A line in the ocean

A Lucky Escape

The Kermadec Islands once had a lucky escape. When the United Kingdom was ready to test its first hydrogen bombs, in 1955, the weapons development laboratory decided that New Zealand’s Kermadec Islands were the perfect site. Uninhabited, far from shipping lanes, and with a better climate than many other remote islands, they met all the requirements.

New Zealand’s Prime Minister, Sidney Holland, deliberated over the request— which came directly from British Prime Minister Anthony Eden—for two months, but eventually declined. Eden was surprised at Holland’s response. It was unusual for 1950s New Zealand to refuse a British request, and Eden had been expecting
New Zealand’s full cooperation in the project, which he had described as being ‘important to the Commonwealth and the defence of the Free World’. After threatening to ask Holland to ‘reconsider the matter’, Eden eventually chose the (inhabited) Christmas and Malden Islands for the hydrogen bomb tests, which went ahead in 1957 and 1958.

It’s easy to feel proud that New Zealand chose to protect the Kermadec Islands’
pristine natural environment, but it was not respect for nature that drove the decision. Holland told Eden that to say yes to the request would be a ‘political H-bomb’ for New Zealand. It was an election year and Holland was worried about how the public would react to hydrogen bomb tests just 1000 km from the mainland. Public concern about hydrogen bomb testing was primarily about human health and the risk of radioactive fallout.

Although Raoul Island was already designated a reserve for flora and fauna protection, there was little scientific understanding, let alone public awareness, of the Kermadec Islands’ land and marine biodiversity, its rich geological history and its role as a breeding ground and safe haven for hundreds of marine and avian species.

Eden Without Eve

The Kermadec Islands, a northeast trending line of five volcanic islands and associated islets and sea stacks, are the only subtropical islands in the South Pacific with no native population. While there is evidence that they were used as a stopping point on Polynesian voyages, and that Maori collected obsidian from RaoulIsland, it’s easy to see how the steep-cliffed islands, prone to regular earthquakes and volcanic eruptions, would have discouraged seafaring peoples from settling.

By the 1950s, however, there was a small population of bearded, goat-hunting meteorological staff living on Raoul Island, the largest and northernmost island in
the group. Island observations provided valuable information about weather conditions around New Zealand and results from their three-hourly weather observations and balloon flights were sent back to New Zealand by radiotelephone.

The three meteorological staff were supported by a carpenter, a mechanic, a cook and two farmers who managed the island’s orchards, crops and livestock— cows, sheep, pigs, chickens and, for special occasions, turkeys. The island’s feral goats were considered a pest—not least for their fondness for the orange orchards—and now and again the staff would engage in some sport hunting, stalking and shooting the goats, and the occasional pig, that the government had marked for destruction.

The men—and they were all men—referred to their balmy, sub-tropical island, with its beachside hot pools and lush groves of orange, banana and peach trees, as ‘Eden without Eve’. But human settlers and visitors had already made their mark on this Eden. The first Europeans to sight the islands were on the Lady Penrhyn, a convict ship travelling from Australia to Tahiti, in 1788. Five years later the French explorer, Bruny D’Entrecasteaux, in command of the Recherche and Esperance, named the island group the Kermadec Islands.

Once they were mapped, the islands became a stopping point for northern hemisphere whalers, who came to the southern ocean to slaughter humpback, sperm, and southern right whales—almost to the point of extinction. These whalers liberated goats and pigs on Raoul and Macaulay islands to provide a supply of fresh meat for passing ships or castaways.

Later, the pioneering Bell family, who farmed Raoul Island from 1878 to 1914, cleared bush and planted orchards of oranges, pawpaw and guavas and fields of kumara, yams, beans and maize. In 1948, a farm was established to supply fresh food to the meteorological staff, who were visited by the supply ship only twice a year.

