Philippa Kaur

Workers for the Billion Oyster Project prepare to place juvenile oysters in a waterway running through New York City.Credit: Diana Cervantes/Redux/eyevine

New York CityAs the Sun dropped behind the Statue of Liberty on Saturday, a staff member for a conservation group unlocked a gate on a nearby island to reveal the ingredients for a potential oyster renaissance: stacks of ‘reef balls’, large domes made of oyster shells and concrete. They will soon be placed in tanks filled with free-swimming oyster larvae. Once the larvae latch onto the balls and mature, the structures will be submerged in the murky waters off New York City in an effort to revive a lost ecosystem.Coastlines around the globe were once protected by oyster reefs, expansive masses of oysters that had fused to rocks and each other. Overharvesting and habitat loss have demolished about 85% of Earth’s oyster reefs in the past two centuries. But bringing them back could help coastlines to become more resilient to the effects of climate change, including intense storms and erosion, scientists say.
Can floating homes make coastal communities resilient to climate risk?
The Billion Oyster Project, a non-profit organization in New York City, is leveraging the bivalve’s engineering skills to slowly build a living breakwater. After a decade of refining the process, the project is generating know-how for other efforts that it has inspired elsewhere.“The foundations are there to rebuild these ecosystems, and there are considerable environmental and social benefits of doing this,” says Melanie Bishop, a marine ecologist at Macquarie University in Sydney, Australia. But it is still unknown1 whether restored reefs can grow large enough to buffer coastlines, and oyster-restoration proponents acknowledge that it will take an untold number of transplanted oysters and many years before reefs can provide a bulwark against rising seas.Mass of molluscsCenturies ago, New York Harbor, which lies between the five boroughs of the city — Manhattan, Staten Island, Brooklyn, the Bronx and Queens — and parts of New Jersey, was home to a massive conglomeration of eastern oysters (Crassostrea virginica) spanning nearly 900 square kilometres. Demand for the succulent molluscs skyrocketed as the city’s population boomed; at the same time, pollution in the harbour escalated, and by 1927, the oyster-reef ecosystem had collapsed.The Billion Oyster Project seeds oyster beds at 18 sites around New York City. Its goal: to initiate the reef-building process. If the oysters can consistently reproduce on their own, they could one day form a structure that buffers against hurricanes and extreme storms while protecting the shoreline from eroding into the rising sea, says Asly Ventura, a public-outreach coordinator for the project. Studies have found that oyster reefs boost biodiversity2 and can improve water quality3, which could create safe havens for other species as ocean conditions change.The larval molluscs need to settle onto hard, stable surfaces to grow. To provide a home for them, the project staff and volunteers mix crushed oyster shells, donated by restaurants, with recycled concrete, and use the slurry to make hollow, domed structures pocked with holes that are roughly one metre in diameter. Staff drop several of these domes at the project’s reef sites each summer, with the goal of forming vast shoals of oysters at each site.

Domed structures called reef balls are stored in New York City. They will be lowered into the nearby waters to provide a home for young oysters.Credit: Alix Soliman/Nature

