As Drought Dries California Rivers, Salmon Take Truck Rides to Sea

Reuters
The drought-stricken American River is pictured near the Glenbrook Park River Access near Sacramento,California, U.S., May 10, 2021. Picture taken May 10, 2021. REUTERS/Nina Riggio

GOLD RIVER, Calif. (Reuters) – During a typical spring, the silver young salmon swimming in long tanks at the Nimbus Fish Hatchery east of Sacramento would be released into the American River and then make their way out to the Pacific Ocean to grow to adulthood.

But with extreme drought now gripping California and much of West Coast, the rivers are too warm for the salmon to survive.

This week, the 3.5-inch (90-mm) smolt, as the young fish are known, embarked on a much different journey when they were loaded on to trucks and driven to the San Francisco Bay for release into cooler waters.

Low amounts of rain and snow led to less water and warmer temperatures in the state’s rivers and reservoirs, said Jason Julienne, who manages several state-run hatcheries in the Sacramento River system, including the Nimbus.

When those conditions occur, “we know we have to really go into high gear to make sure these fish survive,” said Harry Morse, spokesman for the California Department of Fish and Wildlife.

The state plans to truck 17 million of the smolt to the San Francisco Bay this year from various hatcheries, an emergency step not taken since the last major drought in 2014, Morse said.

On Monday, California Governor Gavin Newsom declared a drought emergency for 41 of the state’s 58 counties, including the major watersheds relied on by salmon and other wildlife.

Droughts in California are growing more frequent and more intense as climate change continues, threatening the state’s already tenuous supply of water for wildlife, farmers and urban areas, and creating conditions ripe for dangerous wildfires.

Other portions of the West Coast are also experiencing severe drought. In Oregon, federal officials said on Wednesday that a portion of water from the Klamath River system would not be available to farmers, and that additional protections for salmon and other fish were under consideration.

Even without drought and climate change, salmon and other fish were struggling to survive on the West Coast, as water projects such as dams and reservoirs inhibit their ability to migrate to the sea and back, a natural part of their life cycle that can take about three years.

Two species of Chinook salmon are considered endangered on the West Coast, and seven are considered threatened under the Endangered Species Act, according to the National Oceanic and Atmospheric Administration.

In the American River in California where the Nimbus smolt are usually released, water from rain and snow was flowing at just 31% of its average rate on Tuesday, according to state data. The resulting warmer water has created a desperate situation not only for the fish at the hatchery, but for the hundreds of thousands of fry and eggs laid naturally in the rivers themselves.

“My biggest fear is that each and every egg that is laid this year is going to die because the temperatures in the rivers are going to be too high,” said Mike Conroy, executive director of the Pacific Coast Federation of Fishermen’s Associations.

His organization is asking the state and federal agencies that apportion water from a complex system of reservoirs to make sure that sufficient cool water is released to prevent the rivers from becoming toxic to young fish, Conroy said.

But others – including a California agricultural sector that produces a third of the country’s vegetables and two-thirds of its fruits and nuts – also rely on that water. As more water is reserved for fish, less is available to irrigate farms and for the state’s 40 million residents.

“The pull of one wrong lever can throw the whole system out of whack,” said Conroy. “It has to be carefully balanced.”

FOR MORE INFORMATION: https://www.usnews.com/news/top-news/articles/2021-05-13/as-drought-dries-california-rivers-salmon-take-truck-rides-to-sea

Journey of PFAS in wastewater facilities highlights regulation challenges

Research: Journey of PFAS in wastewater facilities highlights regulation  challenges

Researchers at the University of New Hampshire have conducted two of the first studies in New England to collectively show that toxic human-made chemicals called PFAS (per-and polyfluoroalkyl substances), found in everything from rugs to product packaging, end up in the environment differently after being processed through wastewater treatment facilities making it more challenging to set acceptable screening levels.

“PFAS are persistent substances that are not easily broken down and have been linked to adverse health effects,” said Paula Mouser, associate professor of civil and environmental engineering. “They are found in a wide variety of industrial, commercial and medicinal products and can end up in the body, human waste and the environment. If not managed correctly, they can be further distributed around the environment in landfills, waterways and even stabilized biosolids could be applied to agricultural fields as fertilizers.”

The researchers looked at the journey of 24 different PFAS through six New Hampshire wastewater treatment facilities, including those along the Great Bay Estuary near the N.H. Seacoast, to examine how they are distributed after being treated. PFAS come in two forms, long-chain and short-chain, which refers to the number of carbon atoms attached to fluorine in the compounds. In their first study, recently published in the journal Environmental Science: Processes and Impacts, the researchers found that short-chain PFAS ended up in the facility liquid, or effluent, while long-chain PFAS were more abundant in the sludge due to their higher affinity toward solids.

After going through a range of biological and disinfectant processes in the municipal wastewater treatment facilities, researchers found roughly 10% of the PFAS present in Great Bay could be traced back to the wastewater facilities. This suggests other dominant PFAS sources are contributing to the waterways like septic systems, agricultural land and urban runoff (which can contain biosolids), groundwater discharge from contaminated sites and surface water runoff.

Currently, the United States Environmental Protection Agency (EPA) has only issued a drinking water health advisory for two of the 4,700 known PFAS, so individual states are working to set their own standards for PFAS in drinking water, surface water and biosolids. In 2020, the New Hampshire Department of Environmental Services established maximum contaminant levels (MCLs) for four PFAS in drinking water, while in 2019, the Maine Department of Environmental Protection (DEP) established screening levels for three PFAS in biosolids.

