Wednesday, November 26, 2025

Extensive survey of Eastern tropical Pacific finds remote protected areas harbor some of the highest concentrations of sharks



First-of-its-kind assessment in seven marine parks in Ecuador, Costa Rica, Colombia and Mexico finds bountiful ocean predator populations in remote areas—and worryingly few predators in protected areas closest to coastlines



National Geographic Pristine Seas




Puerto Ayora, Galapagos | 26 November, 2025 – One of the most comprehensive surveys to date of shark and other large predator fish in the Eastern Tropical Pacific (ETP) ocean finds that  remote Marine Protected Areas (MPAs)—including the Galapagos, Malpelo, Clipperton, and Revillagigedo islands—support some of the largest numbers of sharks reported globally, including the critically endangered scalloped hammerhead, while coastal MPAs are showing signs of severe depletion. 

“The oceanic islands of the Eastern Tropical Pacific represent a window into the past, where sharks and large predatory fishes are the norm and not the exception,” says Dr. Pelayo Salinas-de-León, Principal Investigator at the Charles Darwin Foundation and senior author of the study. “These areas provide a glimpse of what a healthy ocean looks like and highlight the key role ocean conservation plays in safeguarding these last strongholds from systematic overfishing”. 

The study, published in PLOS One today, was led by researchers from the Charles Darwin Foundation (CDF), in collaboration with National Geographic Pristine Seas, the Galapagos National Park Directorate and other regional research institutions. The research team used Baited Remote Underwater Video systems (BRUVs) to assess shark and other large predators in seven MPAs, including four oceanic (Galapagos, Malpelo, Clipperton, and Revillagigedo) and three coastal (Machalilla, Galera San Francisco, and Caño Island).  Using a similar assessment approach to the Global FinPrint initiative in other tropical regions of the world, the research closes a gap on knowledge about shark and other predator populations in the Eastern Pacific.  

“Oceanic islands, like Galapagos and Malpelo, are incredible places where extraordinary populations of sharks and other large predatory fishes – like jacks, groupers, and snappers – still thrive at a time when these fish are rapidly disappearing elsewhere,” explains Simon McKinley, lead author of the study. “The Marine Protected Areas around them combined with their remote location provide protection to marine communities from unsustainable fishing practices, allowing animals to live out their natural lives largely undisturbed.”

Additional study findings include:

  • The oceanic island MPAs surveyed support abundant and diverse fish communities across all levels of the food web.  

  • Most Galapagos sharks observed at Clipperton measured at juvenile sizes, suggesting that the MPA functions as an important nursery site. In contrast, mostly larger, mature individuals were measured at other island MPAs, indicating these sites serve as adult aggregation or foraging grounds. These findings highlight the complementarity of different MPAs in a regional network in protecting different habitats that support the different life-stages of sharks. 

  • Predatory fish communities differed between the oceanic islands, likely influenced by regional currents and local environmental conditions such as temperature and food availability. The critically endangered scalloped hammerhead shark (Sphyrna lewini) was recorded most frequently in the southern MPAs of Galapagos and Malpelo, while the vulnerable silvertip shark (Carcharhinus albimarginatus) was the most commonly observed species in the northern MPAs of Revillagigedo and Clipperton. These patterns highlight how each Marine Protected Area harbors distinct marine communities, underscoring the need for management strategies tailored to their unique ecological conditions.

In contrast to assessments of the remote island MPAs, surveys of coastal MPAs revealed few large predators and low fish abundances, which are signs of a marine ecosystem under pressure. Scientists describe this trend as “fishing down the food web”, an unsustainable practice where the removal of large species, like sharks, means fishers catch smaller species at lower levels in the food web, ultimately leading to their extinction. 

“The fact that we observed only a small handful of sharks and large predatory fishes in these coastal MPAs is worrying. Especially as there are past records of them in these areas,” adds McKinley. “The sad reality is that, despite being within protected areas, these species have likely been unsustainably fished over time to the point that they have been partly or entirely removed from marine ecosystems.”

More than 77 MPAs have been designated in Mexico, Costa Rica, Panama, Colombia, and Ecuador, including oceanic islands within their Exclusive Economic Zones (EEZs). These MPAs vary in their level of protection, ranging from allowing extractive activities, to mixed-use management approaches, to fully protected no-take zones, where all human activity is strictly forbidden. 

“This study reinforces what we already know: strictly-protected marine reserves where extractive activity is banned is the best way to help the ocean recover,” remarked Enric Sala, National Geographic Explorer in Residence and founder of Pristine Seas who served as an author on the study. “But it also shows that when fishing is allowed in MPAs — as in many so-called ‘protected areas’ in the Eastern Tropical Pacific — they can’t replenish marine life. Minimally-protected MPAs simply aren’t able to offer the benefits that countries hope for.”

