Explore the Central Pacific

A Huge Blue Backyard

The Pacific Ocean makes up approximately one-third of the Earth's surface. This vast expanse of ocean is home to nearly 25,000 islands. Among these islands stretching 2,350 km in a northwest-southeast direction approximately 1,000 miles south of the Hawaiian Islands are a chain of eleven atolls called the Line Islands.  The geological history of the Line Islands is complex. It is thought that the islands formed as volcanoes over a series of hot-spots. Today only 11 of these islands are visible, at best, a few meters above sea level.  The remote nature of these islands, coupled with the biodiversity found here make them ideal areas to study coral reefs. 


Marine National Monument

Marine National Monument

The Pacific Remote Islands Marine National Monument is a group of unorganized, mostly unincorporated United States Pacific Island territories in the Central Pacific, managed by the Fish and Wildlife Service of the United States Department of the Interior. Proclaimed a national monument on January 6, 2009 by U.S. President George W. Bush, the monument covers 86,888 square miles (55,428,480 acres), spanning areas to the far south and west of Hawaii, including Kingman Reef, Palmyra Atoll, Howland Island, Baker Island, Jarvis Islands, Johnston Atoll, and Wake Island.

Within the national monument, resource destruction or extraction, waste dumping, and commercial fishing will be prohibited, but research, free passage, and recreation will be allowed. Additionally, NOAA manages three marine sanctuaries in the Pacific Islands Region including the Papahānaumokuākea Marine National Monument, the Hawaiian Islands Humpback Whale National Marine Sanctuary, and the Fagatele Bay National Marine Sanctuary. The sanctuaries provide protection for a multitude of marine species including sea turtles, dolphins, whales, pearl oysters, giant clams, coconut crabs, large groupers, sharks, humphead wrasses, and bumphead parrotfishes. Expansive shallow coral reefs and deep coral forests – with some corals up to 5,000 years old – are found here. These small dots of land in the midst of the ocean are vital nesting habitat for millions of seabirds and resting habitat for migratory shorebirds. Protecting and studying these special ocean areas provides an opportunity to secure the future of our marine resources and to better understand the functioning of our oceans. Ecological knowledge is key to reef management and restoration, and ongoing monitoring and evaluation of the status of reefs are essential components of these efforts. The system of marine sanctuaries and national marine monuments hopes to help manage and preserve these valuable coral reed ecosystems for generations to come. Read National Geographic's article announcing marine reserve.

The Southern Line Islands are home to among the most intact and pristine coral reefs on the planet. The islands are all uninhabited and are protected as wildlife sanctuaries by the Republic of Kiribati. There is discussion to extend broader protections to the marine resources of these islands, much like the great efforts of protection in the Kiribati Phoenix Islands Protected Area. However, large-scale marine conservation is challenging and demands investment from beyond just the people of Kiribati. As a global community we need to find ways to facilitate the conservation ethos of our friends in Kiribati.


A Unique Natural Experiment

The atolls of the Line Island chain span several oceanographic and climatic zones. As a result, the terrestrial characteristics of the islands vary from lushly vegetated to nearly desert-like terrains, while the submerged coral reef fauna is subject to varying influences of the El Niño phenomenon. Furthermore, although the Line Islands archipelago is the most isolated collection of islands on the planet—no continent is closer than 5000 km from any of the Line Islands—the chain is now characterized by concentrated pockets of human disturbance; this concentration of human influence has important implications for the study of island resource management. All of these aspects of the Line Islands make the archipelago an essential natural laboratory for understanding the development, evolution, and governing processes of the tropical atoll environment.”

In general, the Line Islands are characterized by uniformly low-lying topography, with elevations rarely exceeding 10 m above present mean sea level. Terrestrial substrates are typically reef sands and rubble, but one notable feature of many of the islands is that the coral rubble can reach boulder size (these coral boulders were presumably deposited by either past tsunamis or large storms).

The characteristics of the Line Islands are shaped not only by their geological history but also by their location with respect to major oceanographic and climatic zones. The southern Line Islands fall within the westward-flowing south equatorial current.

The Line Islands are one of the longest island chains in the world and are geographically divided into two subgroups; the Northern and Southern Line Islands.

The Northern Line Island chain, where our team visited in 2005 and 2010, is comprised of both inhabited and uninhabited islands, making it the perfect area for exploration and scientific discovery. The ecological research taking place in the Northern Line Islands provides valuable insights into the workings of coral reefs and how these can be altered by human activities. While we depend upon coral reefs to provide food and coastline protection worldwide, we currently lack a clear understanding of how best to use (and not overuse) these resources. The Northern Line Islands serve as a natural experimental system that spans a gradient of human disturbance, from pristine to moderately impacted by people.

