In April 2023, fishermen caught a Eurasian otter in their net in the Karnali River, western Nepal, and reported the finding to researchers. A new study now confirms that this marks the northernmost spot in the country where the species has been spotted, Mongabay’s Abhaya Raj Joshi reported in June.

The Eurasian otter (Lutra lutra) occurs widely across Europe and Asia, from as far west as the Iberian Peninsula and British Isles to the eastern borders of Asia, as well as down south to Vietnam to far north as Russia. However, in Nepal, it hadn’t been confirmed for decades until 2021, when there were a number of sightings across the country’s rivers.

The latest sighting of the otter in Karnali River is cause for both excitement and concern, researchers told Mongabay.

“The finding is important as we confirm the northernmost documented record of the animal in Nepal,” said Rinzin Phunjok Lama, co-author of the study. “But that the animal was found dead most likely because it got strangled in a net also raises concerns about its conservation.”

Estimates for the global population of Eurasian otters, classified as near threatened, range from almost 60,000 to more than 360,000 mature individuals. While widespread, the species’ range is likely underexplored, Joshi writes. Recently, it was photographed by camera traps in Malaysia after not being spotted there for more than a decade.

Otters inhabit rivers, wetlands and lakes that are very sensitive to human activities, especially those affecting river flow and bankside vegetation, making them indicators of ecosystem health. In South and Southeast Asia, in particular, Eurasian otter numbers have declined due to overfishing and poaching, as well as strangulation due to nets.

Another concern for otters in this region is the boom in hydropower projects, including the 900-megawatt Upper Karnali project proposed on the Karnali River, which could obstruct the river’s natural flow.

“If the planned hydropower development goes ahead, it will definitely have a long-lasting impact on the otters in the Karnali,” researcher Mohan Bikram Shrestha told Joshi. “The practice of building roads on the banks of the river as well as unsustainable extraction of sand is already adding problems to otters.”

These challenges extend to the two other vulnerable otter species found in Nepal: the smooth-coated otter (Lutrogale perspicillata) and the Asian small-clawed otter (Aonyx cinerea). The latter, the world’s smallest otter, was recently confirmed by scientists in western Nepal after going missing for 185 years.

Despite the 2023 discovery of the Eurasian otter in the Karnali River, there’s no conclusive evidence the area hosts a viable otter population. Shrestha said Nepal first needs to assess the otter population in the country, especially in remote rivers that researchers currently can’t reach.

Read the full story by Abhaya Raj Joshi here.

Banner Image: A Eurasian otter (Lutra lutra), one of the otter species found in Nepal. Image by Alexander Leisser via Wikimedia Commons (CC BY-SA 4.0).

A new WWF report is sounding the alarm on Africa’s freshwater fish: one in four fish species it assessed is at risk of extinction. These declines threaten not only biodiversity, but also the food security, livelihoods and cultural identity of millions of people who depend on inland fisheries across the continent.

Released in the lead-up to the Ramsar conference on wetlands to be held in Zimbabwe, the report notes there are at least 3,281 freshwater fish species in Africa’s rivers, lakes and wetlands. It also highlights the extraordinary diversity of Africa’s freshwater fish — from air-breathing lungfish to blind, cave-dwelling cichlids — that have remained largely invisible in conservation and development policies despite being essential to ecosystems and economies alike.

“Africa is a global hotspot of freshwater fish diversity, home to over 3,200 species, but it’s also a hotspot of risk,” Eric Oyare, WWF’s Africa freshwater lead, said in a statement. “When these fish disappear, we lose much more than species: we lose food and nutrition security, livelihoods, ecosystem balance, and adaptive capacities to climate change.”

The report points to habitat destruction, pollution, overfishing, invasive species and climate change as key drivers of freshwater fish decline. Lake Malawi’s iconic chambo tilapia, for example, declined by 94% from 2006-2016. Meanwhile, Lake Victoria has likely seen hundreds of cichlid species vanish since the introduction of the invasive Nile perch and water hyacinth.

Africa also accounts for almost 30% of global freshwater fish catch, according to the report. The continent’s freshwater fisheries are more than a source of food — they are economic engines. Uganda and Tanzania rank among the top inland fish producers globally, largely thanks to Lake Victoria. Small pelagic fishes like dagaa, kapenta, salanga and usipa provide critical nutrition and income, especially in low-income and landlocked countries.

But these fisheries are under pressure. In Zambezi’s floodplain fisheries, catches have plummeted by about 90%. In Zambia’s Kafue Flats, once among Southern Africa’s most productive freshwater fisheries, dam construction has disrupted natural flood cycles critical for fish breeding.

