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Showing posts sorted by date for query ecology. Sort by relevance Show all posts

Thursday, August 13, 2026


Genomics help identify endangered fish populations most vulnerable to climate change




Flinders University

Southern pygmy perch 

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The small native Australian freshwater fish, the southern pygmy perch (Nannoperca australis), has suffered major declines due to habitat loss, river regulation and prolonged droughts. Photo courtesy Michael P Hammer, a co-author of this study.

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Credit: Photo courtesy Michael P Hammer




Scientists have shown that genomics can help identify which wild populations are most vulnerable to climate change – offering practical guidance for the conservation of threatened species before declines become irreversible.

The study, led by researchers from Flinders University's Molecular Ecology Laboratory and published in the Journal of Heredity, examined the endangered southern pygmy perch across Australia's Murray-Darling Basin.

By combining climate modelling with genome-wide data from hundreds of fish, the researchers identified the populations most likely to struggle as climates continue to warm.

They also showed that carefully managed conservation breeding can preserve a species' capacity to adapt to future warming.

Lead author Dr Emily Booth says the research demonstrates how genomics is becoming an increasingly powerful tool to assist conservation.

"Climate change doesn't affect all populations equally. By combining genomic data with climate modelling, we can identify the populations most at risk and help conservation managers prioritise where actions are likely to have the greatest impact," she says.

The southern pygmy perch is a small freshwater fish native to south-eastern Australia that has suffered major declines due to habitat loss, river regulation and prolonged droughts. In the Murray-Darling Basin, it now survives in small, isolated populations, many with limited genetic diversity and reduced capacity to adapt to environmental change.

To assess its future prospects, the researchers analysed thousands of DNA markers from 467 fish collected at 30 sites across the species' remaining range in the basin.

The study found that populations in upland streams are generally more vulnerable to future climate change than those in lowland wetlands and rivers.

Elevation proved to be a strong predictor of this vulnerability – a finding that suggests conservation managers could use this simple landscape feature to flag high-risk populations in other freshwater ecosystems, without needing detailed genomic data for every case.

The researchers also evaluated one of Australia's best-known freshwater fish recovery programs.

During the Millennium Drought, the southern pygmy perch disappeared from the Lower Lakes region of the Murray River, prompting a genetically informed captive breeding and reintroduction program.

The new study found that the restored population retained its capacity to adapt to future climate change – providing rare empirical evidence that conservation breeding guided by genomic information can preserve long-term evolutionary resilience.

Senior author Professor Luciano Beheregaray says the findings show how conservation genomics can directly inform management decisions.

"This is another study showing that genomics has moved beyond describing biodiversity to actively helping conserve it," says Professor Beheregaray. "We can now identify the populations most vulnerable to climate change and use that information to guide actions such as captive breeding, assisted gene flow and habitat restoration."

The researchers say the findings have implications well beyond the southern pygmy perch and Australia.

Freshwater fish are among the world's most threatened vertebrates, yet receive far less conservation attention than many other animal groups. The study offers a framework for using genomic data to identify vulnerable populations and prioritise conservation investment in freshwater ecosystems facing rapid environmental change.

The article, ‘Genomic vulnerability to climate change of a poorly dispersing and threatened fish, the southern pygmy perch (Nannoperca australis)’, by EJ Booth (Flinders University), CJ Brauer, J Sandoval-Castillo, SD Wedderburn, NS Whiterod, PJ Unmack, MP Hammer and LB Beheregaray (2026), has been published in the Journal of Heredity. https://doi.org/10.1093/jhered/esag052.

 

Pain wasn't the point: new study provides novel perspective on the story of snake venom evolution



Research led by Bangor University challenges assumptions about how snake venoms evolve




Bangor University





Pain wasn't the point: new study provides novel perspective on the story of snake venom evolution

Research led by Bangor University challenges assumptions about how snake venoms evolve.

For many people, the fear of venomous snakes is linked to one thing: pain.

Yet new research led by scientists at Bangor University suggests that, for Europe's vipers at least, causing pain may never have been a driving force in the evolution of their venom.

