Massive marine heat wave caused Caribbean coral reefs to collapse much faster than predicted
For decades, coral reefs throughout the Caribbean have been suffering from disease, pollution, overfishing and rising sea temperatures, yet most have continued to grow—until now.
In 2023 and 2024, surface temperatures climbed to record highs in the world's oceans, and a marine heat wave of unprecedented length and intensity spread across the tropics. Satellites from the US National Oceanic and Atmospheric Administration detected heat stress that could cause corals to bleach across more than 80% of the planet's reef areas.
During these periods of extreme stress, corals expel the symbiotic algae that give them their color and most of their food—turning them stark white and leaving them vulnerable to starvation, diseases and eventually death.
Across the North Atlantic, including the Caribbean, the heat stayed for months, with heat stress two-to-three times higher than reefs had ever experienced. Heat stress, the phenomena of high temperatures putting fragile ecosystems under pressure, can permanently alter their ability to function.
This triggered what is now recognized as the fourth global coral bleaching event, the most severe one that has been documented.
Coral reefs are among the most productive ecosystems on Earth, and their importance to people is fundamental. They feed hundreds of millions through small-scale fisheries, underpin tourism across the Caribbean, and serve as natural breakwaters that protect the coast from storms and reduce flooding events.
Caribbean reefs are eroding fast
In a new study, we found that across the Caribbean, the 2023 marine heat wave—combined with a deadly disease known as stony coral tissue loss disease—has pushed reefs over a threshold scientists thought was a decade or more away. They are now eroding faster than corals can rebuild them.
We studied reefs in the Mexican Caribbean and the Gulf of Mexico, comparing data collected before the heat wave (2018–2022) with surveys after it (2023–24). At each reef, we counted live corals and organisms that break down the reef, like parrotfish and sea urchins. From those counts, we estimated how much reef-building (carbonate production) and reef-breaking (bioerosion) was happening, then calculated the net result—whether the reef was gaining or losing material.
The results were stark: between 70% and 75% of our Caribbean sites had tipped from net growth into net erosion. They are now losing calcium carbonate faster than corals can add it. The threshold that earlier models had suggested might be crossed over during the next decade or so has already arrived.
This shift was driven by the loss of fast‑growing, branching and plate‑forming corals, especially the Acropora species, which have very high growth rates and disproportionately contribute to reef building.
One of our most unsettling findings is that the Caribbean reef sites that still had high coral cover and high carbonate production before the disease and heat wave were the ones that lost the most. Some lost up to 8 kilograms of calcium carbonate per square meter per year.
A tale of two seas
Our survey also revealed a striking contrast. While Caribbean reefs collapsed, reefs in the Gulf of Mexico largely held their ground. The great majority of Gulf sites remained net positive after the heat wave.
The difference comes down to which corals are pre-eminent in each region. In the Gulf of Mexico, reefs are dominated by slow-growing, mound-shaped corals. They grow more slowly, but they are tougher when the heat kicks in. They bleached during the heat wave but mostly survived, keeping the reef's carbonate budget positive.
This is the balance between the constructing and eroding processes. When more is added than removed, the coral reef can grow. When that balance flips, the reef stops growing and may even erode.
Moreover, sites in the Gulf of Mexico have not yet been affected by stony coral tissue loss disease, which preferentially kills the same massive, long-lived species that are keeping Gulf reefs alive. By the time the heat arrived, large parts of the Caribbean had already lost their most resilient corals because of the disease outbreak. When started, the heat wave finished.
Why reef erosion matters
All the benefits reefs provide rely on a delicate balance between reef construction and erosion.
Tropical reefs are essentially vast limestone structures, built slowly over centuries as corals deposit calcium carbonate skeletons. At the same time, waves and various reef organisms like parrotfish, sea urchins and boring sponges chip away at them.
An eroding, flattening reef begins to lose its capacity to provide benefits to other species and people.
We did not expect to be documenting the moment at which a major region of the ocean crossed from growing to eroding. The fact that it happened this quickly, and at some of the most iconic and well-studied reefs in the Caribbean, suggests the timelines scientists have been using may be too optimistic.
Our findings may also force a rethink of how to approach coral restoration. Programs across the Caribbean have invested heavily in replanting fast-growing branching species of coral, such as Acropora, because they rebuild structural complexity quickly. The 2023–24 heat wave wiped out many of these restored populations, along with wild ones.
Restoration will have to diversify. Exploring approaches such as moving heat-tolerant genes between populations (assisted gene flow) and breeding corals that survive heat better (selective breeding) might be a promising path.
But restoration alone will not be enough. Reversing the decline requires rapid cuts in greenhouse gas emissions to slow the frequency and intensity of marine heat waves, alongside serious local action on pollution, nutrient runoff, sedimentation and disease—the stressors that weaken corals before the heat arrives.
Europe's seafloor fishing looks profitable until societal costs turn the math upside down
Credit: Pixabay/CC0 Public Domain
The first study to measure the full economic value of bottom trawling in Europe's waters calculates that the destructive fishing practice imposes up to €16 billion annually in net costs to society. The research is published in the journal Ocean & Coastal Management.
Pooling data from more than 4,900 European-flagged bottom trawlers—together spending more than 5.5 million hours fishing on average each year in the waters of the European Union, the UK, Norway and Iceland—the research demonstrates that atmospheric carbon dioxide (CO2) emissions from disturbed seafloor sediments are a major contributor to these costs. The study concludes that the net costs of bottom trawling to society are 90 times greater than the €180 million in profits raked in by the fishing industry each year.
"Our study makes it clear that bottom trawling in European waters is not just an environmental disaster, it's an economic failure," said Professor Enric Sala, National Geographic Explorer in Residence and one of the authors of the study, titled "The value of bottom trawling in Europe."
"The bottom trawling fleet is decimating marine life in Europe's marine protected areas, from the North Atlantic to the Mediterranean. While we ultimately need to reduce bottom trawling across Europe's waters to unlock societal benefits, banning it in protected areas is a critical first step—a win for the climate, the ocean and even the fishing industry itself," Sala continued.
The study comes as experts and advocates increase pressure on government and industry leaders across Europe to ban bottom trawling, especially in MPAs set aside for safeguarding marine ecosystems. The industrial fishing practice, which involves dragging heavy nets—some as large as twelve Boeing 747s—tears up the seafloor, sweeping up a stunning amount of unintended species, called bycatch.
Earlier research finds that globally, the churning of seafloor sediment by bottom trawling is responsible for injecting up to 370 million metric tons of carbon dioxide into the atmosphere every year. The new study suggests that nearly a third of this (112 million metric tons) is coming from European-flagged trawlers.
"Not all big is bad, nor all small beautiful, but where there is clear evidence that the economic and/or environmental costs of larger-scale mobile fishing gears outweigh any societal benefits from harvesting the resource, then it is right that alternatives are found and such operations are phased out," remarked Jerry Percy, Sr. Advisor to the Low Impact Fishers of Europe (LIFE). "Small-scale fishers in Europe, on the other hand, prove every single day that we can feed communities by catching fish sustainably—without disturbing spawning grounds or kicking up carbon."
This study calculates that 23% of the continent's bottom trawling effort (in terms of hours spent fishing) takes place in MPAs across the area studied. Authors found that the figures vary by country, with more than a quarter of the annual trawling effort in the EEZs of Belgium, Bulgaria, France, Germany, Netherlands, Romania and Spain occurring in MPAs.
Bottom trawling's impacts on marine life in the region's 6,000 MPAs encompassing 900,000 square kilometers (347,492 square miles) are well documented.
A recent study shows that populations of sharks, rays and skates were more plentiful outside the boundaries of MPAs than within the MPAs. Bottom trawling in MPAs undercuts the role these marine reserves play in replenishing fish populations outside their borders, called spillover. The work catalogued more than 3,000 fish species caught in bottom trawls globally, including endangered animals. The impact on ecosystems of so many species being removed from the ocean is not yet fully understood, but it is likely to be highly negative.
