Our Changing World

More and more of us are reaching for low or no-alcohol beers. As the market grows, the options are also expanding – but brewing beer without alcohol fermentation presents a tricky puzzle. In traditional beer brewing the conversion of sugars into ethanol and carbon dioxide through yeast fermentation is a key part of the process. How can you get the same flavour into beer without it? A team at Victo...

Project Tongariro was established as a living memorial for five people who died in a tragic helicopter accident. Last November, the project turned 40 years old. Over those four decades, activities have expanded beyond Tongariro National Park and into the wider area, including urban restoration through tree planting and predator trapping. Claire Concannon visits the Taupō-based projects that Projec...

The battle on the frontlines of conservation continues around the motu. This week we head to the central North Island to join some of the staff and volunteers of Project Tongariro. Ecologist Nick Singers is coordinating the fight against the invasive grey willow that’s taking over a wetland area, while Shirley Potter is applying a ‘let’s get it done’ attitude to reforesting a patch of public conse...

During World War II, sonar operators discovered a ‘false seabed’ that appeared to move upwards during the nighttime. In fact, the sound waves were bouncing off huge numbers of small critters. This daily movement is the largest animal migration on the planet, consisting of deep-water animals that hide in the ocean’s twilight then move to the surface after sunset to feed. By far the most abundant fi...

For a long time, nuclear fusion was viewed as a powerful, but unachievable, energy source, because the technological challenges were just too great. But recent advances, particularly in the development of powerful magnets, have reignited the race to create the world’s first efficient nuclear fusion powerplant. Claire Concannon visits one private company just outside Wellington who have joined the...

In May 2024, 100 strange rocky structures were installed along Tauranga's harbour shoreline. These flower-shaped artificial rockpools, nicknamed 'sea pods', provide prime waterfront real estate for marine life – from colourful sea slugs to sneezing sponges. Justine Murray finds out how 'living sea walls' are bringing back biodiversity to urban harbours around the world, and joins a marine scientis...

Speckled, pencil-thin and sporting an underbite: the lowland longjaw galaxias is New Zealand’s rarest freshwater fish species. With just seven known populations, this species is considered nationally endangered. Join producer Karthic SS at a spring-fed stream in the wild Mackenzie Basin to meet the tiny fish, hear from a researcher studying trout-proof barriers, and chat to a ranger who for 20 yea...

Since the 1800s, tuberculosis (TB) has been responsible for an estimated 1 billion deaths. In New Zealand today, we don’t get many cases of TB, but worldwide it is the leading infectious disease killer. In the early 1900s a TB vaccine was developed. Called the BCG vaccine, it’s still used today. While it is the best TB vaccine we have, it’s not actually great at preventing TB infection, only provi...

2020 saw the start of two global pandemics. Covid-19, of course, but also H5N1 bird flu. The latter has swept around the world leaving millions of dead wild birds and marine mammals in its wake. It has reached everywhere – except Australia, New Zealand and the Pacific. Alison Ballance has been finding out why this strain of bird flu is so deadly, and what we are doing to get ready for its possible...

If you like Our Changing World, you should find and follow Wild Sounds: RNZ's new podcast feed dedicated to incredible natural science stories from New Zealand! Go to this episode on rnz.co.nz for more details

In late 2024 a cluster of sick green sea turtles washed up around the Rangaunu Harbour on the east coast of the Far North. It was just another mystery in a long line of all the things we don’t know about these ocean taonga. But a new telemetry study, using these very turtles, could change all that. The study has officially kicked off with the release of five satellite-tagged honu. Liz Garton finds...

One from the archives! By the 1990s Chatham Island tūī had all but disappeared from the main island. Slightly different to their mainland counterparts, these songbirds had survived on nearby Pitt and Rangatira islands. So a local conservation group decided to try bring them back. In this episode from 2010, Alison Ballance joins the ‘tūī team’ tasked with moving 40 birds from Rangatira island back...

Smoke explosions. Fire tornadoes. Burning couches. It all happens in the fire lab: a purpose-built facility where researchers can safely set stuff on fire and study how it burns, for science. New Zealand experiences 4,500 wildfires every year, with the risk ramping up due to climate change. We visit the fire lab to watch a large gorse bush go up in flames and learn how this helps us prepare for fu...

