This work was centred around the lateral line sensing organ in African cichlid fish, but found in almost all fish species, that enables them to sense and interpret water pressures around them with enough acuity to detect external influences such as neighbouring fish, changes in water flow, predators and obstacles.

The lateral line system as a whole is distributed over the head, trunk and tail of the fish. It is comprised of mechanoreceptors (neuromasts) that are either within subdermal channels or on the surface of the skin.

Lead author Elliott Scott of the University of Bristol’s Department of Engineering Mathematics explained: “We were attempting to find out if the different areas of the lateral line — the lateral line on the head versus the lateral line on the body, or the different types of lateral line sensory units such as those on the skin, versus those under it, play different roles in how the fish is able to sense its environment through environmental pressure readings.

“We did this in a novel way, by using hybrid fish, that allowed for the natural generation of variation.”

They discovered the lateral line system around the head has the most important influence on how well fish are able to swim in a shoal, Meanwhile, the presence of more lateral line sensory units, neuromasts, that are found under the skin result in fish swimming closer together, while a greater presence of neuromasts on the skin tend to result in fish swimming further apart.

In simulation, the researchers were able to show how the mechanisms behind the lateral line work are applicable at not just the tiny scales found in actual fish, but at larger scales too. This could inspire a novel type of easily-manufactured pressure sensor for underwater robotics, particularly swarm robotics, where cost is a large factor.

Elliott said: “These findings provide a better understanding of how the lateral line informs shoaling behaviour in fish, while also contributing a novel design of inexpensive pressure sensor that could be useful on underwater robots that have to navigate in dark or murky environments.”

The team now plan to develop the sensor further and integrate it into a robotic platform to help a robot navigate underwater and demonstrate its effectiveness.

The research for this paper was funded by Engineering and Physical Sciences Research Council (EPSRC), Biotechnology and Biological Sciences Research Council (BBSRC) and the Human Frontier Science Program (HFSP).

Researchers say these findings, published in the peer-reviewed journal Alzheimer’s & Dementia: Translational Research and Clinical Interventions, may point the way to a cure.

“Many of these patients experience cognitive, behavioral and personality changes so severe that they are arrested or placed in nursing homes,” said Wouter Schievink, MD, director of the Cerebrospinal Fluid Leak and Microvascular Neurosurgery Program and professor of Neurosurgery at Cedars-Sinai. “If they have behavioral-variant frontotemporal dementia with an unknown cause, then no treatment is available. But our study shows that patients with cerebrospinal fluid leaks can be cured if we can find the source of the leak.”

Cerebrospinal fluid (CSF) circulates in and around the brain and spinal cord to help cushion them from injury. When this fluid leaks into the body, the brain can sag, causing dementia symptoms. Schievink said many patients with brain sagging — which can be detected through MRI — go undiagnosed, and he advises clinicians to take a second look at patients with telltale symptoms.

“A knowledgeable radiologist, neurosurgeon or neurologist should check the patient’s MRI again to make sure there is no evidence for brain sagging,” Schievink said.

Clinicians can also ask about a history of severe headaches that improve when the patient lies down, significant sleepiness even after adequate nighttime sleep, and whether the patient has ever been diagnosed with a Chiari brain malformation, a condition in which brain tissue extends into the spinal canal. Brain sagging, Schievink said, is often mistaken for a Chiari malformation.

Even when brain sagging is detected, the source of a CSF leak can be difficult to locate. When the fluid leaks through a tear or cyst in the surrounding membrane, it is visible on CT myelogram imaging with the aid of contrast medium.

Schievink and his team recently discovered an additional cause of CSF leak: the CSF-venous fistula. In these cases, the fluid leaks into a vein, making it difficult to see on a routine CT myelogram. To detect these leaks, technicians must use a specialized CT scan and observe the contrast medium in motion as it flows through the cerebrospinal fluid.

In this study, investigators used this imaging technique on 21 patients with brain sagging and symptoms of bvFTD, and they discovered CSF-venous fistulas in nine of those patients. All nine patients had their fistulas surgically closed, and their brain sagging and accompanying symptoms were completely reversed.

“This is a rapidly evolving field of study, and advances in imaging technology have greatly improved our ability to detect sources of CSF leak, especially CSF-venous fistula,” said Keith L. Black, MD, chair of the department of Neurosurgery and the Ruth and Lawrence Harvey Chair in Neuroscience at Cedars-Sinai. “This specialized imaging is not widely available, and this study suggests the need for further research to improve detection and cure rates for patients.”

