Macquarie Island is a subantarctic oceanic island located in the southwestern part of the Pacific Ocean. The island is politically part of the Australian island state of Tasmania and regionally is part of Oceania. Macquarie Island is geographically positioned about 1,500 km southeast of the main island of Tasmania, roughly halfway between the island nation of New Zealand and the mainland of Antarctica. In 1978, Macquarie Island became part of the Tasmanian State Reserve and was subsequently designated a UNESCO World Heritage Site in 1997.

Geography

The main Macquarie Island covers an area of ​​128 km2 and is approximately 34 km long and has a maximum width of 5 km. Many highlands are located in the northern and southern parts of the island. These plateaus rise to an altitude of about 150 to 200 m and are connected by a narrow isthmus. The island has several high points such as Hamilton and Fletcher mountains which are located in the southern part of the island and culminate at an altitude of 410m; while Mount Elder, located on the northeastern coastal ridge of the island, rises to an elevation of 385m. In addition to this, the island also has several small glacial lakes. Much of the southern half of the island is covered with volcanic cushion basalt, lava flows, sediments, and other extrusive rocks.

Macquarie Island also includes two small groups of offshore rocky islets. These include Judge and Clerk Islets, which cover an area of ​​only 0.2 km2 and are located approximately 14 km north of main Macquarie Island; while Bishop and Clerk Islets, which occupy an area of ​​0.6 km2, are located approximately 34 km south of main Macquarie Island.

Macquarie Island forms an exposed part of the submarine Macquarie Ridge and is positioned at the meeting point of the Pacific and Indo-Australian tectonic plates. The main island and its offshore islets are geologically unique as they form the only place on the planet where the rocks of the Earth’s mantle 6 km below the ocean floor are quite actively exposed on the surface. This geological evolution of the island began around 10 million years ago and continues to this day as the island is seismically active, experiencing frequent earthquakes as well as a rapid rate of uplift. Macquarie Island is believed to be the only recognized ophiolite sequence that has formed in a large ocean basin. The unique geology of Macquarie Island is therefore considered to be a link between the ophiolites of the continental crusts and those of the oceanic crusts.

Weather

According to Köppen’s climate classification, Macquarie Island experiences a “tundra climate” with an average maximum temperature of 8.8 ° C in January and 4.9 ° C in July. The island receives annual rainfall of about 967.9 mm and is mostly covered in thick cloud for about seven to eight months per year. The climate is tempered by the strong westerly winds that blow continuously over the island.

The fauna and the flora

The flora of Macquarie Island has taxonomic similarities with marine species from other surrounding subantarctic islands. Most plants on Macquarie Island do not exceed 1 m in height, although some grass species such as Poa foliosa may exceed 2 m in sheltered areas. It has been estimated that around 45 species of vascular flora, 80 species of moss, 141 species of lichen and 50 species of liverworts are found on the island. The main vegetation of the island includes peat bogs, marshes, feldmark, high tussock meadows and fields of grasses. Deep, spongy peat-bed bogs called “ feather beds ” cover the island’s elevated terraces. Some of the endemic flower species found here include Azorella macquariensis, orchids – Nematoceras sulcatum, and Nematoceras dienemum, and the grass – Puccinellia macquariensis.

Macquarie Island has more than 80,000 seals belonging to different species such as Antarctic Fur Seals, Southern Elephant Seals, New Zealand Fur Seals and Sub-Antarctic Fur Seals. In addition to these, southern right whales and orcas are also commonly seen. The island’s endemic breeders include king penguins and Macquarie shags. Macquarie Island has been designated an Important Bird Area by BirdLife International because it is home to over 3.5 million breeding seabirds of 13 species.

Brief history

The uninhabited island was discovered by an Australian seal named Frederick Hasselborough in 1810. He claimed the island for Great Britain and turned it over to the administration of the colony of New South Wales. The island was then named “Macquarie Island” in honor of Colonel Lachlan Macquarie, who was governor of New South Wales from 1810 to 1821. Russian explorer Fabian Bellingshausen in 1820 produced the first map of the island. Macquarie Island. Fabian Bellingshausen landed on the island in 1820 where he traded rum and food with seal hunters in exchange for the island’s wildlife. The ecology of Macquarie Island was severely affected by the visit of Europeans and the island quickly became a hunting ground for seals and penguins, which were nearly hunted until extinction from 1810 to 1919 Various species such as rats, mice, wild cats, rabbits, etc. were also introduced to the island. These invasive species have in turn had a devastating effect on the native wildlife of Macquarie Island.

In 1890, the colony of New South Wales moved Macquarie Island to Tasmania. The Tasmanian government leased the island to New Zealander Joseph Hatch from 1902 to 1920. During this time, Hatch used the island for its oil industry based on penguin hunting. From 1911 to 1914, Macquarie Island served as the base for the Australasian Antarctic Expedition. In 1933, the island was declared a wildlife sanctuary, and eventually became a state reserve in 1972. Macquarie Island was declared a UNESCO World Heritage Site in 1997.