US President George W Bush has designated the Northwestern Hawaiian Islands as a national monument.
The string of islands and atolls, surrounded by coral reefs and shallow seas, are important wildlife habitats for 7,000 fish, birds and other species, including this hermit crab.
The area is home to the only remaining population of the Hawaiian monk seal, the only surviving marine mammal that is completely dependent on coral reefs.
Here, a white tip reef shark lurks under a ledge in the reserve. Sharks and other large predators are common in the area.
A quarter of the species in the reserve, including these Hawaiian squirrelfish, are endemic to the area.
The area has suffered from over-fishing of lobsters and pollution from rubbish and debris.
The red-footed booby is one of an estimated 14 million seabirds living in the reserve.
The islands are the remnants of old volcanoes. The newly designated area will be the world's largest marine reserve, and will have the highest level of protection possible in the US.