The remaining 12 study participants, whose leaks could not be identified, were treated with nontargeted therapies designed to relieve brain sagging, such as implantable systems for infusing the patient with CSF. However, only three of these patients experienced relief from their symptoms.

“Great efforts need to be made to improve the detection rate of CSF leak in these patients,” Schievink said. “We have developed nontargeted treatments for patients where no leak can be detected, but as our study shows, these treatments are much less effective than targeted, surgical correction of the leak.”

Details of this lifestyle switch could provide new insights into the regulation of algal bloom dynamics and its impact on large-scale biogeochemical processes in marine environments.

Single-celled algae, known as phytoplankton, form oceanic blooms which are responsible for around half of the photosynthesis that occurs on Earth, and form the basis of marine food webs. Therefore, understanding the factors controlling phytoplankton growth and death is crucial to maintaining a healthy marine ecosystem. Marine bacteria from the Roseobacter group are known to pair up and coexist with phytoplankton in a mutually beneficial interaction. The phytoplankton provide the Roseobacter with organic matter useful for bacterial growth, such as sugar and amino acids, and the Roseobacter in return provides B-vitamins and growth-promoting factors.

However, recent studies have revealed that Roseobacters undergo a lifestyle switch from coexistence to pathogenicity, where they kill their phytoplankton hosts. A chemical compound called DMSP is produced by the algae and is hypothesised to play a role in this switch.

“We have previously identified that the Roseobacter Sulfitobacter D7 displays a lifestyle switch when interacting with the phytoplankter Emiliania huxleyi,” states first author Noa Barak-Gavish, a PhD graduate in the Department of Plant and Environmental Sciences, Weizmann Institute of Science, Israel. “However, our knowledge about the factors that determine this switch was still limited.”

To characterise this lifestyle switch, Barak-Gavish and colleagues performed a transcriptomics experiment, allowing them to compare the genes that are differentially expressed by Sulfitobacter D7 in coexistence or pathogenicity stages.

Their experimental setup demonstrated that Sulfitobacter D7 grown in a pathogenicity-inducing medium have a higher expression of transporters for metabolites such as amino acids and carbohydrates than those grown in a coexistence medium. These transporters serve to maximise the uptake of metabolites released from dying Emiliania huxleyi (E. huxleyi). Furthermore, in pathogenic Sulfitobacter D7, the team observed an increased activation of flagellar genes that are responsible for the movement of the bacteria. These two factors allow Sulfitobacter D7 to utilise an ‘eat-and-run’ strategy, where they beat competitors to the material released upon E. huxleyi cell death and swim away in search of another suitable host.

The team confirmed the role of DMSP in bringing about the switch to this killer behaviour by mapping the genes activated in Sulfitobacter D7 in response to the presence of DMSP and other algae-derived compounds. However, when only DMSP was present, the lifestyle switch did not occur. This implies that, although DMSP mediates the lifestyle switch, it is also dependent on the presence of other E. huxleyi-derived infochemicals — compounds that are produced and used by organisms to communicate. DMSP is an infochemical produced by many phytoplankton, so it is likely that the other required infochemicals allow the bacteria to recognise a specific phytoplankton host. In natural environments, where many different microbial species exist together, this specificity would ensure that bacteria only invests in altering gene expression and its metabolism when the correct algal partner is present.

The study also uncovers the role of algae-derived benzoate in Sulfitobacter D7 and E. huxleyi interactions. Even in high concentrations of DMSP, benzoate functions to maintain the coexistence lifestyle. Benzoate is an efficient growth factor and is provided by E. huxleyi to Sulfitobacter D7 during coexistence. The authors propose that as long as Sulfitobacter D7 benefits from coexistence by receiving materials for growth, it will maintain the mutualistic interaction. When less benzoate and other growth substrates are provided, the bacteria undergoes the lifestyle switch and kills its phytoplankton host, swallowing up any remaining useful materials.

The exact mechanism of Sulfitobacter D7 pathogenicity against E. huxleyi remains to be discovered, and the authors call for further work in this area. The cellular machinery Type 2 secretion system — a complex that many bacteria use to move materials across their cell membrane — is more prevalent in Sulfitobacter D7 compared to other Roseobacters, hinting at a unique method of pathogenicity that requires further investigation.

