Exploration

Exploration

It is a bit of a fairyland almost every time you go down to some place nobody has ever seen before. It’s cold, it’s dark, there’s so much pressure it would squeeze you to just a small ball if you were out there. It’s as close as we can get to true exploration.

Marine geochemist Gary Massoth describing his first deep-sea dive in a submersible during the 2005 Ring of Fire expedition, broadcast in Our Changing World, National Radio, 29 August 2005

To 19th-century explorers, New Zealand must have seemed a wonderland of strange creatures and natural spectacles. Two centuries later, scientists continue to explore new areas and discover new species, but now the latest frontiers are the deep ocean and the microscopic world.

Ring of fire

The Ring of Fire describes a largely submarine chain of volcanoes that begins in New Zealand and encircles (clockwise) the basin of the Pacific Ocean. It is a zone of frequent earthquakes and volcanic eruptions, with 75 percent of the world’s active and dormant volcanoes.

New Zealand has several active volcanoes on land, but more than 90 percent of the landmass is under water and one of the world’s most unusual underwater landscapes lies offshore. A chain of submarine volcanoes, the Kermadec-Tonga Arc, stretches along 2500km of seafloor between the Bay of Plenty and just south of Samoa. Many of the volcanoes are hydrothermally active, spewing bubbling mineral-rich water and plumes of gas through hot vents. These submarine hotspots are as active as similar vents found along spreading ridges and they have a unique chemistry. At some of these sites, deposits of iron, manganese, copper, zinc, barium and even gold are forming continuously, and there are communities of some of the strangest marine micro-organisms surviving and even thriving in conditions that would be fatal to life forms on land.

As part of a collaborative effort between New Zealand and the United States, a team from GNS Science, led by Cornel de Ronde, and the National Institute of Water and Atmospheric Research (NIWA) embarked on several expeditions to this underwater world, with remote sensing equipment and in a deep-diving manned submersible. They have discovered about 30 major volcanoes and many smaller ones, more than two-thirds of them active, along the first 1300km of the arc in New Zealand territorial waters. Diving to depths of up to 1800m they found vast fields of giant deep-sea barnacles on golden stalks, large cactus urchins and dozens of other new marine species, vast mineral deposits and huge calderas, the size of Wellington harbour, that tell of massive volcanic explosions in the past.

Bizarre beauties

Coffinfish, rattails, spookfish, snotheads and scary-looking fangtooths and humpback anglerfish were among the bounty brought up from the deep sea during a month-long expedition to record the biodiversity along the Norfolk Ridge and Lord Howe Rise. The mid-Tasman Sea region is poorly known and the 2003 NORFANZ voyage, a joint effort between New Zealand and Australia, was the first scientific survey to study the unique and bizarre inhabitants of the deep ocean. This is a world where giant squid roam, sea spiders grow to half a metre across and armourplated crustaceans wander through forests of bamboo corals looking like giant slaters.

With two-thirds of the planet covered by oceans, the deep ocean is the most common habitat. Yet it is also the least explored, and scientists from NIWA and the Museum of New Zealand Te Papa Tongarewa returned with more than 500 different fish species, several of them new to science, and more than 1000 deep sea invertebrates, many of which had not been seen before.

They also explored several seamounts – underwater mountain ranges and pinnacles – that rarely reach the surface. Deep ocean currents concentrate nutrients around seamounts and they become home to a range of slow-growing and long-lived fish such as orange roughy.

Fungal foray

Each year, a team of professional and amateur mycologists gather at a different location to spend a few days scouring the bush for fungi. The aim of the fungal foray is to better understand the diversity and distribution of New Zealand’s native fungi and to increase public appreciation of them. While fungi may appear small and insignificant, they provide several crucial ecological functions. They can act as saprobes, enabling nutrients from fallen trees to be recycled back into the soil, or as mutualists such as the mycorrhizal fungi that help trees extract nutrients from the soil. Fungi are also an important food source for animals, and some are pathogens, causing plant and insect diseases. Each year, the fungal foray uncovers new species.

Molecular discoveries

Tuberculosis is one of the most ancient human diseases, but it is still rife in less developed countries, killing up to three million people each year, and re-emerging in developed countries. As part of a worldwide effort to find more effective anti-TB drugs, researchers at the University of Auckland’s Centre for Molecular Biodiscovery are studying the exact structure and function of one of the enzymes of Mycobacterium tuberculosis, which causes the disease, to investigate potential leads for drug targets. At Victoria University, researchers are screening marine organisms for compounds with the potential to treat cancer and other conditions.

By Veronika Meduna

Further reading and websites

Ring of Fire expedition website

NORFANZ voyage website

Fungal foray - Landcare Research website

Centre for Molecular Biodiscovery website

Image courtesy of Peter Buchanan, Landcare Research

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