“The disappearance of freshwater fish is not just a biodiversity crisis,” Machaya Chomba, Africa freshwater protection manager at The Nature Conservancy, said in the statement. “It is a direct threat to food, livelihoods and cultural identity for millions across Africa.”

Despite this grim outlook, the report, co-authored by multiple conservation organizations including TNC, offers a way forward. It details a six-point emergency recovery plan for freshwater biodiversity, emphasizing restoring natural river flows, improving water quality, protecting key habitats, ending unsustainable practices, managing invasive species, and removing obsolete dams.

African countries have committed to protecting 30% of inland waters and restoring 30% of those already degraded by 2030. The report’s co-authors urge African governments to take bold, concrete steps to revive rivers, wetlands and the freshwater fish species that depend on them at the Ramsar summit.

Banner image of a cichlid species by Kevin Bauman via Wikimedia Commons (CC BY 1.0).

From the volcanic fjords of Tufi in Papua New Guinea, researchers have described a new-to-science species of a coral reef fish called a dwarfgoby with an unusual purplish-black color. The tiny fish is the “darkest of all described dwarfgobies,” the researchers say in the study, naming it Eviota vader after the Star Wars villain Darth Vader.

Dwarfgobies are miniscule fish that live on reefs across the Indo-Pacific, measuring less than 1.8 centimeters (0.7 inches). Researchers found E. vader, also called black dwarfgoby, during a reef fish biodiversity survey at a depth of 4 meters (13 feet) in Tufi’s volcanic fjords. At the time, there were 134 known species of dwarfgobies globally, and the fish they spotted was unlike any of them.

“It stood out to us immediately, as while there are many dwarfgobies in the 1-4m [3.3-13 ft] depth range on coral reefs, none have this unique purplish-black coloration,” Mark V. Erdmann, study co-author and executive director of ReShark and shark conservation director at Re:wild, told Mongabay by email. “So in short, yes, immediately upon seeing this fish we knew it was something special.”

The lone black dwarfgoby the researchers spotted had large yellow eyes and was 1.15 cm (0.45 in) in length. They photographed it perched on a section of a large coral colony. The fish was later collected using clove oil, which is used to sedate small fish. The team didn’t encounter any other similar-looking fish during the survey.

Erdmann said they sent their only specimen to David W. Greenfield, the study’s lead author and an expert on dwarfgobies, who examined it and confirmed it as a previously undescribed species.

Tufi is a “very unique area,” Erdmann added, as its volcanic fjords “offer a unique coral reef environment” protected from waves. “We don’t know if Eviota vader evolved in the fjords, but at this point in time it is the only place on earth where we’ve found this species, despite a LOT of sampling in the surrounding regions of PNG and the Coral Triangle,” he said.

Dwarfgobies, among the smallest vertebrates on Earth, are part of a group called “cryptobenthic reef fishes” that abound on coral reefs but are hard to spot because they’re small and mostly live camouflaged near the seafloor.

“We increasingly believe they play a very important role in the reef ecosystem,” Erdmann said. “[S]ome scientists have referred to dwarfgobies as the ‘rice of the reef’ — meaning, while they are small and hardly a mouthful, they are in many ways a ‘staple’ food that many piscivorous [fish-eating] fishes rely upon to fill their bellies.”

The authors write developments in underwater macrophotography have helped describe new-to-science marine species like dwarfgobies.

This isn’t the first time scientists have drawn inspiration from Star Wars’ iconic villain. In January this year, a new-to-science giant crustacean was named Bathynomus vaderi because its head was reminiscent of Darth Vader’s helmet.

Banner image of the black dwarfgoby courtesy of M.V. Erdmann.

Founder’s Briefs: An occasional series where Mongabay founder Rhett Ayers Butler shares analysis, perspectives and story summaries.

Amid the calls of gibbons and the whir of drones scanning forest canopies, a quieter crisis is unfolding within the ranks of those trying to save nature. Conservationists, often seen as tireless stewards of the planet’s dwindling biodiversity, are burning out. In some cases, they are breaking down. And with disturbing regularity, social media feeds are peppered with tragic news of conservation professionals who have taken their own lives. Yet data on suicide within the field is scarce, both due to stigma and the sector’s fragmented structure.

A study published in Conservation Biology in 2023 surveyed more than 2,300 conservation professionals across 122 countries, offering one of the first comprehensive glimpses into the sector’s mental health. More than a quarter of respondents scored in the moderate-to-severe range for psychological distress. Women, early-career professionals, those with poor physical health, and those lacking social support were particularly at risk.

The study’s authors, led by Thomas Pienkowski of Imperial College London and the University of Oxford in the U.K., emphasize that psychological distress does not equate to mental illness, but high levels can signal serious well-being concerns.