The campaign has had mixed success. Of the 122 million oysters that were transplanted into the harbour by the end of last year, about half have died. “We do expect a large amount of die-off,” Ventura says. Oysters produce a lot of young because so many larvae die, she says. In 2022, the organization reported that oysters were naturally reproducing at about half of the installations.Pollution could partially explain why the molluscs aren’t multiplying on their own at every site. After it rains, a combination of raw sewage and stormwater is piped into the harbour. Lingering industrial waste contributes to poor water quality. Noise pollution could also be interfering with the larvae’s ability to find a suitable place to settle, because they use auditory clues to locate existing reefs, Ventura says.Ray Grizzle, a marine biologist at the University of New Hampshire in Durham, who has done scientific assessments for the project, says that juvenile oysters mostly settle within 400 metres of their parent reef. As a result, oysters might not self-seed readily at sites far from existing reefs.Grizzle’s greatest concern is how pathogens, such as the parasites Haplosporidium nelsoni and Perkinsus marinus, might affect oysters over the long term. “They’re down to about a 3- to 5-year lifespan now, when historically it was probably 10 to 20,” he says. When the lifespan is reduced, so is the population’s ability to form lasting vertical reef structures, he says. All the same, the project is “moving in a good direction”, Grizzle says.Reef resurgenceOther restoration projects are taking off around the world. In Australia, biologists attracted oysters simply by dropping limestone boulders onto a sandy sea bed. Larval flat oysters (Ostrea angasi) naturally settled on the rocks in densities that far exceeded expectations2, suggesting the larvae are travelling from unknown remnant reefs or oyster farms.“We didn’t know we were going to get any natural recruitment when we started,” says study co-author Dominic McAfee, a marine biologist at the University of Adelaide in Australia. The effort is meant to sustain the seafood industry and has increased the biodiversity of invertebrates at the site.In the North Sea, researchers are placing oyster larvae on the granite boulders at the base of wind turbines in an effort to fortify the structures and increase biodiversity.Bishop says that for oyster-reef projects to be successful, they need to be located in areas where the issues that led to their demise are no longer present, constructed to withstand predicted changes to the ecosystem and monitored for much longer than two to three years. Although there is a long way to go, “there is a lot of hope”, she says. More

As a student in China in the late 1980s, I spent several wonderful semesters studying zoology and botany. I vividly remember the joy of a summer field trip, immersed in taxonomy and biodiversity, where I learnt about a weed called goose-grass. Its well-developed root system makes it difficult to pull out of the soil — earning it the nickname the ‘Dunzhao donkey’, because those attempting to extract it look like exhausted donkeys squatting on the ground.Taxonomy is crucial for biodiversity conservation — if we can’t properly identify animals, plants and fungi, we can’t find ways to preserve them. But since my student years, working as an ecologist in Shandong, China, I’ve witnessed a decline in the teaching of this important subject. Credit hours for botany and zoology modules have halved at many universities in China. The length of field trips has been reduced owing to lack of funding.
No basis for claim that 80% of biodiversity is found in Indigenous territories
It’s a similar story worldwide. Funding for projects involving taxonomy dropped drastically in the United Kingdom in the 1990s, replaced by those using molecular biology and genetics. Taxonomists in Europe worry that they themselves are becoming an endangered species, with retiring experts often not being replaced. And some low- and middle-income countries (LMICs), including tropical nations that contain some of the world’s biodiversity hotspots, have long faced a shortage of domestic talent.Decades on, and the costs of these cuts are now apparent. Biodiversity initiatives are struggling to find specialists. For example, in China, hundreds of surveys of animals, plants and fungi are under way, with the aim of improving the conservation of native habitats and species. But many organizers have found it difficult to recruit qualified researchers. Qiao Gexia, an entomologist at the Chinese Academy of Sciences in Beijing, has voiced concern that, as current taxonomists retire, there will be a reduction in studies of important taxa — such as termites, which are crucial to ecosystems but also can damage buildings, roads and bridges, and earwigs, which are useful for pest control but are detrimental to fruit production (see go.nature.com/3msjcxh).Indeed, a lack of taxonomic knowledge, especially at the local level, is leading to errors. For example, in 2022, a common fish in Xiaoqing River, China, was mistakenly reported to be an endangered species, causing confusion among conservationists and the public.
Harrowing trends: how endangered-species researchers find hope in the dark
If taxonomic knowledge is not maintained, it will become harder to prevent species becoming extinct.That’s why I feel it’s so important that the Kunming Biodiversity Fund — aimed at supporting global biodiversity conservation — includes a substantial pot of money for biodiversity education. The fund was launched in Beijing in May. Its co-chairs, the Chinese government and the United Nations Environment Programme, hope that the initial investment of 1.5 billion yuan (US$210 million) from China will attract other countries, institutes and organizations to invest in the fund. The money will be used to help LMICs meet the goals of the Kunming–Montreal Global Biodiversity Framework, which has been agreed on by almost 200 countries. The framework sets out 23 targets to be reached by 2030 and 4 goals for 2050, all of which aim to see humans living in harmony with nature.The first projects to be supported by the Kunming fund are expected to be announced before the start of the COP16 UN biodiversity conference on 21 October, at which progress towards meeting the biodiversity framework targets will be discussed and evaluated. As yet, education has not been mentioned as a focus — but I think it should be.I would like to see 10% of the Kunming fund’s annual budget put aside for education. It’s crucial to build up taxonomic know-how in LMICs that lack it, and to ensure that it is preserved in those where it might be dwindling.One priority should be funding programmes in LMICs that teach students taxonomic methods, such as observation of specimens, and modern techniques for assessing the biodiversity of animal and plant communities.
Can floating homes make coastal communities resilient to climate risk?
Laying camera traps and analysing the footage, for instance, is often cheaper, easier and requires fewer people than using live traps does. Analysis of DNA gathered from soil, water or air can be used to accurately assess the species in a local community, without the need to spot them all in the wild. And training in the use of online digital herbaria and collection galleries will enable young scientists to share knowledge and resources across countries.Universities can support this endeavour by incentivizing biodiversity and taxonomy courses for their students, perhaps by giving them more credits. And they should also offer general courses in taxonomy and biodiversity to students outside the biological sciences, to build awareness.Some might argue that a focus on direct conservation efforts is the best way for the Kunming fund to help achieve the framework’s 2030 targets. But education is the key to reaching many of those goals, especially because those living in a particular country are the ones best placed to understand its flora and fauna.Ignoring education will waste the Kunming fund’s resources. There can be no sustainable support for global conservation efforts without generation after generation of properly educated specialists. A lack of expertise will be devastating for the estimated one million species facing extinction worldwide today. More

