Our Changing World

Our freshwater ecosystems are facing numerous challenges. Many of New Zealand’s lakes have lost much of their native underwater plant life. At the Ruakura ‘tank farm’ in Hamilton, researchers have been working on a project to help restore the freshwater forests.

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Learn more:

• Listen to Invasive: the story of Stewart Smith from the Black Sheep podcast to learn more about New Zealand’s pest fish issue.
• Read more about the koi carp bow hunting that removed tonnes of pest fish.
• While the announcement of the eradication of lagarosiphon from Lake Ngatu was welcome it came on the heels of the disappointing news about finding this invasive weed in two South Island hydro lakes.
• It’s not just invasive plants that are an issue, invasive critters like the gold clam can also cause issues. Contained to the Waikato for the last two years, it has recently been found in a Taranaki lake.
• Restoring freshwater lakes and wetlands is a catchment wide effort, but groups around the motu are working on this.

Guests:

Mary de Winton, Earth Sciences New Zealand

References:

NIWA’s RotoTurf webpage.

Go to this episode on rnz.co.nz for more details

Oil and water don’t mix — unless surfactants step in. At Auckland University of Technology, a team of chemists has created a new kind of surfactant made from wood pulp rather than fossil fuels or palm oil. They hope that the cosmetic industry will be interested in this greener way to make smooth creams and lotions. Plus, what do geothermal spring microbes have to do with smelly wine?

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Learn more:

• Dr Jack Chen has been on RNZ several times to talk about the chemistry of dishwashing, oven cleaning and laundry detergents.
• Soap is also a surfactant, which is what makes it good at washing oils off our hands, as well as busting open viruses.
• The cosmetic industry is not new, and during the Renaissance there were some ‘interesting’ recipes about, but did they have some good ideas?
• Listen to episodes exploring the use of chemistry in reconstructing past lives, honey fingerprinting, reducing the carbon cost of producing ammonia and creating a perfume to trap invasive spiders.

Guests:

• Dr Jack Chen, Dr Mohinder Naiya, Dr Victor Yim and Josh Van Dongen of Dot Ingredients.
• Sarah Manners, University of Canterbury

Go to this episode on rnz.co.nz for more details

Until late 2024, nobody had seen te pua o Te Rēinga “the flower of the underworld” in the Wellington region for more than a hundred years. A chance discovery of a small struggling population has kick started a race to protect the plants and help them return.

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Learn more:

1. First Up interviewed Avi Holzapfel about Te Pua o Te Rēinga in 2024
2. In 2020, OCW looked at efforts to resurrect a transplanted population of Te Pua o Te Rēinga at Zealandia.
3. Graeme Atkins is also one of the driving forces behind an effort to help the ngutukākā plant return to the wild, plus the 1769 Garden – a living library of rare local East Coast native plant species.

Guests:

• Graeme Atkins (Ngāti Purou, Rongomawahine)
• Barrett Pistoll – Greater Wellington Regional Council
• Avi Holzapfel – Department of Conservation
• Rhys Mills - Ngā Manu Nature Reserve
• Bart Cox – Wellington City Council

Go to this episode on rnz.co.nz for more details

An invasive species has taken hold in the Waikato River, and it’s multiplying fast. Gold clams, tiny but relentless, are now found along a large stretch of the awa, where they threaten water infrastructure, and native species. Where might it invade next, and can we control it?

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Learn more:

• Among their other conservation activities, the team at Kids Greening Taupō have taken on the challenge of speaking to every class about the gold clam to raise awareness.
• MPI’s John Walsh spoke to Paddy Gower on Nine to Noon after last year’s gold clam survey, and more recently to Kathryn Ryan about following the rules to prevent the clam’s spread this trout fishing season.
• In Auckland, efforts are underway to protect the native kākahi from the threats of introduced fish.

Guests:

• Dr Michele Melchior, Earth Sciences New Zealand
• Karl Safi, Earth Sciences New Zealand

Go to this episode on rnz.co.nz for more details

New Zealand’s marine search and rescue region stretches from Antarctica to north of Samoa. If someone goes missing without any means of communication, that’s a lot of ocean to search. Now researchers and the New Zealand Defence Force have teamed up to develop and test a low-tech, no-battery device that can be picked up by radar – including that beamed down by satellites orbiting Earth.

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In this episode:

01:30 At Mission Bay Beach Dr Tom Dowling demonstrates the device

03:40 In the University of Auckland’s Space Institute lab the team explain the device design, and how it works.

