Sharks continually shed and regrow teeth throughout their lives, replacing worn or lost teeth with new ones. That makes them particularly good at catching prey. However, these top marine predators could lose their literal edge as ocean acidification damages their teeth and makes it harder to keep and replace them, a new study says.

“Shark teeth are highly evolved and diverse feeding tools developed over millions of years,” lead author Maximilian Baum, a biologist at Heinrich Heine University Düsseldorf, Germany, told Mongabay by email. “If their functionality is reduced due to acidification this could affect hunting success and energy balance and in the long run potentially impact survival and reproductive fitness.”

The world’s oceans are becoming more acidic as seawater absorbs the excess carbon dioxide (CO2) that humans pump into the atmosphere. This acidification disrupts the availability of calcium and other minerals in seawater, which harms organisms like corals and shellfish that use the minerals to form their shells and skeletons.

Shark teeth regeneration also depends on seawater minerals like calcium and phosphate. To find out how acidification might affect shark teeth, Baum’s team scuba-dived and collected naturally shed teeth from captive blacktip reef shark (Carcharhinus melanopterus), a critical predator in tropical coral reefs. “The sharks themselves were not an issue as blacktip reef sharks are very shy and peaceful,” Baum said. “The real difficulty was finding the small, shed teeth among sand and substrate and especially locating intact and freshly lost teeth that were suitable for the experiments.”

Studies project that as CO2 emissions continue to rise, the average pH of the ocean could drop from the current 8.1 to as low as 7.3 by 2300. So the researchers placed 26 undamaged teeth in water with pH 8.1, and 26 others in slightly more acidic water at pH 7.3.

At the end of eight weeks, the teeth exposed to more acidic water were significantly more damaged and weaker than the other group. “[W]e were surprised by how clearly the acidified teeth showed damage even after relatively short exposure times,” Baum said. “The difference in surface structure between the teeth from acidified and control conditions was obvious and consistent across our samples.”

While the experiment tested only shed teeth, Baum said they would expect to see similar damage in wild sharks as ocean acidification intensifies. This is because sharks swim with their mouths slightly open, so their teeth are constantly exposed to seawater.

In acidified seawater, the availability of minerals like calcium and phosphate necessary for new tooth formation may also be lower, Baum said, which could make the teeth regeneration process “even more difficult.”

“An increased need for new teeth combined with reduced mineral availability could create a biological bottleneck that affects shark performance and resilience,” he added. “Future studies on living animals are needed [if] we want to understand these dynamics better.”

Banner image: A blacktip reef shark by Charles J. Sharp via Wikimedia Commons (CC BY-SA 4.0).

Indigenous leaders say land-grabbers are setting fires inside the Karipuna Indigenous Territory in Brazil’s Rondônia state, in the northwest Amazon. The fires come less than one month after Indigenous leaders warned authorities about renewed invasions.

Satellite monitoring detected more than 90 fire alerts in the territory between Aug. 14 and Aug. 25, according to an analysis by Mongabay using data from Brazil’s space agency, INPE.

“These fires are happening because of land-grabbing,” André Karipuna, the chief of the Karipuna people, told Mongabay in an audio message. “The land-grabber comes in, sections the land into lots, then clears it. First, they cut the smaller vegetation, then bigger trees. They leave it to dry and then set it on fire.”

In July 2024, Brazil’s federal government carried out an operation to dismantle illegal access routes and other structures inside the territory. Officials reported destroying 17 bridges and 38 illegally built roads, but no one was arrested.

Karipuna leaders and the global nonprofit Survival International raised the alarm about increased invasions on the land in late July 2025.

According to Brazil’s Ministry of Indigenous Peoples, a federal police unit has been alerted. But as of Aug. 26, Karipuna leaders say no help has reached them on the ground.   

“The Federal Police has already been called in and is monitoring fire alerts and other criminal activities in the region,” the ministry wrote to Mongabay by email. “For security reasons, details of these actions remain confidential, but it is important to stress that they are underway and will continue in order to suppress illegal activities, protect the community and ensure the preservation of natural resources.”

Adriano Karipuna, another Karipuna leader, told Mongabay in July that federal agencies had guaranteed monitoring and surveillance of their territory but were not following through. “Because it is not happening, the invaders are coming back again,” he said.

The Karipuna are one of Brazil’s least-populous Indigenous peoples, with only 63 people left, down from thousands before colonization. Their territory is entirely surrounded by cattle ranching farms and logging operations.

