Manta rays create mobile ecosystems, study finds

A new study reveals how manta rays form unique interactions with other fishes in South Florida waters—highlighting their complex ecological interactions between species that support ocean life.

University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science

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Juvenille Atlantic manta ray swimming over sandflat with remora symbionts in South Florida

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Credit: Bryant Turffs

MIAMI, FL – A new study from the University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science and the Marine Megafauna Foundation finds that young Caribbean manta rays (Mobula yarae) often swim with groups of other fish, creating small, moving ecosystems that support a variety of marine species.

South Florida—particularly along Palm Beach County—serves as a nursery for juvenile manta rays. For nearly a decade, the Marine Megafauna Foundation has been studying these rays and documenting the challenges they face from human activities near the coast, such as boat strikes and entanglement in fishing gear, which can pose significant threats to juvenile mantas

“Using video footage collected between 2016 and 2021, we analyzed 465 videos to better understand which species swim with manta rays and how they interact,” said Emily Yeager, lead author of the study and a doctoral candidate in the Department of Environmental Science and Policy at the Rosenstiel School. “We looked at which fish were present, how many there were, and where they tended to gather—often around the manta’s gills, eyes, wings, and tail.”

The study found that four families of teleost fish, the largest group of ray-finned fishes, regularly associate with young mantas. The most frequent companions are remoras—also known as suckerfish—which attach themselves to larger animals using a suction-like dorsal fin. Other fish that commonly accompany mantas include species important to Florida’s fisheries, such as jacks and cobia.

“Understanding ecological interactions between species is essential to conserving the marine environment,” said Catherine Macdonald, an associate professor in the Department of Environmental Science and Policy, and the director of the Shark Research and Conservation Program at the Rosenstiel School. “Our results suggest that these species may be interdependent and form long-lasting and relatively stable relationships, creating mobile ecosystems where fish may mature, feed, or mate.” 

Because South Florida is a busy area for boating and recreational fishing, juvenile manta rays are especially vulnerable to being struck by boats or caught in fishing lines. The study underscores the importance of responsible boating to help safeguard manta rays and the communities of fish they support.

“Slowing down in areas where mantas are known to feed near the surface is a simple but crucial step toward protecting these young rays,” said Jessica Pate of the Marine Megafauna Foundation, a co-author of the study. “Responsible boating and fishing can help protect these species and their critical ecological interactions long-term.”

“The findings provide valuable insights for marine conservation and policy, showing that manta rays act as living habitats that support biodiversity in coastal waters.” Yeager added.

The research was supported by the University of Miami’s Maytag Fellowship and a Florida Sea Grant–Guy Harvey Fellowship held by Ph.D. candidate Emily Yeager.

The study, titled “Stability and spatial variance of Mobula yarae-associated fish aggregates in South Florida,” was published in the journal Marine Biology on December 15, 2025. The authors include Emily Yeager*¹², Jessica Pate³, Julia Saltzman¹⁴, Christian Pankow¹, and Catherine Macdonald¹². ¹ Shark Research and Conservation Program, University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science, ² Department of Environmental Science and Policy, ³Marine Megafauna Foundation, ⁴ Department of Biology, University of Miami

About the University of Miami and Rosenstiel School of Marine, Atmospheric and Earth Science

 The University of Miami is a private research university and academic health system with a distinct geographic capacity to connect institutions, individuals, and ideas across the hemisphere and around the world. The University’s vibrant academic community comprises 12 schools and colleges serving more than 19,000 undergraduate and graduate students in more than 180 majors and programs. Located within one of the most dynamic and multicultural cities in the world, the University is building new bridges across geographic, cultural, and intellectual borders, bringing a passion for scholarly excellence, a spirit of innovation, and a commitment to tackling the challenges facing our world. The University of Miami is a member of the prestigious Association of American Universities (AAU).

 Founded in 1943, the Rosenstiel School of Marine, Atmospheric, and Earth Science is one of the world’s premier research institutions in the continental United States. The School’s basic and applied research programs seek to improve understanding and prediction of Earth’s geological, oceanic, and atmospheric systems by focusing on four key pillars:

*Saving lives through better forecasting of extreme weather and seismic events. 

*Feeding the world by developing sustainable wild fisheries and aquaculture programs. 

*Unlocking ocean secrets through research on climate, weather, energy and medicine. 

*Preserving marine species, including endangered sharks and other fish, as well as protecting and restoring threatened coral reefs. www.earth.miami.edu.

