The Antipodes Island group is a complex of volcanic cones and vents. Sheer cliffs rise to a tussock strewn plateau.
These cliffs continue beneath the waves where they support sessile (stationary) marine invertebrates in large numbers and a diverse array of seaweeds. To the south of the group the ocean drops away to a depth of 3000 m, some of the deepest waters in any New Zealand marine reserve.
Antipodes Island/Moutere Mahue Marine Reserve was created in 2014, at the same time as marine reserves for the Campbell Island/Motu Ihupuku and Bounty/Moutere Hauriri islands.
The marine reserve covers the entire territorial sea surrounding the islands (to 12 nautical miles). The islands themselves are protected as a Nature Reserve.
The main and by far the largest island, Antipodes Island, was named because it is nearly opposite – antipodal - to London, England. The marine reserve’s Maori name Moutere Mahue is translated as “abandoned” or “deserted” island, recognising its isolation and remoteness.
Antipodes Island is the most remote of New Zealand’s subantarctic islands, 750 km southeast of the South Island. It lies on the eastern edge of the Bounty Plateau – an area of shallower sea (600-1000 m) amidst the Southern Ocean where depths average 4000-5000 m. The island and its islets are the remains of a Pleistocene volcano, and Antipodes Island itself is dominated by a central cone (Mt Galloway, 366 m).
Visiting the islands
You can visit Antipodes Island/Moutere Mahue Marine Reserve as part of a guided trip. You must have a permit, and strictly adhere to the minimum impact code. More information about visiting the subantarctic islands.
Underwater, the extensive rock walls are covered in bright pink layers of encrusting seaweeds which are a particular feature of Antipodes Island. Such extensive areas of plating coralline seaweeds are not known from mainland New Zealand, and Campbell Island is the only other place where similar formations are recorded. The algae’s three-dimensional nature provides habitat for a range of animals such as anemones.
A particular feature of the waters around Antipodes Island is an endemic and still undescribed bull kelp. This seaweed forms beds down to over 20 metres depth. Each plant has a dinner plate-sized holdfast and a stipe or stem as thick as a person’s arm. The plants themselves can be 4 m in length, creating massive forests of kelp.
Underwater surveys indicate that species diversity in some areas around the islands may be the richest of all the New Zealand subantarctic islands. The combination of clear water and proximity to the edge of an undersea plateau creates this diversity.
As with the other subantarctic islands, Antipodes Island has its own suite of marine species, some found nowhere else in the world. Many of the animals found onshore are dependent on the surrounding marine environment for food.
The island is the main breeding ground for the endemic Antipodean albatross (about 5,000 breeding pairs) and large colonies of erect-crested and eastern rockhopper penguins.
The erect-crested penguin population has declined substantially in the past 20-years, but the reason for this is not known. The world’s only known breeding grounds for erect-crested penguins are here and the Bounty Islands.
Antipodes Island is also home to southern elephant seals and New Zealand fur seals.
Many invertebrates cling to the sheer rock walls beneath the surface, creating a dense mosaic of sponges, anemones, bryozoans and many other animals.
There are more than a hundred described seaweeds, and there are almost certainly many more as research has been scarce in this inaccessible and inhospitable place. A research expedition to the Bounty and Antipodes Islands in 2009 found a number of species new to science, including seaweeds and even a species of stalked jellyfish.
There are few nearshore fish species here, but one of the most common is the Antarctic cod (small-scaled notothenid). Offshore, species such as ling and Patagonian toothfish have been recorded, but there has been virtually no fishing around Antipodes Island, making it one of the least disturbed marine environments in New Zealand.