The costs of bottom trawling dwarf industry revenue
Researchers analyzed bottom trawling efforts in European waters between 2016 and 2021, then compared its benefits (fishing revenue, protein supply and jobs) to its costs (fuel and labor, discarded fish, subsidies and carbon emissions), finding that the costs of bottom trawling far outweigh its benefits. While net benefits to the fishing industry alone are positive (estimated at €180 million annually), the net benefit to society is negative on the order of €2.25 billion to €16.15 billion (the range reflects the different valuations of the social cost of a ton of CO2 emitted into the air).
The largest single cost of trawling European waters is the social cost of CO2 emissions—an estimate of the future economic damage caused by climate change impacts, including sea level rise and declining labor productivity and human health. The study estimates two CO2 costs associated with bottom trawling: emissions from burning fuel (gasoline or diesel) and emissions from disturbance to carbon on the sea floor.
"Bottom trawl gear scrapes up the seafloor, releasing carbon that's been stored in the ocean seabed for centuries," said Kat Millage, marine researcher for National Geographic Pristine Seas and lead author on the study. "It is clear that the magnitude of emissions from trawling are substantial. Even when we use a very conservative estimate of the social cost per metric ton of emitted CO2, society is left bearing a heavy economic burden."
Beyond carbon, the study identified a series of additional costs stemming from bottom trawling.
- Subsidies: The new research found a significant cost to European taxpayers through subsidies. European governments spend an estimated €1.17 billion on bottom trawling to offset the price of fuel and other costs in the name of food and job security. However, without these subsidies, bottom trawling activity would be unprofitable for some nations, including Belgium, Spain, Great Britain, Portugal and Romania.
- Food waste: The costs of food waste stemming from bottom trawling are massive. Up to 75% of the marine life caught up in bottom trawling nets die and are discarded back into the ocean, valued at €220 million every year. Discarded animals include unwanted juvenile fish, low-value fish, bottom-dwelling sharks like catsharks and dogfish, rays and skates—as well as sponges, sea squirts, sea stars, corals and sea pens.
- Fuel: Bottom trawling vessels require massive amounts of fuel to drag heavy nets across the seafloor. Norway and Iceland spend the most on fuel. At least half the Dutch fleet stayed in port at the end of March 2026 because of soaring diesel costs amid the Iran crisis, demonstrating the tenuous economic viability of bottom trawling.
Fisheries' benefits are often limited to the revenue generated by the fishing industry. For this study, researchers also quantified some of the social benefits:
- Protein: Ultimately, bottom trawling only provides 2% of the animal protein consumed in all of Europe. This provides an estimated social value of €2.46 billion per year.
- Jobs: Bottom trawlers directly employ less than 20,000 people in Europe, providing a social benefit of approximately €1.78 billion per year. For comparison, small-scale fisheries in Europe generate approximately three times more jobs than industrial bottom trawlers.
"The results of our study suggest that cost-benefit analyses used in marine policy evaluations need to move beyond narrow market metrics and embrace the full scope of economic theory on valuation if they are to capture the full consequences of destructive fishing gears such as bottom trawling," remarked Rashid Sumaila, Ocean and Fisheries Economist at the University of British Columbia and co-author of the report.
The researchers could not quantify the economic cost of the ecological damage inflicted on the ocean by bottom trawling (arising from reductions in habitat complexity, permanent changes in the composition of seabed communities and reduced productivity) nor the cost to other fisheries (arising from bycatch). However, a 2024 paper shows remarkable recovery of marine life in areas after banning bottom trawling, including a 95% increase in reef species and a 400% increase in juvenile lobsters.
Reducing bottom trawling makes economic and environmental sense
In the study, the researchers simulated how changes to the bottom trawling effort could impact the balance between costs and benefits. They concluded that reducing bottom trawling activity across Europe by just over half could increase overall benefits. Such a reduction would help restore Europe's overfished seas, avoid large carbon dioxide emissions, and maximize food production by making European fishing more sustainable. The subsidies currently used to support bottom trawling could be directed towards the industry's transition to less damaging practices.
"Ending bottom trawling in Europe's marine protected areas is essential for saving billions in public costs," said Professor Sala. "This move will save taxpayers money, protect marine life, boost the fishing industry and help us reduce global warming. If European governments were to direct just a fraction of the current fisheries' subsidies to help the industry transition away from bottom trawling, society and marine life would win out."
European leaders have already taken steps to ban bottom trawling. In April 2024, Greek Prime Minister Kyriakos Mitsotakis announced his commitment to ban bottom trawling in Greek MPAs by 2030; Sweden followed two months later. The European Commission's action plan calls for "gradually phasing out bottom fishing in all MPAs by 2030, in view of their key role in restoration of marine biodiversity and the importance of the seabed for healthy marine ecosystems and climate change mitigation."
"Βy moving to phase out bottom trawling across all Greek Marine Protected Areas (MPAs), Greece is taking decisive action to restore marine ecosystems, support sustainable fisheries and safeguard the long-term health of our seas," noted Prime Minister Mitsotakis. "It is the most effective way to implement the two major Marine Parks in the Aegean and Ionian Seas, bringing Greece closer to exceeding the 30x30 target."
"Banning bottom trawling in all Greek MPAs would represent a transformative step in safeguarding Posidonia seagrass beds and other vulnerable habitats, enhance carbon sequestration, support the rapid recovery of fish stocks and generate positive spillover effects into surrounding waters," added Mitsotakis. "In doing so, it would serve both biodiversity conservation and the long-term interests of fishers and local communities, strengthening the resilience and sustainability of the blue economy in Greece's coastal regions."
An Atlantic Forest treefrog, Aplastodiscus leucopygius, at the edge of a rocky forest stream in Brazil's Atlantic Forest, transitioning between aquatic and terrestrial environments. New research led by Penn State biologists found that amphibians in connected natural forests and aquatic habitats were more likely to host beneficial skin microbes that inhibit a deadly fungal pathogen. Credit: Shannon Buttimer, Penn State
Maintaining connections between natural habitats may support beneficial microbes that help wildlife defend against disease. In a new study of tropical amphibians, a team led by Penn State biologists found that amphibians in connected natural forests and aquatic habitats were more likely to host beneficial skin microbes that inhibit a deadly fungal pathogen. But when these habitats become spatially separated due to planted crops, infrastructure development or other human land use, those microbial defenses weaken and pathogen infection levels can increase with potentially deadly results.
The findings, published in the journal Proceedings of the National Academy of Sciences, reveal a previously underappreciated link between landscape connectivity, beneficial microbes and disease resistance in wildlife, according to the researchers.
"Animals rely not only on their immune systems, but also on beneficial microbes that live on their bodies and help protect them from pathogens," said Gui Becker, associate professor of biology in the Eberly College of Science at Penn State and senior author of the study.
"Our results show that when natural habitats become disconnected, these microbial defenses can be disrupted."
The researchers explained that habitat loss and fragmentation are widely recognized as major drivers of biodiversity decline, but scientists are increasingly realizing that environmental change can also alter the microbiome—the community of microbes that live in and on animals and often play key roles in health and immunity.
A fragmented rainforest landscape in Brazil's Atlantic Forest. Credit: Renato Martins
"Our study provides evidence that connectivity among habitats is essential for maintaining multiple levels of biodiversity, from host-associated bacteria with protective functions to their respective host species," said first author Daniel Medina, previously a postdoctoral scholar in Becker's lab at Penn State and currently a lecturer in tropical forest ecology and resource management at The School for Field Studies.
"It highlights a critical link between environmental disturbance, microbial defenses and disease dynamics."
To investigate the connection between habitat fragmentation and animal microbiomes, the researchers studied amphibian populations in Brazil's Atlantic Forest, a biodiversity hotspot that has experienced extensive habitat alteration. Many amphibians depend on both forest habitats and aquatic breeding sites, requiring them to move between these environments during different stages of their life cycle.
The researchers focused on a phenomenon that Becker—a member of the Penn State One Health Microbiome Center—previously coined as "habitat split," where natural forests and aquatic habitats become separated by agriculture, development or other land uses.
Across multiple frog species—collected from 40 sampling sites during the amphibian breeding season—the team found that animals living in landscapes with higher habitat split hosted fewer bacteria known to inhibit the deadly fungus, Batrachochytrium dendrobatidis, which has caused dramatic amphibian declines worldwide. In some species, infection levels of the fungus also increased as habitat split intensified.
