More stories

  • in

    Oil from the Amazon? Proposal to drill at river’s mouth worries researchers

    A Brazilian petrochemical company wants to drill exploratory oil wells in the ocean near the mouth of the Amazon, one of the world’s biggest rivers. Although Brazil’s environmental-protection agency has so far rejected the state-run firm’s request, researchers worry that the plan might one day be approved, encouraging further offshore drilling in the area. In particular, they are concerned about the effects of the drilling — and inevitable oil leaks — on a vast reef system nearby.
    Saving the Amazon: how science is helping Indigenous people protect their homelands
    “There’s a palpable risk of an oil spill if activities proceed — the fact it is an exploratory well for studying the region’s potential for deep-sea oil doesn’t exempt it from accidents,” says Carlos Rezende, a marine biologist at the State University of Northern Rio de Janeiro in Campos dos Goytacazes, Brazil.In May, the Brazilian Institute for the Environment and Renewable Natural Resources (Ibama) turned down oil firm Petrobras’s application to drill in what’s known as the FZA-M-59 block, a parcel of sea floor about 175 kilometres from the coast of northern Brazil, near the border with French Guiana, and about 540 kilometres from the mouth of the Amazon River (see ‘Oil prospecting’). The agency said that the company’s assessment of environmental impacts and its emergency plan in the event of a leak are insufficient. Petrobras, which is based in Rio de Janeiro, has since appealed and filed a new request.The company defended itself to Nature, saying that in the planned drilling location, “there is no record of any nearby conservation units, nor is it located near rivers, lakes, floodplains or reef systems”. But Rezende argues that the Great Amazon Reef System is only about 50 kilometres from the site, and that oil in the water could travel that distance.

    Source: Adapted from L. S. Araujo et al. Mar. Pol. 128, 104465 (2021)

    Threats to the reef system, which lies 70–220 metres below the ocean surface, are of great concern to some scientists. It has been difficult to explore the area because of turbulent waters, but studies estimate that the reef spans between 9,500 and 56,000 square kilometres across the mouth of the Amazon12. When it was first described by scientists in the 1970s, researchers did not observe rich biodiversity. But studies in 20162 and 20193 found a thriving ecosystem that’s home to corals, sponges and fish communities.“It is huge, and it is sensitive,” says Ronaldo Francini-Filho, a marine ecosystems researcher at the University of São Paulo in Brazil. “And we don’t know even 5% of what’s down there.”Rodrigo de Moura, a marine ecologist at the Federal University of Rio De Janeiro who has mapped reefs off the Amazon’s mouth, agrees. “There are a lot of known unknowns there,” he says. Because researchers don’t know a lot about the reef’s habitats and water circulation, “a comprehensive evaluation of the risks from oil and gas exploitation is currently impossible”, he adds.A promising blockIf the project is approved, it could set a precedent to allow drilling at 15 other deep-sea sites nearby that are flagged for exploration, says Suely Araújo, a senior policy specialist at the Climate Observatory, a Rio de Janeiro-based civil-society coalition focused on climate-change policy.So far, 95 exploratory wells have been drilled in the region without striking much oil; some natural-gas deposits have been found, but none big enough for commercial purposes. These wells were all in shallow waters, but FZA-M-59 is at a depth of 2,800 metres, in a part of the ocean that some researchers think is more promising. Egberto Pereira, an organic geochemist at Rio de Janeiro State University, says it’s possible that oil lies beneath FZA-M-59, because the area’s landscape and rock composition are similar to those of an oil-rich region off Guyana, where oil company ExxonMobil has operated since 2015.

