Our Changing World

Alison Ballance plays favourites from the archives - stone-eating spotted shags and urban eagle rays.

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Seabird species are being reintroduced to Mana Island to help restore the ecology of the island.

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The story of a seabird translocation to Mana Island, involving fluffy white-faced storm petrel chicks, artificial burrows and sardine smoothies.

'Bringing back the seabirds' is the rallying call for conservationists working to restore Wellington's Mana Island.

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The latest seabird to be brought back to Mana Island is one of New Zealand's smallest - the white-faced storm petrel.

A handful of these sparrow-sized birds already breed on the island, and the Friends of Mana Island are hoping the 260 chicks they have rehomed to the island in the past three years will soon give this number a welcome boost.

The new arrivals hail from Rangitira, in the Chathams, which is home to a thriving white-faced storm petrel breeding population.

They were collected as late stage chicks, and translocated to Mana Island via crayfish boat, plane and helicopter.

Upon arrival, each chick was fed and transferred to an artificial burrow. The burrow comprises a dark, quiet nesting chamber with a soft floor of dry leaves.

A tunnel made from drainage coil gives access to the world outside, although for the first few days the chicks are barricaded inside to prevent them wandering outside and getting lost.

A team of volunteers from the Friends of Mana Island, led by seabird expert Cathy Mitchell, look after the chicks for several weeks until they develop their full adult plumage and are ready to fledge.

Once a day, each chick is collected from its burrow and taken to the classic caravan that serves as the dining room.

The chick is weighed to check that it is on a perfect trajectory - adding precious grams until the final week before departure, when it needs to slim down to flight weight.

A wing measurement gives an indication of flight readiness - wing feathers grow up to 3 mm a day until they are about 50 mm long.

Health and Plunket check complete, Cathy and sidekick Shane Cotter give each bird its once daily meal - 7 ml of sardine smoothie delivered directly into the crop via a syringe and a soft feeding tube.

A sardine smoothie - made from finely blended sardines, fish oil, boiled water and a vitamin pill - mimics the natural diet of krill that parent birds feed their sole chick once a day.

Once Cathy judges that a chick is getting close to departure, the barricades on its tunnel come down. Then, if the chick is so inclined, it can explore down the tunnel during the night and check the outside world.

Depending on the chick, this stage might last a few days until one night it will leave the burrow and without any fanfare, simply lift off and fly away…

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Rare dolphins and whales were among the discoveries when the Far Out Ocean Research Collective surveyed the seas off Northland.

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The Far Out Ocean Research Collective has been surveying for whales and dolphins in the seas off Northland.

The offshore ocean may seem a flat featureless expanse, but underneath the surface there are interesting features, currents and water masses that make ideal habitats for a range of marine creatures.

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The Far Out Ocean Research Collective is a non-governmental organisation based in Paihia in the Bay of Islands.

Their goal is to survey the Northland offshore area to find out more about what is out there, where they are, and why they are there.

They are interested in marine megafauna - large marine creatures - and the seabird life that can be found offshore.

These types of offshore multi-day surveys are difficult to do. Travelling 20 - 50 nautical miles off the coast to observe and identify marine seabirds and creatures requires excellent weather conditions, a suitable vessel, and the right equipment and expertise.

This is why systematic surveying has not been done in this region before, and why we know quite a bit about New Zealand coastal or inshore marine species, but we lack data about those that live in this offshore environment.

For some species, the only information we have to date has come from strandings, rather than live sightings.

Since starting this work, the Far Out team has identified a wide range of marine life in this area.

Rarely-seen beaked whales, a previously unknown group of sperm whales, a juvenile whale shark and extremely rare dolphin species are just a few of the marine creatures encountered in this year's survey.

Alongside the visual surveys, the team also uses acoustic recordings to help them locate cetaceans that might be in the area.

A few species can be identified by their calls alone.

In the past few years, the scientists have collected incredible recordings of dolphins, false killer whales and pilot whales.

Their latest revelation is Northland sperm whale coda - a distinctive short patterned series of clicks, which sperm whales use to communicate with each other.

The Far Out team is planning further surveys and aims to build a map of this offshore area that integrates marine creature and seabird sightings, acoustic recordings and oceanographic data to give a detailed picture of what is out there.