Conservation work blends passion with precarity. Many are drawn to the field by a sense of duty or love of nature, but are often greeted by underfunding, job insecurity and poor institutional support. The vocational allure of saving the planet is sometimes exploited through long hours, unpaid labor or unsafe working conditions, particularly in field roles where rangers may be enforcing laws in the same communities where they live.

The study found that job-related factors — like organizational instability, lack of resources and constant time pressure — were strongly associated with distress. Conversely, feeling that one’s work makes a meaningful contribution to conservation was one of the strongest protective factors. A sense of impact, it turns out, may be more important than hope that humanity will solve the biodiversity crisis.

Other sectors have long recognized the importance of workplace mental health. Conservation, say the authors, must do the same.

Recommendations include:

• Develop and routinely update workplace well-being plans tailored to conservation contexts.
• Promote healthy work-life balance through flexible schedules and limits on work hours.
• Train managers to support mental health and recognize signs of distress.
• Celebrate contributions to conservation to counter feelings of futility.
• Ensure job security and equitable compensation, particularly for early-career staff and women.
• Require funders to support mental health as part of grant conditions.

Protecting those who protect nature, it seems, is long overdue.

Banner image: Rain over a tropical island in the South Pacific in April 2025. Image by Rhett A. Butler/Mongabay.

TOKYO (AP) — Decontaminated but slightly radioactive soil from Fukushima was delivered Saturday to the Japanese prime minister’s office to be reused in an effort to showcase its safety.

This is the first soil to be used, aside from experiments, since the 2011 nuclear disaster when the Fukushima Daiichi nuclear power plant suffered a cataclysmic meltdown following an earthquake and tsunami that left large amounts of radioactive materials spewing out from the facility, polluting surrounding areas.

The government is desperate to set people’s minds at ease about recycling the 14 million cubic meters of decontaminated soil, enough to fill 11 baseball stadiums, collected after massive clean-ups and stored at a sprawling outdoor facility near the Fukushima plant. Officials have pledged to find final disposal sites outside of Fukushima by 2045.

The Environment Ministry said the 2 cubic meters, now at Prime Minister Shigeru Ishiba’s office complex in Tokyo, will be used as foundation material in one section of the lawn garden, based on the ministry’s safety guidelines endorsed by the International Atomic Energy Agency. The soil does not include any from inside the plant.

Despite assurances, there has been much public unease. The government has already been forced to scrap a plan to experiment using some of the soil in flower beds at several public parks in and around Tokyo following protests.

Banner image: A bag of soil, slightly radioactive but decontaminated one from Fukushima, is delivered to the Japanese prime minister’s office to be reused in the garden, in Tokyo, Japan, Saturday, July 19, 2025. (Kyodo News via AP)

Founder’s Briefs: An occasional series where Mongabay founder Rhett Ayers Butler shares analysis, perspectives and story summaries.

In the Peruvian Amazon, a series of curious encounters has left biologists scratching their heads.

Camera traps have captured an unexpected partnership: solitary, nocturnal ocelots (Leopardus pardalis) strolling alongside common opossums (Didelphis marsupialis). Not once, but four times, in distinct locations over several years, the feline predator and its potential prey were seen moving together—sometimes even returning along the same path minutes later, still in tandem. The opossum, far from appearing alarmed, showed no signs of distress.

This behavior is not only puzzling; it is without precedent. Associations between solitary carnivores and omnivores—especially those that occasionally dine on one another—are vanishingly rare. Yet further evidence suggests this pairing is more than happenstance. In field experiments, opossums showed a distinct preference for the scent of ocelots over that of pumas or neutral controls. They lingered, sniffed, and rubbed themselves against the ocelot-scented fabrics, as though seeking some form of chemical communion.

Why cozy up to a cat that might eat you? The researchers, writing in the journal Ecosphere, suggest two possibilities: improved foraging efficiency or olfactory camouflage. Opossums may benefit from the ocelot’s hunting prowess, while the ocelot may gain from masking its scent with the opossum’s pungency. There is precedent in the animal kingdom: coyotes and badgers have been known to hunt cooperatively, trumpetfish hide behind larger fish to ambush prey, and some marsupials resist snake venom—knowledge the ocelot may intuitively exploit.

“Opossums have a strong smell, and a close-by ocelot might help hide the opossum’s scent from bigger predators, or the opossum’s odor might mask the ocelot’s presence from prey,” Ettore Camerlenghi, an ecologist at ETH Zurich and the lead author of the study, told the New York Times.

Whether this is mutualism, manipulation, or mere curiosity remains unknown. But the discovery is a reminder of how little is understood about rainforest dynamics. Even in well-trodden ecosystems, the wild has secrets yet to reveal—one cautious step at a time.