"We showed such a link by indicating that spatial separation between critical habitats, such as natural forests and aquatic breeding sites, may impair amphibians' ability to recruit protective skin bacteria that defend against the fungus," Medina said.
Becker Lab researchers conducting fieldwork in Brazil's Atlantic forest. Credit: Augusto Gomes / João Marcos Rosa
The researchers propose that in intact landscapes, animals regularly encounter both environmental microbes and low levels of pathogens, which may help maintain microbial communities capable of suppressing disease. When natural habitats become disconnected, those ecological interactions can break down.
Although the study focused on amphibians, the researchers said the findings could extend to many other animals that depend on multiple habitats throughout their life cycles.
"These results suggest that connected landscapes allow animals to maintain microbiomes that are better equipped to fight pathogens," Becker said.
"Many species—from migratory birds to fish and large mammals—move among different habitats as they feed, breed or disperse. When those habitats become disconnected, it may not only affect movement but also alter how animals interact with beneficial microbes and pathogens."
Tropical treefrog Boana faber along an Atlantic Forest stream. Credit: Augusto Gomes / João Marcos Rosa
Restoring and maintaining ecological connectivity between multiple classes of natural environments could serve as a critical strategy not only for fostering genetic diversity in wildlife populations but also for supporting the natural microbial defenses that help them resist disease.
This could include habitat restoration strategies such as protecting riparian zones—vegetation-rich areas at the edges of bodies of water—and reconnecting riparian habitats to larger areas of natural terrestrial vegetation, according to Becker.
"Protecting habitat connectivity may help preserve multiple layers of biodiversity, from the animals we see to the microbial communities that help keep them healthy," Becker said.
The new amphibian species, with the scientific name Gastrotheca mittaliiti, measures 2.7 to 3.3 centimeters (1 to 1.3 inches).
Scientists have discovered a new species of miniature marsupial frog in the Peruvian Amazon that carries its young in a natural pouch on its back, a research institute reported Wednesday.
The new amphibian species, with the scientific name Gastrotheca mittaliiti, measures 2.7 to 3.3 centimeters (1 to 1.3 inches) and was discovered in a mountainous ecosystem in the Amazonas region bordering Ecuador.
The frog is bright green and has small protuberances on its back. The number of specimens in the wild is not known.
Its pouch enables the marsupial frog to nurture its young rather than, as other frogs, rely on aquatic environments for egg development.
The study says the amphibian is at "high risk" because its habitat is suffering the effects of climate change and the impact of fires started by farmers clearing the region.
"This is further evidence of the enormous natural wealth we possess... If we continue our research, there are many species still waiting to be discovered," Manuel Oliva, director of the Ceja de Selva Research Institute for Sustainable Development, part of the Toribio Rodriguez de Mendoza National University, told AFP.
The discovery was published in the New Zealand scientific journal Zootaxa and undertaken in collaboration with research departments at Florida International University and the University of Seville in Spain.
Desert Rain Frog, Breviceps macrops. Credit: Keir and Alouise Lynch, CC BY-NC-ND
Why are frogs diverse in some parts of Africa's rainforests and less so in others? The patterns of cooling and glaciation during the last ice age would probably not have been your first answer or even your last-ditch guess, but it is, nonetheless, correct.
"When the glaciers were at their maximum global extent, the earth's climate was cooler and drier, and forests that are continuous today contracted to what were essentially islands in a sea of savannah," said Gregory Jongsma, the acting curator of Zoology at the New Brunswick Museum.
Jongsma is the lead author of a new study, conducted by researchers at the Florida Museum of Natural History and published in the journal Ecology and Evolution, which shows that even though it's been 12,000 years since the last ice age, tropical African frogs still haven't forgotten about it.
The study specifically focuses on the Lower Guinean Forests of Central Africa, part of what's better known as the Guineo-Congolian rainforest or, more simply, the Congo. Centered around 0 degrees latitude, these forests are a visual representation of the planet's obliquely unequal heating by the sun, which wrings water from the atmosphere like a damp rag onto the equator, creating a humid belt of jungle prominently bookended by deserts.
"I became obsessed with this area of the world, and Gabon specifically, around the age of 10," Jongsma said. "I read a series of National Geographic articles about this individual named Mike Fay doing what was called a mega transect, where he walked from the Republic of Congo west across Gabon."
Afrobatrachian frogs account for roughly half of all frog diversity in Africa, and their modern distribution is significantly influenced by a global climate event that ended 12,000 years ago. Credit: Gregory Jongsma
Fay was a conservationist who made the 2,000-mile, cross-jungle trek wearing sandals and shorts, his blistered feet regularly coated in iodine and laminated in duct tape to stave off infection. He and his crew bushwhacked their way through trailless forest until they reached the Atlantic Ocean, 456 days after they'd started. He undertook the trip to record biological data and stopped frequently to do things like identify the seeds embedded in elephant dung, count gorillas and chimpanzees, and take video recordings of anything that moved, slapping away the maddeningly insistent mosquitoes and tsetse flies all the while.
"So Gabon became enlarged in my brain at a young age, which worked out really well, because it's an incredibly interesting part of the world from the standpoint of an evolutionary biologist," Jongsma said.
Documenting biodiversity is the first, most essential step toward understanding how species in a given area have evolved and why their ecologies look and function in a particular way. Scientists have learned a lot about the diversity of Africa's rainforests since the time of Mike Fay, to the extent that they can now answer some of these higher-order questions.
Jongsma's specialty is frogs. For several years, while working on a doctoral degree at the Florida Museum of Natural History, he'd frequently travel to Central Africa to tick off the miles on his own Fay-esque expeditions in Cameroon, Uganda, Angola, the Republic of Congo and Gabon, collecting frogs along the way.
Slowly, he began to notice a pattern. Some lowland forests that seemed perfectly suitable for frogs strangely supported less diversity than others. Additionally, endemic species—those that live in a restricted area defined by geographic or cultural borders—were mostly clumped together in what appeared to be random spots in Cameroon and Equatorial Guinea.
Back in Florida, Jongsma looked to see whether environmental conditions in central sub-Saharan Africa could explain the distributions he'd seen.
Hyperolius ocellatus. Credit: Gregory Jongsma
African frog clade under the microscope
He narrowed his focus to frogs in the clade Afrobatrachia, a group that study co-author David Blackburn, curator of herpetology at the Florida Museum, has studied since his own days as a graduate student doing fieldwork in Central Africa.
Afrobatrachia was ideal for answering this sort of question for several reasons, not least of which because it accounts for more than half of all frog diversity on the entire African continent. And although species in this group were once thought to be distantly related to each other, with geographic origins in multiple parts of the world, work done by Blackburn and others has shown that it's actually a tight-knit clade that evolved in and is endemic to Africa.
It includes the rainfrogs, known for their visual and auditory similarity to an angrily deflating balloon. It also includes the hairy frog, which has long, hair-like structures protruding from its abdomen and internal claws that it can only deploy against adversaries by breaking its fingers and pushing the claws out through its skin.
Most importantly for this study, there are species in Afrobatrachia that are specialized to live in all sorts of forest environments. Some live in the canopy, others in burrows. Some prefer the more typical pond or stream habitat, while others have evolved a degree of independence from water by skipping the tadpole stage of their lifecycle and laying eggs that hatch into fully assembled frogs.
The environmental conditions most closely associated with frog diversity were sure to be discernible in this ecologically varied group.
The Guinea snout-burrower, Hemisus guineensis. Credit: Gregory Jongsma
Testing present versus past conditions
The next thing to consider was whether the distribution of frogs aligned most closely with current or historical conditions.
"There are two competing hypotheses when predicting diversity," he said. "The ecological hypothesis says species are essentially in equilibrium with current conditions. Therefore, if there's high rainfall and temperature or productivity, you're going to have high diversity."
This was true in some of the areas he'd been to, but the seemingly suitable lowland forests that maintained less frog diversity were just as hot and wet as the others. Current environmental conditions similarly did nothing to explain why endemics showed up where they did.
So Jongsma moved on to the alternative hypothesis.