    The Great Amazon Reef System is home to sea sponges and other organisms.Credit: Greenpeace

    Offshore drilling has been beneficial to Brazil in the past: in particular, drilling off the southeast coast in basins near São Paulo and Rio de Janeiro brought a windfall. In 2010, Petrobras raised more than US$25 billion for exploratory drilling in the region. Aloizio Mercadante, president of the Brazilian Development Bank in Rio de Janeiro, has estimated that the Equatorial Margin — a region that stretches over 2,200 kilometres along Brazil’s north coast and includes FZA-M-59 — could yield between 10 billion and 30 billion barrels of oil.But researchers think it’s premature to make such estimates when oil hasn’t been found yet. And they aren’t convinced that Petrobras has properly assessed the impact of the drilling. The company says its oil-spill modelling fulfils Ibama’s requisites. “The results indicate that there is no likelihood of [oil] touching the Brazilian coast” in the event of a leak, Petrobras says.But the modelling did show that oil could reach French Guiana, Guyana, Suriname and the Caribbean, Rezende points out. He also says that the models used by Petrobras “do not consider wind-generated waves, which are quite intense in the region and would certainly pull oil to the coast”. Petrobras stands by its modelling, saying that it used the “most modern techniques and systems”.Researchers worry that if oil were to reach the coast, it could damage mangroves at the mouth of the Amazon. “The region houses the second-largest continuous mangrove area in the world,” Francini-Filho says. “As it is highly sensitive, oil contamination would be catastrophic.”A greener future?Petrobras tells Nature it has drilled almost 3,000 wells at deep-sea sites without any complications, and that these, “added to the technical expertise and experience accumulated over 70 years, allow the company to open new frontiers with total security towards the Equatorial Margin’s environmental sensitivity”.
    Illegal mining in the Amazon hits record high amid Indigenous protests
    But even if the drilling can be done safely, researchers still question the idea of tapping into new oil reserves — which would create carbon emissions — while the world is battling climate change. Brazilian President Luiz Inácio Lula da Silva campaigned as an environmental crusader who would protect the country’s biodiversity and health. Allowing drilling in FZA-M-59 could cast doubt on his sincerity.“Is this what we want as a country?” asks Araújo. If approved, the project wouldn’t begin producing oil until 2030. “How much will a barrel be worth by then, when nations are supposed to be converting to renewable energy?” she asks. “We should be thinking of a development plan for the twenty-first century.”Ibama says it is analysing Petrobras’s latest request, but has set no date for a decision. More

  • in

    Rings of fire: centuries of tree growth show wildfires increasing in Vietnam

    Increasing human presence in and around Bidoup Nui Ba National Park has resulted in more frequent wildfires.Credit: Evgeniya Pavlova/Getty

    The first centuries-long analysis of wildfires in southeast Asia has been compiled using tree rings from a region in central Vietnam. There has been a drastic increase in the frequency of wildfires in the area over the past 100 years, but climate change is not the primary culprit. Instead, humans lighting fires for agriculture are behind the rising number of forest burns, according to the study1 published in Geophysical Research Letters.“Fire has a big impact on the forest structure,” says Thiet Nguyen, a forest ecologist and PhD student at the University of Melbourne in Australia. “There’s a very high level of biodiversity in that forest.”Many people think of tropical Vietnam as lush with jungle, but in the central highlands, misty montane forests are home to around 100,000 hectares of conifers mixed with broadleaf trees. Whereas tropical trees don’t tend to put on annual growth rings because they grow consistently year-round, the conifers have annual cycles of growth. Nguyen and his colleagues took cross-sections from recently fallen trees of two species, Pinus kesiya and Keteleeria evelyniana, at 12 locations in Bidoup Nui Ba National Park and counted the tree rings back over almost 400 years.When trees are exposed to non-lethal fires, their bark chars, leaving behind a burn scar within the tree rings. The team dated the earliest definite fire scar to 1772. Between then and 1905, only 17% of years contained clear fire scars, although Nguyen admits that the farther they went back in time, the smaller was the available number of samples, reducing their confidence in the findings. After 1905, they had good clear tree rings to work with. From then until 1963, 71% of years showed scars from fires, however the fires often affected only a small number of sites. But from 1964 to the present day, fire has occurred almost every year, often affecting a larger number of sites.‘A big problem’Until the advent of this study, “we had no idea how the fire regime has been changed”, says Nguyen. “If the fires are increasing rapidly, that can reduce biodiversity and forest density,” he adds. “It’s a big problem.”Using statistical analysis, the authors looked for relationships between fires, climate and the human population. They discovered that historically, fire patterns were associated with climate; data from Pacific sea surface temperatures (see ‘Forests on Fire’) showed that weather patterns such as El Niño and La Niña, which determine dry or wet years, could have influenced how much combustible plant material was available and how dry and flammable it was, for example.But after 1963, according to population estimates for the nearby city, Da Lat, an increasing number of people came to live in the area. Humans use fire to clear land for agriculture, Nguyen says, and fire probably spreads to the national park — established in 2004 — from nearby areas. People also start fires in the park. From 1964, the authors found that the signal from humans overwhelmed climate as the driving force behind the fires.