Banner image: A forest fire in the Brazilian Amazon in 2022. Image © Nilmar Lage/Greenpeace.

LAHORE, Pakistan (AP) — Officials say rescuers in eastern Pakistan have evacuated tens of thousands of people to safer areas after neighboring India released water from overflowing dams and swollen rivers into low-lying border regions. The move came a day after New Delhi alerted Islamabad about possible cross-border flooding, marking the first public diplomatic contact between the two nuclear-armed rivals in months. Pakistan’s National Disaster Management Authority said Tuesday it had issued an advance alert about a surge in the Sutlej River and the risk of flooding. It said more evacuations from various districts in the eastern Punjab province are still underway.

By Barbar Dogar and Munir Ahmed, Associated Press  

Banner image: In this photo released by Pakistan’s National Disaster Management Authority, rescue workers evacuate villagers from a low-lying area due to rising water level in the Sutlej River following a release of water in overflowing dams in neighbouring India Tuesday, Aug. 26, 2025. (Pakistan’s National Disaster Management Authority via AP)

The critically endangered Manapany day gecko has long been known only from a small part of Réunion Island, a French territory in the Indian Ocean. A recent study finds the bright green lizard no longer appears in 28% of its previous habitat, but has cropped up in newer, more urban areas where it hasn’t been recorded before.

From 1995-2011, many subpopulations of the Manapany day gecko (Phelsuma inexpectata) disappeared or were close to extinction on the island, the researchers write. To find out where the gecko is now found, they first mapped areas where it had previously been recorded, working with grids of 20 by 20 meters (66 by 66 feet). From 2020-2022, they visited each grid cell up to three times during the gecko’s active hours.

The researchers write the species is brightly colored and doesn’t move away when people appear, which makes it easy to spot if it’s around.

The team found that between 2008 and 2020, the Manapany day gecko had been spotted within an area of 19.44 hectares (48 acres), equivalent to 486 grid cells. Of these, 320 cells contained human-modified habitats, such as housing, farmland and private gardens. Only 97 cell grids had natural habitats, while 69 had mixed natural and human-modified habitats.

During the 2020-2022 survey, the researchers also searched 459 of the previously occupied cells; they didn’t find the gecko in 128 of those — a decline of 28%.

The sharpest decline was in areas with natural habitats. However, the team did find the gecko in 268 new cells, or in about 10.72 hectares (26.5 acres), where it hadn’t been previously observed. Most of these areas contained human-influenced habitats like gardens.

With the species now occupying just 24 hectares (59.3 acres) along Réunion’s southern coast, it is likely “the rarest endemic terrestrial vertebrate on the island in terms of its distribution,” the researchers say.

They further speculate that the recent shift in its distribution to garden-like habitats could be because such areas contain diverse species of palm trees that are frequently watered. The gecko prefers to bask or hide in palm-like trees. Natural habitats, by contrast, support fewer palm species and are more exposed to heat and drought, the authors say. Additionally, gardens provide food sources all year round, including flowers and fruits that attract insect prey, while structures like pipes and buildings protect the geckos from predators and extreme weather. The invasive gold-dust day gecko (P. laticauda) is a rising competitor and threat to the Manapany day gecko.

The researchers recommend urban areas could be made more suitable for the Manapany day gecko by planting gecko host plants. Additionally, educating local people about the gecko,  and preserving the remaining 2.72 hectares (6.7 acres) of its natural habitat would safeguard the gecko’s survival in its historical range, they say.

Banner image of a Manapany day gecko by B.navez via Wikimedia Commons (CC BY-SA 3.0).

The Democratic Republic of Congo has banned the capture and trade of African gray parrots nationally, protecting one of the world’s most trafficked birds, according to a national decree signed Aug. 13.

Gray parrots (Psittacus erithacus), known for their intelligence and mimicry skills, are widely trapped from the wild for the international pet trade. This has decimated their populations across their range in Africa, including in DRC, where the birds have been partially protected since 2006.

Gray parrots were assessed as endangered on the IUCN Red List in 2016, and were added to Appendix I of CITES, the global wildlife trade treaty, banning the international commercial trade in the species. The DRC government, however, entered a “reservation” to the CITES listing, declaring it would continue exporting gray parrots, said Terese Hart of the NGO Lukuru Foundation that works to protect the birds in the DRC.