The US National Wilderness Preservation System, created by the Wilderness Act of 1964, was a profound invention. In his review of Sophie Yeo’s book Nature’s Ghosts, Douglas Erwin trivializes the legislation’s origin as forester Aldo Leopold’s ‘pragmatic’ solution to allow undisturbed hunting (Nature 632, 974–975; 2024).
Competing Interests
The author declares no competing interests. More

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Download the Nature Podcast 11 September 2024 In this episode:00:45 What ancient DNA has revealed about Rapa Nui’s pastAncient DNA analysis has further demonstrated that the people of Rapa Nui did not cause their own population collapse, further refuting a controversial but popular claim. Rapa Nui, also known as Easter island, is famous for its giant Moai statues and the contested idea that the people mismanaged their natural resources leading to ‘ecological suicide’. Genomes sequenced from the remains of 15 ancient islanders showed no evidence of a sudden population crash, substantiating other research challenging the collapse idea.Research Article: Moreno-Mayar et al.News and Views: Rapa Nui’s population history rewritten using ancient DNANews article: Famed Pacific island’s population ‘crash’ debunked by ancient DNA17:03 Research HighlightsThe extinct bat-eating fish that bit off more than they could chew, and how manatee dung shapes an Amazonian ecosystem.Research Highlight: Ancient fish dined on bats — or died tryingResearch Highlight: The Amazon’s gargantuan gardeners: manatees19:29 A macabre parasite of adult fruit fliesDespite being a hugely studied model organism, it seems that there’s still more to find out about the fruit fly Drosophila melanogaster, as researchers have discovered a new species of parasitoid wasp that infects the species. Unlike other parasitic wasps, this one lays its eggs in adult flies, with the developing larva devouring its host from the inside. The minuscule wasp was discovered by chance in an infected fruit fly collected in a Mississippi backyard and analysis suggests that despite having never been previously identified, it is widespread across parts of North America.Research article: Moore et al.32:04 Briefing ChatHow a dye that helps to give Doritos their orange hue can turn mouse tissues transparent, and an effective way to engage with climate-science sceptics.Nature News: Transparent mice made with light-absorbing dye reveal organs at workNature News: How to change people’s minds about climate change: what the science saysSubscribe to Nature Briefing, an unmissable daily round-up of science news, opinion and analysis free in your inbox every weekday.Never miss an episode. Subscribe to the Nature Podcast on Apple Podcasts, Spotify, YouTube Music or your favourite podcast app. An RSS feed for the Nature Podcast is available too. More