    The fires’ increasing frequency, coupled with heightened fire conditions brought on by climate change, will be a problem in the future, says Brendan Buckley, a dendrochronologist at Columbia University in New York, who was a master’s programme adviser to Nguyen but was not involved in this study. “There might very well be some burning that gets out of control in these areas that are protected rainforest.”Understanding historical and modern fire occurrence is crucial because it gives researchers a baseline to work from, helping forest managers to prepare for climate change, Buckley says. Although fire can be beneficial to a coniferous forest, the rainforest is a totally different ecosystem and can be destroyed by fire, he says.Nguyen says that the species used in this study are common across other parts of southeast Asia, such as Thailand and the Philippines, meaning that the same technique could be used to explore fire history and climate change in other countries.“If we had this kind of study in other countries in southeast Asia, a big historical fire reconstruction for the region, that would be cool.” More

  • in

    Brazil: threat to Indigenous peoples persists

    World leaders have backed commitments by Brazilian President Luiz Inácio Lula da Silva to defend Indigenous peoples’ rights and the environment (see, for example, go.nature.com/44wpdvb). But insufficient support for the new president’s government in the National Congress means that his predecessor’s opposing policies on the issues still stand.
    Competing Interests
    The author declares no competing interests. More

  • in

    My glacier is melting — and I’m charting its decline

    I grew up in Salzburg, Austria, and was always very fond of mountaineering. During my PhD, I used satellite data to measure the ice flow of large and remote glaciers in Iceland and polar regions that couldn’t be accessed in the field. This helped me study how quickly glacial ice flows. The subject fascinated me, and I decided to pursue a career in which I could travel to and study the glaciers in person instead of spending my days in front of a computer screen.In October 2021, on a fieldwork trip to the Jamtalferner glacier near Galtür, Austria, my colleagues and I found this big, beautiful cave in the middle of the glacier. In this photo, I’m inside the cave. In the background, there are bubbles of 300-year-old air trapped in the ice. It’s quite unusual for glaciers to be hollow, so I was curious about how the cavities formed.During the trip, we discovered that the cavities were much larger than we expected, especially compared with those that had already been documented.
    Who wants to be a polar bear?
    This glacier has been studied extensively since 1892. I go there with my colleagues about once every three weeks to measure the ice ourselves: it is melting rapidly. We are seeing changes not only in the glacier’s mass, but also where local plant species grow. For instance, certain plants and trees have begun to appear in regions that had previously been covered by glacial ice.On this trip, we figured out how large the cavities were. At that time, the cave was already showing signs of collapse, and by June 2022, it was completely gone.In glaciology, there is often no way to determine the precise conditions of an earlier time. A glacier might look the same from the outside, but it changes constantly inside: ice flows down and melts, snow cover grows and subsides. You can never come back to the exact same glacier; we can observe only the now. More

  • in

    To save bears, we must learn to live alongside them

    Brown bears are drawn to urban areas by food waste in open bins.Credit: Gribov Andrei Aleksandrovich/Shutterstock