The study, published in the journal Functional Ecology by an international team of researchers from across Europe and Australia, examined the venoms of multiple European viper species to investigate a long-standing question in evolutionary biology: how are snake venoms shaped by the competing demands of catching prey and defending against predators?

The answer came as a surprise.

Professor Wolfgang Wüster, a venom evolution expert at Bangor University and senior author of the study explained

"We expected to find evidence that some vipers had evolved venom components specifically to cause rapid pain as a defensive mechanism.

“Instead, we found no evidence that the venoms directly activate pain-sensing nerve cells. This suggests that, in European vipers, venom evolution is driven overwhelmingly by the need to subdue prey."

A biological balancing act

Venom is one of nature's most sophisticated weapons. Snakes rely on it to immobilise and kill prey, but it can also help deter predators.

However, these dual roles present an evolutionary challenge. Venom glands contain a finite chemical cocktail, meaning different venom functions may compete for space and resources.

The researchers set out to test whether vipers that feed on relatively defenceless prey (insects) have more opportunity to evolve pain-inducing toxins for defence than species that regularly hunt tougher, more dangerous prey such as rodents.

To investigate, the team analysed venom samples collected from European vipers across the continent and tested their effects on specialised nerve receptors involved in sensing pain.

The scientists predicted that at least some species would show evidence of evolving toxins that trigger immediate pain, helping them fend off predators.

But that is not what they found.

No gain from pain

Despite considerable differences in venom composition between species, none of the venoms directly activated the pain-sensing receptors tested in the study, regardless of their diet.

The findings suggest that natural selection has prioritised hunting efficiency over defensive pain production during the evolution of European viper venoms.

In other words, venom appears to be optimised for securing a meal rather than delivering a warning.

Lead author Dr Bálint Üveges, a research fellow, who conducted the research as part of his work with Bangor University's Molecular Ecology and Evolution group and the Centre for Ecological Research of the Hungarian Research Network said:

"This challenges the idea that defensive and predatory functions drive venom evolution in different directions in snakes. Our results indicate that prey capture is the dominant force shaping venom composition in these species."

Why it matters

Understanding how and why snake venoms evolve is far more than an academic question.

According to the World Health Organisation, snakebite is a neglected tropical disease that kills more than 100,000 people every year and leaves hundreds of thousands more with permanent injuries or disabilities.

One of the biggest challenges in developing effective antivenoms is the enormous variation in venom composition, even within individual snake species.

By revealing the evolutionary forces that shape venom, scientists hope to better understand why these differences occur and how they may affect medical treatment.

Professor Wüster said: "To improve treatments for snakebite, we first need to understand what drives venom diversity. Studies like this help us uncover the evolutionary processes behind the venoms that cause so many medically important bites around the world."

An international effort

The research brought together scientists from institutions across the UK, Europe and Australia, combining expertise in venom biology, ecology, evolutionary science and neurobiology.

Ends

Note for editors:

  • The study was supported by the Leverhulme Trust, The Bangor Fund, Bangor University School of Environmental and Natural Sciences Research Support Funds, and the Welsh Government's Taith Research Mobility Programme.
  • The findings offer a fresh perspective on one of nature's most famous weapons and suggest that, for European vipers, evolution has focused on the practical business of putting food on the table rather than inflicting pain on would-be attackers.

 

 

Two oceans, one country, twenty times the number of sharks



Fossil shark scales from Panama reveal that its two coasts never had the same number of sharks




University of California - Santa Barbara

Shark Denticles 

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The shape of a dermal denticle is related to its primary function and can be used to identify the kind of shark it came from.

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Credit: Erin Dillon, Aaron O’Dea, and Jorge Ceballos





(Santa Barbara, Calif.) — How many sharks should a coral reef have? It sounds like a simple question, but almost nowhere on Earth is there a pristine, untouched reef. So there is no yardstick against which to measure shark decline or recovery.