Visitors to the islands had brought other species too. Polynesian voyagers had introduced the kiore (Pacific rat) along with ti pore, a fibrous plant that could also be used as food, and candlenut, whose seeds were used to make a black dye. European ships brought Norway rats and cats, and early settlers had introduced useful plants like hemp and pampas grass and radiata and Norfolk pine.
Serendipitous Arrivals

New Zealand has an unusual flora and fauna, with creatures like the flightless kakapo and the carnivorous giant land snails that naturalist George Gibbs has called the ‘outlandish freaks’ of the animal world. The Kermadecs have no native land mammals and birds dominate the land fauna. But where New Zealand’s species have evolved over tens of millions of years of isolation, the Kermadec flora and fauna are serendipitous arrivals. The first of these young islands emerged from the ocean only 1.4 million years ago, creating a new home for the random collection of tropical and temperate species that flew or swam to the islands, or were unintentionally transported there by storms, or on pieces of driftwood carried by ocean currents. But not all these species survived. The climate might be warm and pleasant, but species gaining a foothold on these islands had to endure volcanic eruptions, regular earthquakes, tropical cyclones and occasional droughts— as well as the onslaught of a number of introduced species.

There are no meteorological staff on Raoul Island today. The island is cared for by a small group of resident Department of Conservation staff who, with help from volunteers, study and protect the island’s native species. Apart from a daily weather balloon, meteorological observations are now taken by automatic weather stations. Goats, cats, Norway rats and kiore have been eradicated from the island, along with such introduced plant species as fig, fennel and bamboo. The island’s workers are now eradicating exotic species of passionfruit and guava as well as invasive thorns and vines to let the native tree, fern and grass species flourish and allow birds to feed on their natural foods.

Raoul Island, which makes up more than 90 percent of the Kermadec Islands’ land area, is the only forested island in the group. Getting onto the island is tough. In the 1950s, the meteorological staff and their stores were lifted in a basket swung from a derrick at Fishing Rock, and then taken to the top of the cliffs by flying fox. The derrick and flying fox are still used today. These islands are made for birds, not people.

On Raoul Island, tuis and red-crowned parakeets forage for nectar, fruit and seeds in the pohutukawa and nikau that blanket the mist-shrouded slopes. Near the centre of the island, a caldera— a depression formed by land subsidence after a large eruption—holds three lakes that are home to the island’s grey ducks and pukeko. The smallest, Tui Lake, is a pond nestled in the bush, but Blue Lake is large enough for swimming and, until a 1964 volcanic eruption deposited sediment in the lake, was a fresh water source for the meteorological camp.
The eruption came from Green Lake, Raoul Island’s steaming volcanic crater, where it’s said that the alkaline water will erase your fingerprints in 10 minutes. The Raoul Island volcano remains active. In 2006, a Department of Conservation worker was killed when the volcano erupted while he was taking a temperature measurement from Green Lake. The 30-minute eruption— the first in more than 40 years—came without warning and deposited metres of ash, mud and rocks around the lake. There have been no eruptions since, but earthquakes are an almost daily occurrence.

Raoul, with its fresh water and cloud forests, is the only island of the Kermadec group with a human settlement. The rest of the islands belong to the seabirds. Six million birds breed on the islands, and twice that many—representing more than 40 other species, including albatrosses, prions, petrels and frigatebirds—frequent the area. While some seabirds make annual visits to the islands from breeding sites in Siberia and Alaska, 14 species breed on the islands, building their nests in branches of trees, high on cliffs, on rocky ledges and in crevices and underground burrows. Three of the nesting species are endemic—the Kermadec storm petrel, the Kermadec little shearwater and the white-naped petrel. Now that the rats are gone, the bird population is growing.

Some birds, the pelagic species, forage widely. A black-winged petrel was tracked travelling to Tonga and the Chatham Islands, a round trip of 3000 km, before returning to the burrow to feed her chick the oily mix of digested squid, krill and fish she had gathered. Other birds—like the small noddies and storm petrels—stay close to the islands, where they feed on tiny fish eggs, larvae and crustaceans from just beneath the water’s surface; or dive for squid, wings outstretched, as if in flight.