“Our work provides a contextual framework for the switch from coexistence to pathogenicity in Roseobacter-phytoplankton interactions,” concludes senior author Assaf Vardi, a Professor in the Department of Plant and Environmental Sciences, Weizmann Institute of Science. “These interactions are an underappreciated component in the regulation of algal bloom dynamics and further study in this area could provide insights into their impact on the fate of carbon and sulfur in the marine environment.”

Scientists at the University of Reading studied the relative fortunes of 50 species of large carnivores worldwide over the past fifty years. They found social and economic factors, such as quality of life, were more closely associated with declines of large carnivore species, than purely environmental features like habitat loss.

The first-of-its-kind study suggests that the best way to save carnivores, such as lynx, bears and lions, is to encourage a sustainable model of social and economic development, rather than focusing only on issues such as climate change. As people get richer, their tolerance for big cats and other carnivores increases.

Rapid declines

Dr Thomas Frederick Johnson, who led the study while based at Reading, said: “Our habitat and climate has become degraded and chaotic to make-way for rapid economic development. We know this has driven biodiversity declines, but our research found that this economic development is causing far more extreme declines than anyone expected and imagined.

“In the midst of rapid development, people appear to become less tolerant of carnivores, conflicts explode, and we suspect that incidences of poaching and persecution rocket.

“The decline of large carnivores is stark. Lions and tigers are already absent from more than 90% of their historic range. At home, many of the UK carnivore species, such as lynx, wolf and bear have already been hunted into extinction.”

‘Turning point’

The study, published in Nature Communications in partnership with the UK Centre for Ecology & Hydrology and the Argentinian Instituto de Biología Subtropical, involved the research team examining how changes to the social and economic system could promote carnivore recoveries.

While rapid economic development pushes species to the brink of extinction, it has also delivered enormous improvements in our quality of life. However, analysis from Dr Johnson and his fellow ecologists suggests that once people achieve a high quality of life and economic development slows, a turning point is reached and persecuted species have an opportunity to recover.

The researchers suggest the recovery is partly linked to improved habitat protection in advanced economies, but also a more harmonious relationship between people and carnivores. What would once have been considered a dangerous pest is now being recognised as an important component of our ecosystems and culture.

The resurgence of large carnivores can already be seen in western Europe, where an improved quality of life and slower economic development has allowed populations of grey wolves to rocket 1,800% since the 1960s.

Dr Johnson said: “This gives us hope that we can restore our lost ecosystems and we could one day see lost carnivores return to British shores. But we also need to think about how we can save wildlife in countries currently experiencing rapid growth, where species extinctions are likely.

“Our results suggest that a slower, more sustainable, economic model can protect carnivore populations, but this also risks locking people into poverty for longer. We urgently need to develop solutions that can support both biodiversity and people, and perhaps the world’s advanced economies need to offer more financial aid to protect our global biodiversity.”

Snaring CO₂ before it floats into the atmosphere is a key component in slowing global warming. Creating incentives for the largest emitters to adopt carbon capture technology, however, is an important precursor. The high cost of commercial capture technology is a longstanding barrier to its widespread use.

PNNL scientists believe methanol can provide that incentive. It holds many uses as a fuel, solvent, and an important ingredient in plastics, paint, construction materials and car parts. Converting CO₂ into useful substances like methanol offers a path for industrial entities to capture and repurpose their carbon.

PNNL chemist David Heldebrant, who leads the research team behind the new technology, compares the system to recycling. Just as one can choose between single-use and recyclable materials, so too can one recycle carbon.

“That’s essentially what we’re trying to do here,” said Heldebrant. “Instead of extracting oil from the ground to make these chemicals, we’re trying to do it from CO₂ captured from the atmosphere or from coal plants, so it can be reconstituted into useful things. You’re keeping carbon alive, so to speak, so it’s not just ‘pull it out of the ground, use it once, and throw it away.’ We’re trying to recycle the CO₂, much like we try to recycle other things like glass, aluminum and plastics.”

As described in the journal Advanced Energy Materials, the new system is designed to fit into coal-, gas-, or biomass-fired power plants, as well as cement kilns and steel plants. Using a PNNL-developed capture solvent, the system snatches CO₂ molecules before they’re emitted, then converts them into useful, sellable substances.

A long line of dominoes must fall before carbon can be completely removed or entirely prevented from entering Earth’s atmosphere. This effort — getting capture and conversion technology out into the world — represents some of the first few crucial tiles.