Profits from rooibos tea are being shared with South Africa’s Indigenous Khoi and San People, in recognition of their contribution to its development.Credit: Mike Hutchings/Reuters

For at least two decades, scientists, policymakers and journals, including Nature, have cited a statistic without determining its validity. The data point in question is that 80% of global biodiversity is under the stewardship of Indigenous Peoples. There is no doubt that Indigenous communities are core to the conservation of biodiversity, but to say that they are stewards of 80% of the world’s genetic, species and ecosystem diversity isn’t supported by evidence, as the authors of a Comment article last week stated (Á. Fernández-Llamazares et al. Nature 633, 32–35; 2024).
No basis for claim that 80% of biodiversity is found in Indigenous territories
A single, unsubstantiated number also does not reflect Indigenous values and world views, the authors add. There are better indicators and statistics on Indigenous communities and biodiversity, says Álvaro Fernández-Llamazares, a co-author of the Comment article and an ethnobiologist at the Autonomous University of Barcelona, Spain, in an accompanying Nature Podcast.Biodiversity — defined as the variety of life on Earth, including its variation at the level of genes, species and ecosystems — is extremely hard to quantify. Even the simplest statements come with great uncertainty: there is no consensus, for example, on the number of species on the planet1. There are at least 50 ways to value nature, according to researchers working with the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) in Bonn, Germany2.
Podcast: The baseless stat that could be harming Indigenous conservation efforts
The authors of the Comment article, three of whom identify as Indigenous, reveal that the 80% statistic seems to have emerged in policy reports, from which it spread into the scientific literature. As of 1 August, the researchers found the 80% claim mentioned in 186 peer-reviewed journal articles. The earliest mention that they found was in a 2002 United Nations document that said that Indigenous Peoples “nurture 80% of the world’s biodiversity on ancestral lands and territories”, without a citation. The number is repeated in an influential 2008 World Bank report.So why might this number appear in policy documents first? It stems from Indigenous Peoples’ centuries-old encounters with more-powerful interests, the resulting exploitation and mistreatment, their fight for rights, and the international community’s ongoing policy response.
Assessing the values of nature to promote a sustainable future
Worldwide, there are some 467 million Indigenous People across 90 countries. Today, they are among the poorest, most vulnerable and least protected people in their nations. Some international laws and modern research practices pertaining to biodiversity derive from the 1992 UN Convention on Biological Diversity. This agreement has its origins in a movement to create protected areas — ironically, areas often initially created by taking away Indigenous Peoples’ rights to land or expelling them. During the negotiation, representatives of low-income countries and Indigenous Peoples fought to ensure that the agreement included provisions for the equitable sharing of biodiversity’s benefits, such as profits from food or medicines.By the early 2000s, organizations such as the World Bank were working with Indigenous Peoples’ representatives, and examining the impact and legacy of their own previous lending practices on Indigenous Peoples and creating ways to involve them in their decisions.The research community also had work to do. When IPBES was established in 2012, it pledged, for the first time, to incorporate Indigenous and local knowledge in its global scientific assessments of biodiversity. Studies are now being co-produced between Indigenous and non-Indigenous authors. A next step needs to be more studies designed and led by Indigenous authors3.Around the world, the struggle for Indigenous rights has a long way to go. Researchers have a crucial role in supporting communities, which includes being rigorous with data. As Fernández-Llamazarez says in the Nature Podcast, unproven data risk fuelling scepticism on the role of Indigenous communities in biodiversity stewardship. More