"In the evolutionary camp, you'd say it's the past conditions that have the largest impact on current-day diversity."
Scientists infer the climatic conditions of past environments using multiple lines of evidence, including the composition of greenhouse gases trapped in the air bubbles of ancient glaciers, the types of plants that grew in a given time period based on spores and pollen preserved in lake sediments, and the ratio of oxygen isotopes in the fossils of marine protists. This type of data has been collected and compiled for several decades and is easily accessible to anyone attempting to reconstruct general patterns of temperature and rainfall on Earth over the past few million years.
The authors created a 2.58 million-year historical climate map for Central Africa, but the resolution wasn't fine enough to track the distribution of frogs. Earth's complicated topography creates atmospheric currents and eddies as air flows over it, and these local patterns become increasingly hard to measure and predict as climate changes drastically on a global scale, as notably occurred during the last ice age.
Hyperolius ocellatus. Credit: Gregory Jongsma
Modeling frog niches through time
The authors needed another variable in the mix to determine whether historical conditions in sub-Saharan Africa were responsible for the modern diversity of frogs.
So, naturally, they added more information about frogs! This time Jongsma chose ten abundant species that were not in Afrobatrachia, for which he created niche models.
"They're common, widespread, and largely co-distributed, so there's enough data there to build a really robust model of their distribution," he said.
The extra step of modeling their distributions meant they could tie modern rainfall and temperature to the presence or absence of a frog species in a particular area, then hindcast back through time to see whether the general diversity of Afrobatrachian frogs would have been high or low in an environment based on the historical climate data.
Having done this, the authors used their analyses to peer into the past and compare what they observed to what exists now.
Ice age refuges shape diversity
For the most part, the Congo rainforest remained stable throughout the Pleistocene ice ages. But as Earth's climate cooled and dried, the Congo's forest borders receded in some places, creating pockets of more or less stable forested areas called refugia. The name comes from the idea that when the global climate rapidly warms or cools, environments that remain stable offer a refuge to species that are otherwise displaced in areas that undergo significant change.
According to the study's results, the ancient forest refugia in Central Africa aligned with the modern diversity of frogs. They are also closely aligned with the small distributions of endemic species.
There are two main reasons why refugia may harbor more diversity than surrounding areas, even after they've ceased to be a refuge.
The first is a sort of lag effect. As suitable environments contract during climate change, species crowd into refugia, and when environments expand again, they fan out. But this doesn't happen automatically. Though the 12,000 years since the last ice age seems like a long time to humans, who live on the order of decades, it's hardly even worth mentioning on the vast scale of geological processes on which evolution and migration operate. It's possible, therefore, that frogs simply haven't had enough time to even out their distributions since the last cold snap.
Secondly, the isolation that's inherent to living in a refugia does funny things to species. Most notably, it makes more of them.
"Refugia have been proposed as species pumps," Jongsma said.
In this case, explained Blackburn, that might look like a frog that once had a wide distribution throughout much of the historic Congo. As the forest was partitioned by climate change, this one big population of frogs would have become several smaller populations, all isolated from each other. If this went on long enough, these populations would eventually evolve into new species. Refugia tend to have higher rates of diversity as a result.
Conservation lessons from ancient patterns
Additionally, while some species expand back out into their former ranges when the climate reverses course, others stay put for one reason or another, which explains the higher rate of endemism in refugia.
The results have implications far beyond the interests of frog enthusiasts.
"All of the countries where this study was conducted have signed on to the 30X30 goal, which is an initiative to conserve 30% of their country's land area by 2030," Jongsma said. "If you're going to expand a protected area or create a new one, considering where forests have been most stable might be an important consideration, depending on what you're trying to conserve."
Additional co-authors of the study are Narayana Barve of the Florida Museum of Natural History; Julie Allen of Virginia Tech; and Hannah Owens of the University of Florida.
Publication details
Gregory F. M. Jongsma et al, Pleistocene Forest Stability Predicts Patterns of Frog Diversity in Central Africa, Ecology and Evolution (2026). DOI: 10.1002/ece3.73207
Journal information: Ecology and Evolution
Live holotype of Nymphargus dajomesae sp. nov. QCAZ-A 68586. (A) dorsal view, (B) ventral view, (C) Frontal view and (D) lateral view. Photos by BIOWEB-Museo QCAZ-A archive. Credit: Masache-Sarango et al., 2026, PLOS One, CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/)
Researchers have discovered a new species of glassfrog in Ecuador—the Dajomes glassfrog—named after Neisi Dajomes, the first Ecuadorian woman to receive an Olympic gold medal, which she won in Tokyo 2020 in women's 76 kg weightlifting. Mylena Masache, a Biology student of the Pontificia Universidad Católica del Ecuador, and colleagues describe the frog in a new study published April 8, 2026 in the journal PLOS One.
Glassfrogs are a group of about 167 species of frogs that live in trees in tropical forests in Central and South America. While most glassfrogs are green on top, they get their name from the transparent skin that covers the underside of some species in the group. This see-through skin sometimes reveals their heart and other organs in great detail.
Researchers encountered the Dajomes glassfrog in 2017 and 2018 during biological surveys conducted in El Quimi Nature Reserve, which is located in a mountainous region in southern Ecuador. The new species has uniformly green skin with a pebbly texture across the top of its body. On its underside, it has a white membrane covered in specialized light-reflecting cells that covers its heart, esophagus, stomach and kidneys, but other internal membranes are clear. Based on comparisons of its DNA to related species, Masache's team estimated the new species likely originated during the Pliocene Epoch, about 4.5 million years ago.
Currently it is unknown whether the frog is threatened or endangered. The first Dajomes glassfrog was found just a few miles from an agricultural region and a large-scale mining operation. Mining in the area has caused a decline in local amphibian populations and may threaten this species in the future.
The new species was discovered at a place where many species were unknown to science, a biodiversity hidden world. Credit: PUCE-BIOWEB (CC-BY 4.0, https://creativecommons.org/licenses/by/4.0/)
After fieldwork, genomic samples were analyzed at the molecular laboratories of Pontificia Universidad Católica del Ecuador in Quito. The results demonstrated that the population found represented a new species. Credit: PUCE-BIOWEB (CC-BY 4.0, https://creativecommons.org/licenses/by/4.0/)
Habitat at the type locality, Reserva Biológica El Quimi. (A) Slow-flowing blackwater stream rich in tannins. (B) Surrounding vegetation composed of dense shrubs, bromeliads, and mosses. Credit: Masache-Sarango et al., 2026, PLOS One, CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/)
During the two expeditions to El Quimi Nature Reserve that yielded the Dajomes glassfrog, more than 85% of the amphibian species observed were previously unknown. The researchers suggest this region could be a "lost world of amphibian diversity," and call for continuing biodiversity surveys and species identification efforts in southeastern Ecuador and across the border in northeastern Peru.
The authors add, "We were astonished by the high number of new species found at the site. Few places in the tropical Andes harbor amphibian assemblages as novel as the one found at El Quimi."
Author Dr. Diego Cisneros adds, "It is especially meaningful that this discovery is led by a young woman scientist and honors an Ecuadorian Olympic champion—this species becomes a symbol of how science and society can recognize and celebrate women shaping the future."
- A scientist who was part of a major 2008 expedition exploring the promise of deep-sea mining writes in a new analysis that what they found offshore of Papua New Guinea ended his enthusiasm for the nascent industry.
- The biodiversity documented by their remotely operated vehicle — added to the fragility and uniqueness of the geology and ecology they documented — was clearly too special to perhaps permanently decimate for electric vehicles and renewable energy.
- “I entered this project in good faith, working with the mining company to help determine whether or not deep-sea mining at Solwara I could be conducted with minimal harm to the marine environment. I exited convinced that there is no viable path forward for hydrothermal vent mining, anywhere in the ocean.”
- This article is an analysis. The views expressed are those of the author, not necessarily of Mongabay.