Deploying this technology will reduce emissions, said Heldebrant. But it could also help stir the development of other carbon capture technology and establish a market for CO₂-containing materials. With such a market in place, carbon seized by anticipated direct air capture technologies could be better reconstituted into longer-lived materials.

The call for cheaper carbon capture

In April 2022, the Intergovernmental Panel on Climate Change issued its Working Group III report focused on mitigating climate change. Among the emissions-limiting measures outlined, carbon capture and storage was named as a necessary element in achieving net zero emissions, especially in sectors that are difficult to decarbonize, like steel and chemical production.

“Reducing emissions in industry will involve using materials more efficiently, reusing and recycling products and minimizing waste,” the IPCC stated in a news release issued alongside one of the report’s 2022 installments. “In order to reach net zero CO₂ emissions for the carbon needed in society (e.g., plastics, wood, aviation fuels, solvents, etc.),” the report reads, “it is important to close the use loops for carbon and carbon dioxide through increased circularity with mechanical and chemical recycling.”

PNNL’s research is focused on doing just that — in alignment with DOE’s Carbon Negative Shot. By using renewably sourced hydrogen in the conversion, the team can produce methanol with a lower carbon footprint than conventional methods that use natural gas as a feedstock. Methanol produced via CO₂ conversion could qualify for policy and market incentives intended to drive adoption of carbon reduction technologies.

Methanol is among the most highly produced chemicals in existence by volume. Known as a “platform material,” its uses are wide ranging. In addition to methanol, the team can convert CO₂ into formate (another commodity chemical), methane and other substances.

A significant amount of work remains to optimize and scale this process, and it may be several years before it is ready for commercial deployment. But, said Casie Davidson, manager for PNNL’s Carbon Management and Fossil Energy market sector, displacing conventional chemical commodities is only the beginning. “The team’s integrated approach opens up a world of new CO₂ conversion chemistry. There’s a sense that we’re standing on the threshold of an entirely new field of scalable, cost-effective carbon tech. It’s a very exciting time.”

Crumbling costs

Commercial systems soak up carbon from flue gas at roughly $46 per metric ton of CO₂, according to a DOE analysis. The PNNL team’s goal is to continually chip away at costs by making the capture process more efficient and economically competitive.

The team brought the cost of capture down to $47.10 per metric ton of CO₂ in 2021. A new study described in the Journal of Cleaner Production explores the cost of running the methanol system using different PNNL-developed capture solvents, and that figure has now dropped to just below $39 per metric ton of CO₂.

“We looked at three CO₂-binding solvents in this new study,” said chemical engineer Yuan Jiang, who led the assessment. “We found that they capture over 90 percent of the carbon that passes through them, and they do so for roughly 75 percent of the cost of traditional capture technology.”

Different systems can be used depending on the nature of the plant or kiln. But, no matter the setup, solvents are central. In these systems, solvents wash over CO₂-rich flue gas before it’s emitted, leaving behind CO₂ molecules now bound within that liquid.

Creating methanol from CO₂ is not new. But the ability to both capture carbon and then convert it into methanol in one continuously flowing system is. Capture and conversion has traditionally occurred as two distinct steps, separated by each process’s unique, often non-complementary chemistry.

“We’re finally making sure that one technology can do both steps and do them well,” said Heldebrant, adding that traditional conversion technology typically requires highly purified CO₂. The new system is the first to create methanol from “dirty” CO₂.

Dialing down tomorrow’s emissions

The process of capturing CO₂ and converting it to methanol is not CO₂-negative. The carbon in methanol is released when burned or sequestered when methanol is converted to substances with longer lifespans. But this technology does “set the stage,” Heldebrant said, for the important work of keeping carbon bound inside material and out of the atmosphere.

Other target materials include polyurethanes, which are found in adhesives, coatings, and foam insulation, and polyesters, which are widely used in fabrics for textiles. Once researchers finalize the chemistry behind converting CO₂ into materials that keep it out of the atmosphere for climate-relevant timescales, a wide web of capture systems could be poised to run such reactions.

In lieu of today’s smokestacks, Heldebrant envisions CO₂ refineries built into or alongside power plants, where CO₂-containing products can be made on site. “We are at a turning point,” Heldebrant and his coauthors wrote in a recent article published in the journal Chemical Science, “where we can continue to use 20th century, monolithic capture and conversion infrastructure or we can begin the transition to a new 21st century paradigm of integrated solvent-based carbon capture and conversion technologies.”