 

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Journal

Marine Biology

DOI

10.1007/s00227-025-04764-8 

Method of Research

Observational study

Subject of Research

Animals

Article Title

Stability and spatial variance of Mobula yarae-associated fish aggregates in south Florida

Article Publication Date

15-Dec-2025

Soil bacteria and fungi emerge as a top predictor of childhood allergic disease

Soil microbial communities appear more strongly linked to disease rates than demographics, wealth, or climate, new research suggests

American Geophysical Union

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NEW ORLEANS — The unique blend of fungi and bacteria in a region’s soil may be the strongest factor explaining its rates of childhood allergic disease, with certain assemblages of soil critters appearing linked with better health outcomes, according to new research to be presented at AGU’s 2025 Annual Meeting in New Orleans. Although a causative connection has yet to be established, the researchers say the pattern appears with remarkable consistency across the globe.

“We’ve analyzed the data in every way we can think of—adding datasets, looking at different measures of [soil] diversity…but no matter how we’ve done it, this result is consistent,” said Joshua Ladau, a microbial ecologist involved in the research and working at Arva Intelligence, a farmer-focused environmental solutions company. “At this point, I’m exceedingly confident this association is real.”

Ladau will present his research on 16 December at AGU25, joining more than 20,000 scientists discussing the latest Earth and space science research.

A global question

Allergic disease affects an estimated 2.5 billion people worldwide, or roughly 30% of humanity. A growing body of research indicates that exposure to a diversity of soil microbes, especially in childhood, can help limit allergic disease — potentially by helping us develop immune tolerance early in life, experts hypothesize. However, how much this matters in comparison to other influencing factors remains unclear.

“When you compare the effects of beneficial microbes with things like access to health care, genetics, climate, and pollution, how do they stack up? That was our question,” Ladau said. “Soils are not generally the things people point to first when thinking about health.”

To dig into this, the team drew on datasets recording the prevalence and severity of atopic dermatitis, asthma, and allergic rhinitis among over a million children in over 250 cities across 97 countries, plus three global surveys of soil fungal and bacterial diversity amounting to over 8,200 soil samples from around the globe. They then used a model to tease out the associations between the disease rates and soil biodiversity represented in the data.

The sheer volume of information made this a daunting task. Just preparing the massive datasets for analysis took many months, Ladau said. And the soil samples didn’t always come from the exact same locations as the allergic children, requiring the researchers to develop a mathematical method to account for the distance between them when drawing connections. Even so, Ladau said, “the fact that we’re seeing such a strong signal despite this mismatched dataset points to how important the microbial measures are in predicting allergic disease.”

On top of that, each soil sample contained thousands of microbial taxa, making it difficult to determine which ones were actually associated with lower rates of allergic disease. But having carried on this project since 2022, Ladau said his team is starting to figure it out. Based on their model, soil microbes are the most important predictor of regional differences in allergic rhinitis and asthma, in terms of both disease prevalence and severity. Compared to already-known predictors of allergic disease like climate, wealth, and demographics, soil microbes are up to four times more predictive than the next most important variable.

(Microbial) community matters

Crucially, simply having a broader diversity of microbes doesn’t seem to matter. Instead, it’s all about which microbes a soil has. “It looks like there are a number of taxa that are promoting health, and ones that are negatively associated, which makes sense — not everything out there is good,” Ladau said. What’s more, he added, those negative ones weren’t already known as pathogens, adding to the novelty of the discovery.

This doesn’t prove that soil microbes are causing kids to have less allergic disease, only that the two seem to go hand-in-hand. But so far, Ladau said, no other factor has emerged that accounts for that link.

Besides establishing whether the connection is causative, Ladau would like to investigate ways to promote public exposure to potentially healthful soils. This could happen through encouraging people to spend more time outdoors, but also through policies and land management strategies aimed at conserving and restoring soils—which can also improve soils’ ability to sequester carbon, remediate fire damage, decompose detritus, and control pest prevalence. Human health only adds to that list of boons, Ladau said.

“Linking soil biodiversity to public health provides a major additional facet to the importance of soils and what’s living in them,” he said.

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Abstract information:

Microbial Diversity in Soils Is the Top Predictor of Global Rates of Childhood Allergic Disease
Tuesday, 16 December, 2:15 – 5:45 P.M. CST

Hall EFG, Poster Hall (Convention Center)

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AGU’s Annual Meeting (#AGU25) will bring more than 20,000 Earth and space scientists to the Ernest N. Morial Convention Center in New Orleans, LA from 15-19 December. Members of the press and public information officers can request complimentary press registration for the meeting now through the end of the conference. Learn more about the press AGU25 experience in our online Press Center.

