A few short generations ago, New Zealand was beset by a virus that closed schools, churches, cinemas and campgrounds and put people in quarantine. Polio killed at least 835 New Zealanders and paralysed many more. Regular epidemics were only banished in the 1960s by a vaccine decades in the making. Now, as the world awaits the rollout of COVID-19 vaccines, how have things changed? What has science learned about designing tools to help our immune systems fight back?
Whanganui is Aotearoa’s third-longest river. It begins on Mount Tongariro and flows 290 kilometres to the Tasman Sea, joined by thousands of small tributaries along the way. Whanganui iwi have long sought legal recognition of their relationship with the river. They petitioned Parliament in the 1870s for protection of their awa. From the 1880s, the Crown undertook a series of damaging ‘improvements’ to the river. Works to establish steamship services destroyed eel weirs and fisheries. Mineral extraction and the introduction of foreign fish and plants further damaged the river’s ecologies. The Crown did not consult iwi on the diversion of Whanganui waters into the Tongariro Power Scheme before construction began in 1971. In March 2017, Te Awa Tupua (Whanganui River Claims Settlement) Act passed into law. The Act covers the main river and “all tributaries, steams and other natural watercourses” that flow into it. Like Te Urewera Act 2014, the Act recognises the Whanganui River as a legal person. The legislation describes the river as an ancestor of the Whanganui people: Te Awa Tupua is an indivisible and living whole from the mountains to the sea, incorporating the Whanganui River and all of its physical and metaphysical elements. This map shows the Whanganui catchment’s astonishing complexity.
It’s one of New Zealand’s most important wetland habitats, and it’s also one of our most polluted lakes. Restoring it to its former abundance of birds and fish will take generations, but it’s possible.
If you’ve ever smoothed on a blister pad, popped in a contact lens, or changed a disposable nappy, you’ve probably used a hydrogel—a type of material that can absorb large amounts of liquid. Hydrogels are usually made of petroleum, a fossil fuel. Now, a new hydrogel has been developed in New Zealand from one of the most abundant resources in the country: seaweed. A three-year research programme led by Scion developed the seaweed hydrogel after testing the properties of different species around New Zealand, including the introduced, invasive species Undaria pinnatifida and the native species Ecklonia radiata, which is commercially harvested. Seaweed-based hydrogels have been made before, but never from species that are growing around New Zealand in sustainably harvestable quantities. Scion has licensed the hydrogel to AgriSea, a Paeroa-based company, which is now trialling the hydrogel for use in wound dressings and as a growing medium for seedlings. AgriSea general manager Tane Bradley says seaweed remains an underrated resource: “People don’t realise how cool seaweed is and what we can do with it.”
There are two answers to this question: To intrigue you so that you pick up the magazine and buy it, or to make a statement about what’s important in this country. I’ve learned that if we put a bird on the cover, or a tiny house, or a tramping track, it’s much more appealing to buyers than if we feature a social issue, such as climate change, ocean pollution, or P addiction. But we would be neglecting our mandate not to feature the human world as well our wildlife. We thought about putting a tree on the cover: an awe-inspiring, thousand-year-old forest giant. We thought about putting a historic bach on the cover: something that speaks of idyllic childhood summers and simpler lives. But the most important challenge facing New Zealand right now is a virus, and how we build our defences to it. As I write this, COVID-19 has killed 2.4 million people around the world. Some scientists now believe SARS-CoV-2 won’t ever be eradicated, but that humanity will build enough immunity to the virus that it will circulate harmlessly among us—like the four coronaviruses that cause common colds. The question is how many people will die, or become permanently harmed, before that happens. How much will it alter our economy, our relationship with our neighbours in the Pacific, our lives and environment? This is a challenge we’ve faced before, points out Dave Hansford on page 40. New Zealand experienced polio epidemics about once a decade throughout the 20th century, until the polio vaccine ended them. As with COVID-19, most people who caught polio were asymptomatic; a small number required help breathing with a ventilator, and some found themselves permanently paralysed or had lifelong health issues as a result. Our victory had a price: polio vaccines were poorly tested, and bad batches harmed innocent people. While vaccine development has improved immensely, public trust has not recovered. Vaccination is one of the most important technologies humans have developed. A recent study found that 37 million deaths were prevented between 2000 and 2019 by vaccinations. Those lives saved were estimated to be mostly those of children under the age of five, and particularly from measles. Yet New Zealand has never attained the World Health Organization’s measles vaccination coverage target of 95 per cent—the level required to achieve herd immunity from measles. This has had devastating consequences. In August 2019, a person infected with measles travelled from Auckland to Samoa, causing an outbreak of the disease; 5707 people were infected, and 83 died. The majority of deaths were children aged under four. Which is worse: not having a treatment for a disease, or having a treatment and failing to use it? Dangerous public doubt swirls around this technology, and more now than existed half a century ago. The COVID-19 vaccines enter a world filled with suspicion. In this issue we’ve attempted to address some of the things you may be wondering about them: how they were tested, how they work, what their limitations are and what they might achieve. The answers to these questions may be some of the most important messages our mercifully isolated society needs to hear.