This technology is available for licensing. Please contact Sara Hunt, PNNL commercialization manager, to learn more.

This work was supported by the Department of Energy’s Technology Commercialization Fund, the Office of Fossil Energy and Carbon Management, and Southern California Gas. Part of the work was performed at EMSL, the Environmental Molecular Sciences Laboratory, a DOE Office of Science user facility at PNNL.

When the 350-400 degree Celsius fluid exiting the Earth’s crust through deep-sea hydrothermal vents mixes with sea water it creates large porous rocks often referred to as ‘chimneys’ or hydrothermal deposits. These chimneys are colonized by microbes that thrive in high-temperature environments. For decades, Reysenbach has collected chimneys from deep-sea hydrothermal vents across the world’s oceans, and her lab uses genetic fingerprinting and cultivation techniques to study the microbial diversity of the communities associated with these rocks.

In this new study, Reysenbach and the team were able to take advantage of advances in molecular biology techniques to sequence the entire genomes of the microbes in these communities to learn more about their diversity and interconnected ecosystems.

The team constructed genomes of 3,635 Bacteria and Archaea from 40 different rock communities. The amount of diversity was staggering and greatly expands what is known about how many different types of Bacteria and Archaea exist. The researchers discovered at least 500 new genera (the level of taxonomic organization above species) and have evidence for two new phyla (five levels up from species). “Phyla is way up on the taxonomic rank, so that’s really cool,” says Reysenbach.

The team also found evidence of microbial diversity hotspots. Samples from the deep-sea Brothers volcano located near New Zealand, for instance, were especially enriched with different kinds of microorganisms, many endemic to the volcano.

“That biodiversity was just so huge, off the charts,” says Reysenbach. “At one volcano there was so much new diversity that we hadn’t seen elsewhere before.” This finding may suggest that the increased complexity of the subsurface rocks of a volcano makes them more likely to house diverse microbial species compared to deep-sea hydrothermal vents.

Besides finding a jaw-dropping amount of microorganism biodiversity in these high-temperature ecosystems, the genomic data from this study also showed that many of these organisms depend on one another for survival. By analyzing the genomes, the researchers found that some microorganisms cannot metabolize all of the nutrients they need to survive so they rely on nutrients created by other species in a process known as a “metabolic handoff.”

“By looking at these genomes, we really got a much better understanding of what a lot of these microorganisms are doing and how they’re interacting,” says Reysenbach. “They’re communal; they share food with each other.”

This study has inspired a new phase of research for Reysenbach: gaining an in-depth understanding of the interactions between these deep-sea microorganisms. “For me the most exciting part is that I really want to be able to grow these things in the lab,” says Reysenbach. “I want to be able to see [a microorganism] under a microscope and understand if it needs somebody else to live with.”

The research, published recently in the journal Limnology and Oceanography Letters, compiles over 118 million readings of dissolved oxygen and temperature taken from over 125,000 locations in rivers across six continents and 93 countries and spanning over 100 years, from 1900 to 2018. Hypoxia, defined in this study as dissolved oxygen concentrations below 2 milligrams per liter, was detected in rivers and streams in 53 countries, with 12.6% of all locations exhibiting at least one hypoxic measurement.

“Hypoxia in coastal waters and lakes is widely recognized as a detrimental environmental issue, yet we have lacked a comparable understanding of hypoxia in rivers,” Blaszczak, with the University’s College of Agriculture, Biotechnology & Natural Resources, said. “While 12.6% might not seem like a huge percentage, previously it was generally thought that occurrences of hypoxia in rivers and streams were exceedingly rare. Having shown presence of hypoxia in one of every eight river locations with data is definitely a game changer in terms of how we need to think of and give attention to the issue of hypoxia in rivers and streams.”

Blaszczak says that advances in measuring hypoxia over the past 15 years or so using field-deployable dissolved oxygen sensor technology that allows for constant monitoring, such as every hour, has given researchers the tools to get a better handle on the presence of hypoxia. Previously, readings were taken manually using a handheld probe or by collecting water samples mostly during the day, when oxygen levels are naturally higher, due to photosynthesis occurring during daylight hours.

“Photosynthesis by algae produces oxygen that is released into the water column,” Blaszczak explains. “So, you’re not getting a true picture of hypoxia occurrence if you only measure during the day. Hypoxic conditions are much more likely to develop in the early morning hours, after the lack of photosynthesis all night. The newer technology allows for us to capture that data.”

