Rnz: Our Changing World

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 fish in this crowd are the lanternfishes. New Zealand researchers are investigating what impact lanternfish migration has on the life cycle of fish we like to eat, and how it may also play a huge role in the Earth’s carbon cycle. Sign up to the Our Changing World monthly newsletter for episode backstories, science analysis and more.Guests:Professor Jeff Shima, Victoria University of WellingtonAlisha Gill, Victoria University of WellingtonNiamh Smith, Victoria University of WellingtonLearn more:Read the article for this episode: Lanternfish: small fish, big impactBelow the twilight zone, in the deepest parts of the wor

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 nuclear fusion effort, with a unique approach they believe might be the key. Sign up to the Our Changing World monthly newsletter for episode backstories, science analysis and more.Guests:Dr Ratu Mataira, Founder and CEO of OpenStar TechnologiesEmily Hunter, Lead Engineer Cryogenics and Docking, OpenStarThomas Berry, Deputy Direct of Plasma Science, OpenStarLearn more:Read the article that accompanies this episode: Could a Kiwi company crack nuclear fusion?Kim Hill had a lengthy and fascinating interview with Dr Ratu Mataira in 2023 on RNZ’s Saturday Morning show. He also spoke with Alexa Cook on Morning Report in 2

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 scientist to check out what creatures have moved into Tauranga's sea pods.Sign up to the Our Changing World monthly newsletter for episode backstories, science analysis and more.In this episode:00:49 – What is a sea pod?06:27 – Living sea walls in Sydney with Dr Aria Lee10:25 – Sea pods around the world and in Tauranga13:06 – Monitoring marine life in the sea pods with David Culliford20:50 – Port of Tauranga21:48 – Looking for critters in the sea pods…Go to this episode on rnz.co.nz for more details

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 years has cared for the little fish he calls 'Jaws'. Sign up to the Our Changing World monthly newsletter for episode backstories, science analysis and more.Guests:Dean Nelson, Senior Ranger, Biodiversity, Department of ConservationMartha Jolly, PhD candidate, University of CanterburyLearn more:Otago farmers are looking out for another species of rare non-migratory galaxiid.In Auckland’s Lake Rototoa, introduced perch are the problem for the native kākahi.Karthic produces the Tune Into Nature podcast about New Zealand’s unique wildlife.Go to this episode on rnz.co.nz for more details

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 providing some protection for the youngest of patients. However, scientists have discovered that the BCG vaccine can boost people’s immune systems in other ways. Now researchers at the Malaghan Institute in Wellington are investigating these findings further. Sign up to the Our Changing World monthly newsletter for episode backstories, science analysis and more.Guests:Dr Kerry Hilligan, Malaghan InstituteRebecca Palmer, Malaghan InstituteLearn more:In 2017, Alison Ballance reported on the looming antimicrobial resistance crisis, with drug-resistant TB part of the problem.Other Our Changing World episodes about research a

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 arrival on our shores. Sign up to the Our Changing World monthly newsletter for episode backstories, science analysis and more.Guests:Dr Kate McInnes, Department of ConservationDr Megan Jolly, Wildbase Hospital, Massey UniversityDr Mary van Andel, Ministry for Primary IndustriesRob Schuckard, Birds New ZealandDavid Melville, Birds New ZealandLearn more:Read the article that accompanies this episode: A deadly bird flu strain is coming. Are we ready?Find out about Biosecurity NZ’s bird flu surveillance work and what New Zealand is doing to prepare for the possible arrival of avian influenza.The Exotic Pest and Diseas

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 out what secrets the researchers hope to uncover.From now on Our Changing World will appear on Tuesdays in your podcast feed!Sign up to the Our Changing World monthly newsletter for episode backstories, science analysis and more.Guests:Dr Karen Middlemiss, Department of ConservationDr James Chatterton, Auckland ZooCeline Campana, Auckland ZooKim Evans, SEA LIFE Kelly Tarlton’sLearn more:Find out more about the honu that visit our shores.RNZ’s Peter de Graaf describes the release of the first lot of satellite-tagged turtles in Northland.Learn more about the international effort to protect leatherback turtlesGo to thi

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 to the main island. From now on Our Changing World will arrive in your podcast feed first thing on a Tuesday morning!Sign up to the Our Changing World monthly newsletter for episode backstories, science analysis and more.In this episode:00:00 – 02:30 Introduction and background info02:30 – 12:14 Catching tūī on Rangatira Island12:15 – 12:24 Team has caught 40 birds12:25 – 24:46 Moving the birds to main Chatham Island24:47 – 25:55 Update on the birds…Go to this episode on rnz.co.nz for more details

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 future wildfires. Sign up to the Our Changing World monthly newsletter for episode backstories, science analysis and more.In this episode:01:54–09:39 – Watching a gorse bush burn in the fire lab10:45–12:43 – Burning couches, smoke explosions and fire tornadoes12:44–19:08 – Mini burn experiments and how research is preparing for wildfires of the future19:08–23:32 – Kate's experience as a wildland firefighter in Canada…Go to this episode on rnz.co.nz for more details