AGU (www.agu.org) is a global community supporting more than half a million professionals and advocates in Earth and space sciences. Through broad and inclusive partnerships, AGU aims to advance discovery and solution science that accelerate knowledge and create solutions that are ethical, unbiased and respectful of communities and their values. Our programs include serving as a scholarly publisher, convening virtual and in-person events and providing career support. We live our values in everything we do, such as our net zero energy renovated building in Washington, D.C. and our Ethics and Equity Center, which fosters a diverse and inclusive geoscience community to ensure responsible conduct.

Study showcases resilience and rapid growth of “living rocks”

Bigelow Laboratory for Ocean Sciences

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A pool of water dominated by microbialites in South Africa's Eastern Cape.

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Credit: Rachel Sipler, Bigelow Laboratory for Ocean Sciences

South Africa is home to some of the oldest evidence of life on Earth, contained in rocky, often layered outcroppings called microbialites. Like coral reefs, these complex “living rocks” are built up by microbes absorbing and precipitating dissolved minerals into solid formations.

A new study, co-led by researchers at Bigelow Laboratory for Ocean Sciences and Rhodes University, suggests that these microbialites aren’t just surviving — they’re thriving.

The paper, recently published in Nature Communications, quantifies how microbialites along the South African coast take up carbon and turn it into fresh layers of calcium carbonate. They show how these structures utilize photosynthesis and chemical processes to absorb carbon day and night, relating those rates for the first time to the genetic makeup of the microbial community. The findings highlight just how efficient these microbial mats are at removing dissolved carbon from their environment and sequestering it into stable mineral deposits.

“These ancient formations that the textbooks say are nearly extinct are alive and, in some cases, thriving in places you would not expect organisms to survive,” said Senior Research Scientist Rachel Sipler, the study’s lead author. “Instead of finding ancient, slow growing fossils, we’ve found that these structures are made up of robust microbial communities capable of growing quickly under challenging conditions.”

Scientists have struggled to understand how these microbial communities interact with their environment based on data from fossilized remains of microbialites — some of which are billions of years old. Fortunately, living microbialites are still widely distributed.

Inspired by how these mats can produce compounds with direct human use, Sipler and her colleagues aimed to understand the underlying geochemical processes at play in this novel environment. Across several field expeditions over multiple years, the team examined four microbialite systems in southeastern South Africa where calcium-rich hard water seeps out of coastal sand dunes.

“The systems here are growing in some of the harshest and most variable conditions,” Sipler said. “They can dry out one day and grow the next. They have this incredible resiliency that was compelling to understand.”

The team found that these systems were precipitating calcium carbonate rapidly, estimating that the structures can grow almost two inches vertically every year.

More surprising was the finding of carbon uptake day and night. These systems have long been assumed to be driven solely by photosynthesis, so Sipler says they were surprised to find nighttime uptake rates as high as during the day. After repeating their experiments several times, the researchers confirmed that the microbes are utilizing metabolic processes other than photosynthesis to absorb carbon in the absence of light, similar to how microbes living in deep-sea vents survive.

Based on daily rates of carbon uptake, the team estimates that these microbialites can absorb the equivalent of nine to 16 kilograms of carbon dioxide every year per square meter. That’s like a tennis court-sized area absorbing as much CO2 every year as three acres of forest, making these systems one of the most efficient biological mechanisms for long-term carbon storage observed in nature.

“We’re so trained to look for the expected. If we’re not careful, we’ll train ourselves to not see the unique characteristics that lead to true discovery,” Sipler said. “But we kept going out and kept digging into the data to confirm that the finding wasn’t an artifact of the data but an incredible discovery.”

Coastal marshes are similar to microbialites in that they’re a microbial mat ecosystem that’s been found to take in carbon at a similar rate. Yet, marsh microbes put all of that energy into organic matter, which can be easily broken down compared to stable, mineral structures. Given those differences, the team is continuing to investigate how environmental factors and variations in microbes present influence the fate of carbon in these different microbial systems, using the interdisciplinary expertise and international perspective of the research team.

“If we had just looked at the metabolisms, we would have had one part of the story. If we had just looked at carbon uptake rates, we would have had a different story. It was through a combination of different approaches and strong scientific curiosity that we were able to build this complete story,” Sipler said. “You never know what you’re going to find when you put people from different backgrounds with different perspectives into a new, interesting environment.”

The research was partially supported by internal funding from Bigelow Laboratory to kickstart new use-inspired research. Other sources of funding include the South African National Research Foundation, the Gordon and Betty Moore Foundation, and the International Development and Research Centre.

A cross sectional image of an actively growing microbialite from South Africa.

Credit

Thomas Bornman

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Journal

Nature Communications

DOI

10.1038/s41467-025-66552-8 

Method of Research

Experimental study

Subject of Research

Cells

Article Title

Integration of multiple metabolic pathways supports high rates of carbon precipitation in living microbialites

Article Publication Date

8-Dec-2025