Researchers at UC Santa Barbara and the Smithsonian Tropical Research Institute (STRI) in Panama answered this question with fossilized shark scales that the team jokingly call “shark dandruff.” The study, featured on the cover of Science, compares ancient shark populations from Panama’s Pacific and Caribbean coasts. The paper was led by Erin Dillon (Ph.D. ’22), who began this research during her doctoral studies at UCSB. The findings reveal that the two regions once supported vastly different densities of sharks, suggesting historical shark populations on one coast should not be used as a benchmark for the other.

“Sharks are a critically important part of healthy ocean ecosystems. But they've been hammered by overfishing, shark finning and habitat destruction,” said co-author Douglas McCauley, a professor in UCSB’s Department of Ecology, Evolution and Marine Biology. “Our efforts to bring back sharks have been hampered by our inability to answer a seemingly straightforward question: How many sharks are there actually supposed to be in the sea? Erin's research finally gives us a big part of that answer.”

Sharks Shed

Sharks are covered in dermal denticles, tiny tooth-like scales that they continuously shed through life. These tough scales settle into reef sediments, where they can be preserved for millions of years. Counting the denticles in a well-dated slice of sediment can yield an estimate of how many sharks swam overhead. That’s a boon to shark ecologists and marine managers, who have long wondered how many sharks were in the ocean before humans started dramatically altering the seas.

Assaying the deposits of ancient shark scales enabled the authors to finally establish historic baselines for shark abundance. “The shark denticle approach operates a little bit like a time machine,” McCauley explained, “giving us a peek at how many sharks there used to be in these areas of the oceans – and what kinds of sharks were there.”

The team applied this approach on both sides of the Isthmus of Panama, comparing sediments laid down between 7,000 and 3,000 years ago — long before intensive fishing — with sediments from the past century. The researchers collected 3,497 denticles from 157 samples.

The data took more than a decade to build, providing insights along the way. “This project began 12 years ago with a wild idea to search for shark scales in reef sediments,” said Dillon, now a postdoctoral researcher at STRI. “Finding the first denticle was exhilarating.”

The team had to work out what information the denticles could provide, how to collect them from reef sediments and how to interpret a fossil assemblage. “Panama represented the perfect place for applying the approach, because it let us compare shark baselines across two very different oceans separated by a single strip of land,” Dillon explained.

Hints of the results came early in the study. “In Bocas del Toro, on the Caribbean coast of Panama, we were finding around 50 shark denticles in 10 kilograms (22 pounds) of reef sediment,” said Aaron O'Dea, STRI staff scientist and co-corresponding author.  “When we took our first, much smaller sample, from a Pacific reef, we were shocked to find 200 denticles in just one kilogram (2.2 pounds).”

A tale of two coastlines

This difference continued to hold as the authors began modeling the data to account for variation in dating and effort. Before humans began heavily fishing, reefs in the Gulf of Panama on the Pacific coast supported roughly 20 times more sharks than their counterparts in the Caribbean. Yet the two regions are only about 100 kilometers away and share many of the same shark species.

The two coasts have diverged further in the intervening centuries. Caribbean denticle accumulation fell by about 75%, while Pacific rates today are statistically unchanged from their prehistoric baseline. The upshot is that reefs on Panama's Pacific coast now yield about 100 times more denticles than those on its Caribbean coast.

Scientists generally sensed that the Caribbean’s sharks had been hit hard. “But a 75% drop in abundance is a lot,” McCauley said. “That was a sobering result.”

What makes this particularly puzzling is that the Pacific coast has been fished much more heavily. More than 98% of Panama's fishing happens there.

“When we think about the oceanographic context of our samples, this pattern makes sense,” Dillon said. “The Gulf of Panama is a highly productive environment fueled by seasonal upwelling, which brings deep nutrients to the surface and provides enough food to support large predator populations.

“The Caribbean, on the other hand, is more nutrient-poor,” Dillon continued. The result is the glassy water from postcards of Caribbean coral reefs, where energy and nutrients are locked up in biomass, rather than available in the water column. The result is lower shark abundances that are more vulnerable to fishing.”

