Orcas, or killer whales, are the apex predator in the ocean when they work together.

A new study documents how a pod of orcas is able to hunt and kill the largest fish in the world, the whale shark (Rhincodon typus), which can be twice the size of an individual orca (Orcinus orca), though the pod most often targets smaller, juvenile sharks.  

Anecdotal observations in Mexico’s Gulf of California found that orcas appeared to prey on whale sharks. However, the behavior wasn’t well understood or scientifically recorded until recently, when between 2018 and 2024, a team of researchers recorded videos and photos of the same pod of orcas successfully hunting and killing whale sharks on four separate occasions.

“In all the events that we have registered since 2018, it’s been always the same pod, the same individuals, the same members of this orca family,” marine biologist Erick Higuera Rivas, study co-author from Conexiones Terramar, a conservation science NGO in Mexico, told Mongabay by phone.

Several members of the research team were in the water for other research purposes along with tourists with video cameras when they happened to observe the orcas’ whale-shark-hunting strategy. They saw the orca pod work together to keep the whale shark near the water’s surface, after which they flipped the shark upside down, causing it to go into a state of tonic immobility, or temporary inactivity. Once rendered unable to move, the orcas bit and tore at the shark’s belly to get to its lipid-rich liver.  

“The liver of sharks is very big, it’s a very big organ,” Francesca Pancaldi, the study’s lead author and marine biologist at WWF, told Mongabay by phone. “It’s very fatty, has a lot of nutrients. And it’s very important for the orcas to consume that because it provides a lot of calories for them.”

Once the orcas have the prize liver, the family eats together.

“When they feed, they share food between the individuals of the pod. [They even] pass a piece of shark from one individual to another,” Pancaldi said.

In this way, the youngest members of the pod develop a taste for whale shark liver, she added. By observing the hunt, they also learn the process of carrying out this complex behavior from their elders. Flipping over an animal potentially much larger than themselves to access a very specific part of its body isn’t an instinct, but a learned behavior that requires coordination and skill, passed down through generations, Pancaldi said.

Banner image of a whale shark being brought to the surface as an orca bites near the pelvic area, courtesy of Kelsey Williamson.

A critical legal case filed by four East African NGOs against a controversial oil pipeline is facing yet another delay, but the NGOs say they remain hopeful.

“What we need is for the court to hear the case on its merit, and we believe we have presented good evidence,” Dickens Kamugisha, CEO of the Africa Institute for Energy Governance (AFIEGO), told Mongabay.

In November 2020, AFIEGO and the Center for Food and Adequate Living Rights (CEFROHT), both from Uganda, Natural Justice (Kenya), and the Centre for Strategic Litigation (Tanzania) filed a case with the East African Court of Justice (EACJ) to halt construction of the East African crude oil pipeline. Known as EACOP, the $5 billion project is led by French oil giant TotalEnergies and involves state-owned companies from China, Uganda and Tanzania.

The NGOs allege that the project violates Ugandan, Tanzanian and regional laws protecting human rights and the environment, as well as breaches the two countries’ climate commitments.

Kamugisha said they filed the case with the EACJ because the project’s impacts were cutting across the borders of Uganda and Tanzania: communities have been displaced without adequate compensation or sufficient public participation, and the pipeline threatens critical ecosystems like Lake Victoria.

However, the plaintiffs faced a setback at the first hearing in November 2023. Tanzania and Uganda argued the NGOs should have filed their complaint within 60 days of the signing of agreements in 2017, not three years later. The court agreed that the time for objections had lapsed and dismissed the case.

But David Kabanda, a human rights lawyer from CEFROHT representing the NGOs, said they only learnt about the project when the Ugandan government briefed the media in 2020. “All of these agreements are under lock and key, we have never read them.”

The NGOs filed an appeal, arguing for the case to be heard on its merit. During the appeal hearing on Nov. 15, Tanzania’s lawyers said the NGOs hadn’t submitted certain documents. The court postponed the hearing, asking the documents to be resubmitted by Nov. 29, which the NGOs have now done.

“These are delaying tactics that they have played before,” Kabanda said. The appellate court has granted them time for oral submissions, he added, and they’re awaiting a new hearing date.

The delays, however, further impact the communities, Kamugisha said.

“Many people are being displaced; the government of Uganda has been filing cases against poor people who have no capacity to hire lawyers to defend themselves, and they are getting eviction and demolition orders against those poor people,” he said. “They are arresting, detaining, harassing, intimidating NGOs and civil societies and human rights groups.”

Yet both Kabanda and Kamugisha say they’re hopeful.

“Our case is very strong,” Kabanda said. “Yes, there was this hiccup, but we are confident that we will get the judgment in our favor.”

Banner image by Rhett A. Butler/Mongabay.

Residents of the Carteret Islands in Papua New Guinea are on a “green migration,” contributor Thibault Le Pivain reports for Mongabay. 

The islanders are leaving their homes due to food shortages resulting from environmental degradation and rising sea levels, and sailing to a larger island in the country, taking with them plants that play important roles in their way of life. 