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 between local iwi and visiting scientists enabled knowledge sharing. Sign up to the Our Changing World monthly newsletter for episode backstories, science analysis and more…Go to this episode on rnz.co.nz for more details

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 episode backstories, science analysis and more…Go to this episode on rnz.co.nz for more details

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 explains her project exploring how a plant-fungus combination could have the potential to help clean up stormwater. Sign up to the Our Changing World monthly newsletter for episode backstories, science analysis and more.Guests:Professor Jemma Geoghegan, University of OtagoRena Misra, Epsom Girls’ Grammar School in AucklandDr Linda Johnson, Endophyte Discovery Team, AgResearchIn this episode:00:06–02:05: The main science prize was awarded to a group who have discovered a way to protect pasture ryegrass from pests.02:06–02:57: The winners of the Science Teacher Prize and the MacDiarmid Emerging Scientist Prize.02:58–19:

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 things are changing over time. They are also investigating the resilience of its iconic black corals to local landslides and marine heatwaves. Sign up to the Our Changing World monthly newsletter for episode backstories, science analysis and more.Guests:Professor James Bell, Victoria University of WellingtonMiriam Pierotti, Victoria University of WellingtonAmber Kirk, Victoria University of Wellington Learn more:Our Changing World visited Professor James Bell at the Coastal Ecology Lab in 2023 to learn more about sponges.The 2022 marine heatwave mentioned here led to one of the largest ever recorded sponge mass blea

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, like all orchids, the Cooper’s orchid can only produce seedlings with the help of the right soil fungus. After years of lab experiments to produce in vitro seedlings, botanists are now ready to boost dwindling wild populations. Guests:Dr Carlos Lehnebach, botany curator, Te Papa TongarewaDr Karin van der Walt, conservation advisor, Ōtari Wilton’s BushJennifer Alderton-Moss, plant conservation researcher, Wellington City CouncilLearn more:Read the article that accompanies this episode: Rare orchids reintroduced into the wild.Alison Ballance talked to Carlos Lehnebach about why some orchids smell like mushrooms and how

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 the mussels safe from invasive fish through all the steps of their complicated – and fascinating – life cycle. Guests:Madison Jones, Senior Healthy Waters Specialist, Auckland CouncilBelinda Studholme, Senior Biosecurity Advisor – Freshwater, Auckland CouncilEbi Hussain, Submerged Environmental and Aotearoa LakesAndrew Simpson, Global DiveLearn more:Read the article that accompanies this episode: A rescue mission saving rare freshwater mussels.Meet the bullies – the native freshwater fish that host the kākahi in their parasitic stage – in this 2023 episode recorded by Claire at Zealandia, where the fish have been tra

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 analysis and more.Guests:Eloise Gibson, RNZ climate correspondentLearn more:Read Eloise’s recent analysis about New Zealand’s international climate targets, or New Zealand's glacier loss. Eloise has also recently fact checked Winston Peters on climate accord, reported on our 2035 Paris Agreement target and delved into the recent uptake of solar demand in New Zealand.The Climate Action Tracker website keeps tabs on the targets and pledges of different countries and monitors whether they are on track to keep the world below 2 oC of warming (compared to pre-industrial temperatures).Go to this episode on rnz.co.nz f

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 as a nation? And should we be bothering with individual actions or is that simply a bait-and-switch tactic by those who want to delay real change?Guests:Eloise Gibson, RNZ climate correspondentDr Jess Berentson-Saw, Director of Narrative Research and Strategy, The Workshop Learn more:Read the article that accompanies this episode: Is New Zealand doing its bit in combating climate change?Read Eloise’s recent analysis about New Zealand’s international climate targets, or listen to this episode of The Detail.Eloise has also recently fact checked Winston Peters on climate accord, reported on our 2035 Paris Agreement tar

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 Antarctica, what this means for us, and how they feel about it.Guests:Dr Natalie Robinson, NIWA Dr Jacqui Stuart, Victoria University of WellingtonDr Greg Leonard, University of OtagoDr Daniel Price, University of Canterbury and Kea AerospaceDr Inga Smith, University of Otago Dr Michelle LaRue, University of CanterburyLearn more:Read about the recent State of the Global Climate Report.The world’s biggest iceberg recently ran aground, but to get up close and personal, listen to the Voice of the Iceberg miniseries.The world is also experiencing ice loss from its glaciers. New Zealand’s glaciers have shrunk by 29% since

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 decisions. Guests:Arek Aspinwall, University of CanterburyDr Michelle LaRue, University of CanterburyProfessor Steve Wing, University of OtagoLearn more:Meet other seals and penguins with Peregrin Hyde on his journey to South Georgia Island as part of an Inspiring Explorers expedition.In ‘Best Journey in the World’ from the Voices from Antarctica series, Alison Ballance travelled to Cape Crozier with a team from NIWA studying the emperor penguins.This series was made with travel support from the Antarctica New Zealand Community Engagement Programme. Sign up to the Our Changing World monthly newsletter for episode b