The study was conducted over a series of expeditions across the ETP region together with local partners such as the Malpelo Foundation in Colombia, Pelagios Kakunja in Mexico and France, Osa Conservation in Costa Rica and Ecuador’s Ministry of Environment. These 2-3 week-long expeditions were mostly undertaken as part of the Pristine Seas efforts to explore, document and help safeguard some of the most pristine parts of our oceans. This research is also part of ongoing efforts by CDF to strengthen science-based conservation across the Eastern Tropical Pacific. 

Currently, less than 10% of the ocean is in some form of protection — and only 3% is highly protected from damaging activities. An overwhelming body of peer-reviewed research shows that MPAs that ban fishing are the most effective mechanism to replenish marine life and deliver countless benefits to people, the economy and the climate. 

“We only have five years left to achieve the global goal of protecting 30% of the ocean by 2030, with research showing we must establish 300 large, remote MPAs and 190,000 smaller, coastal MPAs to achieve the target,” said Sala. “The success of the remote island MPAs of the Eastern Pacific Ocean serve as inspiration to us all.” 

This research was made possible thanks to the financial support of the Save Our Seas Foundation, the Mark Rohr Foundation, the Darwin and Wolf Conservation Fund, MAC3 Impact Philanthropies, Rolex Perpetual Planet, Sven Lindblad and National Geographic Pristine Seas donors.

For over 65 years, the Charles Darwin Foundation has worked in close partnership with the Galapagos National Park Directorate to conduct scientific research that supports conservation and the sustainable management of the Galapagos Islands—one of the world’s most extraordinary natural laboratories. Today, CDF is actively working as part of the CMAR network (Eastern Tropical Pacific Marine Corridor) to create a safe corridor for migratory species to roam freely throughout the region.

- ENDS -

About the Charles Darwin Foundation 

The Charles Darwin Foundation for the Galápagos Islands (CDF) is an international non-profit organization that has operated in Galapagos since 1959 under a special agreement with the Government of Ecuador. Its mission, and that of its Research Station, is to address the greatest threats and challenges facing Galapagos through scientific research and conservation actions, to protect one of the world’s most important natural treasures. Today CDF supports more than 25 research, conservation, and education projects across land and sea, and is the custodian of over 137,000 specimens in its Natural History Collections. Its diverse team of more than 140 scientists, educators, and support staff is composed primarily of Ecuadorian citizens, with over 60% from Galápagos. For more information, please visit: www.darwinfoundation.org 

About National Geographic Pristine Seas 

National Geographic Pristine Seas works with Indigenous and local communities, governments, and other partners to protect vital places in the ocean through research, policy, and filmmaking. Since 2008, Pristine Seas has helped establish 31 marine protected areas, spanning more than 6.9 million square kilometers of ocean.

Pristine Seas is part of the global non-profit, the National Geographic Society. Our mission is driven by science and filmmaking — we are fully independent from National Geographic publishing and its media arm.

 

Tsunami from massive Kamchatka earthquake captured by satellite





Seismological Society of America

Model animation of M8.8 Kamchatka, Russia 2025 tsunami 

video: 

This animation shows the simulated tsunami wave heights generated by the M8.8 earthquake. Around 70 minutes after the earthquake, the path of the SWOT satellite appears, shown in slow motion to illustrate how the fast-moving satellite captured the tsunami and the dispersive waves that followed the main crest. 

view more 

Credit: Angel Ruiz-Angulo




A satellite deployed to measure ocean surface heights was up to the challenge when a massive earthquake off the Kamchatka Peninsula triggered a Pacific-wide tsunami in late July.

The Surface Water Ocean Topography or SWOT satellite captured the first high-resolution spaceborne track of a great subduction zone tsunami, researchers report in The Seismic Record.

The track shows an unexpectedly complex pattern of waves dispersing and scattering across the ocean basin, one that could help tsunami scientists better understand how these events propagate and how they could threaten coastal communities.

Angel Ruiz-Angulo at the University of Iceland and colleagues also used data from DART (Deep-ocean Assessment and Reporting of Tsunamis) buoys in the path of the tsunami to build a better picture of the magnitude 8.8 earthquake rupture. The 29 July event in the Kuril-Kamchatka subduction zone was the sixth largest earthquake recorded globally since 1900.

“I think of SWOT data as a new pair of glasses,” said Ruiz-Angulo. “Before, with DARTs we could only see the tsunami at specific points in the vastness of the ocean. There have been other satellites before, but they only see a thin line across a tsunami in the best-case scenario. Now, with SWOT, we can capture a swath up to about 120 kilometers wide, with unprecedented high-resolution data of the sea surface.”