Plant sex is the ultimate form of a long-distance relationship, with animals co-opted into carrying out the act. The result: much of life on Earth depends on the habits of hungry insects, bats, reptiles and birds. But we don’t know exactly who’s doing what to whom, and when—and what might happen if they disappear.
Plants are our best technology for soaking up carbon dioxide from the atmosphere, but a new study shows the world’s forests and grasslands could flip over to become a source rather than a sink of CO2. Currently, the world’s green spaces absorb about a third of the emissions we produce by burning fossil fuels. But at the current rate of warming, plants’ ability to inhale more carbon dioxide than they exhale will slow down, then reverse, shrinking the carbon sink to almost half its size by as early as 2040. A study published in Science Advances in January looked at the link between temperature and photosynthesis (the process plants use to turn carbon dioxide and the sun’s energy into oxygen and sugars for their growth) and respiration (which releases carbon dioxide). Researchers analysed datasets from a global network of meteorological sensors known as FLUXNET, which tracks a suite of atmospheric variables, including carbon fluxes above different biomes. The study found that photosynthesis has a much lower ideal temperature, between 18°C and 28°C depending on the type of plant, than respiration, which means that as global temperatures continue to climb, photosynthesis will slow while respiration keeps rising. Some ecosystems in warmer parts of the world, including the Amazon, already reach this threshold during certain times of the year. Earlier studies on specific trees suggested that some would grow faster at higher atmospheric levels of carbon dioxide, but this wider study found no such effect. Nor did it find any evidence that plants adjust to perform higher rates of photosynthesis at higher temperatures. The results are a wake-up call, says one of the study’s authors, University of Waikato soil scientist Louis Schipper. “The biosphere has been harvesting our emitted CO2 and we assumed that would carry on. But this data shows the size of this terrestrial carbon sink will go down. It blows me away how near this is.” Add to this the increasing risk of wildfire and drought, and stressed plants’ lessened resilience to pathogens, and it’s clear, says Schipper, that we can’t count on “this idea of just planting trees”.
Amber Aranui searches the world for Māori and Moriori human remains to bring home as a researcher for Te Papa’s Karanga Aotearoa Repatriation Programme.
When a kiwi probes soil with its long beak, it’s not only scenting for prey, it’s using an extra sense to detect the wriggling vibrations of a grub. Known as “remote touch”, this ability is due to a special organ on the tip of its bill. Some shorebirds, such as the royal spoonbill, also have these beak mechanoreceptors to help them locate their prey in mud. Emu and ostriches have similar remote-touch organs in their bills, although they don’t forage by probing, or have any other habits that rely on this sixth sense. These birds are part of the palaeognath family, which includes moa. Could their remote-touch sense be a remnant from a distant ancestor of both moa and kiwi? Scientists from South Africa traced the palaeognath family tree back to the extinct lithornithids—long-legged, beak-probing birds that evolved during the Cretaceous period, more than 66 million years ago. To figure out if these avian ancestors had the remote-touch sense, the researchers compared the skeletal structures of 353 living birds with and without bill-tip organs, looking for patterns that would allow them to decide whether a fossil had the organ. Remote-touch organs are embedded in bony pits in the beak, and analysis of fossil bones suggested that the ancient birds did have bony pits and the extra sense of wiggle detection. Moreover, the fossils had been found by lakebeds, suggesting the lithornithids had foraged in mud, too. The researchers speculate that the remote-touch sense may have evolved even earlier: in the sensitive snouts of dinosaurs.