The Southern Line Islands are all uninhabited islands within the Republic of Kiribati. These islands protect some of the most pristine and intact coral reefs remaining on the planet, and serve as an invaluable setting to study how coral reefs work in the absence of human disturbance. Interestingly, these islands span a wide range of natural, oceanographic conditions, with the local waters ranging from very nutrient-poor to higher-nutrient upwelling zones. The Southern Line Islands present an unparalleled opportunity to study how oceanographic conditions alter the ecology of a coral reef independently of any effects of humans.

Locations and populations for the Line Islands from North to South:

Kingman Reef population 0 6°24′N 162°24′W   |   Palmyra Atoll population 4 5°52′N 162°6′W   |   Teraina population 1,155 4°43′N 160°24′W   |   Tabuaeran population 2,539 3°52′N 159°22′W   |   Kiritimati population 5,115 1°53′N 157°24′W Jarvis Island population 0 0°22′S 160°03′W   |   Malden Island population 0 4°01′S 154°59′W   |   Filippo Reef population 0 5°30′S 151°50′W   |   Starbuck Island population 0 5°37′S 155°56′W Millenium Island population 0 9°57′S 150°13′W   |   Vostok Island population 0 10°06′S 152°25′W   |   Flint Island population 0 11°26′S 151°48′W   

The Northern Line Islands

Kingman Reef

Kingman Reef36 nautical miles northwest of Palmyra is the uninhabited Kingman Reef, a mostly submerged reef of less than one square mile. The U.S. annexed the reef in 1922. Its sheltered lagoon served as a way station for flying boats on Hawaii-to- American Samoa flights during the late 1930s. There are no terrestrial plants on the reef, which is frequently awash, but it does support abundant and diverse marine fauna and flora. In 2001, the waters surrounding the reef out to 12 nautical miles were designated a U.S. National Wildlife Refuge.



Palmyra Atoll

Palmyra AtollThe same year Fanning "discoverd" Teraina he visited Palmyra Atoll after dreaming of finding an island the night before but never landed. Four years later an American ship, Palmyra, was blown ashore during a storm giving the atoll its name. In 1898 Palmyra was annexed to the USA as part of the Territory of Hawaii but was later excluded from becoming the 50th Sate along with the Hawaiian islands. This makes Palmyra the only privately owned territory in the United States. The Palmyra region is currently administered by the U.S. Department of Fish and Wildlife Service and the land is owned by The Nature Conservancy. Truly uninhabited, there is a crew of about 10 residents who maintain the island for ocean science research.


Tabuaeran Island

TabuearanMuch closer to Kiritimati at a distance of only about 153 miles is Tabuaeran, also called Fanning Island, with a population of about 1,900. Visited by the American explorer Edmund Fanning in 1798, it was renamed Tabuaeran when it gained independence as part of Kiribati in 1979. Copra is the island's only export. Residents of overcrowded islands in Kiribati have been resettled on Tabuaeran. Reef fishes and shellfishes, babai, coconut, pigs, chickens, and seaweed (limu) grown in lagoons are local foods, supplementing a main diet of imported rice and tinned meats. The maximum elevation is about 10 feet (three meters) above high tide.


Teraina Island

TerainaAnother island visited by Edmund Fanning (June, 12, 1798) is Teraina, a three-square mile island with a population of about 900. Fanning named the island Washington Island after George Washington. Also called Prospect Island, the name was changed to Teraina after Kiribati gained independence in 1979.





KiritimatiKiritimati, also known as Christmas Island is the largest of the Line Islands at 222 square miles and has a population of about 10,000. Its chief agricultural product is copra, dried coconut meat yielding coconut oil. The atoll was explored by Capt. James Cook in 1777, annexed by Great Britain in 1888, and included in the Gilbert and Ellice Islands colony in 1919. British nuclear tests were conducted on the atoll in 1957 and 1958 and U.S. tests in 1962. Because of its size and area, it is believed to be the oldest atoll in the world. There are four villages on the atoll: London, Tabwakea, Banana (Banana Wells), and Poland. Many of the place names are from Father Emmanuel Rougier, a former French priest who leased the island from 1917 to 1939 and planted some 800,000 coconut trees. La colline de Joe (Joe's Hill) is the highest point on the atoll, less than 40 feet (12 meters). If a traveler were to leave Christmas Island and sail directly west nearly 1,000 miles, they would land on Howland Island, where history's most famous female aviator, Amelia Earhart, mysteriously disappeared in 1937. In between Howland and Christmas islands is expansive open ocean, perfect for conducting ocean science research, but nowhere to land a plane.

