America’s Tropical Treasures

U.S. marine national monuments in the Pacific comprise some of the planet’s healthiest ecosystems, yet even in these remote locations, refuge managers struggle to erase the human imprint

09-15-2010 // Paul Tolmé
The riches of America’s Pacific national monuments include (clockwise from left): the endangered Laysan duck; palm-shrouded islands; a fairy tern nestling; Rose Atoll, a volcano remnant; a milletseed butterflyfish off Lehua Rock; and leathery anemones at Kingman Atoll.

A MOTHER LAYSAN DUCK and her fuzzy brown ducklings waddle through the grass on Midway Atoll, a U.S. national wildlife refuge in the western Pacific Ocean. Biologist John Klavitter, assistant refuge manager, smiles at the sight. The Laysan is the second-most endangered duck species in the world; it once lived on many islands in the Hawai’i Archipelago, but invasive rats and habitat loss reduced it to one isolated island uninhabited by people. Now, thanks to a team of scientists, including Klavitter, Laysan ducklings are an increasingly frequent sight at Midway.

In 2004 and 2005, Klavitter and colleagues translocated 42 of these tiny ducks to the island. Other duck species might have colonized Midway on their own by flying here, but Laysans evolved without land predators and thus have small wings good for only short bursts of flight rather than long ocean journeys. So far, the project is a success—the Midway population has grown to 473 ducks. “Our dream of seeing Laysan ducks thriving at Midway has come true,” Klavitter says.

Located at the outer edge of the Hawaiian island chain, 1,200 miles from Honolulu, Midway is part of a grand new experiment in the restoration and conservation of Pacific islands and their wildlife. It is part of Papahānaumokuākea Marine National Monument, in the Northwestern Hawaiian Islands. Encompassing almost 140,000 square miles of ocean and a string of tiny uninhabited islands, it is one of four U.S. marine monuments in the Pacific. Little-known to the public, these monuments cover 215 million acres of open ocean, islands, atolls, reefs and chunks of the seafloor.

The monuments also provide scientists with an opportunity to study ocean ecosystems that are virtually unaffected by human activity. In addition to translocating endangered species such as the Laysan duck, U.S. Fish and Wildlife Service (FWS) officials who manage the refuges are working to erase damage done by military bases, commercial fishing and other human activities. “It’s difficult to call any place on the planet pristine anymore, but these remote island ecosystems are as close as you get,” says Project Leader Barry Stieglitz, who oversees the federal wildlife refuges within the Pacific islands.

The reason is simple: Nobody lives nearby to mess them up. Midway, with a year-round staff of refuge workers and employees who carry out restoration projects, maintain the federal airport and oversee the upkeep of former military buildings, is the only refuge with a significant population. Consequently, refuges within the four monuments are home to some of the world’s largest seabird nesting colonies and some of the healthiest coral reef ecosystems. The diversity and abundance of fish species within the monuments, where commercial fishing is prohibited, is off the charts. Sharks, mercilessly overfished throughout the world’s oceans, exist in numbers and varieties seldom seen anywhere else. “The waters around these islands provide a vision of the apex predator ecosystems that used to exist around the world,” Stieglitz says.

At the Papahānaumokuākea monument green sea turtles gather to bask on a beach, a rarely seen behavior; a male great frigate bird stretches its wings; and an endangered monk seal, one of the world’s rarest seals, finds refuge from threats that imperil it.

Discoveries are frequent. A potentially new species of beaked whale was recently documented off Palmyra Atoll, where schools of rare melon-headed whales reside. In 2008, a research expedition discovered 100 new coral and fish species in Papahānaumokuākea. “The Pacific is the last frontier,” says FWS coral reef biologist Jim Maragos. “The coral reef ecosystems out here have not been degraded to the extent of reefs elsewhere in the world. That means we can monitor and study them in the absence of direct human influence. That is very rare these days.”

