The Pacific Ocean's mysterious deep sea terrain is as varied as the land mirrored above. From hulking sea mounts, island atolls, and lagoons, to a monumental network of a barrier reef so long it can be seen from space, the complex ecosystems of reefs are the lifeblood of the Pacific Ocean.

Of the Pacific's 25-thousand islands, roughly two-thirds are in the Coral Triangle. The Triangle is a small western Pacific pocket from Indonesia, north of the Philippines and across to the Solomon Islands. Though marveled for its reefs, within the volcano-lined bays, another astonishing ecosystem is emerging.

The Great Barrier Reef, which runs parallel to the coastline of northeastern Australia, is so big it can be seen from space. A chain of 3,000 individual reefs and some 900 islands, this system is greater in size than the United Kingdom, Holland, and Switzerland combined. This living superstructure is so significant to the world, it's deemed one of its seven natural wonders.

The Pacific Ocean spans 9 and a half thousand miles of latitude across vastly varying temperatures and topography. With such far-reaching boundaries, it's little wonder that the 25,000 islands within the Pacific Ocean are so vastly different. Across the Pacific, long chains of atolls support life on the remnants of ancient volcanoes.