Hart told Mongabay that her group’s monitoring of the airport at Kisangani, a major city in eastern DRC, showed that gray parrot shipments initially decreased after 2016, but then rose steadily, surpassing pre-ban numbers.

“Mortality rates of 65-70% throughout the commercial chain mean that that for every parrot exported, two additional birds were also captured and removed from the wild, but did not survive,” she said.

To halt the overexploitation of gray parrots, three provinces key in DRC’s parrot trade recently banned their capture and trade within their limits. This set a precedent for the environment ministry to issue a national decree banning all domestic trade in the birds, Hart said, potentially closing a loophole used in other wildlife trade to hide illegal wildlife exports.

Wildlife trade researcher Neil D’Cruze from the nonprofit Canopy told Mongabay that the new national decree, if effectively enforced, could bring enormous benefits for both conservation and animal welfare. “It will also be important to extend protections to other parrot species that are often used to mask the smuggling of African greys, ensuring traffickers cannot simply switch tactics.”

However, one of the provisions in the original draft decree — to end the trade in red-fronted parrots (Poicephalus gulielmi), as all three provinces have done — was strongly opposed, Hart said. Traffickers often pass off African grays as red-fronted parrots, which can be legally exported from DRC. But protection for red-fronteds was ultimately withdrawn from the national decree, Hart said.

Official retraction of DRC’s reservation for the Appendix I CITES listing of gray parrots also faced opposition, Hart said, adding that traders use the reservation to claim DRC needn’t follow the treaty’s rules.

While the new national decree offers a rationale for the reservation’s retraction, a formal letter to CITES from DRC is further needed, said John Hart of Lukuru Foundation.

He added that his group’s priorities include the African gray’s insertion on DRC’s list of totally protected species. “The front door has been closed, so to speak; now, all the back doors must be fastened.”

Banner image: Gray parrot by L.Miguel Bugallo Sánchez via Wikimedia Commons (CCBY-SA3.0).

HANOI, Vietnam (AP) — Vietnam has evacuated hundreds of thousands of people and closed schools and airports as it braces for Typhoon Kajiki, its strongest storm of the year so far.

Forecasters said the typhoon had winds of up to 166 kilometers (103 miles) per hour at 10 a.m. Monday but is expected to weaken slightly before making landfall between central Vietnam’s Thanh Hoa and Ha Tinh provinces later in the afternoon.

The typhoon started as a weak tropical depression on Aug. 22 but grew into a powerful storm in less than two days, matching last year’s Typhoon Yagi as one of the region’s fastest-growing, according to state media. Its rapid strengthening forced Vietnamese authorities to rush emergency measures as strong winds and heavy rain hit the region.

Last year, Typhoon Yagi killed about 300 people and caused $3.3 billion in damage.

Kajiki has already caused devastation in China, with strong winds and heavy rain whipping Hainan Island and nearby parts of Guangdong province on Sunday. About 20,000 people were evacuated from high-risk areas, China’s official Xinhua News Agency reported.

One man in Nghe An province died Friday after being electrocuted while trying to secure his roof ahead of the storm, state media reported.

The storm is expected to move inland into Laos and northern Thailand.

Vietnamese state media reported plans to evacuate nearly 600,000 people in the provinces of Thanh Hoa, Quang Tri, Hue and Danang, where more than 152,000 homes are in high-risk areas.

The government said over 16,500 soldiers and 107,000 paramilitary personnel have been deployed to assist with evacuations and remain on standby for search and rescue.

Vietnam halted flights at two airports in Thanh Hoa and Quang Binh provinces on Monday, the Civil Aviation Authority of Vietnam said while dozens of flights have been cancelled.

Scientists published a study last year warning that seas warmed by climate change will result in Southeast Asia’s cyclones forming closer to land, strengthening faster and lasting longer, raising risks for cities.

“It’s frightening to see our projections from just last year already materializing,” said Benjamin Horton, Dean of the School of Energy and Environment and a professor of earth science at City University of Hong Kong.

He said that the speed at which these changes were unfolding was a “clear signal” that the climate crisis is moving faster than expected. “We are no longer predicting the future — we are living it,” he said.

By Aniruddha Ghosal, Associated Press

Banner image: People sit on a boat to get to their flooded homes in the aftermath of Typhoon Yagi in An Lac village, Hanoi, Vietnam Friday, Sept. 13, 2024. (AP Photo/Hau D