destructive activity, we know it is equally important to do so for the sea. The president's announcement is an important step in what we hope will be greater efforts to protect the ocean, while also addressing broader problems of overfishing, pollution and habitat destruction.

There are few opportunities for a president to protect such a large swath of ocean or land at little cost to the government, while garnering strong regional support. This is one, and we applaud Bush for taking the initiative to preserve one of the world's most spectacular marine environments.

Joshua Reichert directs the environment division of the Pew Charitable Trusts. Theodore Roosevelt IV is an investment banker. They wrote this commentary for The New York Times.