When I set sail on the MV NorSky in the summer of 2008 to probe the depths of Manus Basin off the coast of Papua New Guinea, I believed in the promise of deep-sea mining. As an early-career deep-sea ecologist, I was swayed by arguments in favor of this emerging industry. It offered a new way to obtain the metals needed for the renewable energy revolution, one allegedly free of the human rights and environmental abuses of terrestrial mining. The company was Nautilus Minerals, and the plan was to mine an active hydrothermal vent field called Solwara I.
What is a hydrothermal vent and why would anyone want to mine one? When seawater is drawn down into the earth and heated under enormous pressure, it rises through cracks in the crust, erupting from the seafloor in metal-rich plumes. Those metals are deposited on the walls of a growing chimney. Deep-sea miners call this structure a seafloor massive sulfide. They can be rich in gold and silver, as well as copper, zinc, lead and rare earth elements.
By most estimates, Solwara I is among the most valuable seafloor massive sulfides ever discovered. And it is not only rich in metals, it is rich with life.
The dumbo octopus is a species only found in the deep sea. Image courtesy of the NOAA Office of Ocean Exploration and Research.
The communities that grow around hydrothermal vents depend on the chemical energy of the vent plume. The geological process that deposits metals also supports ecosystems found nowhere else in the ocean. These vent fields are rare: the total area of all known hydrothermal vent fields is smaller than the island of Manhattan.
Understanding how these rare communities are connected across oceans is critical to understanding how mining could reshape the deep sea. Which is how I found myself aboard this ship, on an expedition to study the biodiversity and connectivity of hydrothermal vent communities at Solwara I.
Hydrothermal vents can be ephemeral. They turn over to a decadal rhythm, with old vents shutting down and new vents opening as the geological forces driving their formation fluctuate. For Nautilus, the dynamic nature of these vents presented an opportunity. Unusual for a hydrothermal vent field, Solwara I lies immediately beneath an active submerged volcano. The natural dynamics of the site present the possibility that the ecosystems it supports could be resilient to mining impacts. Solwara I already experiences natural disturbance. Perhaps it could endure a little unnatural disturbance, too?
It wasn’t a bad hypothesis, but it needed to be tested.
The first thing you see as you approach the towering edifices of Solwara I are squat lobsters, small crustaceans of the genus Munidopsis that look like hermit crabs pulled from their shells. Startled by the lights and noise of our remotely operated vehicle (ROV), the underwater robot we use to study the deep sea, they would launch themselves into the water column. Legs and claws spread wide, they’d drift back to the seafloor.
Only then do you see the vent plumes, great billowing black clouds. Surrounding these plumes are swarms of pale, eyeless shrimp of the genus Chorocaris. The ROV’s lights reflect off a glittering spot on their carapaces, a sensory organ like an eyespot that senses the black-body radiation (thermal electromagnetic radiation) emitted from the vent. These shrimp can “see” the heat of the hydrothermal plume, allowing them to swim close enough to feed, but not so close to boil.
A squat lobster documented in coral at a depth of 669 meters (almost 2,200 feet) on a seamount. Image courtesy of ROV SuBastian / Schmidt Ocean Institute.
You are guided to the mouth of the vent chimney by a bull’s-eye of biodiversity. Two fist-sized snails dominate the vents of Solwara I: a ghostly white snail with a paper-thin shell covered in long, stiff hairs from the genus Alviniconcha, and an abyss-black snail with a thick, heavy shell, from the genus Ifremeria. Alviniconcha prefers the warm waters immediately around the vent outflow, while Ifremeria likes its home a little cooler. Together, they create concentric rings of snails that encircle the vent.
Closer still, scale worms crawl through crevices. Mussels crowd around small cracks where cooler vent plumes emerge from the seafloor. Limpets cling to the shells of Ifremeria, but avoid the bristles of Alviniconcha. Crabs scuttle across mounds of snails. Octopuses and eelpout fish wind through rocky outcroppings. In the sediment, at the base of the chimney, a predatory snail from the genus Eosipho lies in wait for a hapless Alviniconcha or Ifremeria to fall from their perch at the top of the chimney.
Even around the periphery, and among the so-called inactive areas, where hydrothermal venting has slowed or stopped, strange communities form. Predatory glass sponges that look like lollipops hunt for copepods that drift through their domain. Cold-water corals sprout from rocky outcrops, brittle stars wrapped around them. An octopus broods her eggs. A chimera, a cartilaginous fish in the order Chimaeriformes, drifts slowly past the ROV.
What I learned studying the communities that thrive around Solwara I, as well as hydrothermal vents across the Western Pacific, is that, though these ecosystems are dynamic, they are also deeply interconnected. Those connections are fragile. The impacts from mining would be catastrophic to the communities at Solwara I, and the knock-on effects would threaten surrounding ecosystems.
There is a curious paradox in the deep sea: while most of the seafloor is characterized by exceptional biodiversity and extremely low biomass (there are lots of species, but few individuals of those species), hydrothermal vents tend towards the opposite. Biomass is high. Biodiversity is low.
Not so at Solwara I, which hosts both incredible biodiversity and tremendous biomass. Of all the vent ecosystems in the ocean, the hydrothermal vents of the Western Pacific, including Solwara I, are the most biodiverse.
Alviniconcha snails and Austinograeid crabs around a deep-sea hydrothermal vent in the Northern Mariana Islands. Image courtesy of MARUM, University of Bremen and NOAA-Pacific Marine Environmental Laboratory.
Faith displaced
I entered this project in good faith, working with the mining company to help determine whether or not deep-sea mining at Solwara I could be conducted with minimal harm to the marine environment. I exited convinced that there is no viable path forward for hydrothermal vent mining, anywhere in the ocean. Solwara I may present the best-case scenario for mining a hydrothermal vent, but the best-case scenario is not good enough. Nautilus Minerals thought otherwise, and they applied for the world’s first commercial deep-sea mining permit.
Nautilus Minerals received a commercial permit to mine Solwara I from the government of Papua New Guinea in 2011. Despite clearing the last regulatory hurdle, they were never able to start mining. Unable to secure a ship and reeling from several blows to their business, the company went bankrupt in 2019, its assets auctioned off, its three massive mining robots rusting away in Port Moresby. That same year, in response to both growing pressure across the Pacific and increasing local resistance to the Solwara I project, Papua New Guinea instituted a 10-year moratorium on deep-sea mining within its waters.
Today, the deep ocean off the coasts of Alaska, American Samoa, and the Northern Mariana Islands face a renewed threat from deep-sea mining. Though an early pioneer, the United States has long sat on the sidelines of this developing industry.
Now, under directives from the Trump administration, the Bureau of Ocean Energy Management (BOEM) and the National Oceanic and Atmospheric Administration have begun the process of permitting mining across vast regions of the deep seafloor in both U.S. waters and the high seas, beyond any nation’s borders. While most presume that polymetallic nodules, metal-rich cobblestones scattered across the abyssal plain, are the prime target for this new push to mine the deep, the permitting process under consideration and the executive order that kick-started this process include not just nodules, but hydrothermal vents and metal-rich crusts on seamounts.
Just this month, BOEM released its recommendations for leasing areas of the seabed around the Mariana Trench, doubling the size of the initial proposed area and adding 33 million acres (more than 13 million hectares) of seafloor, on which the only potential significant mineral deposits are locked in hydrothermal vent sulfides.
Potential effects of mining-generated sediment plumes and noise on marine creatures. Image courtesy of Drazen, et al. (2020).
Polymetallic nodule mining promises access to the abundant mineral resources of the abyssal plain, including cobalt, nickel and manganese, with a lighter touch than hydrothermal vent or seamount mining. But nodule mining is not without its own environmental risks.
The nodules are habitat, and removing them from the seafloor threatens the animals that depend on them. The sediment plumes produced by mining tools can spread throughout the water column, threatening seafloor ecosystems as well as commercially important fisheries. With significant research and technological advances, those potential impacts may yet be overcome, but nodule mining is not ready, yet.
There’s an argument that permitting is the only thing holding back deep-sea mining, that with the renewed push from the Trump administration to develop the industry through an expedited permitting process, deep-sea mining is inevitable.
Deep-sea mining is a wickedly challenging endeavor. At full scale, commercial deep-sea mining will be among the most logistically complex offshore operations ever undertaken, with robotic technologies as yet unproven. An expedited permit is no guarantee of success: even in the best-case scenario, with a commercial license in hand and mining tools waiting at the dock, Nautilus Minerals failed.