There’s the rub

These differences have practical consequences: Conservation targets set from the wrong baseline can be way off.

Resource managers routinely estimate how many sharks a reef ought to have by looking at the healthiest reef they can find nearby. In Panama, using the Pacific as a reference for the Caribbean, or assuming the two coasts have suffered comparable impacts, would set a conservation target off by an order of magnitude, or more. Ocean productivity, the authors argue, deserves as much weight as fishing history when recovery goals are set.

The findings are not, however, a clean bill of health for Pacific sharks. “Our samples from the last 100 years may not be telling the whole story,” said O'Dea. “Targeted shark fishing in the Gulf of Panama ramped up in the 1980s, so recent declines could be diluted when averaged across a century.”

Work by STRI staff scientist Héctor Guzmán shows that shark populations in Pacific Panama are under pressure from intensified fishing today. It could be enough to overpower the region’s historical resilience.

Climate change also looms over the future of the Pacific sharks. Last year the group reported that the upwelling that pumps cold, nutrient-rich water into the Gulf failed for the first time on record.

“Putting this together, sharks along Panama's Pacific coast have a high capacity to recover, but overfishing combined with changing ocean conditions may be pushing them into a state not seen for millennia,” O'Dea said.

This story was adapted for The Current from a release by The Smithsonian Tropical Research Institute.

 

Climate change decided who ruled as top predator 35 million years ago



A new study on European fossils reveals strong changes in body mass in predatory mammals occurred mainly after major environmental shifts




University of Liège

The rise of carnivoran mammals in Europe through the lens of body mass 

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Evolution of temperature (top) and body mass of carnivoramorphans (middle) and hyaenodonts (bottom) across the Paleogene.

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Credit: ULiège Valentin Fischer






An international team of researchers from Belgium, France, Switzerland, Spain, and the USA has reconstructed the evolution of body mass in carnivorous mammals during the Paleogene – a crucial window in the diversification of mammals, that follows the extinction of dinosaurs. This work, published in Biology Letters, challenges the long-standing hypothesis that competition decided the fate of ancient top predators.

Our cats, dogs, bears, and walruses, and their ancestors – forming together the clade Carnivoramorpha – once shared the planet with other groups of large meat-eating mammals that have since vanished. These groups, chiefly among them hyaenodonts, evolved large body size early in the Paleogene and became the top predators of their ecosystems. They disappeared in a step-wise fashion tens of million years afterwards, while carnivoramorphans diversified into a myriad of shapes, sizes, and ecologies.

 

The long-standing theory explaining this shift held that carnivoramorphans won their place at the top of the food chain by outcompeting the other clades, thanks to their more versatile teeth; but this idea rests almost entirely on the North American fossil record. To test this, the team investigated the rich fossil record of Europe and focused its efforts on reconstructing body mass trends from that record.

 

“Body mass is a powerful clue of the ecological role of continental animals” explains Prof. Valentin Fischer, director of the Evolution & Diversity Dynamics Lab at the Université of Liège and co-lead author of the study. “Because of these strong bonds between ecology and body mass, it is actually possible to reliably infer the body mass of ancient predators by measuring key traits in their dentition.”

Armed with body mass data on 155 fossil species spanning nearly the entire Palaeogene period, the scientists found that carnivoramorphans grew larger and far more diverse in body mass shortly after an abrupt global warming event 40 million years ago, known as the Middle Eocene Climatic Optimum. Contrary to what is seen in North America, their supposed rivals showed no associated decline; European hyaenodonts remained diverse for millions of years afterward, only declining following a major cooling event around 34 million years ago known as the “Grande Coupure”.

By showing that Europe's carnivoramorphans and their rivals coexisted for a long time, and that body-size change tracks climate events rather than diversity, this study suggests that regional climate, not a universal competitive advantage, decided who ruled as top predator, with strong differences in tempo across continents. The lineages that gave rise to todays’s lions, wolves, grizzlies, and racoons were shaped by past climate changes, and are now threatened by it.