Listen to the full episode to take a trip to the open ocean and dive deep into the acoustic world of sperm whales.

Far Out Ocean Research Collective

The Far Out Ocean Research Collective is a group of five marine scientists who set up a not-for-profit trust in 2017…

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Shaun Eaves talks about glaciers in the North Island and how evidence left behind by glaciers can help reconstruct past climates.

Talk about glaciers in New Zealand and most of us think about the great glaciers of the South Island - Fox and Franz Josef glaciers on the West Coast, and Tasman Glacier near Mount Cook.

But glaciologist Shaun Eaves has been pondering the forgotten glaciers of the North Island, and their past and future.

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Making a glacier

"The recipe for a glacier? You need cold temperatures and precipitation," says Shaun. "Snow is what the glacier wants."

Over time this snow compacts to become ice and eventually becomes large enough to be counted as a glacier.

Weather is critical to a glacier's survival.

"The colder the temperature, the less snow and ice you'll lose over the course of a year, particularly during summer."

"If you manage to keep some of your winter snow through the summer then that will add mass, and either sustain or start to build a glacier," says Shaun.

Sweet spot for a glacier

Glaciers occur at higher altitudes, where it is colder.

Shaun says they exist above a hypothetical line that glaciologists call the snowline, the altitudinal point where it is cold enough for snow to last year round.

Snowline in the South Island is about 2000 metres above sea level, so there are plenty of mountains higher than that where glaciers can form.

Although glaciers are born at higher colder altitudes, their ice can flow well below the snow line, almost to sea level in the case of Fox and Franz Josef glaciers.

Shaun says there are more than 3,000 glaciers in the South Island, although some smaller ones at lower elevations have disappeared in the past few decades.

The North Island's forgotten glaciers

He says that people may be surprised to know that there are still glaciers in the North Island, although it's difficult to put an exact number on them as defining exactly what a glacier is can be difficult.

"To me, a glacier is a perennial body of snow and ice that is deforming under its own weight," says Shaun.

Shaun says that physics shows that an ice patch needs to be at least 30 metres thick for it to start deforming.

There has not been any research to measure ice thickness on Mount Ruapehu, which at 2797 metres tall is the only North Island mountain high enough to rise above the snowline. The snowline is at about 2600 metres on the central volcanic plateau…

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Developing a new test for detecting IVF embryos carrying too many chromosomes, and what past and present glaciers can tell us about climate.

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Fertility researchers are developing a new way of testing IVF embryos that have too many chromosomes.

Researchers at Victoria University of Wellington are developing a new non-invasive test that they hope will help fertility clinics quickly determine if embryos are carrying too many chromosomes.

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Fifty percent of human embryos carry too many chromosomes.

This is a condition known as aneuploidy and it is usually fatal, with most of these embryos failing early on in a pregnancy.

The rate of aneuploidy increases as a mother's age increases.

Down's syndrome is an example of aneuploidy that is not fatal, although people carrying three copies of chromosome 21 instead of the usual two, experience intellectual and health difficulties.

This is particularly an issue in fertility clinics, where about 90 percent of embryos are implanted without undergoing pre-implantation genetic testing, which is expensive and involves collecting cells from an embryo when it is about a week old.

https://players.brightcove.net/6093072280001/default_default/index.html?videoId=6236823692001

Victoria University of Wellington fertility expert Janet Pitman says that aneuploidy, therefore, significantly contributes to a low success rates of IVF in New Zealand, of around 18 percent.

Janet, and colleagues Zaramasina Clark and Melanie Olds, are working on a new test that could be used to test the embryo indirectly.

The idea is to identify biomarkers excreted by the embryo and see if they can be detected in the culture media that the embryo is being grown in.

"We have been aware for some time that the embryo communicates with the uterus," says Janet. "They send these little signals to each other."

"They actually get rid of some genetic material in these membrane-enclosed vesicles."

Janet says the vesicles, known as exosomes, contain micro-ribonucleic acids (miRNAs) which are tiny molecules comprised of non-coding RNA.

Janet says that these encapsulated and secreted miRNAs have been shown to be expressed at levels that correlate to various diseases, so the idea is that a cell containing three copies of a chromosome will excrete proportionally more miRNA than one containing just two copies.