    Eight Bears: Mythic Past and Imperiled Future Gloria Dickie W. W. Norton (2023)The probability of seeing a giant panda in the wild is practically nil. Even if you were to spend weeks trekking through the dripping bamboo forests of Sichuan, China, hoping to catch a glimpse of the famous black-and-white bear, there’s a good chance you would still not see one.This was a problem environmental journalist Gloria Dickie encountered as she travelled from South America to Asia to North America and the Arctic, doing research for her book Eight Bears. Her encounters with wild bears were few and typically in urban landscapes, so her account is more about the relationship between humans and bears than it is about the animals themselves. It’s an engaging travelogue nonetheless, weaving together evolutionary biology, physiology, ecology, history, culture, economics and politics to reveal the importance of each ursine species to our own. In doing so, the book highlights how the damage humans have done to the world poses a challenge to animals.In crude terms, the eight bear species divide into two categories. Some have a large cultural footprint, because they are conservation icons or common subjects of films and television (the giant panda, Ailuropoda melanoleuca; the American black bear, Ursus americanus; the brown bear, Ursus arctos; and the polar bear, Ursus maritimus). Others are not so familiar (the spectacled, or Andean, bear, Tremarctos ornatus; the sloth bear, Melursus ursinus; the Asiatic black bear, Ursus thibetanus; and the sun bear, Helarctos malayanus). It is Dickie’s accounts of these lesser-known bears that are most surprising.Dwelling in the cloudsIn Cusco, Peru, Dickie teams up with scientists who use camera traps to spy on shy Andean bears. As the climate warms, these black bears with spectacle-like rings of brown fur around their eyes are retreating ever higher into the cloud forests, where they are becoming trapped at high altitudes. The fogged and mossy cloud forests are slowly becoming drier, with more than half expected to be lost by the middle or end of this century (E. H. Helmer et al. PLoS ONE 14, e0213155; 2019). If climate change cannot be slowed, the bears will run out of mountain. The scientists hope to learn more about the behaviour of these elusive animals — in particular, why they are not moving to lower altitudes.In India, Dickie hears horror stories about the world’s most dangerous bear — the sloth bear, which can rear up onto its hindlegs and use its long, knife-like claws to inflict savage injuries. Although there are probably fewer than 20,000 sloth bears left in Asia, the author reports that they are responsible for around 150 attacks on humans each year. Understandably then, there’s not a lot of love lost for the sloth bear. “Too shaggy and sloppy to be respected for its physical powers … and excluded from the huggable genre to which the panda and the sun bear belong”, the sloth bear has a short temper that “poses an almost insurmountable challenge in the ethos of human—wildlife coexistence,” writes Dickie. With few people prepared to think strategically about conserving this vulnerable species, it’s likely that its numbers will decline as deforestation and the human population in India continue to grow.

    Attacks by aggressive sloth bears are increasing in India as the booming human population strays into the bears’ habitat more often.Credit: Mark Newman/Getty

    Asiatic black bears (also called moon bears) and sun bears face a more direct human threat. Across Asia, traders capture and illegally farm these animals for bear bile, which is regarded by some as a treatment for a host of ailments. According to the book, this distressing trade is currently thought to involve more than 20,000 bears. Dickie poses as a foreign investor interested in getting into the bile business. Her real aim is to raise awareness of its torturous techniques, such as the crushing cages that animals are housed in, often for life, and the cruel methods used to extract the bile, which can include a painful process to establish a permanent tunnel into the gallbladder.Despite this commonality, it is frustrating that Dickie bundles sun bears and moon bears into a single chapter. Although they look similar — black with a crescent of pale fur on their chests — they are highly distinct species that diverged some 4.5 million years ago (V. Kumar et al. Sci Rep. 7, 46487; 2017). Dickie’s decision probably reflects a lack of material about the sun bear, which is little studied because of its penchant for hiding high up in dense vegetation, out of sight of humans and their dart guns.Iconic bearsEach of the other chapters brings with it a different take on our relationship with bears. “In a largely agnostic society, the panda, it seems, has ascended to be China’s greatest cultural deity,” writes Dickie, as she explores the animal’s extraordinary attraction. The American black bear, with a global population of around one million, offers a case study in whether humans can manage the tensions that arise from living alongside bears. It’s an expensive and never-ending process of education and bear management, but testimonies from staff at Yosemite National Park indicate that it is possible.

