Indonesia Undersea

What scientists found when they surveyed the waters of the Raja Ampat Islands six years ago set off an international alert for their preservation. The archipelago's reefs were not just rich—the region would prove to have the greatest coral reef biodiversity for its size in the world. Even a short initial voyage confirmed more than 450 species of reef-building coral, nine newly discovered. The entire Caribbean, by contrast, holds fewer than 70 species. With so many of the world's reefs destroyed or suffering catastrophic decline, efforts to safeguard this treasure went into high gear.

One of the first divers to get an inkling of the abundance that lay below wasn't a scientist but an adventurer named Max Ammer, who came to the sparsely populated Raja Ampat Islands from the Netherlands in 1990 looking for abandoned jeeps and sunken aircraft from World War II. He stayed for the coral and carved out two eco-resorts on the small island of Kri. In 1998 he guided renowned Australian ichthyologist Gerry Allen on a few dives. "Each dive was a mini-exploration," says Gerry. "A light snapped on in my brain, and I thought: This is it."

Gerry lobbied Conservation International (CI) to conduct a marine survey. Both the region's remoteness and the political turmoil in Indonesia had made it difficult to study these waters systematically, but in 2001 Gerry was among the scientists gathered by CI to make a rapid assessment of Raja Ampat. His intuition had been spot-on. The survey brought Raja's fish species count to an astounding 970; Gerry set a record for personally counting 283 species on one dive. Follow-up surveys coordinated by CI and the Nature Conservancy added to Raja's species count in fish, corals, and other marine life, and confirmed that this biological frontier was an El Dorado of coral reefs.

But these are not all vacation-poster reefs bathed in bright, gentle waters. This is an unruly frontier. Fortified with plankton, key to the reefs' fecundity, the waters are often murky and veiled, churned by currents so powerful you feel as if you're diving in a washing machine and so dizzying with life that the scene could have been painted by Jackson Pollock.

As diving partner Jennifer Hayes and I swam over the lip of a reef off a rocky islet near Kri, the sea changed from lighthearted blue to brooding green. Purple fields of leather coral rippled as the current came at us like threatening gusts of wind. Reaching a protected undercut, we entered a grove of orange, red, and yellow sea fans surrounded by a pink and purple hedge of soft corals. Swarms of orange anthias fish hovered at the edge of the current, while a squadron of plate-size batfish patrolled the perimeter of the soft coral garden.

Running low on air, I pushed off to return to the boat and spun into the propelling current, one hand on my cameras, one hand stretching for the boat's ladder, which I caught like a trapeze artist. The islet itself was trailing a wake from the current whipping around it. It's easy to believe the local tale that during World War II the Americans bombed this islet at dusk, thinking it was a Japanese patrol boat steaming across the bay.

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