At the end of July, a wildfire driven by extreme winds blazed through Jasper National Park in Canada, forcing the evacuation of 25,000 citizens and visitors. For a month, more than 350 firefighters worked to control the fire, which grew to cover 33,000 hectares, making it the largest wildfire in the park in at least 100 years. Last year’s fire season was also catastrophic: about 4% of the nation’s forest area burnt (15 million hectares) — more than twice the previous record, set in 19891.
‘Fire clouds’ from super-hot wildfires are on the rise as Earth warms
Wildfires are not always bad — they have been fundamental to forest ecosystems for hundreds of millions of years2, affecting the composition, structure and biodiversity of landscapes3. Some plant species, such as jack pine (Pinus banksiana) and lodgepole pine (Pinus contorta), require the heat and smoke generated by fires to release their seeds from a resin-coated cone and to germinate.But wildfires in Canada have been increasing in number, size and intensity since the mid-twentieth century4,5. This is mainly the result of anthropogenic climate change and the accumulation of undergrowth and other fuel after decades of fire suppression as a way to manage forests.The situation is dire, but not hopeless. In many parts of the nation, efforts are shifting from suppressing fires to a variety of responses, including lighting controlled fires to manage vegetation — often referred to as prescribed burning. Indeed, two decades of such proactive fuel mitigation in the forests surrounding Jasper has meant that firefighters were able to save around 70% of the town’s infrastructure after the July wildfire.

Credit: Sarah Smith-Tripp and Liam Irwin

As forest scientists and fire practitioners, we urge the public and those involved at all levels of forest management to think about fire more holistically. As humanity prepares for a future in which fires become more common, we need all the tools at our disposal. Two sources of knowledge that are often overlooked are crucial — Indigenous-led fire stewardship and technological advancements in data acquisition.Indigenous-led stewardshipHumans have used fire to influence landscapes for millennia6,7. Indigenous Peoples around the world continue to recognize the importance of fire stewardship to maintain desirable, diversified and resilient ecosystems and to achieve cultural objectives that have ecological benefits7.Many Indigenous communities use fires for a variety of purposes — from protecting nearby infrastructure and settlements to managing territories for crops, food and medicinal plants. For example, First Nations communities across Canada use fires to boost the abundance, productivity and nutritional value of huckleberries.

Forest regrowth after a wildfire in British Columbia in 2017.Credit: Liam Irwin

Wildfire agencies in Canada are beginning to show an interest in incorporating Indigenous fire practices — known as cultural burning — into forest landscape planning processes. For example, the We Are Fire project involves Indigenous knowledge holders using cultural fire practices to improve biodiversity in the Saskatchewan River Delta.
Are we all doomed? How to cope with the daunting uncertainties of climate change
Crucially, cultural burning is not something that can simply be captured and appropriated into plans by agencies to inform wildfire management7,8. Indigenous communities, which hold the cultural, technical and place-based expertise to engage in both proactive fire stewardship and wildfire response, must lead these processes and make decisions according to their cultural and ecological values9. This is all the more important because Indigenous Peoples disproportionately bear the burden of wildfire impacts through evacuations, alteration of their territories and other adverse effects on their ways of life10,11.Not everyone is convinced by the usefulness of prescribed and cultural burning, however. Some doubt the ability of public authorities to control the fires, and worry that, in a rapidly warming and drying climate, the risk of a fire ‘escaping’ beyond its intended area is too high. Such accidents can erode public trust. Research is needed to better understand and address this resistance. Practical restrictions also exist regarding who is allowed to ignite fires, who is responsible for each event and who can approve and oversee the processes12. Forest and landscape management planning processes must be revisited.