“We’re not just leaving. We’re trying to bring a part of our islands with us,” resident Maria Kamin told Mongabay after they moved to the main island of Bougainville, on lands donated by the Catholic Church.

Back in 2005, when the Carteret Islanders first announced their plans to relocate, they were dubbed the “world’s first climate change refugees.” Since then, Tulele Peisa, a community organization, has coordinated the relocation 17 families to Bougainville. An additional 14 million kina ($3.5 million) is needed to relocate 350 more families, or half of the island’s remaining population, Ursula Rakova, executive director of Tulele Peisa, told Mongabay. 

Rising tides and saltwater intrusion have killed staple crops in the Carteret Islands, Rakova said. The groundwater has become too salty to drink, while fish stocks have declined due to heat waves and illegal fishing by foreign vessels.

The 17 families who have moved brought with them hundreds of plant specimens, replanting them alongside local flora at their new home in Bougainville. The result is a thriving forest of more than 175,000 trees and plants, Le Pivain writes. This way, the residents say they hope to not just preserve the biodiversity of Carteret Island but also maintain the community’s culture and sense of place. Some of the plants they relocated include seedlings of essential crops like breadfruit (Artocarpus altilis), giant swamp taro (Cyrtosperma merkusii), coconut and medicinal herbs.

Although the Carteret Islands and Bougainville share many species, the migrating families wanted to bring their own varieties, Le Pivain reports. Carteret breadfruit is seedless, for example, while its coconuts are said to be sweeter and some of the medicinal plants aren’t found on Bougainville.

Christian Giardina, forestry director at the Institute of Pacific Islands, told Mongabay that such “canoe plants” have long been part of the human migration history through the Pacific. It was through canoe voyages that crops such as taro, banana and sweet potato came to Hawai‘i from Polynesia.

Carol Farbotko, a researcher at Griffith University, Australia, said that while such “green migrations” can become part of relocation plans for vulnerable communities, the transfer of species needs to be carefully considered using both local knowledge and science. There’s a risk of introducing invasive species that can harm native wildlife, which is why ecological compatibility is important to consider, she added.

This is a summary of “In a Noah’s Ark move, PNG migrants bring thousands of trees to safer ground” by Thibault Le Pivain. 

Banner image of the Bougainville forest planted by Carteret Islanders, by Thibault Le Pivain for Mongabay

India is bracing for intense rainfall over the next few days as a deep depression over the Bay of Bengal is set to intensify into what will be called Cyclone Fengal by Nov. 29, according to local media reports. 

The India Meteorological Department (IMD) said the cyclone is likely to pass near the coast of Sri Lanka and move toward India’s southernmost state, Tamil Nadu, where the agency issued rainfall alerts until Dec. 1. As it intensifies, the storm is expected to result in wind speeds of 50-60 kilometers per hour (31-37 miles per hour), with gusts of up to 70 kph (43 mph).

As of Nov. 28 morning, many schools had shut, while in some parts of the state, thousands of hectares of rice fields are already submerged in water, authorities said. 

Flights to cities in Tamil Nadu have been disrupted, while the local fisheries department has issued warnings to fishers not to go out to sea, and to secure their boats and equipment. Fishers who are already out were asked to return to avoid being caught up in the potential cyclone.

Although the cyclone is said to likely weaken as it makes landfall, the Indian Navy and disaster response agencies said they’ve put various measures in place, including preparing cyclone shelters and relief camps stocked with food, water, medicines and other relief materials. 

A recent report found that the state of Tamil Nadu faced 67 days of extreme weather events in 2024, a 131% increase from 29 such days in 2023.

Also feeling the pain of extreme weather is the U.K., where heavy rainfall and strong winds from Storm Bert, which struck on Nov. 23 morning, resulted in five deaths and caused power outages and transportation disruptions, CNN reported. Flight and train services were affected, and more than 500 homes and businesses were flooded in Wales and England.

“Storm Bert has caused a tragic loss of life and misery to families and businesses across the country,” Geoffrey Clifton-Brown, chair of parliament’s public accounts committee, said in a statement. “Such devastating floods are becoming an annual feature of our national life. They are a symptom of our changing climate, and as such there is no excuse for the Government to not tighten its grip in tackling such a predictable risk.”

Storm Bert also impacted Ireland, resulting in power outages at 60,000 properties. 

Another storm this week, Storm Conall, has prompted fresh flood warnings in the U.K. The BBC reported the storm is expected to intensify as it moves toward the Netherlands.

Meanwhile, the 2024 Atlantic hurricane season, from June to November, has ended after 18 named storms, five of which made landfall in the U.S. 

Banner image of high river waters in Cardiff, Wales, by Sionk via Wikimedia Commons (CC BY-SA 4.0).

A mass fish die-off in Brazil’s Amazon River region has killed an estimated 20-30 metric tons of fish and other aquatic animals, following one of the worst droughts in Amazonian history.