The deep sea does not offer guarantees, except for this: near limitless potential for discovery.
We have barely begun to explore the deepest places on our planet. Less than a tenth of a percent of the deep seafloor has ever been observed. As researchers, explorers and even miners increase our presence in the deep ocean, we will discover new animals, ecosystems and ecological processes. Some, like hydrothermal vent communities, will be so unlike anything seen before that we lack the necessary biological framework to predict their existence.
See a related Mongabay & CNN investigation: China’s deep-sea mining fleet may also track US submarines
Collage of 24 newly described Amphipod species living in the Clarion-Clipperton Zone of the deep sea. Image courtesy of National Oceanography Centre, Southampton, CC BY.
We’ve found octopuses brooding their offspring and skates laying their eggs in the warm waters of diffuse flow vents, for instance. At a long-inactive hydrothermal vent field, scientists discovered more than 30 new species of snail in communities that endure by living off traces of chemical energy that persist long after the vent stops. In the Indian Ocean, we found another surprising snail, this time with a shell made from iron. When brought to the surface and exposed to air, it begins to rust.
Hydrothermal vent mining has largely — but not entirely — fallen out of favor with the principal companies pushing for the rapid development of the deep-sea mining industry, but this potential for discovery is not limited to seafloor massive sulfides.
In a hadal trench, Chinese scientists uncovered a hitherto undiscovered ecosystem, the deepest animal habitat ever observed. In Pacific nodule fields, researchers delighted in the discovery of a whiplash squid that hides among the cobblestones, waiting to ambush its prey. On ferromanganese crusts on the Rio Grande Rise, Brazilian scientists found vibrant communities built atop cold-water coral reefs. On the Blake Plateau, at the site of the very first experimental deep-sea nodule mine from the early 1970s, U.S. researchers documented a coral reef larger than the state of Vermont. It is the largest cold-water coral reef in the world and it wasn’t discovered until half a century after it was almost dredged by a deep-sea miner. This near miss on the Blake Plateau highlights just how easy it is for enormous ecosystems to go unseen in the deep, even in areas being explored for deep-sea mining.
How will deep-sea mining operations respond to the discovery of something truly novel on the seafloor? Within the first two to three years of a full-scale commercial deep-sea mining operation, we will nearly double the amount of time humans have spent observing the deep seafloor. Within the 30-year operational life of a polymetallic nodule mine, the likelihood of discovery is guaranteed, and not just new species of nematodes or interesting snails, but whole ecosystems and ecological processes, with the potential to fundamentally change our understanding of life on Earth.
A discovery on the scale of hydrothermal vent communities or cold-water coral reefs would mandate an operational full stop, a complete overhaul of any environmental management plan, and years, if not decades, of focused study. When deep-sea mining companies are the only ones with the resources and capacity to monitor these sites, how do we safeguard this potential for discovery?
Discovery is inevitable. The tragedy before us now lies in rushing to exploit the deep sea before we understand what we could lose.
Andrew D. Thaler is a deep-sea ecologist, conservation technologist and ocean educator. He is also a Public Voices Fellow on Technology in the Public Interest with The OpEd Project.
Banner image: A squat lobster in the deep sea. Image by Schmidt Ocean Institute (CC BY-NC-SA 4.0).
Amphibian and reptile conservation is asking residents of the Scottish Solway coast to listen out for the iconic call of Scotland’s rarest amphibian, the natterjack toad.
The natterjack toad (Epidalea calamita) can only be found at a handful of locations in Scotland, all on the Solway coast.
Natterjack numbers have declined dramatically in recent years, largely due to habitat loss caused by sea level rise, coastal erosion, agricultural intensification, urban expansion and commercial forestry. Natterjack breeding habitat – shallow, seasonal pools found near the coast - is especially susceptible to extreme weather events such as prolonged periods of drought or severe winter storms, which are becoming more frequent due to climate change.
The natterjack toad is now Scotland’s rarest amphibian. It is a target species for ‘Species on the Edge’, a partnership programme of NatureScot, ARC, and six other nature charities, all working together to fight the decline of Scotland’s rarest and most vulnerable coastal species.
Through the Species on the Edge programme, action to boost Scotland’s natterjacks is in full swing on the Solway coast. Conservation activity includes habitat creation and enhancement work to address the decline in suitable natterjack breeding and hibernation habitat.
Photo: The distinctive Natterjack Toad—with its bold yellow stripe and unmistakable presence—stands as one of the remarkable species spotlighted by Species on the Edge, a programme dedicated to protecting some of the UK’s rarest wildlife. <Credit: ARC>
As part of this suite of conservation activity, ARC is asking Solway locals to listen out for and report if they hear the natterjack toad. These reports will help ARC assess the impact of ongoing conservation activity and help inform future efforts to support this struggling species.
Male natterjack toads call to attract a mate during the breeding season, which usually starts in April and can run until July. They have a loud, rasping call which can be heard up to 1km away. The toads are most active on warm evenings following periods of heavy rain.
Species on the Edge Project Officer for the Solway Coast, Liam Templeton, said:
“The natterjack toad is truly a 'species on the edge' - in more than one sense. Here in Scotland the natterjack is at the very edge its range; the Solway Coast is the most northerly place on earth you'll find it. And with its coastal habitat now being at almost
constant risk, whether from storms, droughts, or sea level rise, it's future in Scotland is teetering on the brink.
In order to ensure the survival of the natterjack toad on the Solway coast, it's vital we understand how populations are faring. Local residents have a brilliant opportunity to help by reporting any natterjack calls they hear – a simple action that could make a real difference to the future of this rare and much-loved species."
If you hear the natterjack toad, you can let ARC know by sending the date, time and location of where the toad was heard, and, if possible, an audio recording, to sote@arc-trust.org.
For more information on the natterjack toad and how you can get involved in conservation efforts, visit www.speciesontheedge.co.uk/natterjack-toad or www.arc-trust.org.
Meet kungaka—'the hidden one.' This ancient lizard could be the rarest reptile in Australia
Credit: Tom Parkin, CC BY-ND
Hidden among the red sandstone escarpments of Mutawintji National Park in western New South Wales lives a rare lizard, long isolated in this arid landscape.
Known to Wiimpatja Aboriginal Owners as kungaka—"the hidden one"—we have now scientifically described it as a new species: Liopholis mutawintji.
For decades, this little lizard was thought to be an isolated population of a widespread skink. However, through a research collaboration between Wiimpatja and scientists, we have confirmed it as a distinct species found nowhere else on Earth.
We have been monitoring them for 25 years. We believe there may only be up to 20 individual kungaka remaining. It may be one of Australia's rarest reptiles.
A kungaka peeks out from underneath a rock. Credit: Tom Parkin, CC BY-ND
How we identified this new species
The kungaka was previously thought to be a highly isolated population of White's skink (Liopholis whitii), a widespread species that lives in rocky habitats across southeastern Australia.
But through analyzing its genetics and variations in body shape, we confirmed this skink is actually three distinct species. Two of these, the southern White's skink (Liopholis whitii) and northern White's skink (Liopholis compressicauda) occur across large areas of southeast Australia. The third—the kungaka—is restricted to Mutawintji National Park, about 500km from its closest relatives.
The kungaka represents an ancient lineage that likely originated during earlier, wetter periods in Australia's history. As the continent dried, this skink persisted in humid rocky refuges. Today, it survives in a tiny, isolated pocket of sheltered gorge in Mutawintji, surrounded by a hot and dry expanse of saltbush and stony plains.
Wiimpatja have worked alongside ecologists and the NSW National Parks and Wildlife Service to monitor the kungaka population since 2000, with surveys intensifying since 2019. Over that time, the outlook has become increasingly concerning. Fewer than 20 individuals have been counted since surveys in 2024, using pattern recognition methods from photographs. And there has been a decline in its range, the number of skinks observed and the habitat where it lives.
A feral goat in Mutawintji National Park. They overgraze vegetation and trample fragile rocky areas. Credit: Tom Parkin, CC BY-ND
Goats, cats and foxes
One of the most significant threats to the kungaka is feral goats. These occur in large numbers in the region and damage the environment by overgrazing vegetation and trampling fragile rocky areas.