    The lush cloud forests where Andean bears live are drying out.Credit: Getty

    Dickie uses aggressive brown bears to examine arguments for and against trophy hunting. She meets conservationists who have worked hard to bring the species back from the brink of extinction, and ranchers and hunters keen to see it delisted from the US Endangered Species Act. In the Arctic, she writes about how, with a rapidly declining population of 26,000, the polar bear is “one of the Anthropocene’s most charismatic victims”. Sea-ice coverage is diminishing at such an alarming rate that, even in the best-case scenario, there might be no polar bears left in the wild by the end of this century.With teddy bears and lovable TV characters such as Paddington Bear, Yogi Bear and Baloo common features of childhood, it is understandable that many people have a fondness for bears. But with the futures of their real cousins at stake, it is “a luxury”, writes Dickie, “to conceive of these animals as fable protagonists, majestic arbiters of wilderness, and cuddly cartoon characters.” Through Dickie’s personal journey and her interviews, Eight Bears delivers on its promise to offer “an unromanticized view of bears’ tenuous position in the Anthropocene”. More

  • in

    Deep-sea mining could soon be approved — how bad is it?

    An excavating machine on the Japanese research vessel Hakurei collected cobalt-rich ocean sediments in a 2020 test run.Credit: Kiyoshi Ota/Bloomberg via Getty

    Commercial mining of the sea floor could soon get the green light. The International Seabed Authority (ISA), a body associated with the United Nations that oversees deep-sea mining in international waters, is now meeting in Kingston, Jamaica, where it could decide whether companies can begin excavating the sea floor for minerals and metals such as cobalt, nickel and sulfides.Proponents say that this move could help with meeting the growing demand for rare-earth metals used in batteries both for electric cars and for storing renewable energy, aiding the shift to a low-carbon economy. However, research hints that the potential ecological impacts of deep-sea mining are larger than previously thought. Nature explores just how bad deep-sea mining could be.What’s the evidence for the effects of deep-sea mining on marine life?Scientists say that very little is known1 about deep-sea ecosystems, making it difficult to assess how they will be affected by mining. However, a few new studies are providing clues to the damage that large-scale mining might cause.A study2 published today in Current Biology is the first to examine the environmental effects of mining cobalt-rich crusts. These rock-hard, metallic layers, which form on the side of underwater mountains called seamounts, are among three deep-sea resources that have been proposed to the ISA as a target for mining. In 2020, a two-hour operation funded by the Japanese government excavated a roughly 120-metre-long strip of cobalt-rich crust on a seamount in the northwest Pacific Ocean, as a test run for mining activities.To investigate the operation’s effects, scientists reviewed video footage collected by a remotely operated vehicle. They found that, in the year after the excavation, the density of active swimming animals, such as fish and shrimp, dropped by 43% in areas directly affected by sediment kicked up by mining, and by 56% in adjacent areas.

    Animals observed during a study of the effects of deep-sea mining included those in the categories Actiniaria, Holothuroidea, Pentametrocrinidae (top row, left to right), Euplectellidae, Notocanthiformes and Aspidodiadematidae (bottom row, left to right).Credit: JOGMEC