On the night of Nov. 12, fishers from the riverine community of Igarapé do Costa, near the city of Santarém in northern Brazil, began noticing fish dying in large numbers along the Aramanaí Channel, a waterway connected to the Amazon River and home to hundreds of fishing families.

Over the following days, the situation worsened as the channel became blanketed with dead marine animals, Manuel Pinheiro, the social and environmental director of the Z20 fishers union, which represents the impacted area, told Mongabay in an audio message.

Native fish, such as pirarucu (Arapaima gigas), one of the world’s largest freshwater fish, red-bellied pacu (Piaractus brachypomus), the talking catfish (Acanthodoras spinosissimus) and tambaqui (Colossoma macropomum) were among the affected species.

Caimans, turtles and stingrays were also found dead in the fetid water. Fishermen have been transporting surviving animals to other locations.

“We have never seen anything like this,” Pinheiro said. “It’s a tragic situation. We’ve informed the environmental agencies so that they can investigate and try and identify the causes behind this disaster.”

Fish die-offs are often triggered by hot weather followed by sudden rainfall, which can cause a thermal shock. “But that’s not what happened this time, it didn’t rain. We think it might be the high temperatures or the [low] oxygen levels,” Pinheiro added.

In 2024, temperatures in the Brazilian Amazon were 5.1° Celsius (9.2° Fahrenheit) higher than the historical average, according to data from Brazil’s National Institute of Meteorology. A biologist on scene reported the average water temperature was 32°C (89.6°F), while the acceptable limit for the local aquatic life would be around 28°C (82.4°F).

The die-off also contaminated the channel’s water, adding strain to the families who depend on the freshwater supply.

“It’s paradoxical that riverine communities in the Amazon face water stress while living in the world’s largest freshwater basin,” Caetano Scannavino, coordinator of the nonprofit Projeto Saúde e Alegria (“Health and Joy Project”) which works in the region, told Mongabay in an audio message.

Scannavino added that the event would undoubtedly affect food security for local populations and could also disrupt next year’s fish supply.

Fishers say they’re concerned about the long-term impact of the die-off. “All these fish that died also aren’t going to have offspring, so I’m worried about whether we will have fish in the future,” said Erick Penna Ribeiro, president of the Igarapé do Costa community residents’ association.

Banner image: Thousands of fish died suddenly in a waterway connected to the Amazon River. Image courtesy of Manoel Pinheiro/Z 20 Fishers Union.

From water bottles and food wrappers to microplastic in the air, plastic and its chemical components are nearly impossible to avoid today. Researchers have now measured the extent to which people are exposed to these chemicals using an innovative approach: specially designed wristbands.

Researchers with the International Pollutants Elimination Network (IPEN) gave the wristbands to 30 workers in Thailand from three different groups: recycling workers, plastic waste workers, and office workers. Each person wore the wristband, designed to absorb chemicals their skin has been exposed to, for five workdays, after which it was sent to an independent lab for analysis. The lab tested for 73 chemicals in six different chemical groups, including phthalates and bisphenols.

Lab tests found that all workers, despite their occupation, were exposed to at least 21 different chemicals. The waste and recycling workers had the most chemicals registered on their wristbands, as well as the highest concentrations of the chemicals.

In a related study, the IPEN researchers gave the wristbands to 12 international delegates currently meeting in Busan, South Korea, for the U.N. plastics summit. These delegates, from Asia, Latin America and Europe, are mostly office workers or university professors, with little obvious occupational exposure to plastic. Nonetheless, each delegate wristband registered at least 29 chemicals in all the six different categories.

“The wristband study has been a wake-up call,” said participant Elisa Morgera, professor of global environmental law at the University of Strathclyde, Glasgow, and U.N. special rapporteur on climate change and human rights. “I see now how much more I can do to eliminate plastic in my daily life, but I am also thinking about how much plastic is surrounding me that I didn’t ask for or need,” she said in a statement.

Chemicals from plastic, many of them endocrine disrupters, have been linked to a wide variety of health problems, including elevated risk of stroke and cardiovascular disease, infertility, obesity, diabetes, and certain cancers.

While more than 13,000 chemicals are associated with plastic, the 73 selected for the studies were chosen because they’re very common, associated with known health hazards, and aren’t currently regulated internationally, the researchers write. However, the expensive lab testing of the wristbands makes it difficult for average people to assess their own exposure the same way.

John Norman, senior director of regulatory and scientific affairs with the American Chemistry Council (ACC), a plastics industry association, told Mongabay in an email that the IPEN study “includes broad generalizations and lacks sufficient scientific detail.”

IPEN science adviser Sara Broche told Mongabay by phone that very few chemicals are internationally regulated, so addressing the global plastic chemical problem will take a coordinated effort.

“That’s why we are hoping and encouraging governments at this plastics treaty negotiations to put in strong measures to address these chemicals because this is an opportunity do so,” she said.

Banner image of plastic bottles ready for recycling. Image by Hans Braxmeier from Pixabay.