How do you go about dissecting the world’s rarest whale? In December 2024, images from a concrete room in Mosgiel, just south of Dunedin, spread around the world as a team of people spent a week doing a scientific dissection on a spade-toothed whale that had washed up five months before. Claire Concannon joins them to find out what’s involved, what they have learned, and how the arrangements betwe...

For nearly 30 years, researchers have been banding black petrel fledglings before they make their maiden migration to Ecuador. Only a handful of birds have ever come back. RNZ’s In Depth reporter Kate Newton travels to Aotea-Great Barrier Island to meet the birds, and the dedicated team trying to figure out the mystery of where they go. Sign up to the Our Changing World monthly newsletter for epis...

Each year, five Prime Minister’s Science Prizes are awarded in the most prestigious New Zealand science awards. We explore the AgResearch science that got the top recognition this year and catch up with two of the other winners. Science Communication prizewinner Professor Jemma Geoghegan talks about the hundreds of interviews she’s done about viruses, and Future Scientist prizewinner Rena Misra ex...

With its steep sides, forested slopes and heavy rainfall, Fiordland has interesting ecosystems both above and below the water. Below the surface of the inner fiords, a variety of sponges, corals, and other filter-feeding animals cling to the cliff-like reefs. Claire Concannon heads to Doubtful Sound with a research team who are habitat-mapping the fiords to better understand what’s there, and how...

Cooper’s orchid is New Zealand’s rarest and most elusive, with fewer than 250 plants left in the wild. It belongs to the group of potato orchids, which grow mostly underground as tubers – except for a brief period every few years when they push out a leafless stick with a few flowers. This largely subterranean lifestyle already presents a challenge, but saving this species is even harder because,...

Kākahi are a keystone species in lake and river ecosystems, keeping the water clean by filtering one litre of water every hour. These native mussels once blanketed lakebeds across Auckland – but recent surveys found an alarming decline and disappearance across many lakes. A team of scientists and divers have mounted a rescue mission for one of the last remaining kākahi populations, trying to keep...

Claire Concannon spoke to RNZ's climate correspondent Eloise Gibson for the last episode of the Voice of the Sea Ice series. Listen to the full interview between Eloise and Claire in which they talk about the Paris Agreement, New Zealand's international climate commitments, and what we can do as individuals. Sign up to the Our Changing World monthly newsletter for episode backstories, science anal...

Human-induced climate change is impacting Earth’s global systems, including ice melt in Antarctica. What is the world doing to combat it? Signed in 2016, the Paris Agreement is the current global plan to tackle it. Countries pledge different emission reduction targets and then produce their workings and homework about how they are going about it. Where does New Zealand fit in? Are we doing our bit...

In February 2025, the world hit a new low for global sea ice extent. Arctic sea ice has been declining for several decades now, but Antarctic sea ice had been holding steady, until recently. With low summer sea ice extents for four years in a row, it appears that Earth’s warming has kicked Antarctic sea ice into a new regime. Claire Concannon speaks to scientists to understand what this means for...

Penguins that return to the ice in the middle of winter to lay their eggs. Seals that use cracks in the ice to keep their pups safe. And fish that have antifreeze proteins to survive in the icy cold waters... Antarctic life is tough, and full of surprises. Scientists are keen to piece together the Antarctic food web puzzle to better understand the interconnections, and to enable smart conservation...

What’s it like to live and work on the frozen ocean? A team of researchers is camping out on the sea ice to investigate the small critters that live on the bottom of the ice, and among the sloshy platelet ice layer just below it. From microalgae to krill, these tiny organisms hold up the big complex food web of Antarctica. Scientists are keen to understand these communities, and how they might shi...

Step out on the sea ice just outside New Zealand’s Scott Base with researchers studying the physics of its annual cycle. Each year a massive patch of ocean around Antarctica freezes and then melts again come summer – Antarctica’s heartbeat. In winter, the ice effectively more than doubles the size of this already massive continent, and it plays a huge role in controlling our planet’s climate. Gues...