(Press-News.org) Key takeaways:
By analyzing rare nitrogen isotopes in 5-million-year-old plankton fossils, researchers reconstructed past Pacific Ocean conditions to better forecast the future.
Even during the warmer Pliocene Epoch, nutrient-rich upwelling in the tropical Pacific remained stable, sustaining marine productivity.
The findings challenge predictions of a fisheries collapse.
TAMPA, Fla. (Oct. 1, 2025) – A team of scientists has uncovered a rare isotope in microscopic fossils, offering fresh evidence that ocean ecosystems may be more resilient than once feared.
In a new study co-led by Patrick Rafter of the University of South Florida, researchers show that warming in the tropical Pacific — home to some of the world’s most productive fisheries — may not trigger the severe declines predicted by earlier models. Instead, the region’s fisheries could remain productive even as ocean temperatures rise.
The paper will publish online in Science on Thursday, Oct. 2, 2025, at 2 p.m. ET and is embargoed until that time.
Rafter, a chemical oceanographer at USF’s College of Marine Science, said the findings are welcome news.
“Our measurements suggest that, on a warmer planet, the availability of marine nutrients to fuel plant growth and fisheries may not necessarily decline,” Rafter said.
The paper highlights a cutting-edge approach to predicting future ocean conditions by examining the distant past. Further study could reveal more reason for optimism about global ocean productivity.
The team turned to the Pliocene Epoch, 5.3 to 2.6 million years ago, when ocean warming trends were similar to today’s. By analyzing nitrogen isotopes preserved in the shells of tiny plankton called foraminifera (forams), researchers reconstructed nutrient characteristics in the tropical Pacific.
Today, nutrient upwelling in the region supports vast blooms of plankton — the base of the marine food chain. During warming events like El Niño, this process weakens, reducing nutrients and harming fisheries. Previous studies suggested such conditions could become permanent in a hotter world.
But Rafter and his colleagues found no evidence of reduced nitrate concentrations — a key nutrient for plankton — in the eastern tropical Pacific over the last five million years. The results suggest that nutrient upwelling and biological productivity remained stable despite higher global temperatures.
“We’ve used this nitrogen isotope like a geochemical fingerprint,” Rafter said. “We don’t have a time machine, but we can use our detective toolkit to reconstruct what happened in the ocean the last time Earth was as warm as today.”
Extracting the isotopes required painstaking work. Researchers from USF, the University of Massachusetts Boston, the University of California Irvine and Princeton University hand-sorted foram shells from deep-sea cores, dissolved them and analyzed the nitrogen isotopes with the help of bacteria.
“Analyzing nitrogen isotopes derived from forams has allowed us to reconstruct the past with precision,” Rafter said. “We can compare these past conditions to today and make better predictions about the future. The methods we’ve used represent a big step forward in improving our predictive capabilities.”
For Jesse Farmer, co-lead author and assistant professor at UMass Boston, the findings provide cautious optimism.
“Our current warming is happening so quickly that the ocean may behave differently than it does when it’s been warm for a long time, as was the case in the Pliocene,” Farmer said, also noting modern threats such as ocean acidification and overfishing. Still, he added: “It’s good news that the nutrient supply to the eastern Pacific food web will be maintained in a warmer ocean.”
Looking ahead, the team plans to apply their “detective toolkit” to other parts of the ocean.
“We’re looking at a changing system,” Rafter said. “What’s clear from this study is that the system is more complicated than we previously thought.”
Much of the research for the study was conducted while Rafter and Farmer were postdocs at Princeton in the lab of Daniel Sigman, the paper’s senior author.
###
About the University of South Florida
The University of South Florida is a top-ranked research university serving approximately 50,000 students from across the globe at campuses in Tampa, St. Petersburg, Sarasota-Manatee and USF Health. In 2025, U.S. News & World Report recognized USF with its highest overall ranking in university history, as a top 50 public university for the seventh consecutive year and as one of the top 15 best values among all public universities in the nation. U.S. News also ranks the USF Health Morsani College of Medicine as the No. 1 medical school in Florida and in the highest tier nationwide. USF is a member of the Association of American Universities (AAU), a group that includes only the top 3% of universities in the U.S. With an all-time high of $738 million in research funding in 2024 and as a top 20 public university for producing U.S. patents, USF uses innovation to transform lives and shape a better future. The university generates an annual economic impact of more than $6 billion. USF’s Division I athletics teams compete in the American Conference. Learn more at www.usf.edu..