SWOT was launched in December 2022, as a joint mission of NASA and the French space agency Centre National d’Etudes Spatiales, to provide the first global survey of Earth’s surface water.

Ruiz-Angulo said he and study co-author Charly de Marez “had been analyzing SWOT data for over two years understanding different processes in the ocean like small eddies, never imagining that we would be fortunate enough to capture a tsunami.”

Since the wavelength of a big tsunami is longer than the ocean’s depth, researchers often consider these tsunamis to be “non-dispersive.” That is, they mostly remain intact as a singular wave shape as they travel, instead of breaking up or “dispersing” into a leading wave and a train of trailing waves.

“The SWOT data for this event has challenged the idea of big tsunamis being non-dispersive,” Ruiz-Angulo explains.

Numerical models of tsunami propagation with dispersion were a better match for the satellite observations of the Kamchatka tsunami, he and his colleagues concluded.

“The main impact that this observation has for tsunami modelers is that we are missing something in the models we used to run,” Ruiz-Angulo added. “This ‘extra’ variability could represent that the main wave could be modulated by the trailing waves as it approaches some coast. We would need to quantify this excess of dispersive energy and evaluate if it has an impact that was not considered before.”

The researchers also realized the tsunami predicted by an earlier model based on seismic and land deformation data did not exactly match the tsunami observations collected by two of the DART tide gauges. The tsunami based on the earlier model was predicted to hit one gauge earlier and one gauge later than observed. The researchers used the DART data in an analysis called inversion to reevaluate the tsunami source.

They concluded that the Kamchatka earthquake source extended further to the south and that the earthquake rupture length was 400 kilometers—significantly longer than the 300 kilometers predicted by other models.

“Ever since the 2011 magnitude 9.0 Tohoku-oki earthquake in Japan, we realized that the tsunami data had really valuable information for constraining shallow slip,” said study co-author Diego Melgar.

Since then, Melgar’s lab and others have been working on ways to include DART data in inversions, “but it is still not always done because the hydrodynamic models needed to model DARTs are very different than the seismic wave propagation ones for modeling the solid Earth data. But, as shown here again, it is really important we mix as many types of data as possible,” Melgar said.

One of the largest recorded Pacific tsunamis was triggered by a massive magnitude 9.0 earthquake in 1952 in the same Kuril–Kamchatka subduction zone. That tsunami led to the creation of the international alert system that led to Pacific-wide warnings during the 2025 event.

“With some luck, maybe one day results like ours can be used to justify why these satellite observations are needed for real or near-real time forecasting,” Ruiz-Angulo said.

 

Tai chi as good as talking therapy for managing chronic insomnia


Results support use of tai chi for long term management of chronic insomnia in over 50s



BMJ Group


Tai chi, a form of mind-body exercise widely practiced in Chinese communities, has similar benefits to talking therapy for middle aged and older people with chronic insomnia, finds a trial from Hong Kong published by The BMJ today.

These results support the use of tai chi for the long term management of chronic insomnia in middle-aged and older adults, say the researchers.

Chronic insomnia is one of the most common sleep disorders in middle aged and older adults and has been linked to increased risks of cardiovascular diseases, mental disorders, and cognitive impairment.

Cognitive behavioural therapy (CBT) is the preferred treatment for chronic insomnia, but access is often limited by the high costs and low availability of therapists.

Previous studies have also shown benefits of tai chi in middle aged and older adults with insomnia, but direct comparisons with active treatments such as CBT are lacking.

To address this gap, researchers set out to assess whether tai chi is comparable (“non-inferior”) to cognitive behavioural therapy for insomnia (CBT-I) for managing chronic insomnia in middle aged and older adults.

Their findings are based on 200 Chinese adults aged 50 years or older diagnosed with chronic insomnia and enrolled at a research centre in Hong Kong between May 2020 and July 2022. 

Participants were able to walk without assistance, were free of chronic conditions that may affect sleep, were not taking part in regular aerobic or mind-body exercise, had not received previous CBT-I treatment, and were not working shifts. 

Participants were randomised to receive tai chi or cognitive behavioural therapy interventions for insomnia (CBT-I), consisting of one hour group sessions twice a week for a total of 24 sessions.

The Insomnia Severity Index (ISI) was used to assess change in perceived insomnia severity immediately after the 3-month interventions and at 12-month follow-up (month 15) by scoring symptoms such as difficulty falling and staying asleep, waking up too early and being unable to go back to sleep, and impact on daily life. 

An ISI threshold of four points was used as the margin to assess non-inferiority. 

