Our Changing World

A multi-year research project aims to find out the risks from two Bay of Plenty offshore island volcanoes: Tūhua / Mayor Island and Whakaari / White Island

In the National Isotope Centre in Gracefield, Jacqueline Grech Licari is bent over half a sediment core section, carefully looking for a dark line of ash - a clue left behind by Whakaari, a volcanic island in the Bay of Plenty.

Tracing the history of past eruptions

Jacqueline is a PhD candidate at Te Herenga Waka Victoria University of Wellington using sediment collected from the seabed around Whakaari, White Island, and its neighbour, Tūhua, Mayor Island to investigate their eruptive pasts.

Layers of ash - also called tephra - are carefully logged and sampled. Chemical analysis identifies exactly which volcano it came from, while the thickness of the layer gives hints at the eruption's size.

With 38 cores taken from the seabed around both these volcanic islands, Jacqueline has a lot of work to do. But she's hoping to be able to build a picture of the frequency, timing, and scale of previous eruptions. And, importantly, how widespread the effects were.

Her work will feed into the wider Beneath the Waves programme - a five-year research project led by GNS Science to investigate these two nearshore island volcanoes.

The anatomy of a volcano

The overall goal of the programme is to identify the full extent of the risks these active island volcanoes might pose to mainland communities.

Could they trigger tsunamis that would impact the coastline? Might ash make it across the ocean buffer and cause air quality and soil problems? And at what frequency might eruptions of this scale occur?

One aspect of the project has been to map the anatomy of the two volcanoes.

Using sensors that can detect changes in the conductivity of the rocks in the crust, the researchers are able to reconstruct a 3D map of the pluming of the volcanoes - where the magma chambers, and hydrothermal systems (the paths that water heated by the magma takes) are. GNS Science geophysicist Dr Craig Miller hopes this will give context to future monitoring and help them better interpret any signals they see.

This mapping will also enable them to look for any spots in the seabed floor weakened by volcanic activity that might have the potential to slide and cause a tsunami when an eruption occurs.

Listen as Craig explains to Claire Concannon the differences between the two volcanoes, and how the team hopes this research will help with hazard mitigation.  …

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Meet two winners of the 2023 Prime Ministers Science Prizes. In the wake of the 2019 Whakaari eruption, Professor Ben Kennedy engaged communities with the science of volcano hazards - mahi that earns him the 2023 Science Communication Prize. Meanwhile, Future Scientist prizewinner 17-year-old Sunny Perry has developed a helpful soil map.

When Sunny Perry decided to make a map identifying locations of corrosive soil around Northland, she didn't foresee the extra benefits. 

Winning the 2023 Prime Minister's Future Scientist Prize was a big one. Heaps of driving practice with her dad - which helped her pass her driving test - was another. 

But there were downsides too: 5am starts, turning her bedroom into a chemistry lab, and having to let her dad pick the road trip tunes. "There were some very questionable choices sometimes," Sunny says.

Road tripping for soil samples

In total, the duo visited 20 sites across Northland: from north of Kaitaia, all the way south to Mangawhai, and across to the west coast. 

At each site, Sunny took triplicate soil samples at different depths which she then brought back to her makeshift chemistry lab to test for the presence of a certain type of soil - one that has the potential to cause damage to the environment and infrastructure if disturbed. 

An aggressive soil

You may not have heard the term "acid sulphate soil", but Whangārei District Council certainly has. This soil was the culprit behind corrosion of concrete pipes in the Marsden City development at Ruakākā, which cost ratepayers $5 million. Auckland Airport is aware too, since it had to add eight tonnes of lime to a stream on its property in 2016, after plants started to die around it. 

These acid sulphate soils can form in waterlogged areas devoid of oxygen and rich in organic matter. They contain crystals of pyrite - iron sulphide minerals. When they lie undisturbed, they are safe and harmless. 

But, if they are dug up or drained, and exposed to oxygen, the pyrite in the soil reacts with the oxygen, producing sulphuric acid. The acid lowers the pH of the soil, which can cause damage to plants, creatures, and infrastructure. 

Where are these soils found?

To avoid disturbing these soils, you need to know where they are likely to be. 

That's what Sunny set out to determine. Using knowledge of the conditions needed for these soils to form, mapping skills developed throughout the project, and her soil sample testing, she has created a map of Northland which shows where these acid sulphate soils might be. …

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Kate Evans visits a passionate team as they carpet a remote volcanic island in Tonga with poisoned bait, hoping to eradicate rats. What does it take to complete this kind of project, what are the chances of success, and what will it mean for the island's ecosystems if they manage to remove the rats once and for all?