END
CAMBIRDGE, MA -- At the heart of all lithium-ion batteries is a simple reaction: Lithium ions dissolved in an electrolyte solution “intercalate” or insert themselves into a solid electrode during battery discharge. When they de-intercalate and return to the electrolyte, the battery charges.
This process happens thousands of times throughout the life of a battery. The amount of power that the battery can generate, and how quickly it can charge, depend on how fast this reaction happens. However, little is known about the exact mechanism of this reaction, or ...
Polytetrafluoroethylene (PTFE) is a synthetic fluorine-based polymer with a wide range of applications, including non-stick cookware production and electrical and optical fiber cable coating, owing to its high durability, thermal stability, and low friction. Ironically, its durability also presents an environmental challenge for its disposal. PTFE is mainly disposed of via incineration, landfilling, and defluorination. However, incineration requires high energy and involves the release of hydrogen fluoride, which is highly corrosive. Meanwhile, landfilling leads to an environmental burden of undegraded PTFE. By contrast, defluorination, in ...
Bioengineers at the University of California San Diego have developed a powerful new technology that can map the entire network of RNA-protein interactions inside human cells — an achievement that could offer new strategies for treating diseases ranging from cancer to Alzheimer’s.
RNA-protein interactions regulate many essential processes in cells, from turning genes on and off to responding to stress. But until now, scientists could only capture small subsets of these interactions, leaving much of the cellular “conversation” hidden.
“This technology is like a wiring map of the cell’s conversations,” said ...
Adolescence is a period of social reorientation: a shift from a world centered on parents and family to one shaped by peers, schools, and broader networks. This expansion is critical for healthy development, but it also heightens susceptibility to social stressors. When those stressors lead young people to withdraw — choosing solitude more often than connection — the brain itself may be altered.
Using brain imaging and behavioral data, Caterina Stamoulis, PhD, and her team in the Division of Adolescent/Young Adult Medicine at Boston Children’s Hospital have found that adolescents who are ...
When University of Texas at Arlington researcher Paul J. Fadel and his colleagues launched a study on vascular health in people with chronic kidney disease, they expected to better understand a long-standing belief. For years, scientists have pointed to a blood marker called ADMA—asymmetric dimethylarginine—as a warning sign for vascular problems.
But the team’s findings, recently published in the American Journal of Physiology-Renal Physiology, told a different story.
Instead, another blood marker, SDMA—symmetric dimethylarginine—long considered mostly inactive, showed a stronger connection to vascular health than ADMA.
“The ...
Since 2022, American companies, consumers, and even the United Nations have used large language models—artificial intelligence (AI) systems such as ChatGPT that are trained to create text that reads like human-generated writing. In a study publishing October 2 in the Cell Press journal Patterns, researchers reveal that AI is used in an average of 17% of analyzed corporate and governmental written content, from job posts to press releases, and this rate will likely continue to increase.
“This is the first comprehensive review of the use of AI-assisted ...
The ‘big bad wolf’ fears the human ‘super predator’ – for good reason
Fear of the fabled ‘big bad wolf’ has dominated the public perception of wolves for millennia and strongly influences current debates concerning human-wildlife conflict. Humans both fear wolves and, perhaps more importantly, are concerned about wolves losing their fear of humans – because if they fear us, they avoid us and that offers protection.
A new Western University study shows that even where laws are in place to protect them, wolves fully fear the human ‘super predator.’
These findings ...
Chronic kidney disease (CKD) affects more than 700 million people worldwide and is caused by genetic and environmental factors, as well as existing medical conditions. Known genetic risk factors for CKD include mutations in a gene called APOL1. These are rare in most populations, but two risk variants are present in as much as 13 percent of people with West African origin and another 38% possess one copy (carriers). The causes for APOL1-mediated kidney disease (AMKD) are currently not well ...
About The Study: This repeated cross-sectional study provides a picture of the evolution of cardiometabolic risk factors in children over the last 30 years, showing that, in Spain, despite the concerning prevalences of excess weight, lipid parameters and blood pressure have improved over the studied period.
Corresponding Author: To contact the corresponding author, Sergio Nunez de Arenas-Arroyo, PhD, email sergio.nunezdearenas@uclm.es.
To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/
(doi:10.1001/jamanetworkopen.2025.35004)
Editor’s ...
About The Study: This multicenter quality improvement study found that use of an ambient artificial intelligence (AI) scribe platform was associated with a significant reduction in burnout, cognitive task load, and time spent documenting, as well as the perception that it could improve patient access to care and increase attention on patient concerns in an ambulatory environment. These findings suggest that AI may help reduce administrative burdens for clinicians and allow more time for meaningful work and ...