At the start of the trial, both groups showed moderate levels of insomnia severity. At month 3, the tai chi group showed a reduction of 6.67 points in ISI scores, while the CBT-I group had a reduction of 11.19 points, resulting in a between group difference of 4.52. Tai chi was therefore deemed inferior to CBT-I at month 3 because the upper confidence limit exceeded the non-inferiority margin. 

However, at month 15, the reductions for the tai chi and CBT-I groups were 9.51 and 10.18, respectively, with a between group difference of 0.68. At this point, tai chi was considered non-inferior to CBT-I because the upper limit fell within the non-inferiority margin.

Tai chi and CBT-I also had comparable benefits on subjective sleep parameters, quality of life, mental health, and physical activity level. No adverse events occurred during the intervention period. 

The authors acknowledge that the positive effects of tai chi may be partially due to participants’ continued practice after the end of the interventions, and say further studies are needed to determine whether the benefits of tai chi can be applied to other countries or regions with different demographic characteristics.

However, they conclude: “Our study supports tai chi as an alternative treatment approach for the long term management of chronic insomnia in middle aged and older adults.”

 

Study links America’s favorite cooking oil to obesity




Scientists uncover metabolic pathway behind weight gain in mice



University of California - Riverside





Soybean oil, the most widely consumed cooking oil in the United States and a staple of processed foods, contributes to obesity, at least in mice, through a mechanism scientists are now beginning to understand.

In an experiment conducted at UC Riverside, most mice on a high-fat diet rich in soybean oil gained significant weight. However, a group of genetically engineered mice did not. These mice produced a slightly different form of a liver protein that influences hundreds of genes linked to fat metabolism. This protein also appears to change how the body processes linoleic acid, a major component of soybean oil.

“This may be the first step toward understanding why some people gain weight more easily than others on a diet high in soybean oil,” said Sonia Deol, a UCR biomedical scientist and corresponding author of the study published in the Journal of Lipid Research.

In humans, both versions of the liver protein HNF4α exist, but the alternative form is typically produced only under certain conditions, such as chronic illness or metabolic stress from fasting or alcoholic fatty liver. This variation, along with differences in age, sex, medications, and genetics, may help explain why some people are more susceptible than others to the metabolic effects of soybean oil.

The study builds on earlier work by UCR researchers linking soybean oil to weight gain. “We’ve known since our 2015 study that soybean oil is more obesogenic than coconut oil,” said Frances Sladek, a UCR professor of cell biology. “But now we have the clearest evidence yet that it’s not the oil itself, or even linoleic acid. It’s what the fat turns into inside the body.”

Linoleic acid is converted into molecules called oxylipins. Excessive consumption of linoleic acid can lead to increased amounts of oxylipins, which are associated with inflammation and fat accumulation.

The genetically engineered, or transgenic, mice in the study had significantly fewer oxylipins and showed healthier livers despite eating the same high-fat soybean oil diet as regular mice. Notably, they also exhibited enhanced mitochondrial function, which may help explain their resistance to weight gain.

The researchers narrowed the obesity-linked compounds down to specific types of oxylipins derived from linoleic acid and alpha-linolenic acid, another fatty acid found in soybean oil. These oxylipins were necessary for weight gain in regular mice.

However, transgenic mice on a low-fat diet also had elevated oxylipins without becoming obese, suggesting that the presence of these molecules alone isn’t enough, and other metabolic factors likely contribute to obesity.

Additional analysis revealed that the altered mice had much lower levels of two key enzyme families responsible for converting linoleic acid into oxylipins. Notably, the function of these enzymes is highly conserved across all mammals, including humans. Levels of these enzymes are known to be highly variable based on genetics, diet, and other factors.

The team also noted that only oxylipin levels in the liver, and not the in the blood, correlated with body weight. This means common blood tests may not reliably capture early metabolic changes linked to diet.

Soybean oil consumption in the U.S. has increased five-fold in the past century, from about 2% of total calories to nearly 10% today. Although soybeans are a rich source of plant-based protein and their oil contains no cholesterol, the overconsumption of linoleic acid, including from ultra-processed foods, may be fueling chronic metabolic conditions.

Additionally, despite the lack of cholesterol in the oil, the UCR study found that consumption of soybean oil is associated with higher cholesterol levels in mice.

The researchers are now exploring how oxylipin formation causes weight gain, and whether similar effects occur with other oils high in linoleic acid, such as corn, sunflower, and safflower.

“Soybean oil isn’t inherently evil,” Sladek said. “But the quantities in which we consume it is triggering pathways our bodies didn’t evolve to handle.”

Though no human trials are planned, the team hopes these findings will help guide future research and inform nutrition policy.

“It took 100 years from the first observed link between chewing tobacco and cancer to get warning labels on cigarettes,” Sladek said. “We hope it won’t take that long for society to recognize the link between excessive soybean oil consumption and negative health effects.”