Macquarie Island

Macquarie Island Nature Reserve protects one of Australia's most extraordinary natural places, an isolated subantarctic island in the Southern Ocean approximately 1,500 kilometres southeast of Tasmania, listed as a UNESCO World Heritage Site. The island rises from the sea as the exposed crest of the Macquarie Ridge, a major oceanic feature, and is the only place on Earth where rocks from the Earth's mantle are actively being exposed at the surface through a process called obduction. The island is home to millions of penguins and seals and hosts the Australian Government's most remote research station at Macquarie Island Station, maintained year-round by the Australian Antarctic Division.

Macquarie Island supports one of the greatest concentrations of wildlife of any place on Earth. Approximately 3.5 million penguins of four species breed on the island: royal penguins (endemic to Macquarie Island), king penguins, gentoo penguins, and rockhopper penguins. Four species of seals breed on the island: southern elephant seals, Antarctic fur seals, New Zealand fur seals, and sub-Antarctic fur seals, with southern elephant seal numbers in the hundreds of thousands. Wandering albatrosses and other albatross species, giant petrels, and numerous other seabirds breed on the island. The island is a critical staging point in the great migration routes of Southern Ocean wildlife.

Macquarie Island's vegetation has been heavily impacted by introduced species, particularly rabbits which were brought by sealers in the nineteenth century and devastated the island's vegetation through intensive grazing. Following a successful multi-year eradication program completed in 2014, the island's native vegetation is recovering dramatically, with native megaherbs and tussock grassland re-establishing across previously degraded areas. The island supports endemic and subantarctic plant species including giant Macquarie Island cabbage and various cushion plants adapted to the cold, wet climate.

Macquarie Island is geologically unique in the world: it represents the only place where ocean floor rocks (ophiolite) and mantle materials are being actively exposed at the Earth's surface through ongoing tectonic uplift, rather than being found in ancient mountain ranges. The island sits on the boundary of the Indo-Australian and Pacific tectonic plates, and the convergence of these plates forces the ocean floor upward. The island's rocks include pillow basalt, gabbro, serpentinite, and harzburgite, providing geologists with a rare window into the composition of the oceanic lithosphere.

Macquarie Island experiences one of the world's most consistently harsh climates, with temperatures rarely exceeding 8 degrees Celsius even in summer, constant winds frequently exceeding 100 kilometres per hour, 300 or more rain days per year, and precipitation in all forms throughout the year including frequent snow and sleet. The island is a true subantarctic environment, a climate zone between the temperate and Antarctic regions characterised by persistent overcast conditions, high humidity, and cold, persistent winds. Research station staff describe the climate as relentlessly challenging.

Macquarie Island was discovered in 1810 by the British sealer Frederick Hasselborough, who immediately recognised its commercial potential. Within years, sealers had nearly exterminated the southern elephant seal and fur seal populations for their oil and pelts. Penguins were boiled for their oil in the late nineteenth century, with millions of king and royal penguins killed. The exploitation of Macquarie Island's wildlife was one of the most devastating in the history of wildlife exploitation. Scientific interest in the island began in the early twentieth century, and Ernest Shackleton's Australasian Antarctic Expedition stopped at the island in 1911. Australia established permanent research presence in 1948.

Macquarie Island was declared a nature reserve in 1933, one of Australia's earliest wildlife protection designations. Tasmania administers the island as the responsible jurisdiction despite its enormous distance from the state. The island was inscribed on the UNESCO World Heritage List in 1997 for its outstanding geological and biological values. A major management achievement was the eradication of all introduced rabbits, rats, and mice from the island, completed in 2014 after a multi-year program, which has allowed extraordinary vegetation recovery across the formerly barren, rabbit-grazed landscape.

Macquarie Island is accessible only to expedition cruise passengers and Australian Antarctic Division personnel, with very limited tourist access in summer. The overwhelming attraction is the extraordinary wildlife spectacle: millions of penguins in dense colonies, beaches crowded with elephant seals of enormous size, wheeling albatrosses overhead, and the drama of Southern Ocean wildlife in one of the world's most remote settings. The geological features of the island are of scientific interest, and guided walks are provided for cruise passengers.

Macquarie Island is accessible by icebreaker expedition cruise from Hobart, with voyages taking approximately five days each way. Only a limited number of passenger vessels are authorised to land, and passenger numbers per landing are strictly controlled. The Australian Antarctic Division's research station is not open to tourists. Costs are substantial and bookings must be made well in advance. The island cannot be reached by light aircraft due to the absence of a runway.

The successful eradication of rabbits, rats, and mice from Macquarie Island, completed in 2014, is considered one of the world's greatest wildlife management achievements. The program used aerial baiting and ground control over multiple years on a remote island the size of a small city. The subsequent vegetation recovery has been remarkable, with native plants recolonising bare hillsides within years. Ongoing conservation focuses on biosecurity to prevent re-introduction of invasive species and on monitoring the recovering wildlife populations, including the continuing seal and penguin colony size assessments that are fundamental to understanding Southern Ocean ecosystem health.