"We're really interested in the genes on chromosome 21, to see whether they are expressed at a 1.5-fold rate than those in a normal embryo because there are three chromosomes instead of two," says Janet…

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University of Canterbury freshwater biologists are using a joint mātauranga Māori and western conservation science framework for their work translocating species.

Freshwater researchers from the University of Canterbury say that conservation translocations should be a true collaboration between iwi and experts, that involves mātauranga Māori perspectives as well as western science.

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The following article is reprinted from The Conversation

Aisling Rayne, Channell Thoms, Levi Colllier-Robinson

https://counter.theconversation.com/content/143890/count.gif?distributor=republish-lightbox-advanced

When rehoming wildlife, Indigenous leadership delivers the best results

Te Nohoaka o Tukiauau (Sinclair Wetlands) Glen Riley, Author provided

Aisling Rayne, University of Canterbury; Channell Thoms, University of Canterbury, and Levi Collier-Robinson, University of Canterbury

Whakapapa binds tākata whenua to the mountains, rivers, coasts and other landscapes, linking the health of the people with that of the environment. Like humans, species have whakapapa that connects them to their natural environment and to other species. If whakapapa is understood thoroughly, we can build the right environment to protect and enhance any living thing.

These are the words of Mananui Ramsden (with tribal affiliations to Kāti Huikai, Kāi Tahu), coauthor of our new work, in which we show that centring Indigenous peoples, knowledge and practices achieves better results for wildlife translocations.

Moving plants and animals to establish new populations or strengthen existing ones can help species recovery and make ecosystems more resilient. But these projects are rarely led or co-led by Indigenous peoples, and many fail to consider how Indigenous knowledge can lead to better conservation outcomes.

Co-author Levi Collier-Robinson (Ngāi Tahu, Ngāti Apa ki ta rā tō, Te Whānau-ā-Apanui, Ngāti Porou) with students from Te Kura o Tuahiwi. Ashley Overbeek

We argue that now more than ever, we need transformative change that brings together diverse ways of understanding and seeing to restore ecosystems as well as cultural practices and language.

Read more: Indigenous peoples are crucial for conservation - a quarter of all land is in their hands

Reimagining conservation

Where Western science often focuses on specific parts of complex systems, Indigenous knowledge systems consider all parts as interconnected and inseparable from local context, history and place…

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Much of New Zealand's freshwater flows underground, and a team from GNS Science is in the process of mapping it.

GNS Science researchers are mapping where water flows underground across New Zealand, which will help with better management of groundwater resources.

Waikoropūpū Springs in Golden Bay are fed by groundwater springs.

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Te Whakaheke o Te Wai is a five-year project funded by MBIE's Endeavour Fund to map where groundwater comes from and where it flows to.

"Groundwater is all of the water beneath the ground," says GNS scientist Catherine Moore. "It's also the source of base flow in rivers, so when river flows get low that's basically groundwater."

New Zealand's groundwater resources include about 20 significant aquifers, which are places where the water flows through permeable rocks and can be easily extracted.

Canterbury and Hawke's Bay are examples of places where aquifers created by large gravel alluvial plains supply significant amounts of water for urban use and rural irrigation.

How old is the water?

The age of the water is a vital clue in this mapping project.

Uwe Morgenstern says that he uses radioactive isotopes of hydrogen, such as tritium, to date the water.

"We are measuring isotopic signatures of water molecules. That can tell us where the water has been recharged and how long it took the water to flow through the aquifer," says Uwe.

He compares the concentration of tritium in rain and groundwater to get a date for the age of the water.

Uwe says that most aquifers that are being used in New Zealand have water that is less than a hundred years old and it is more commonly 10-20 years old.

In Christchurch, however, the city's water supply comes from deep aquifers and is thousands of years old.

Future problems that we have already created

Uwe says the age of groundwater can have large implications for its quality in the future.

He says that Lake Rotorua is a prime example of what groundwater experts call 'the load to come.'

Since the 1970s, efforts have been underway to remediate growing levels of nutrient pollution from nitrate and phosphate runoff, but in that time water quality has continued to deteriorate.

Age measurements show that the water in streams and rivers in the catchment that feed the lake is between 50-100 years old.

"So the nitrate load we see going into the lake today is actually the load from 50 years ago," says Uwe…

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