Rat eradication from islands is a team sport. It's not a competition - but if it were, New Zealand would surely be up there. That's why on most pest removal teams around the world you can probably find one or two Kiwis right in the thick of things. 

It takes a village

A team lined up to complete the rat eradication project for the island of Late in the kingdom of Tonga is no different. The New Zealand Department of Conservation is supporting the operation and have provided some skilled staff. The helicopter team (pilot, engineer, ground crew) are all Kiwi too. 

They're joined by a project manager from the NGO Island Conservation, and Tongan conservationists from the national environment department. 

Years of feasibility studies, finding funding, planning and logistics have come down to this - a second, and final, aerial application of poisoned bait across the island. 

Island paradise

It may not be what you picture when you think of a tropical island, but its jagged basalt cliffs and remoteness has made volcanic Late a potential wildlife haven. 

Here you can find the Tongan whistler and ground dove, two rare birds on the IUCN red list of threatened species. And it has the habitat needed for the malau - the Tongan megapode - to breed. Malau don't incubate eggs by sitting on them, instead they bury them in warm volcanic soils and sands, and Late's smoking surface is perfect. 

Rat eradications elsewhere have allowed forests to rejuvenate, land birds to rebound and seabirds to return. The bird guano ripples the effect out further - feeding the coral reefs and allowing nearby ocean ecosystems to flourish. 

Science journalist Kate Evans joins the team on the last day of bait spreading, in what they hope will be the first day of a bright future for the island and its inhabitants.  …

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Journalist Rebekah White meets two people who have been counting albatrosses on remote islands in the subantarctic for more than three decades. Their research shows that at least one species is en route to extinction. A few changes to the way we fish could save it.

Gibson's and Antipodean albatrosses are citizens of no one nation. They are ocean birds, living on the wind and waves, travelling massive distances, passing back and forth over the high seas and the imaginary boundary lines we draw on maps. 

But when they land to chat, to flirt, to lay an egg and raise a chick, they come to two of New Zealand's subantarctic islands. 

Three decades of albatross study

And when they return, some of them meet with two familiar human faces. 

Across the last 34 years, Department of Conservation researchers Kath Walker and Graeme Elliott have been visiting these islands to count the birds, and to study them.   

At first everything seemed fine. In the early 1990s numbers were low but increasing. Things were positive. Then came the summer of 2006/2007. There was a population crash, reason still unknown, and on both islands, albatross numbers plummeted.  

These albatrosses don't breed until they at least eight-years-old, only breed every two years, and tend to mate for life. Since the crash, Gibson's albatross numbers have come back slightly, but Antipodean albatross numbers continue to decline. 

And adult birds, especially females, are still going missing. 

Hooks don't discriminate

Tuna fishing boats use a method called surface longlining to catch their prey. The lines can be up to 100 kilometres long, with thousands of hooks. 

Squid is used as bait, a tasty morsel for tuna. Unfortunately, albatrosses agree. 

Using satellite tags Graeme and Kath have watched missing albatrosses' paths overlap with those of boats, and in one case, in which leg bands and the satellite tag were returned to them, follow the path of the boat. 

Listen as science journalist Rebekah White explores the albatross bycatch problem, and what we could do about it.  …

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New Zealand once led the world in marine protection. Now it looks like we will fail to meet our international promise to protect 30 percent of our ocean estate by 2030. Why is stopping fishing so politically fraught? How might our ideas about marine protection need to change? And why, when our seas are in need, is it taking us so long to learn to talk to each other?

This is an updated excerpt from the July - August 2023 New Zealand Geographic feature article 'Taking on water'.

In 1975 five square kilometres from Cape Rodney to Okakari Point was made a marine reserve, the first in New Zealand, and possibly, the world.

"Nothing to do at Goat Island anymore," declared the local newspaper.

Three hundred thousand people now visit every year. And research indicates that this small, protected patch is helping to contribute fish to surrounding areas.

Lunching on experiments

The Marine Reserves Act was created in 1971 in response to campaigning by the late Bill Ballantine, among others. He was director of the University of Auckland's Leigh Marine Laboratory which was established in 1964. But staff and students soon discovered people were eating their experiments.

So that's what the Act was created for: 'the purpose of preserving, as marine reserves for the scientific study of marine life, areas of New Zealand that contain underwater scenery, natural features, or marine life, of such distinctive quality, or so typical, or beautiful, or unique, that their continued preservation is in the national interest.'

Today, with our ocean ecosystems under increasing pressure from commercial and recreational fishing, sedimentation, pollution, and warming, we need our marine protection to do more than preserve small areas for scientific study.

