Washington ? Parts of three remote and uninhabited Pacific island chains are being set aside by President George W. Bush as national monuments to protect them from oil and gas extraction and commercial fishing in what will be the largest marine conservation effort in history.

The three areas — totaling some 195,274 square miles — include the Mariana Trench and the waters and corals surrounding three uninhabited islands in the Northern Mariana Islands, Rose Atoll in American Samoa and seven islands strung along the equator in the central Pacific Ocean.

Each location harbors unique species and some of the rarest geological formations on Earth — from the world’s largest land crab to a bird that incubates its eggs in the heat of underwater volcanoes.

All will be protected as national monuments — the same status afforded to statues and cultural sites — under the 1906 Antiquities Act. The law allows the government to immediately phase out commercial fishing and other extractive uses.