Wildfires are becoming more frequent and more severe in British Columbia.Credit: BC Wildfire Service/Xinhua/Alamy

The first steps must be to accelerate capacity in Indigenous communities to participate in, and lead, wildland fire management. There should be more communication, joint training — and, importantly, overlap — between Indigenous fire practitioners and wildfire agencies to share knowledge of fire behaviour and its effects in a respectful way. This will help communities to devise practices that are grounded in cooperative and considerate fire management8,13. Although the Canadian government has piloted programmes and grants that focus on training and collaboration, more permanent funding sources are needed to ensure continuity of these successes.Measure, monitor, modelAdvanced technologies should also be used more widely. Remote-sensing data from satellites, aircraft, hand-held devices and drones can be used at all stages of fire — before, during and after the event14.Satellite data have long been used to track land cover and changes brought on by fire. They can also help to determine pre-fire fuel loads, monitor recovery and identify areas that are less prone to burning. Known as refugia, such areas are valuable for regeneration after a fire and for conserving biodiversity. State-of-the-art technologies can map in exquisite detail the state of forest fuels, including species composition, soil moisture, vertical structure and connectivity, hotspots and vegetation health.
How record wildfires are harming human health
Future satellites will do even more. For example, WildFireSat, a joint programme involving three Canadian federal agencies that is expected to launch in 2029, will be the first public satellite mission to be purpose-built to monitor wildland fire. It is designed to observe fires at their peak — typically during the afternoons, when temperature, humidity and wind are most conducive to fire activity — to track their boundaries and spread. It will also be able to measure radiative heat power, so that resources can be prioritized to the most intense fires, particularly in remote, northern communities in Canada, where early and safe evacuations are crucial. Researchers can improve models that measure emitted carbon and track fire spread to help reduce economic losses and improve public safety.In the past decade, drones have helped to characterize the structure of forests in great detail — including fuel loads and proximity to or connectivity between trees. They do this by, for example, measuring sunlight reflected from Earth’s surface and gathering topographic data by emitting laser pulses and timing their return to a sensor. Such light detection and ranging (lidar) instruments can draw a 3D picture of fire-fuel distribution by mapping forest height, cover, species and crown attributes. Photographs from drones can assist firefighters and be used to help regenerate disturbed ecosystems after fires15. Linking such drone-based data with fuel metrics — the amount of understorey material, such as shrubs and grasses, that is present — is currently under way.

A worker watches a prescribed-burn site at High Park in Toronto, Canada.Credit: Lance McMillan/Toronto Star via Getty

Drones with on-board sensors are becoming cheaper — from hundreds of thousands of dollars a decade ago to a few thousand today. Their controls, mission-planning software and safety features have improved. And processing techniques are advancing, for example through machine learning and other types of artificial intelligence. These technological advances are beneficial only if they reach all relevant users, however, and they require users to be trained.Come togetherConversations led by Indigenous Peoples and involving researchers and other knowledge holders must happen urgently, so that local management strategies can be devised. And international collaborations — between scientists and policymakers as well as between disciplines — are a top priority that would help to mitigate the rise in the number and intensity of North American wildfires. This will require a huge effort, but there are precedents. In the 1980s, after the discovery of a ‘hole’ in Earth’s ozone layer over the South Pole that posed a major threat to human and environmental health16, leaders worldwide agreed on the Montreal Protocol. Its aim was to phase out the use of ozone-depleting substances, such as the chlorofluorocarbons commonly used in spray cans and refrigerants. In doing so, they averted the collapse of a global Earth system. Now, there is evidence that the southern ozone hole has recovered and that ozone levels are on track to return to pre-1980 levels by the middle of this century17. Cross-border arrangements such as the US–Canada Air Quality Agreement also showcase success and opportunities for collaboration.The same level of international urgency is needed for wildfires. Environmental assessments must be done, both domestically and across borders, to explore how to mitigate fires and coordinate efforts. At local or regional levels, ‘conservation economies’ should be put in place, in which members of a community are employed to protect carbon and biodiversity. Existing Indigenous ‘guardian programmes’ should be supported, including financially, and expanded.Wildfire is a crucial ecosystem process. Proactive management led by Indigenous Peoples and supported by advanced technologies is key to decreasing fire risks and increasing resilience in forests. Only with such a change in perspective can forests be protected in Canada and beyond. More

RESEARCH HIGHLIGHT
07 September 2024

The aquatic mammals disperse seeds of their favourite foods as they migrate, according to a serendipitous study of their poo. More