WOTD WORD OF THE DAY

Eco‑nanozymology: a catalytic paradigm integrating energy, environment, and ecology





Shanghai Jiao Tong University Journal Center
Eco‑Nanozymology: A Catalytic Paradigm Integrating Energy, Environment, and Ecology 

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  • Eco-nanozymology is proposed as an ecosystem-oriented framework integrating cross-scale energy and matter cycling.
  • Ecological nanozymes demonstrate significant advances in energy conversion and environmental remediation.
  • Eco-nanozymes enable improved remediation efficiency, green energy technologies, and carbon neutrality.
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Credit: Limin Shang, Ziqi Zhang, Hongyu Lin, Zichang Wang, Dehong Chen*, Zhiling Zhu*.





As global challenges in energy scarcity, environmental pollution, and climate change intensify, conventional enzymatic catalysis faces limitations in stability, cost, and operational lifespan. Now, researchers from Qingdao University of Science and Technology, led by Professor Zhiling Zhu, Professor Dehong Chen, and their team including Limin Shang, Ziqi Zhang, Hongyu Lin, and Zichang Wang, have presented a groundbreaking conceptual framework that bridges nanotechnology, enzymology, and ecology—Eco-Nanozymology.

Why This Framework Matters

Traditional nanozyme research has largely focused on isolated catalytic reactions and material-level optimization, lacking systematic integration with ecosystem-level processes. Eco-nanozymology overcomes this limitation by positioning nanozymes as embedded regulatory nodes within coupled environmental transformation networks. Rather than treating nanozymes as standalone catalysts, this framework explicitly incorporates feedback coupling between nanozyme-mediated reactions and system-level matter and energy fluxes—enabling artificial regulation of energy flow and material cycling across scales.

Innovative Concept and Mechanism

The framework is built on the precise modulation of interfacial microstructures, electronic distributions, active site configurations, multienzyme cascade catalysis, and functionalized carrier engineering. By harnessing and amplifying natural ecological processes, eco-nanozymology enables effective modulation of biogeochemical cycles—including carbon fixation, nitrogen fixation, methane oxidation, and hydrogen production—while achieving efficient environmental remediation and low-value biomass valorization.

Outstanding Performance Across Domains

Energy Conversion: Eco-nanozymes demonstrate remarkable advances in artificial nitrogen fixation (NH3 production rates up to 50.82 μmol g-1 h-1 with Faradaic efficiencies exceeding 97%), photocatalytic CO2 reduction (CO generation rates of 740.7 μmol g-1 h-1 sustained over 188 h), and hydrogen evolution (915 L h-1 g-1). In energy storage systems, biomimetic nanozymes enhance lithium–oxygen batteries (1000 mAh g-1 after 100 cycles), lithium–sulfur batteries (991 mAh g-1 after 200 cycles), and zinc–air batteries (power densities up to 217.8 mW cm-2).

Environmental Remediation: Nanozyme systems achieve >90% mineralization of microplastics into CO2 and water without toxic intermediates, 94.27% degradation of methylene blue, and >80% removal of antibiotic pollutants within 30 minutes. For agricultural applications, symbiotic nanozymes boost soybean nitrogen fixation efficiency by 260% while enhancing photosynthetic performance by 67.2%.

Applications and Future Outlook

Eco-nanozymology establishes a unified theoretical foundation for designing next-generation catalytic systems with multi-responsiveness, tunability, and evolvable characteristics. The framework charts a development roadmap: short-term (1–3 years) focus on performance evaluation and ecological risk quantification; medium-term (3–7 years) AI-guided optimization and system integration; and long-term (7–15 years) realization of low-carbon, large-scale production across energy, environmental remediation, and ecosystem management.

By integrating emerging technologies such as AI-driven design, multi-scale modeling, and high-throughput synthesis with quantitative structure–activity relationships, eco-nanozymology opens promising avenues for addressing global sustainability challenges—offering green, environmentally friendly, and technologically viable pathways toward carbon neutrality and circular bioeconomy.

Stay tuned for more groundbreaking research from this collaborative team at Qingdao University of Science and Technology!