August 27, 2008--An aerial photograph shows a small isle near Saipan, the largest island and capital of the U.S. Commonwealth of the Northern Mariana Islands.

A new proposal by U.S. President George W. Bush, made public on August 25, 2008, could grant national-monument status to some of the 15 islands in the archipelago chain, making them—along with parts of the central Pacific islands—the largest protected marine reserve on the planet.

The total area would be nearly as large as Texas and Alaska combined.

But its success will hinge on whether the sanctuaries will be fully protected from fishing and other activities, conservationists say.