In fact, the research showed a dramatic difference in results between using the older methods and the newer technology, due to the times of day measurements are taken.

“We find that if we only sampled during the day every day, between 8 a.m. and 5 p.m., it would under detect the number of river locations where we observe hypoxia by about 25%,” she said.

Blaszczak says that much of the data from the study is more recent, and taken using the newer technology.

“There wasn’t a lot of testing going on, especially before the 1950s,” she said. “Even all the way up to around 2005 or so, the data at a global scale is pretty scarce.”

Research shows natural and human influences

As expected, the data showed hypoxia in rivers was most present in warmer, smaller and lower-gradient, stiller waters, where oxygen isn’t being “stirred” into the water from turbulence. Blaszczak says the research found these conditions occur most often in rivers draining naturally occurring wetlands, as well as in rivers draining some urban areas, where human actions have created hypoxic conditions.

“We as people managing waters often influence these conditions — by extracting water, building dams and increasing the amount of organic matter released into rivers, for example,” she says. “We can set up these conditions of very low flows. Rivers surrounded by wetlands and urban areas had about the same probability of hypoxia occurrence. That shows that while it can occur naturally, we also can create these conditions that are conducive to hypoxia.”

Blaszczak says that hypoxia often isn’t recognized until it’s too late.

“You’ll see a report in the media of a fish kill that was caused by hypoxia — from very low flows from dams, a release of something into a river, or something else we can control,” she says. “If we can put out more sensors to monitor conditions, we can get early warning signals, and take action to mediate the problem, such as modifying the flow in some way.”

Blaszczak says newer sensor technology that provides constant monitoring is also important because the duration of hypoxic conditions affects the harm it might induce.

“Fish do have, in some cases, avoidance strategies. So, if it is only for a couple of hours, they can try to manage themselves, by staying up closer to the surface, for example,” she says. “But if it is more extended, then they have a harder time. And, there are other factors. The size of the organism may influence its ability to survive, and some organisms are not as mobile, so they can’t adjust to survive a more prolonged hypoxic event.”

Besides the harm hypoxia can cause to aquatic life, it can also stimulate production of the greenhouse gases methane and nitrous oxide.

“There’s just nothing good about hypoxia in rivers or other bodies of water,” Blaszczak says. “We can’t eliminate it completely, but we can certainly do a better job of monitoring it and take actions to prevent it, rather than to stimulate it.”

Taking a global view

On a more positive note, Blaszczak says that looking at data from 1950 to 2018, the research showed that, globally, there doesn’t seem to be an overall increase in hypoxic conditions in rivers. However, in certain locations, there are increases. And, in some locations, the presence is extreme, she says. The researchers put together a worldwide map that is featured in the research article, which color codes the number of hypoxia occurrences they found by region, with blue being rare occurrences and red being the highest presence of hypoxia.

“You’ll see that Florida is completely red, off the charts,” Blaszczak noted.

Much of the U.S. is in the yellow, or midrange. Blaszczak says that there is much more data available from the U.S. overall than other countries. She and a team of researchers compiled data from government-supported work and other published data to create the data set that spans all continents except Antarctica, but is dominated by data from North America. Each location had to have a geographic coordinate, at least one measurement of dissolved oxygen, a corresponding water temperature and a date-time stamp. Blaszczak then analyzed the data, as part of her research for her College’s Department of Natural Resources & Environmental Science and Experiment Station.

She embarked on leading the study after attending a workshop in September 2018 held in Switzerland and convened by Jim Heffernan and Tom Battin from Duke University. The workshop aimed to advance the global understanding of the dynamics of hypoxia in rivers and streams and was supported by the Swiss National Science Foundation and the U.S. National Science Foundation.

Moving forward, Blaszczak says more monitoring with newer technology is key to mitigating harmful effects of hypoxia in rivers.

“We need to further develop our capacity to identify when and where rivers are vulnerable to the development of hypoxic conditions, so that we can guide river management in the face of continuing climate and land-use change. Supporting ongoing monitoring and expanding monitoring to regions where data is sparse is essential,” she said.

Blaszczak is grateful for researchers and governments that provided data used in the study and for the co-authors of the study, including Lauren E. Koenig, Francine H. Mejia, Lluís Gómez-Gener, Christopher L. Dutton, Alice M. Carter, Nancy B. Grimm, Judson W. Harvey, Ashley M. Helton and Matthew J. Cohen.