A monumental step.

Byline: The Register-Guard

President Bush has rolled back many more environmental protections than he's expanded. But on Thursday he took a historic step toward protecting coastal waters by designating a 1,400-square-mile swath of islands northwest of Hawaii as the largest protected marine reserve in the world.

At a time when the oceans' coral reefs are in a dangerously fragile state, Bush's decision to assign monument status - the highest level of protection that a president can impose - to an area nearly the size of Montana is cause for celebration.

Known as the Northwestern Hawaiian Islands, the mostly uninhabited archipelago is an array of reefs, atolls, shoals and seamounts northwest of Maui. It is home to more than 7,000 marine species, a fourth of which are unique to the region, and is regarded as the most pristine tropical marine ecosystem under U.S. jurisdiction.

Bush's announcement was appropriately hailed by conservation groups, including some of his most outspoken critics, as the most significant environmental policy decision of his presidency. Some even went so far as to compare it to Teddy Roosevelt's establishment of Yellowstone National Park. That's not hyperbole, considering that the new monument area will be larger than the entire national park system and slightly larger than Australia's Great Barrier Reef Marine Park.

The islands include 70 percent of the nation's tropical, shallow-water coral reefs, a rookery for 14 million seabirds and an abundance of large predatory fish at a time when 90 percent of such species have vanished from the world's oceans. The area also provides critical habitat for threatened and endangered marine species, including the Hawaiian monk seal and the green sea turtle.

The protection for the coral reefs is particularly welcome. Such reefs cover less than 1 percent of the world's oceans but play a pivotal role in sustaining a diversity of sea life. They also provide natural barriers to storm surges from hurricanes, and help process and recycle carbon dioxide from the atmo- sphere.

The decision to phase out fishing in the new reserve within five years is essential to preserving the delicate ecosystem. Experience with the nation's existing marine sanctuaries has shown that those with outright fishing bans experience far more dramatic resurgences of fish populations and coral reefs than those where conservation competes against commercial activity.

While the decision has been under consideration for years, Bush reportedly was persuaded to act in April after watching a movie by filmmaker Jean-Michael Cousteau depicting the damage that commercial fishing has caused to the islands.

Now, if someone at the White House could just arrange for a presidential screening of Al Gore's "An Inconvenient Truth" ...

CORRECTION (ran 6/23/2006): June 19 editorial included incorrect information on the creation of Yellowstone National Park. Congress voted to set aside 2.2 million acres for Yellowstone National Park on March 1, 1872, under the Grant administration.