Emerald green with a distinctive yellow smile: meet Naultinus flavirictus, the newest addition to New Zealand’s treasure trove of more than 100 endemic lizard species. Found in the Far North, this gecko has been recognised as a distinct species since at least the late 1990s. It was finally described and named in a January 2021 paper published in Zootaxa, based on three specimens held at Te Papa Tongarewa. Its name refers to the yellow markings at the corner of its mouth. With its small home range and the ever-present threat of invasive mammals, the newly minted N. flavirictus is classified as “at risk” of extinction. The study’s authors speculate that these geckos once occupied tall, subtropical rainforest—which has dwindled to 3.2 per cent of its former extent since human arrival. The Te Paki area of Northland is a biodiversity hotspot, home to an array of unique and rare species, including 17 plants, 30 land snails, several stick insects and one skink found nowhere else. N. flavirictus is the ninth gecko in the Naultinus genus to be formally described. Its other eight family members are scattered around the country.
More than a century ago, people were granted temporary leases to build baches on Rangitoto Island, and a thriving community grew around these rudimentary dwellings. But Rangitoto is public land. A debate over the legitimacy of private baches existing there began in the 1920s and continues today. Meanwhile, three of the historic baches have now been opened for public use, welcoming a new generation of people to the island.
Scientists have filmed multiple instances of octopuses punching fish in the Red Sea during so-called collaborative hunting expeditions. An octopus may join forces with several species of fish to increase its chances of nabbing a meal. Groupers patrol the water column, using gestures to signal where prey is hiding. Octopuses can reach into tight cracks with their tentacles. Other species, like goatfishes, may scour the seafloor and join in a pursuit. To untangle the dynamics of these complex inter-species interactions, researchers filmed several cooperative hunting bouts using underwater cameras. They filmed eight instances of octopus-on-fish violence, finding a number of possible reasons for the octopus picking a fight. For example, if a fish partner failed to pull its weight or took more than its fair share, they might receive a jab. A sneaky parasitic fish might be shooed away with a tentacle. Sometimes, the octopus punched fish out of the way in order to take the prey for itself. Collaborative hunting also occurs between reef fish and moray eels—but, eels don’t have arms.
How do you trace the travels of a humpback whale? You listen to its song. Whales learn songs from each other, so their vocal patterns are clues to who they’ve been hanging out with—and where. Every winter, humpback whales leave their Antarctic feeding grounds and swim 5000 kilometres north to the tropics to breed. Some swim up the east coast of Australia, while others pass through New Zealand waters. Rochelle Constantine and Victoria Warren from the University of Auckland analysed acoustic recordings of humpback whale song to figure out the likely destination of individuals passing by New Zealand. They compared local whale recordings—captured off Kaikōura, the Wairarapa, in Taranaki Bight and Cook Strait—to audio samples from both eastern Australia and New Caledonia. The New Zealand songs shared more similarities with recordings from New Caledonia than from Australia, suggesting a stronger connection with the breeding grounds around the French archipelago. Eavesdropping on the whales also taught researchers about their preferred migratory routes. On their way north, most whales followed the east coast of the South Island, hung a left through Cook Strait, then powered north.
Out there in forest reserves, down remote back roads and tucked away in corners of small towns hide giant tōtara, mataī and rimu. A tiny group of obsessive people, guided by old records and half-remembered stories, regularly hit the road in search of these monsters. Their aim: to bag a champion tree, one whose size, age and majesty will put it at the top of New Zealand’s notable tree register.
Ornithologist Colin Miskelly was up before dawn, his face lit by the reflected glow of his laptop, entering data into a spreadsheet while his expedition boat lay at anchor in Doubtful Sound. At 5.35am, something soft—“like a feathered butterfly”—hit him in the chest. Miskelly grabbed it—and there, its heart beating against his hand, was a grey-backed storm petrel. You may not have heard of this New Zealand bird, and you probably haven’t seen one, either. That’s because they spend most of their lives at sea, and were thought to breed only in the country’s farthest outposts: the subantarctic and Chatham islands. None of New Zealand’s early naturalists recorded grey-backed storm petrels anywhere on the mainland. But one was collected in Preservation Inlet in 1889, and there have been occasional sightings in Fiordland over the past 50 years. Seabirds only really hang out near land when they’re breeding, says Miskelly, “because no bird has ever figured out how to incubate a floating egg”. So are they a mainland bird after all? Hoping to solve this mystery, Miskelly’s team had spent much of the November 2020 research trip looking for grey-backed storm petrels, shining the ship’s spotlight into the sky on dark nights to attract them onto the deck. They had caught five birds, and seen them at six different sites along a 120-kilometre stretch of Fiordland’s northern coastline—but this one had landed in Miskelly’s lap. And it had a bare brood patch. “That pretty much says this bird is caring for an egg or very young chick at this moment and therefore should be within a day or two’s flight of its nest or possibly even closer,” he says. In 2017, Miskelly—who is Te Papa’s vertebrates curator—had caught another storm petrel with a brood patch at Chalky Inlet at the far southern end of the fiords. Together, the signs point to the species “breeding throughout the length and breadth of Fiordland”, probably on steep cliffs that are inaccessible to rats and stoats (and researchers). To prove this, Miskelly would need to GPS-track the birds, but this would require tracking devices that are lighter and more powerful than existing ones. Or a storm-petrel feather could turn up in the nest lining of one of Fiordland’s alpine rock wrens—a method previously used to indicate the presence of kākāpō.
