Macquarie Island

Site information

• Official name: Macquarie Island
• Location: Tasmania, Australia
• Type: Natural
• Year of inscription: 1997

Popularly known as "Macca," Tasmania's Macquarie Island is like no other place in the world because it offers a unique glimpse into the earth's formation. It was shaped over a ten-million-year period by winds and seas from the earth's mantle located some six kilometers below the floor of the Southwestern Pacific Ocean. The island is only thirty-four kilometers long and five kilometers wide. Situated some fifteen hundred miles south-southeast from Tasmania, Macquarie Island is composed of the visible portion of the Macquarie Ridge, the undersea barrier that separates the Pacific and Indian Oceans. The island is also located roughly halfway between Australia and Antarctica and is home to several species of fur seal, including subantarctic, Antarctic, and New Zealand fur seals, as well as southern elephant seals.

Macquarie Island is also the only breeding site in the world for the royal penguin. Other breeds of penguin found on the island include the king, the southern rockhopper, and the gentoo. There are also four species of albatrosses on the island. With a total area of 12,785 hectares, the island is composed of Macquarie Island, Judge and Clerk Islets to the north, and Bishop and Clerk Islets to the south. It also includes twelve nautical miles of water, rocks, and reefs.

History

Macquarie Island was discovered in July 1810 by sealers looking for new prey, and it has been estimated that two hundred thousand skins of elephant seals were taken in that first year. Within a decade, sealers had almost devastated the seal population, and sealing was prohibited on the island after 1824. Similar activities were taking place in other parts of the world, and by the mid-twentieth century, the world's population of elephant seals had been reduced by 50 percent. While other populations have essentially recovered, the Macquarie Island population has continued to decline at a rate of around 13 percent each year. The Hooker's, or New Zealand, sea lion was almost made extinct because it was a popular food for the Maori people. That seal population on Macquarie Island is now considered stable. In 1948, the New Zealand fur seals were first brought to the island, and the first pup of the protected population was born in 1955.

The Australian Antarctic Program (AAP) (formerly the Australian National Antarctic Research Expedition [ANARE]) station is located near Wireless Hill on Macquarie Island. Established in 1948, AAP is the oldest of all the stations found in the area and has been responsible for repopulating decimated wildlife populations on the island. The station comprises a complex of thirty buildings where scientists are engaged in studying geophysics, biology, atmospheric physics, meteorology, medicine, remediation, and climate change.

Because of its location along a fault line, Macquarie Island is subject to frequent earthquakes that cause changes in the island's formation. All species of flora and fauna on Macquarie Island are protected. However, because of centuries of habitat modification by humans, the island is facing climate change threats. Scientists have expressed concern about the cross-species mating habits of some of the island's wildlife. Habitat changes have led to a hybridization that threatens genetic integrity and may make some species extinct.

The major threat to biodiversity on Macquarie Island has traditionally been the commercial exploitation of seals and penguins, which led to the extinction of some species and the vulnerability of others. An ongoing threat is posed by natural predators such as skuas, sheathbills, falcons, kelp gulls, and giant petrels. In the 1960s, a concerted effort was made to manage the island's resources. One significant effort involved eliminating the island’s feral cats—the descendants of cats previously brought to the island to control black rats and mice—that were decimating the island’s bird population. However, the eradication of cats by 2000 left 130,000 rabbits uninhibited. The rabbits destroyed 130,000 acres of vegetation in 2009 and decimated an entire penguin colony. Between 2011 and 2014, the last invasive, non-native pest flora and fauna were eliminated from the island, allowing native birds, animals, and plants to reclaim their habitat. Officials announced that the island had recovered and was exhibiting renewed vegetation, and birds such as the gray and blue petrels and the light-mantled sooty albatross were returning.

Management of Macquarie Island is provided by the Tasmanian Parks and Wildlife Service (PWS) under the Macquarie Island Nature Reserve and World Heritage Management Plan of 2006. The Australian government and PWS jointly manage the marine area of the island under the Island Commonwealth Marine Reserve. Legal protections are guaranteed by the Environmental Protection and Biodiversity Conservation Act of 1999.

Significance

Macquarie Island was inscribed as a World Heritage Site in 1997 after being rejected for inclusion in 1992. Its inscription is based on its meeting Criteria vii and viii. Its acceptance under Criterion vii is largely a result of the biodiversity created by its penguin and seal population. Scientists have recorded over 850,000 pairs of royal penguins living on the island. The 150,000 to 170,000 pairs of king penguins continue to expand. The elephant seal has been a particularly popular field of study among the numerous fur seals. Much of the area is devoted to featherbeds that lie along the coast covered by land that is waterlogged and overlaid with vegetation. Around those featherbeds are lakes, tarns, and pools. Macquarie Island meets the requirements for Criterion viii because of its unique position as the only place in the world where the earth's mantle is above sea level. The island is known chiefly for its wide variety of penguins and seals. There are only four species of elephant seals anywhere in the world, one of which is found on Macquarie Island. That seal is shaped like a torpedo and is adept at swimming and diving.

The island is home to an estimated 3.5 million seabirds of twenty-five species, including four species of albatrosses. Conservation efforts have successfully reintroduced and protected the populations of several birds native to the island that were driven near extinction at the end of the twentieth century. The blue and grey petrels were once extinct on the island, but by the late 2010s and early 2020s, they had recolonized the main island, with populations increasing by 10 percent each year.

The king penguin found on Macquarie Island is the second largest species of penguin, outranked only by the emperor penguin. The yellow-crested royal penguin live in colonies that range in size from thirty birds to several thousand. One colony was estimated at 500,000 pairs. Because of decades of being hunted by oilers who boiled them for oil, the species is considered near threatened by the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. They are migratory but return to the island for breeding, which takes place nowhere else in the world. One of the smallest of the penguin populations on the island is the red-orange-billed gentoo penguin, which is estimated at 387,000 pairs. The number of breeding pairs of this species decreased by 1.8 percent per year between 1984 and 2017. The southern rockhopper penguin, populations of which vary from 100,000 to 500 individual birds, is also migratory and is considered vulnerable.

Bibliography

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