While most of Kermadec Islands—Macauley, Cheeseman, Curtis and L’Esperance Rock— are dormant, Curtis Island, like Raoul, is an active volcano. The masked booby, which nests on the island, must avoid the crater with its boiling mud pools and sulphur- rimmed fumaroles.

The Endless Sea

The ocean around the Kermadec Islands, once a favourite with whalers, is now home to at least 35 species of whales and dolphins, many of them vulnerable or endangered. Bottlenose dolphins now frolic around the islands while families of sperm whales and mother and calf humpback whales pass by in their hundreds on an annual migration to Antarctic feeding grounds. Alongside them, critically endangered giant leatherback turtles, far from their tropical nesting sites, paddle through the deep water in pursuit of their jellyfish prey. Smaller green and hawksbill turtles forage in waters closer to shore.

For 12 nautical miles around each island, the waters are protected—part of a marine reserve from which no species may be taken. These waters provide sanctuary for a unique mix of tropical, sub-tropical and temperate species of fish. This is a rare ecosystem, where large predators rule, untroubled by fishing lines or nets. In the shallow waters, the Galapagos sharks and the spotted black grouper swim fearlessly. Deeper down the spiny dogfish competes with bass and bluenose for the tastiest prey.

Raoul Island is only the top 516 metres of a giant volcano whose slopes extend for thousands of metres beneath the ocean. On the submerged flanks of the volcano, giant limpets park on the rocks and anemones wave their multi-coloured tentacles in the crystal-clear waters, gathering and grazing on passing plankton. Strange and wonderful species of corals, crustaceans, and molluscs make up a complex ecosystem that scientists are only beginning to understand.

The Zone of Imagination

Around the islands, deep beneath the ocean, is an undersea world of seamounts, trenches, black smokers and strange exothermic species that stretch the limits of the scientists’ imagination. The Kermadec Islands extend over two degrees of latitude, or 250 km. But in recent years, exploration of the ocean between New
Zealand and Tonga has revealed that these islands are part of a 2500 km chain of mostly underwater volcanoes. This line of mountains—the longest underwater volcanic arc on the planet and the most hydrothermally active—is the result of a collision between the Pacific and Australian Plates. On the east side of the collision zone is the Kermadec-Tonga Trench, a slash in the ocean floor that extends 10,800 metres deep and into which no one has seen. West of the trench, stretching from New Zealand’s Bay of Plenty to Tonga, are more than 50 underwater volcanoes and the Kermadec Islands.

Scientists are only just beginning to learn about these underwater volcanoes, or seamounts, which were discovered in the 1990s. Recent underwater excursions by deep sea submersible have found widespread volcanic activity in the form of diffuse hydrothermal vents, where gas-rich hot water flows into the surrounding sea, and black smokers, where high pressure plumes of super-heated, mineral-rich water jet out of the rock, leaving chimney-like deposits of heavy minerals like iron and manganese, copper and gold.

Some of the strangest creatures in the Kermadecs exist around the hydrothermal vents. Living so far from sunlight, with no opportunity to photosynthesise, these ‘chemosynthetic’ species draw energy from chemicals and minerals in the hydrothermal fluids. Around the vents are forests of stalked barnacles and clumps of giant mussels that provide food for predatory starfish and gastropods. Tiny orange shrimps swarm towards the warm waters where hot vent fluid mixes with the cool sea. Among the many odd creatures are the giant tubeworms, with their symbiotic bacteria that turn hydrogen sulphide— a poison to many species—into food. On top of the vent mussels, strange and tiny marine animals called bryozoans—whose intricate structures can only be seen through powerful microscopes—form colonies of hermaphrodite clones. Other species of bryozoan are found throughout the Kermadec waters—from the shallows around the islands to 8000 metres down the Kermadec Trench. The scientists who first named these creatures had a creative bent, and their names are rich with metaphor: different types of bryozoan are known as lace corals, moss animals, or sea mats.