The four marine monuments are the newest additions to a national system that includes 10 terrestrial monuments, such as Colorado’s Dinosaur National Monument. The marine monuments were created between 2005 and 2009 by President George W. Bush, representing perhaps the single great conservation achievement of an administration known primarily for rolling back environmental protections. First Lady Laura Bush, who visited the Northwestern Hawaiian Islands, is believed to have been a key persuader.

Refuge Riches

Rose Atoll Marine National Monument is located west of Tahiti in American Samoa. It covers 13,451 square miles and includes two islets totaling 21 acres, a fringing reef with an enclosed lagoon, plus the surrounding waters out to 50 nautical miles. The reefs and nearby waters are home to giant clams, green and hawksbill turtles and at least 270 species of reef fish.

The islands and atolls of the Pacific Remote Islands Marine National Monument—Howland, Baker and Jarvis Islands in addition to Palmyra Atoll, Kingman Reef and the waters surrounding Johnston and Wake Atolls—span the equator and are among the most isolated U.S. territories. These dots of land are vital nesting grounds for millions of seabirds and provide stopovers for migratory shorebirds; surrounding waters are home to dolphins, groupers, giant clams, pearly oysters and rare fish, including the humphead wrasse and bumphead parrotfish. Kingman Reef is the least disturbed coral reef in U.S. territory, possibly home to more sharks and large predatory fish than any other coral reef on the planet.

The Marianas Trench Marine National Monument lies in the western Pacific near Guam and includes the deepest point on Earth. If Mount Everest were placed in the trench, its peak would be underwater. Undersea volcanoes and thermal vents support extremophiles and strange lifeforms that remain little studied. “People think man has conquered the Earth, but we have visited the moon more times than we have been to the bottom of the trench,” Stieglitz says.

Papahānaumokuākea is the largest marine monument, and its islands are the remnants of ancient volcanoes that have eroded into the sea. Kure Atoll is the northernmost coral reef in the world. Nearby Midway Atoll harbors the largest colonies of Laysan and black-footed albatrosses on the planet. “I have worked at refuges around the country, and there is no place where wildlife so dominates the ecosystem as it does here on Midway,” refuge manager Matt Brown says. Aside from staff, the islands within the marine monuments are off-limits to visitors; even scientists who want to do research there must receive permits. The one exception to the no-visitation rule is Midway Atoll, a former military base that has one of only three runways in the marine monument system. Planes must land and depart at night to prevent collisions with seabirds that fill the air during daylight.

Visiting Midway during seabird nesting season is a bird-watcher’s dream. More than a million adult Laysan albatrosses fill the skies and cover the ground. Their chicken-sized hatchlings sit on the ground, squawking and clapping their beaks while awaiting the return of their parents, which depart for a week or more on foraging excursions. Having evolved without land predators, the birds have virtually no fear of humans.

Laysan albatrosses perform a bonding ritual. Mating for life, both sexes incubate the single egg laid each year. Their nests on Laysan Island (below) and elsewhere may be little more than scrapes in the sand.

Other seabird species—frigate birds, boobies, noddies—seem to take up every inch of space not occupied by albatrosses. Red-tailed tropic birds roost at the base of trees while white terns fill the branches above. Some birds even go subterranean: Visitors must be careful not to step on the burrows of Bonin petrels, which nest underground.

Midway’s seabird populations have exploded since 1997, when the U.S. Navy, which formerly operated a military base here, funded a project to eradicate invasive rats that eat seabird eggs and pose a major threat to Pacific islands. FWS staff hope to eradicate rats from Palmyra Atoll next, benefiting sooty terns and native trees that produce seeds and fruit that the rats eat. Similar projects have taken place throughout the monument system. The elimination of feral cats has allowed blue noddies, the smallest tern species and one of the few tropical seabirds to feed on marine insects, to return to Jarvis Island. Introduced rabbits that ravaged the vegetation of Laysan Island have been eradicated, and FWS staff are now replanting bunchgrass and other native plants.

