The 15 islands and rocks that make up the Kermadec Islands are the only emergent volcanoes in the extensive volcanic arc that stretches from White Island to Tonga. They are New Zealand’s only subtropical islands and have a total area of 3330 hectares (ha).
Raoul Island is the largest at 2943ha and the only island in the group covered in forest, with rugged hillsides clad in endemic Kermadec pohutukawa and nikau. At the centre of the anvil-shaped island is a huge caldera with three lakes – evidence of the island’s explosive nature. The most recent eruptions occurred in 1814, 1870, 1964 and 2006.
Video created by Sian Potier and Toby Shanley showing life for staff on Raoul Island in 2011.
Macauley Island – the second largest island of the group at 323ha – has a simple cake-like topography with an open flattish top, called the Plateau, with several deep canyons cut into the soft rock. New Zealand established a castaway depot on the island in 1889 serviced regularly by government steamers through to the end of the First World War. Polynesian rats, pigs and goats were established on the island. Pigs died out naturally, goats were shot out by 1970, and the last invaders, the rats, were eradicated in 2006. Virtually tree-less, the island’s flora is now dominated by sedge Cyperus and a species of giant fern Hypolepis. Despite the previous trampling of goats, the island is home to over 6 million seabirds. This includes the world’s largest colony of black-winged petrel, the only population of the near endemic white-naped petrel, Kermadec petrel, Kermadec little shearwater and, most likely now that rats are gone, the tiny Kermadec storm petrel.
Curtis Island is 52ha and is an active volcano, with steaming vents and fissures. Vegetation consists entirely of coastal herbs dominated by ice plant. Early visits before the 1900s accessed a sheltered cove but subsequent volcanic activity has eliminated this cove entirely. Always rat free, it supports a large colony of the endemic Kermadec little shearwater. Cheeseman (8ha), L’Esperance (4.8ha), Haszard (6ha) and the 7 islands in the Herald group (total 51ha) also support important seabird populations and have always been rat free. The Herald Group has been particularly important in re-establishing native birds on Raoul, once decimated by predators.
The archaeological and historic landscape of the Kermadec Islands, especially Raoul, is extensive and extremely important. As the only islands between Polynesia and New Zealand, they were periodically occupied by Polynesians on their great ocean voyages. Evidence of their presence includes plants they would have brought with them such as taro, flax, candlenut, ti and kumera.
The islands were uninhabited when Europeans first arrived. Whalers from the 1820s used the islands to source wood, water and fresh provisions such as seabirds and their eggs. They were followed by a series of attempts at settlement by people dreaming of an idyllic tropical lifestyle maintained by supplying whaling ships with fresh produce. Read in 1836 was the first settler. The Bell family settled for the longest (from 1878 until 1914). They grew an impressive array of vegetables and fruit including “edible arum, 14 varieties of banana, six varieties of taro, kumara, oranges, lemons, citrons, shaddocks, limes, custard apple, pawpaw, rose apple, yellow guava, pomegranate, yams, melons, calabash, grapes, apples, pears, peaches, Spanish chestnut, pineapple, mango, strawberries, Tonga bean, sugar cane, ufilei (a very fine kind of yam), peanuts, marrow, fat beans, kapi (a New Guinea plant with an edible root) and maize besides ordinary vegetables in great confusion”1. Governor Grey supplied plants from his Kawau Island residence: a special strain of Havana tobacco, tea and coffee plants, varieties of Smyrna figs and cuttings of black and white grapes.
The Kermadec Islands were annexed by the New Zealand Government in 1887, and in 1889 the island was subdivided by Government Proclamation into landing reserves and grazing runs which were then offered for lease, but were never a a great success.
From 1939 the meteorological and aeradio station (ZME, Raoul Island) conveyed data by radio for aviation and South Pacific meteorological services. During World War II, coast-watchers were also based on Raoul Island.
The Kermadecs are a seabird refuge of major international importance. Over six million seabirds breed on the islands. For eleven of the 14 seabird taxa, the Kermadecs are the only New Zealand breeding location.
This abundance of birdlife is a far cry from the decimated populations recorded by the Ornithological Society of New Zealand on its visit to the island in 1967. At this time, the ravages of Norwegian or brown rats (likely to have arrived when the ‘Columbia River’ was wrecked here in 1921) and other pests were having a serious effect on native fauna and flora. When WRB Oliver visited on a scientific expedition for 10 months in 1908 he found vast numbers of seabirds present. By 1967 they were all but gone, as were the Kermadec parakeets.
Concerted efforts to rid the island of pests have been hugely successful. Goats were eradicated during the 1970s and rats and cats from 2002-2003. Land birds are once again dominated by tui and Kermadec parakeet. Also present are kingfisher, spotless crake and some introduced passerines such as blackbird and yellowhammer. Seabirds are also returning since the eradication of rats and cats including Kermadec sooty tern, wedge-tailed shearwater, black-winged petrel and Kermadec petrel.
The flora of the Kermadec Islands is internationally important due to its unique assemblage of species of subtropical and temperate origins, and the number of endemic taxa. For example, two endemic species – the nettle tree and the Kermadec poplar – have tropical origins. There are also strong affinities with Norfolk Island species. The Kermadec nikau, for example, may be the same as the Norfolk Island species. There are 23 endemic plants on the Kermadecs. Some became threatened while goats were present but most are now recovering, including Hebe breviracemosa.
Settlement, including the Metrological station and associated farm, has seen plants introduced both for cultivation and by accident. Few introduced species are a problem, but some are being eradicated as they have the potential to damage native ecosystems. Four of the major weed problems are plants which originated in the tropics: Mysore thorn, Brazilian buttercup, and two species of guava. Weed eradication began in 1972 and continues to the present with notable successes including pampas grass and Lombardy poplar.
The Kermadec Islands were gazetted a Flora and Fauna Reserve in 1934. They are now classified as a Nature Reserve in terms of the Reserves Act 1977. The Department of Conservation took over management of the islands in 1987 and undertakes the Meterological programme under contract to the MetService. The islands have a permanent DOC presence on Raoul Island with staff and volunteers there for 12 months of the year.