Jarvis Island

Jarvis IslandLocated 25 miles south of the equator is Jarvis Island; a 4.5 square kilometer (1.75 sq. mile) small coral island.  The island's first known sighting by Europeans was on 21 August 1821 by the British ship Eliza Francis owned by the Jarvis family and commanded by Captain Brown. In March 1857 the uninhabited island was claimed for the United States under the Guano Islands Act and formally annexed on 27 February 1858. For the following twenty-one years, Jarvis was commercially mined for guano, sent to the United States as fertilizer. The United Kingdom annexed the island on 3 June 1889 and the United States reclaimed it in March of 1935, under the Baker, Howland, and Jarvis Colonization Scheme. Since 27 June 1974, Jarvis Island has been administered by the U.S. Fish and Wildlife Service as the Jarvis Island National Wildlife Refuge.


The Republic of Kiribati


The Republic of Kiribati was founded in 1979. Made up of 33 atolls and one island the Republic of Kiritimati is scattered over nearly two million square miles in an ocean region largely thought of as the South Pacific.  Within this vast area lie the Line Islands, a group of mostly atolls, approximately 1,000 miles south of the Hawaiian Islands. The Line Islands are remote and far from bustling cities and active airports. Their distance from civilization created a history is full of explorers, pirates, and fortune hunters. Their location also makes them the perfect place to study and conserve the practically untouched coral reefs that dominate the underwater landscape.

The Southern Line Islands


MaldenThe margins of Malden consist of continuous land, whereas the interior of the island has salty inland lakes.

Malden is approximately 29 km2 with a large lagoon. It has evidence of previous habitation by Polynesians before European discovery. Guano deposits were worked and depleted by 1920. The British used it to test nuclear weapons in the late 1950’s. It became a wildlife sanctuary and reserve in 1975 and was incorporated into the nation of Kiribati four years later. It is currently uninhabited (Encyclopedia Britannica).

Photo credit: Image Science and Analysis Laboratory, NASA-Johnson Space Center (Digital File Number: ISS006-E-38455)



Similar to Malden, in its continuous land and salty inland lakes.

The island is named after Valentine Starbuck, who first spotted the island in 1823 from his British whaling ship. It was annexed by Britain in 1866 and mining for guano began shortly thereafter, continuing for the next 50 years. In 1979 Starbuck became part of independent Kiribati. The island is barren and uninhabited, but home to breeding populations of millions of sooty terns, among other seabirds. (Encyclopedia Britannica)

Photo credit: Image Science and Analysis Laboratory, NASA-Johnson Space Center (Digital File Number: ISS013-E-7103)




MilleniumMillennium is a series of islets that enclose the lagoon, only 20 feet above sea level. It was named in 1999 (formerly Caroline Atoll or Thornton Island) because it is the easternmost point west of the dateline. The first place to see the new millennium (Encyclopedia Britannica).

Notably, among the land animals inhabiting the island, is the coconut crab (Birgus latro), named for its ability to crack open coconuts with its claws. These crabs can grow to be 70 cm in thoracic length, have a leg span of 1 m, weigh a few kilograms (with some estimates over 4 kg), and live for decades. Because of their large size and their fabled taste, the coconut crab has been harvested extensively from the inhabited Line Islands. However, remnant populations of crabs thrive on the uninhabited islands (Millennium, Flint), with population estimates of hundreds of thousands to millions of crabs on the southern islands.

Photo credit: Image Science and Analysis Laboratory, NASA-Johnson Space Center (Digital File Number: ISS002-E-6368)


VostokVostok is a small uninhabited island that occupies most of the reef platform upon which it rests. Vostok and Flint are the most southern of the Line Islands and receive less rainfall than the other islands (approximately 500 mm yr-1 ). These average rainfall patterns are related directly to the mean annual position of the intertropical convergence zone, which, while under- going some seasonal north–south migration, nevertheless remains north of the equator throughout the year in the region of the Line Islands.

Vostok is only one square mile with no anchorage in the lagoon. It was named in 1820 by a Russian Antaractic explorer, who named the island after his ship. The island was never exploited for guano and attempts at establishing a plantation there in 1922 failed. As a result, Vostok’s indigenous flora is the least disturbed of the Line Islands (Encyclopedia Britannica).



Flint is the southernmost island of the Southern Line Islands. It has an area of one square mile with several brackish lagoons. The island was developed for guano working and copra plantations in the late 1800’s. Most of the native flora has been replaced. It became part of Kiribati in 1979.

Photo credit: Image Science and Analysis Laboratory, NASA-Johnson Space Center (Digital File Number: ISS014-E-5382)






Content borrowed from Scripps Institution of Oceanography, Line Islands Expedition 2009 , Wikipedia, and The Nature Conservancy.