Threats and Progress

Preventing the introduction of invasive species to the monuments is a primary objective. Researchers who visit any of the protected sites, aside from Midway and Tern Islands and Palmyra Atoll, must wear new clothing that has been frozen to kill any invasive seeds or insects. But accidents happen. Nonnative yellow crazy ants recently turned up on Johnston Atoll. These aggressive insects threaten ground-nesting seabirds. Nobody knows how the ants arrived; they could be evidence of an illegal visit.

Shipwrecks are a threat to pristine coral reefs because they leak fuel and their iron hulls spur the growth of blue-green algae harmful to certain corals. Currently, shipwrecks lie off Palmyra Atoll and Kingman Reef; officials are struggling to find the estimated $10 million needed to remove them.

Giant clams, here on a Rose Atoll coral reef, are the world’s largest mollusks and among the most endangered clams. The monuments protect them from the exploitation that jeopardizes them in other areas. Some giants grow to 54 inches across and to more than 700 pounds.

Plastic trash is another problem. It not only washes up on refuge shores in ever-growing amounts but also is transported inland by albatrosses, which eat plastic lighters, bottle caps and other bits of colorful floating trash and feed it to chicks, with sometimes fatal results. Over time, the amount of plastic is dramatically increasing on Midway, Laysan, Tern and other islands in Papahānaumokuākea. Colorful bits of trash glint in the sun where once there was only white sand.

Global warming is the biggest threat to these low-lying islands. Rising seas will eliminate nesting grounds for seabirds and sea turtles. Already, changes in ocean currents are altering the locations of prime feeding grounds. Endangered monk seals in Papahānaumokuākea, the rarest seals in U.S. waters at only 1,300 individuals, must now travel farther to find food, unwelcome news for a species in decline.

But it is easy to forget the bad news when visiting Midway, where I watch a Laysan duck flutter clumsily through the air on its way to a nearby pond. In the next few years FWS scientists hope to translocate the endangered Nihoa millerbird to Laysan and Midway. These moth-eating warblers survive only on Nihoa, also located within Papahānaumokuākea. Millerbirds were extirpated from Laysan in the early 1900s when introduced rabbits denuded the island of vegetation, wiping out a native honeycreeper and a native rail as well.

“Some people might say, ‘If these places are doomed, why bother restoring them?’” Brown, the Midway refuge manager, says. “But the opposite argument can be made. Let’s make these habitats as productive as we can so these species have the best opportunity to persist.”

California writer Paul Tolmé is a frequent contributor to National Wildlife.

Distant Shores

For Marine Monument Staff, Getting to the Workplace is Half the Challenge

Federal coral reef biologist Jim Maragos was diving off Baker Island in 2008 when his boat captain lost sight of him for several hours. As sharks circled, Maragos yelled for help until the boat crew finally located him. On another occasion, off Palmyra Atoll, Maragos again got separated from his boat and was spotted only when brown boobies began circling him. “Thank God for boobies,” Maragos says.

Working conditions are challenging for the federal officials who oversee the distant wildlife habitats in the four U.S. marine national monuments. Just getting to the monuments can be a trial, because there are only three airplane runways in the system. Most islands must be visited by ship, a journey that can take weeks. “You can’t just jump in a pickup truck like on most refuges,” says the U.S. Fish and Wildlife Service’s (FWS) Susan White, who oversees three of the marine monuments. “We need ships and airplanes. Getting there is a logistical challenge.”

In the future, federal officials would like to establish a remote monitoring network of audio and video equipment that would beam images and sounds back to workers in Honolulu and the mainland. This would not only alert researchers to the arrival of seabirds or whales but also would provide a law-enforcement tool to supplement the Coast Guard planes and cutters that patrol the monuments for illegal fishing and other trespassing. But money is short. The annual FWS budget for the marine monuments is just $16 million. “We are so far away from Washington,” says Barry Stieglitz, who oversees federal wildlife refuges in the marine monuments. “We would like to be on the radar screen of the American people.”

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