This damages the rocks kungaka rely on for shelter, and exposes them to predators and extreme temperatures. Goats are also a significant threat to Mutawintji's endangered Wangarru, or yellow-footed rock-wallaby, as they compete for the same food and shelter. However, conservation work for Wangarru has been a major success story, with the population growing over the past decade.
Other threats are compounding the problem for the kungaka. Introduced predators such as cats and foxes may prey on them, while climate change is intensifying heat and drought across the region. The 2017–19 drought was the hottest and driest on record for far western NSW. For a species with such a small population, these pressures may be overwhelming.
Kungaka as family
From Warlpa Thompson: For Wiimpatja, the kungaka is inseparable from people, country and culture. Every animal and every plant have people attached to them. There would have been people whose meat, their blood, their family is the kungaka. And these people are now gone. But the lizards aren't.
In some places, the animal is gone out of the landscape, but the people are still there. Like the bilby mob that live in Wilcannia, or the dingo mob from Mutawintji. With the kungaka, we've got the reverse. The people are gone but the lizards are still here.
Our old people had to fight for the right to get their country back. Now we've got it, we're looking at how do we bring things back. How do we bring culture back? How do we bring our animals back?
The Wangurru, or yellow-footed rock wallaby, in Mutawintji National Park. Conservation work for Wangarru has been a success story, with the population growing over the past decade. Credit: Tom Parkin, CC BY-ND
The numbers of Wangurru have boomed in the last ten years. Hopefully we can do the same with the kungaka. A big part of that is making sure that our young people are involved so they know what it means to look after Country, and the plants and animals from our country.
It's important our kids don't just get the cultural knowledge from us, but they get the scientific knowledge and understanding, so they know everything that it is to talk for that animal, not just balanced with one side or the other.
The future of the kungaka
There is a shared responsibility to protect and conserve the kungaka. We need to control goats, cats and foxes, search for additional populations and monitor them long-term. Given the kungaka's extremely small population size, actions such as captive breeding may be required.
Scientific description of the kungaka is just the first step. If fewer than 20 individuals remain, it stands on the brink of extinction. The survival of this unique lizard will depend on sustained, long-term collaborative partnerships.
From Warlpa Thompson: Whatever we do needs to be done on Country, and led by Wiimpatja. That knowledge has to be driven by us but we need help to look after this lizard. It's in such a bad position that we're going to need everyone working together, in a culturally grounded way.
Acknowledgements: scientific description and conservation of the kungaka has been a truly collaborative effort, made possible through the dedication and knowledge of many individuals. We acknowledge the important work and contributions of Gerry Swan, Lyndy Marshall, Keanu Garni Bates, Ray Hunter-McKeller, Nhalpa Thompson and Dane Trembath, whose involvement have been integral to this research and its outcomes.
Scientists in Brazil described a new-to-science species of poison dart frog last year. It was first found among the leaves of wild banana plants on a research expedition to the Juruá River Basin in the western Amazon in 2023.
The frog, around the length of a paperclip (14–17 millimeters, or 0.5-0.7 inches), is reddish-brown and blue on top, bright blue with black spots underneath, and has copper-colored legs. It was named Ranitomeya aetherea, in reference to the word “ethereal.”
“We attribute this name to one’s feeling of enchantment and delicacy when encountering these frogs, as if they were from outside this world,” the study’s authors wrote in the species’ description.
The species has only been found at one site, where it lays its eggs in the small pools of water that collect inside plant leaves. This remote habitat is largely intact, with no immediate threats from deforestation or wildfires, creating a shield of protection from human-led activities.
This is in stark contrast to most other amphibian species, 40% of which are threatened with extinction. However, researchers stressed that biopiracy — the illegal collection and trade of rare species — and climate change are still threats.
The frog’s exact toxicity is unknown, but the whole Ranitomeya family is known to be poisonous, with toxins on their skin and bright colors to alert would-be predators.
“We know it’s poisonous to those that try to prey on it,” lead author Alexander Mônico, a researcher at the National Institute for Amazonian Research (INPA), told Mongabay. “But for us it’s fine, we’re able to handle them with our bare hands. We just need to be careful about any cuts.”
The tiny Amazon molly (Poecilia formosa) has always fascinated researchers because, according to the rules of evolution, it shouldn't have survived as a species, let alone thrive as a species for over 100,000 years. Using advanced genetic mapping and comparison techniques to track how the Amazon molly's DNA has changed over time, a new study set out to uncover the genetic secrets behind this apparent rebellion against evolutionary theory.
The molly undergoes asexual reproduction and gives live birth to its young, which are its clones, because the species is made up entirely of females—much like the all-female Amazonian warriors of Greek mythology, from whom it gets its name, not the Amazon Basin (where it doesn't live).
As per Muller's ratchet, a standard evolutionary theory, they should have gone extinct because clonal organisms accumulate harmful mutations over time due to a lack of genetic diversity.
The genetic evidence from this study, published in Nature, shows that the Amazon molly picks up mutations faster than its sexual relatives, yet somehow avoids the expected genetic decay—the secret behind this surprising act of resilience is gene conversion. This process purges harmful mutations by spotting damaged genes, "copying" a healthy version of the same gene from another part of the fish's own DNA, and "pasting" it over the faulty region to overwrite the mistake.
Accidental origin of the species
The Amazon molly didn't slowly evolve into a new species, it was the result of a 100,000-year-old accident. A long time ago, near Tampico, Mexico, a female Poecilia mexicana mated with a male Poecilia latipinna and created the hybrid—the Amazon molly. Every fish of that species alive today traces its lineage back to that single cross.
Unlike hybrid animals like a liger or mule, which are sterile and cannot reproduce, the Amazon molly is fully capable of reproducing asexually. Inside the mother's ovaries are specialized cells that undergo a modified version of meiosis—a type of cell division in sexually reproducing organisms—where the pairing up of chromosomes from two parents and swapping genetic information before dividing doesn't occur.
Instead, the mother produces eggs that already contain a full, double set of DNA that develops into new fish that are genetically identical to the mother. This form of cloning is called apomixis.
For a long time, scientists believed sexual reproduction was essential for long-term survival because it shuffles genes, removing harmful mutations and combining beneficial ones. The Amazon molly, however, gets the same advantages without ever mating.
Previous studies hinted at its high genetic diversity and signs of gene conversion, but detailed, haplotype-resolved genomic data were still missing.
Clues hidden in the genetic code
In this study, the researchers filled in this knowledge gap by creating a highly detailed and complete map of the entire genetic code for the Amazon molly and its two parent species using advanced long-read sequencing technology.
The researchers combined Hi-C and trio-binning to unravel the Amazon molly's genome. While Hi-C showed how DNA folds into chromosomes, trio-binning separated the two parental DNA sets, letting them study each lineage independently.
They found widespread presence of gene conversion, which supports two different pathways to reverse or correct unwanted genetic mutations: adaptive, or positive, selection, which promotes beneficial genetic mutations that enhance an organism's fitness, and second is purifying, or negative, selection, which helps reduce the presence of harmful genetic variations within a population.
The team also observed a higher rate of genetic repairs happening near DNA that carry crucial biological instructions, such as immunity or cell signaling.
Another fascinating detail revealed by the genome map was that out of the two sets of DNA present in the Amazon molly, one from each ancestral parent, is that the P. mexicana half of the fish's DNA is mutating and changing faster than the P. latipinna half, with changes mirroring those happening to the original species in the wild.
The study sheds light on long-debated questions about the evolutionary costs of asexual reproduction and establishes gene conversion as a powerful mechanism for effectively offsetting the negative effects. The findings give rise to a new question for future studies to explore: Do other long-lived asexual species avoid Muller's ratchet through the same process or is there something completely different at play?
Climate refuges may be key to restoring imperiled amphibians
Panamanian golden frogs (Atelopus zeteki) suffered significant declines due to chytrid. The species has not been seen in the wild since 2009. Credit: Roshan Patel, Smithsonian's National Zoo and Conservation Biology Institute.