The first major scientific exploration of the Kermadec Islands was in 1908, when New Zealand naturalist Walter Oliver led a small group of scientists in a year-long exploration of Raoul Island’s flora, fauna and geology. More than 100 years later, visiting geologists and biologists are still making discoveries about this remarkable group of islands and the ocean that surrounds them. Even so, the Kermadec region remains the least explored of New Zealand’s waters, and every visit yields new discoveries. In 2011, a group of plant, fish, shark and ecology specialists travelled to the islands on a biodiscovery expedition that revealed new marine species, like the brilliant orange zebra fish, a small left-eyed flounder, and a silver flying fish that landed on the boat in front of a surprised photographer.

Just as the biology and geology of the Kermadecs have long inspired scientists, who have shared their understanding of this world through articles, lectures and photographs, the islands have now inspired a group of artists, who are sharing their experiences through poetry, paintings, sculpture and music.

Science and art might seem, at first glance, to be two different worlds, but in these islands the disciplines intersect, each driven by a desire to discover, to interpret, to see things no one has seen before.

Art and science merge when a scientist lovingly renders a map or an illustration, or carefully frames a photograph; or when an artist spends hours watching a bird or a fish, immersing herself in her subject and obsessively recording every detail. Beyond the specialist languages of science and art, visitors to the islands use a common language, describing the Kermadecs as ‘exhilarating’, ‘spectacular” or “stupendous’; ‘a frontier of wonders’ that’s ‘better than my imagination’; a ‘classroom’, a ‘mystic garden’ that’s ‘wonderful and frightening’. But there’s one word that comes up more often that most. Again and again, visitors refer to the islands and the marine ecosystem as ‘pristine’. To scientists, this pristine, unspoilt environment is a ‘baseline of normality’ that shows us what the world was like before humans began changing the planet.


For artists and scientists, the Kermadec Islands, where birds fly underwater and fish jump into the air, where black smokers spew into the sea and earthquakes shake the land, are a place of imagination and inspiration. For the seabirds, sea creatures and marine mammals that live on and around the islands, they are a safe passage from breeding grounds to feeding grounds or, to many species, home.

But at the same time as new underwater species and ecosystems are starting to be documented—many of them weird and wonderful, and some of them endemic to the Kermadecs—they are under threat. The Kermadec Islands Marine Reserve, established in 1990, protects the waters near the islands, but outside of the 12 nautical mile no-take zone around the islands, fishing boats gather to net species shoaling above the newly-discovered seamounts, and mining companies fund exploration to assess the seafloor for minerals like gold, copper and lead.

More than 50 years after the Kermadec Islands were selected as a hydrogen bomb testing site, their remote location now makes them an ideal spot for one of the Comprehensive Test Ban Treaty’s seismic monitoring stations. The treaty’s international system includes a global network of stations designed to detect clandestine nuclear blasts. The islands are no longer at risk from hydrogen bomb testing, but so-called peaceful human activities, like mining and fishing, can pose just as great a threat. Our planet is currently facing its biggest mass extinction in 65 million years. If we want to protect our planet’s biodiversity—which scientists believe is essential for the health and resilience of our earth ecosystem—this pristine group of islands, and the expanse of ocean around them, is a great place to start. There are not many ‘baselines for normality’ left on this planet. Let’s protect the ones we still have.

—Rebecca Priestley

 

PUBLICATIONS REFERRED TO
Various authors, DEEP: Talks and thoughts celebrating diversity in New Zealand’s untouched Kermadecs, Pew Environment Group and Te Papa, Wellington, 2010
George Gibbs, Ghosts of Gondwana: the history of life in New Zealand, Craig Potton, Nelson, 2006

Elsie K. Morton, Crusoes of Sunday Island, W. W. Norton, New York, 1958

Rebecca Priestley, Ernest Marsden’s Nuclear New Zealand: from nuclear reactors to nuclear disarmament, Journal of the Royal Society of New South Wales, 2006

Thanks also to Chris Gaskin, Karen Baird, Rochelle Constantine and Steve Knowles.

Background image: Galapagos shark swims off the shores of Raoul Island
photograph by Malcolm Francis