    Travis Washburn, a benthic ecologist and co-author of the study who at the time was at the National Institute of Advanced Industrial Science and Technology in Tsukuba, Japan, says that he didn’t expect to see any ecological impacts from such a small mining operation. He suggests that the fish and shrimp swam away from the area because the mining and sediment pollution might have affected their food supply. The results show that effects are felt beyond the mining areas “by a pretty substantial amount”, he says.A study3 published last week suggests that tuna near the ocean surface could gravitate to areas likely to be affected by mining. Writing in npj Ocean Sustainability, scientists project that climate change will drive large numbers of the fish into the Clarion–Clipperton Zone (CCZ), a 4.5-million-square-kilometre area in the eastern Pacific Ocean between Hawaii and Mexico where much of the mining interest is focused. The study predicts that by middle of the century, the zone’s total biomass of skipjack (Katsuwonus pelamis) will rise by around 31% and yellowfin (Thunnus albacares) by 23%.
    Tuna catch rates soared after creation of no-fishing zone in Hawaii
    Data about deep-sea mining’s effects on animals in the upper layers of the sea are scare. But co-author Diva Amon, a marine biologist and a scientific adviser to the Benioff Ocean Science Laboratory at the University of California, Santa Barbara, says that deep-sea mining could harm tuna and other organisms, such as Pacific leatherback turtles (Dermochelys coriacea).Plumes of sediment stirred up by mining could contaminate sea water and damage fishes’ gills and filter-feeding apparatus, says Amon. The same problems could occur when mining waste is thrown back into the water. Furthermore, noise from the mining operations could alter the tunas’ feeding and reproductive behavior, she adds.“Deep-sea mining will potentially have impacts from the sea surface right down to the sea floor,” says Amon.Is deep-sea mining more damaging than mining for these minerals on land?Proponents of deep-sea mining, such as The Metals Company, a mining start-up based in Vancouver, Canada, that is seeking permission to harvest metals on the sea floor, argue that deep-sea mining will benefit the environment by helping the shift to a green economy. They also argue that sediment plumes’ effects can be minimized and that mining contractors don’t currently propose to release waste from exploiting mineral-rich sea floor deposits called polymetallic nodules.Amon says that deep-sea mining is unlikely to replace terrestrial mining, so comparing one with the other is not helpful. “Both will proceed, and we’ll see double destruction in two different parts of the planet,” she says.Washburn says that deep-sea mining might cause less direct damage to people than does terrestrial mining. But by spoiling huge swathes of the sea floor, it could disrupt marine processes such as carbon sequestration, which helps to offset humans’ greenhouse gas emissions.“I don’t think anybody has enough information to say which one is better or worse,” he says.What are the key questions that still need to be answered?Scientists first need to know more about what lives in the deep ocean, says Amon. Then they can begin to investigate how extensive mining can be before it causes serious harm to key ecosystem functions, such as the ocean’s ability to sequester carbon. The challenge, she says, is that deep-ocean science is slow and expensive, and scientists need more time and money to understand mining’s consequences.
    Electric cars and batteries: how will the world produce enough?
    Matthew Gianni, co-founder of the Deep-Sea Conservation Coalition, a conservation group based in Amsterdam, says that deep-sea mining could become unnecessary thanks to advances in recycling and the advent of batteries that use iron and phosphate instead of nickel and cobalt. Furthermore, improvements in environmental standards for terrestrial mining will lessen the industry’s ecological damage.Washburn, who started his career studying ecological disasters such as 2010’s Deepwater Horizon oil spill, is buoyed by the efforts to assess potential impacts before the mining operations begin. Historically, humanity tends to act first and consider the consequences later, he says.“We’re actually trying to figure it out beforehand so that’s a pretty good place to be,” he says. More

  • in

    Oceans are turning greener due to climate change

    Phytoplankton bloom off the coast of France in 2004. The greener ocean colour over the past 20 years might be related to increased phytoplankton activity.Credit: NASA/AFP via Getty