As a deadly fungal disease ravages wild frog populations around the globe, scientists have identified potential locations in Panama where amphibians might persist despite the disease, according to new research from the Smithsonian's National Zoo and Conservation Biology Institute (NZCBI) and Smithsonian Tropical Research Institute (STRI) published in the Journal for Nature Conservation.
The amphibian chytrid disease, also known as chytridiomycosis or simply chytrid, is caused by the fungus Batrachochytrium dendrobatidis. It has spread like wildfire through Central and South America since the 1970s and is now ubiquitous. It is believed to have driven numerous species of neotropical frogs to the brink of extinction, including many in the genus Atelopus, commonly known as harlequin toads.
Now, as conservationists attempt to reintroduce captive-bred species to the wild, they hope to give the animals a leg up by identifying climatic refugia—places that are environmentally unsuitable for chytrid but well-suited to frogs.
Mapping seasonal disease risk
The chytrid fungus is present across almost all of the historic range of Atelopus species, but just as human influenza cases change with the seasons, the severity of chytrid disease fluctuates with temperature and humidity.
Using previously developed models that identified where the disease was present and when it was most severe, the authors built new chytrid suitability maps to identify places where reintroduced frogs might thrive without the threat of chytrid.
"We have tried releasing captive-bred harlequin toads back into the wild and experienced high losses due to the amphibian chytrid fungus that persists in the environment," said Brian Gratwicke, conservation biologist at NZCBI and senior author of the article.
"By mapping climatic refuges, we finally have a tool to rank potential release sites, allowing us to select places where the released animals have the best chance of survival."
Variable harlequin frogs (Atelopus varius) were the only species found surviving in chytrid-suitable sites, which scientists say is consistent with evidence that the species may have evolved resistance to the disease. Credit: Brian Gratwicke, Smithsonian's National Zoo and Conservation Biology Institute
Surviving toads reveal potential refuges
Researchers found that most harlequin toad species in Panama persist only at sites where more than 80% of the seasons were unsuitable for medium- and high-intensity infections. Only one species, the variable harlequin toad (A. varius), was found at sites suitable for the disease, which scientists say is consistent with evidence that the species may have evolved resistance to chytrid.
The models not only identify potential reintroduction sites but also point to places where wild Atelopus populations might remain.
"Our ability to identify climate refugia is critical if we hope to locate populations that might have disappeared from most places in their former range," said Carrie Lewis, a doctoral candidate at George Mason University and lead author of the publication. "These persisting populations could provide a source of genes to bolster populations under human care and provide opportunities to augment wild populations."
Like other Atelopus species, the critically endangered Pirri harlequin frog (A. glyphus) has experienced significant declines due to the amphibian chytrid disease. Credit: Brian Gratwicke, Smithsonian's National Zoo and Conservation Biology Institute.
A prior reintroduction trial conducted with Limosa harlequin frogs (Atelopus limosus) resulted in the deaths of numerous frogs due to chytrid. By choosing reintroduction sites considered unsuitable for chytrid, researchers hope to reduce losses in future reintroduction trials. Credit: Roshan Patel, Smithsonian's National Zoo and Conservation Biology Institute.
Researchers established captive assurance colonies for numerous species, including the critically endangered Toad Mountain harlequin frog (Atelopus certus), at the Panama Amphibian Rescue and Conservation Project in Gamboa, Panama. Credit: Roshan Patel, Smithsonian's National Zoo and Conservation Biology Institute.
Although there are currently a limited number of potential refuges, additional opportunities have been identified. The models also forecast areas that, while currently suitable for the disease, might become unsuitable in the coming years because of climate change. Researchers note that the shifting climate could also have negative effects on frogs adapted to cooler mountainous habitats.
"Guided by these climate refugia and Atelopus habitat-suitability maps, we have already begun surveying potential sites for habitat suitability and potential release trials," said Roberto Ibáñez, a STRI staff scientist and co-author of the study. "These tools will allow us to experimentally test the climate refugia hypothesis through future release trials."
Climate refuges may be key to restoring imperiled amphibians
Panamanian golden frogs (Atelopus zeteki) suffered significant declines due to chytrid. The species has not been seen in the wild since 2009. Credit: Roshan Patel, Smithsonian's National Zoo and Conservation Biology Institute.
As a deadly fungal disease ravages wild frog populations around the globe, scientists have identified potential locations in Panama where amphibians might persist despite the disease, according to new research from the Smithsonian's National Zoo and Conservation Biology Institute (NZCBI) and Smithsonian Tropical Research Institute (STRI) published in the Journal for Nature Conservation.
The amphibian chytrid disease, also known as chytridiomycosis or simply chytrid, is caused by the fungus Batrachochytrium dendrobatidis. It has spread like wildfire through Central and South America since the 1970s and is now ubiquitous. It is believed to have driven numerous species of neotropical frogs to the brink of extinction, including many in the genus Atelopus, commonly known as harlequin toads.
Now, as conservationists attempt to reintroduce captive-bred species to the wild, they hope to give the animals a leg up by identifying climatic refugia—places that are environmentally unsuitable for chytrid but well-suited to frogs.
Mapping seasonal disease risk
The chytrid fungus is present across almost all of the historic range of Atelopus species, but just as human influenza cases change with the seasons, the severity of chytrid disease fluctuates with temperature and humidity.
Using previously developed models that identified where the disease was present and when it was most severe, the authors built new chytrid suitability maps to identify places where reintroduced frogs might thrive without the threat of chytrid.
"We have tried releasing captive-bred harlequin toads back into the wild and experienced high losses due to the amphibian chytrid fungus that persists in the environment," said Brian Gratwicke, conservation biologist at NZCBI and senior author of the article.
"By mapping climatic refuges, we finally have a tool to rank potential release sites, allowing us to select places where the released animals have the best chance of survival."
Variable harlequin frogs (Atelopus varius) were the only species found surviving in chytrid-suitable sites, which scientists say is consistent with evidence that the species may have evolved resistance to the disease. Credit: Brian Gratwicke, Smithsonian's National Zoo and Conservation Biology Institute
Surviving toads reveal potential refuges
Researchers found that most harlequin toad species in Panama persist only at sites where more than 80% of the seasons were unsuitable for medium- and high-intensity infections. Only one species, the variable harlequin toad (A. varius), was found at sites suitable for the disease, which scientists say is consistent with evidence that the species may have evolved resistance to chytrid.
The models not only identify potential reintroduction sites but also point to places where wild Atelopus populations might remain.
"Our ability to identify climate refugia is critical if we hope to locate populations that might have disappeared from most places in their former range," said Carrie Lewis, a doctoral candidate at George Mason University and lead author of the publication. "These persisting populations could provide a source of genes to bolster populations under human care and provide opportunities to augment wild populations."
Like other Atelopus species, the critically endangered Pirri harlequin frog (A. glyphus) has experienced significant declines due to the amphibian chytrid disease. Credit: Brian Gratwicke, Smithsonian's National Zoo and Conservation Biology Institute.
A prior reintroduction trial conducted with Limosa harlequin frogs (Atelopus limosus) resulted in the deaths of numerous frogs due to chytrid. By choosing reintroduction sites considered unsuitable for chytrid, researchers hope to reduce losses in future reintroduction trials. Credit: Roshan Patel, Smithsonian's National Zoo and Conservation Biology Institute.
Researchers established captive assurance colonies for numerous species, including the critically endangered Toad Mountain harlequin frog (Atelopus certus), at the Panama Amphibian Rescue and Conservation Project in Gamboa, Panama. Credit: Roshan Patel, Smithsonian's National Zoo and Conservation Biology Institute.
Although there are currently a limited number of potential refuges, additional opportunities have been identified. The models also forecast areas that, while currently suitable for the disease, might become unsuitable in the coming years because of climate change. Researchers note that the shifting climate could also have negative effects on frogs adapted to cooler mountainous habitats.
"Guided by these climate refugia and Atelopus habitat-suitability maps, we have already begun surveying potential sites for habitat suitability and potential release trials," said Roberto Ibáñez, a STRI staff scientist and co-author of the study. "These tools will allow us to experimentally test the climate refugia hypothesis through future release trials."