But it's not an easy task. Most marine protection proposals face extensive push back that delays the process for years, sometimes decades.

"It's really, really hard to manage it appropriately," says Professor Chris Hepburn, marine scientist at the University of Otago. "It's land, sea. It's different user groups, it's rights, it's things like the settlement, it's people not understanding each other's points of view."

The act that ignored the Treaty

'The settlement' is the Treaty of Waitangi (Fisheries Claims) Settlement Act 1992, an attempt to restore some of the rights taken from Māori when it comes to fisheries…

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Kuaka bar-tailed godwits make the longest non-stop flights, and researchers are using hi-tech tags to solve the mystery of how and when they sleep.

Godwits hold the record for non-stop long-distance flight - and scientists are wondering when they find time to sleep on the wing.

The long-distance godwit migration

Eastern bar-tailed godwits or kuaka spend up to six months every year in Australasia. At last count, in 2020, the total summer population was estimated at 126,000 birds - 78,000 birds were in New Zealand and the rest in eastern Australia.

After spending the summer feeding on rich intertidal mudflats in the southern hemisphere, the godwits fly north in March. They follow a route known as the East Asian-Australasian Flyway, which takes them to Alaska, via the Yellow Sea. From New Zealand they take seven or eight days to cover the 10,000-or-so kilometres to reach large areas of tidal mudflats in China, Taiwan and Korea. They feed here for four to six weeks, before moving on to the Alaskan tundra, where they breed.

In October they return south, and it is these journeys that have catapulted the godwits into the record books.

Long-haul champions

Godwits make the longest non-stop migration of any bird. We only discovered this when satellite trackers got small enough to be used on them. 

In 2007, a female known as E7, set the first record: 11,680 kilometres non-stop. With no breaks for food or rest, she flew for more than eight days, over the open Pacific Ocean, from Alaska to New Zealand.

E7's epic migration has since been eclipsed by the 13,560 kilometre non-stop journey made by bird B6 in 2022. B6 was tagged as a juvenile in Alaska and was just 5 months old when it made its first-ever 11-day flight to Tasmania. Scientists do not know how these young birds find their way to New Zealand and Australia on that first flight - they fly in flocks, and perhaps these flocks include an adult guide?

Sleep in birds

If you've ever taken a long-haul flight from New Zealand you've probably experienced sleep deprivation. Now imagine you're a small bird, flapping your wings continuously, unable to land or feed, on a flight that will take anywhere from 8 to 11 days. When and how do you sleep?

How godwits sleep during their epic flights is the focus of a new research project involving 45 godwits from the Motueka sandspit.

This sleep project involves ornithologist Jesse Conklin, from the United States, and Bart Kempenaers, Mihai Valcu and avian sleep expert Niels Rattenborg, all from the Max Planck Institute for Biological Intelligence, in Germany. …

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The Bounty Islands are tiny in terms of area - just some bits of granite jutting out of the ocean. But they are huge in terms of seabirds. James Frankham joins a team researching the erect-crested penguins who breed in this remote archipelago. Recent counts suggest the penguins of the Bounties are doing fine. But this is not the case on the Antipodes Islands, and the researchers desperately want to know why.

The Bounty Islands jut out of the water like giant granite fins. Steep and sheer, with no greenery in sight. They are covered instead by a mottled white - guano or bird poo from the tens of thousands of penguins and albatrosses that come here to breed. 

The least studied penguin

The Bounty Islands is one of two remote, subantarctic island groups home to the erect-crested penguin. Stout and handsome, with bright yellow crests that look like elaborate punk rock hairdos, their remote breeding sites means they've not been studied in depth. 

But Dr Thomas Mattern of the Tawaki Project plans to change that. 

Good news and bad

Using drones to make photo mosaics of all the Bounty islands, Thomas has counted each penguin breeding pair and arrived at a number that suggests the Bounty Island population of penguins has remained relatively stable since the mid-1990s. Good news. 

Not the case for their other breeding sites at the Antipodes Islands, where early evidence suggests a significant decline. 

But these island groups are a mere 200 kilometres apart - a hop, skip and a jump in penguin swimming distance. How is one group seemingly doing fine while the other is in trouble? 

New Zealand Geographic's James Frankham joins an expedition to these remote and wild islands as the scientists begin to unravel this mystery. 

Learn more:

• Read the accompanying New Zealand Geographic article by James Frankham, with photography by Richard Robinson.
• As part of this expedition Claire Concannon also visited the Antipodes Islands to learn how they have fared since mice were eradicated. 

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