    More than half of the world’s oceans have become greener in the past 20 years, probably because of global warming. The discovery, reported today in Nature1, is surprising because scientists thought they would need many more years of data before they could spot signs of climate change in the colour of the oceans.“We are affecting the ecosystem in a way that we haven’t seen before,” says lead author B. B. Cael, an ocean and climate scientist at the National Oceanography Centre in Southampton, UK.The ocean can change colour for many reasons, such as when nutrients well up from its depths and feed enormous blooms of phytoplankton, which contain the green pigment chlorophyll. By studying the wavelengths of sunlight reflected off the ocean’s surface, scientists can estimate how much chlorophyll there is and thus how many living organisms such as phytoplankton and algae are present. In theory, biological productivity should change as ocean waters become warmer with climate change.But the amount of chlorophyll in surface waters can vary markedly from year to year, making it hard to differentiate any changes induced by climate change from the big natural swings. Scientists thought it might take up to 40 years of observations to spot any trends2.Another complicating factor is that numerous satellites have measured ocean colour over time, and each did so in a slightly different way, so the data cannot be combined. Cael’s team decided to analyse data from MODIS, a sensor aboard NASA’s Aqua satellite, which was launched in 2002 and is still orbiting Earth, far surpassing its anticipated six-year lifetime. The researchers looked for trends in seven different wavelengths of light from the ocean, rather than sticking with the single wavelength used to track the often-used single measure of chlorophyll. “I’ve thought for a long time that we could do better by looking at the full colour spectrum,” Cael says.With two decades of MODIS data, the scientists were able to see long-term changes in ocean colour. They observed notable shifts in 56% of the world’s ocean surface, mostly in the waters between the latitudes of 40º S and 40º N. These tropical and subtropical waters generally don’t vary much in colour throughout the year, because the regions don’t experience extreme seasons — and so small long-term changes are more apparent there, Cael says.The intensity of the colour change depends on the wavelength of light measured. In general, the waters are becoming greener over time.To see if the shifts could be linked to climate change, the researchers compared the observations to the results of a model3 that simulated how marine ecosystems might respond to increasing levels of greenhouse gases in the atmosphere. The observed changes matched those in the model.Shades of greenNow, the question is what is turning the oceans greener. It’s probably not a direct effect of increasing sea surface temperatures, Cael says, because the areas where colour change was observed do not match up with those where temperatures have generally risen. One possibility is that the shift might have something to do with how nutrients are distributed in the ocean. As surface waters warm, the upper layers of the ocean become more stratified, making it harder for nutrients to rise to the surface. When there are fewer nutrients, smaller phytoplankton are better at surviving than larger ones, and so changes in nutrient levels could lead to changes in the ecosystem that are reflected in changes in the water’s overall colour.But this is just one idea; the researchers can’t yet say exactly why the changes are happening. “The reason we care about the colour is because the colour tells us something about what’s happening in the ecosystem,” Cael says.The discovery ramps up expectations for the next big mission to monitor ocean colour — NASA’s Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) satellite. Set to launch in January 2024, PACE will measure ocean colour in many more wavelengths than any previous satellite, a capability known as ‘hyperspectral’.“All of this definitely confirms the need for global hyperspectral missions such as PACE,” says Ivona Cetinić, an oceanographer at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who works on PACE. The spacecraft “should allow us to understand the ecological implications of the observed trends in ocean ecosystem structure in years to come.” More

  • in

    A sustainable way to control the parasitic disease schistosomiasis

    Schistosomiasis, one of the most common human parasitic diseases, is a global menace because of its high rates of infection and contribution to poverty. Over the past two decades, global campaigns using antiparasitic medication have been carried out to combat the scourge of the disease. In 2022, the World Health Organization released guidelines1 to further expand the scale of these mass-treatment campaigns, with the goal of eliminating schistosomiasis as a public-health problem by 2030. Although this strategy has yielded clear public-health benefits2, the following key question remains: what solutions can be devised to further combat schistosomiasis and forge a sustainable future? Writing in Nature, Rohr et al.3 identify an innovative and transdisciplinary solution to reduce cases of schistosomiasis.
    Competing Interests
    N.C.L. reports personal fees from the World Health Organization related to work on public-health guidelines for schistosomiasis. More