Humans have a new ally in the battle against mosquito-borne diseases: artificial intelligence. Researchers have deployed machine learning to classify images of mosquitoes in order to distinguish the dangerous from the annoying. There are more than 3500 mosquito species worldwide, but only a handful of these (and only the females) transmit deadly diseases such as malaria. It’s notoriously tricky to tell these tiny insects apart. Even trained medical entomologists struggle to differentiate one mosquito species from another. Using a dataset of 1709 mosquito images representing 15 different species, researchers in the United States trained a neural network—an algorithm loosely based on the way the human visual system works—to identify Anopheles, the malaria-carrying genus. The neural network also learned to differentiate species within Anopheles, as well as the sex of each individual, and to tell apart two strains of the species Anopheles gambiae. It was able to identify the class of the mosquito (genus, species or strain) with 96.96 per cent accuracy, and to separate sexes with 98.48 per cent accuracy, outstripping the ability of humans. This new technology aims to improve mosquito surveillance—a key component of public health programmes, including in New Zealand.
Increasing the diversity of crops keeps plant-eating insects under control, according to a study published in Science Advances in November. University of Waikato ecologist Andrew Barnes led the research, which used data from two long-running grassland biodiversity experiments in Germany and the United States. The scientists compared the food webs in monoculture plots with those in plots of increasing plant diversity, up to a mix of 16 species. Barnes’s colleagues used a modified vacuum-cleaner to collect all the insects and arthropods living in each plot. “You just vacuum them all up into a bag,” says Barnes. Pest insects ruin between 18 and 26 per cent of global crops, leading farmers to use pesticides. Barnes’s study found that less crop damage occurred as plant diversity increased. That’s because in diverse fields, insects are less likely to find their preferred kind of lunch. More varied ecosystems also create homes for more of the pests’ natural predators, like spiders, beetles and wasps. The effect was most noticeable where crops were increased from one or two species to three or four, meaning farmers could make a small change to have a big impact. Another study published in the same journal—a meta-analysis of more than 5000 studies—found that diversifying crops enhances biodiversity, pollination, pest control, and soil fertility without compromising yields (though there are trade-offs in some contexts). More research needs to be done to figure out how to apply these findings from the northern hemisphere to New Zealand grazed pastures, says the University of Waikato’s Louis Schipper, who was not involved in either study. “If we can increase the diversity of our pastures, can we decrease pests while maintaining or even improving production? A real challenge is to identify which plants and what proportions matter.” Barnes is hopeful this kind of research could eventually lead to a reduction in pesticide use—which doesn’t kill just pests but their predators, too. “There are also all these other services that insects bring, like pollination,” says Barnes. Imagine if farmers could get the best of both worlds: “To increase biodiversity, but also get some of the benefits for agriculture from that biodiversity that nature provides for free.”
Connecting the Central Otago towns of Clyde and Cromwell, the Lake Dunstan Trail skirts the water. Its final section, through the Cromwell Gorge, is set to open at the end of this summer, featuring bridge sections cantilevered from the sheer schist faces and suspended over the artificial lake. The track is a feat of engineering, with the result being a relatively easy ride—it will be rated Grade 1-2. It connects to Central Otago’s 536 kilometres of existing cycle trails, including several Great Rides.
On a brief visit to Auckland, the celebrated author of Treasure Island almost didn’t make it out of the harbour.
And fixing things that might appear unfixable.
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