Kingman Reef
Kingman Reef

Photograph by Brian Skerry National Geographic July 2008

Written By Robin A. Palmer, National Geographic researcher

Kingman Reef is an uninhabited, mostly submerged atoll reef located nearly one thousand miles south of Hawaii. Shaped like a triangle, Kingman's exposed land, with a maximum elevation of just three feet, is barren—it consists only of long, narrow stretches of sun-bleached coral reef and the broken shells of giant clams (_Tridacna maxima_). Enclosed by the triangle, however, is a lagoon with one of the healthiest coral reef ecosystems in the world. For centuries Kingman's remote location has kept this vibrant underwater environment in a virtually pristine state. Since 2001, the reef has enjoyed protection as part of the Pacific/Remote Islands National Wildlife Refuge Complex, which is managed by the U.S. Fish and Wildlife Service.

Despite the outstanding health of the waters around Kingman Reef, a diver who peeks beneath the surface might be surprised. While the postcard image of a tropical atoll shows it surrounded by a sea thronging with colorful fish, there is considerably less visible activity around Kingman Reef. Large predatory fish, primarily sharks and red snappers, are most in evidence; smaller prey fish, both herbivores and carnivores, spend little time out in the open, preferring to hide in the nooks and crannies of the corals. A team of researchers led by Enric Sala, a National Geographic emerging explorer, has determined that 85 percent of the fish biomass at Kingman is made up of top predators. This is dramatically different from the situation at Kiritimati, a populated island a few hundred miles away, where top predators make up just 15 percent of the fish biomass. Fishing and pollution have contributed to the degradation of the reefs around Kiritimati, and Sala and other ecologists are convinced that the unusual "inverted pyramid" of predators and prey at Kingman is evidence of its extraordinary health. Near-pristine coral reefs like Kingman are becoming increasingly rare; Sala thinks there may be no more than 50 such reefs left in the world's oceans.

Warne, Kennedy. "An Uneasy Eden," National Geographic (July 2008), 144-57.

Pacific Islands—Kingman Reef NWR. U.S. Fish and Wildlife Service.

Sandin, Stuart A., and others. "Baselines and Degradation of Coral Reefs in the Northern Line Islands." PLoS ONE (February 2008).

Other resources
"Virgin Reefs: Expedition to Kingman."

Dinsdale, Elizabeth, and others. "Microbial Ecology of Four Coral Atolls in the Northern Line Islands."
PLoS ONE (February 2008).

United States Pacific Island Wildlife Refuges. The World Factbook. Central Intelligence Agency.

Pala, Christopher. "Life on the Mean Reefs." Science (December 14, 2007), 1719.

Shipwreck at Kingman Reef

By Robin A. Palmer, National Geographic researcher

Even a remote, virtually unspoiled coral reef like Kingman is vulnerable to human impact. In late 2007—American ecologists aren't sure exactly when—a large wrecked ship went aground off the reef’s northern windward side. Scientists suspect that the ship—which appears to be made of teak and might be a fishing vessel from Southeast Asia—was badly burned by fire and abandoned, and then floated several thousand miles east to Kingman. Photographs taken on a U.S. Coast Guard flyover in March 2008 show that a dark-colored cyanobacteria is growing in the tide pools in the area of the wreck; it's likely that its growth is being stimulated by dissolved iron from corroded metal on the boat. This bacteria can be invasive and may hinder the recovery of the damaged reef. The ship is just one of many ships—mostly Asian fishing vessels—that have washed up on atolls and reefs of the northern Line Islands in the past two decades. Says Jim Maragos, a coral reef biologist with the U.S. Fish and Wildlife Service, "These wrecks are symptoms of a much larger crisis affecting the entire Pacific—thousands of fishermen taking fish without asking, leaving their wreckage behind without paying, and otherwise disrespecting the custodians responsible for the care of these islands and their survival for future generations."

Last updated: May 30, 2008