10:00 Dr Tom Dowling talks about the radar reflector trials in Campbell Island and Omaha beach

13:00 Dr David Galligan, director of Defence Science and Technology on why DST is interested in the device

19:00 The satellites are the second side of the equation. Dr Tom Dowling explains how that works.

20:50 Back at Mission Bay Beach Dr Tom Dowling explains how the radar reflector would be an additional part of a kit on a boat and how it would work to narrow down the search area…

Go to this episode on rnz.co.nz for more details

It’s been 30 years since a dramatic series of eruptions at Mount Ruapehu. In that time, there have been great advances in monitoring and modelling volcanoes – but we still can’t look inside a volcano to see exactly what’s going on. Claire Concannon heads to Wairakei, near Taupō, to meet researchers working on the next best thing: recreating Ruapehu’s eruptions in the lab.

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In this episode:…

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Two years ago, the Australasian crested grebe, the pūteketeke, took out the title of New Zealand’s Bird of the Century. But when the Paris billboard got swapped out, and 'Lord of the Wings' ads no longer peppered Wellington's bus stops, who stuck around? Claire Concannon meets two dedicated grebe supporters battling different challenges at two Central Otago lakes.

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In this episode:

00:06 – John Oliver’s pūteketeke campaign

01:15 – Richard Bowman at Lake Hayes

16:45 – Markus Hermanns at Lake Wānaka

Learn more:

• Read more about the pūteketeke and the people helping them in this RNZ story, What happened when the pūteketeke's fame faded?
• In 2016 Alison Ballance visited Lake Wānaka to speak to John Darby about the grebes.
• It’s not news that New Zealand’s freshwater lakes and wetlands are generally in trouble, but there are many groups around the motu trying to improve their patch – whether that’s the Taiari river catchment, lakes in Auckland that are home to the kākahi, or a wetland area in the Waikato battling an unusual pest problem.
• This year’s Bird of the Year is the karearea, learn about the New Zealand falcon in this 2018 episode.

Guests:

1. Richard Bowman, Friends of Lake Hayes
2. Markus Hermanns, The Lake Wānaka Grebe Project

Go to this episode on rnz.co.nz for more details

From the public service sector to businesses to individuals, AI’s uptake across New Zealand has been rapid. And it’s not just large language models. Claire Concannon meets researchers who are harnessing different kinds of artificial intelligence to boost aquaculture, prepare for a measles outbreak and assist in urban conservation. But alongside the benefits sit potential harms. How can we try to minimise them in our AI future?

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In this episode:

01:00 – Introduction to Dr Andrew Lensen and about AI

06:00 – Professor Bing Xue and applied AI for aquaculture

09:15 – Dr Fiona Callaghan models measle outbreak scenarios

13:30 – Dr Andrew Lensen and the kākā project

18:30 – Social and ethical issues of AI…

Go to this episode on rnz.co.nz for more details

This week, an underwater mystery connecting New Zealand and Ireland - the puzzle of the disappearing sponges of Lough Hyne. In the late 1990s/early 2000s James Bell was doing PhD research on the sponge communities that coated the underwater cliffs of this small sea inlet in West Cork. When he returned 15 years later, they had vanished. Why did they disappear, are they starting to recover, and can they be helped to return? Now a Professor at Victoria University of Wellington, these are the key questions that James, and PhD candidates from his lab, have been working to answer.

Sign up to the Our Changing World monthly newsletter for episode backstories, science analysis and more. See more photos on the webpage for this story. 

In this episode:

00:00 – Divers return, introduction to Lough Hyne and its scientific history.

02:50 – James Bell on his early research at Lough Hyne and the surprising disappearance of sponge communities.

05:15 – Gabi Wood and Kea Witting get ready to dive at Whirlpool Cliffs.

06:30 – James Bell explains the unique tidal regime of Lough Hyne that means it has many diverse habitats.

09:00 – Gabi Wood is collecting water samples to study sponge feeding and nutrient levels.

11:00 – What caused the sponges to disappear.

14:00 – Kea Witting is investigating sponge community recovery.

21:00 – Experiments to help the sponges return…

Go to this episode on rnz.co.nz for more details

Need a nature fix? RNZ now has a podcast feed dedicated to our beautifully produced series telling stories from te taiao nature. Check out the Wild Sounds feed – now playing Voices from Antarctica, featuring Alison Ballance reporting from the frozen deep south.

Find and follow Wild Sounds on your favourite podcast platform, or listen on RNZ

Go to this episode on rnz.co.nz for more details