In the UNH researchers’ second study, featured in the New England Water Environment Association Journal, the researchers used Maine’s screening levels to look at both PFAS and PPCPs, pharmaceutical and personal care products like antibiotics and flame retardants, in biosolids from wastewater treatment facilities in both New Hampshire and Vermont. Of the 39 biosolids reviewed in the sludge waste, 29 had PFAS levels that exceeded screening levels set by the Maine DEP.

“State agencies across New England are all considering regulating PFAS in wastewater biosolids, but there is still more we need to know about how the treatment of wastewater sludge influences these forever chemicals,” said Mouser.

The researchers say the challenge is finding a safe and acceptable level for waste residue that doesn’t force facilities to deposit these solids in landfills which would be enormously costly, fill up landfills faster than anticipated and possibly lead to the leaching of PFAS into landfill wastewater that may continue the cycle by returning the not easily broken-down chemicals right back to treatment facilities.

The researchers say the studies highlight the knowledge gaps around contaminants of emerging concern, like PFAS, in wastewater residuals and stress that more research is needed to look at the influence of the facility design and operation on their treatment before costly upgrades are implemented in wastewater treatment facilities.

This research was funded by New Hampshire Sea Grant and the UNH Collaborative Research Excellence (CoRE) Initiative.

FOR MORE INFORMATION: University of New Hampshire

Stormwater could be a large source of microplastics and rubber fragments to waterways

Stormwater could be a large source of microplastics and rubber fragments to  waterways

In cities, heavy rains wash away the gunk collecting on sidewalks and roads, picking up all kinds of debris. However, the amount of microplastic pollution swept away by this runoff is currently unknown. Now, researchers in ACS ES&T Water report that stormwater can be a large source of microplastics and rubber fragments to water bodies and, with a proof-of-concept experiment, show that a rain garden could keep these microscopic pieces out of a storm drain.

Most cities’ storm drains end up discharging directly into wetlands, creeks or rivers. Rainwater running into these drains becomes a concoction of whatever is on the ground, including dirt and grass clippings, leaked car fluids, fertilizer and garbage. Recently, researchers also found that strong rains can displace microplastics, sweeping them into stormwater, but the importance of this runoff as a source of contamination is not well understood. So, Chelsea Rochman and colleagues wanted to see whether microplastics and other tiny particles are carried into waterways by storms in urban areas, and whether a rain garden could prevent that from happening.

The researchers collected water during heavy rainstorms from 12 streams flowing into the San Francisco Bay. First, they separated floating microparticles — which they define as less than 5 mm in size — by color and shape and tallied them, finding higher concentrations in the streams than previous researchers had found in treated wastewater that was discharged into the bay. Microscopic fibers and black rubbery fragments were the most common microparticles, while natural debris, glass, paint and wool were only minor components. Then, the team identified a subset of plastic- or rubbery-looking fragments as being made mostly of plastic polymers or other synthetic materials, and many of the black rubbery particles originated from tires. Finally, the researchers compared the microparticles entering a rain garden to those at the garden’s outflow into a storm drain. Their results showed that the rain garden captured 91 to 98% of the microparticles and 100% of the black rubbery fragments during three rain events. The researchers say that while rain gardens are known to reduce the amount of metals, nutrients and other pollutants in stormwater runoff, this study shows rain gardens could also be effective at reducing microplastic pollution.

FOR MORE INFORMATION: American Chemical Society

Clean water and toilets for healthy shelters

Clean water and toilets for healthy shelters | EurekAlert! Science News

Regular, standardized assessments of evacuation shelters can help keep people healthy following natural disasters, according to research published by Tohoku University scientists and colleagues in the journal Heliyon. The study found that a clean tap water supply and hygienic toilets were especially important for protecting evacuees from the spread of infectious diseases.

“A clean water supply and maintaining hygiene are important for reducing environmental health risks among victims of natural disasters,” says Tadashi Ishii, who specializes in disaster medicine at Tohoku University. “But scientists have not yet established a strong evidence base that describes the relationship between damage in resource supplies and infrastructure on the one hand and disaster victims’ health status on the other.”

Ishii led the Ishinomaki Zone Joint Relief Team following the Great East Japan Earthquake of March 11, 2011. More than 15,000 people died and 2,500 went missing following the disaster, with some 500,000 evacuated to shelters across Japan. It took nearly a year before all shelters were shut down.

The team conducted regular visits to the shelters in order to assess resource availability, infrastructure, and the health status and needs of people residing in the shelters. Now, Ishii and his research team have analysed these 2011 records to evaluate the impacts of resource supply levels and infrastructure damage on the physical health of evacuees.

Their study included 28 mid- to large-sized shelters regularly assessed in the weeks following the earthquake. The study looked specifically at changes made to resources and infrastructure between days 14 and 25 after the earthquake.

The team found that inadequate clean tap water and toilets were insufficiently improved during the assessment period in about half the shelters. Clinical symptoms of common respiratory and gastrointestinal infections were more prevalent in shelters where these two resources had not improved. Shelters that were able to improve the supply of clean tap water and toilet hygiene witnessed significant reductions in the prevalence of gastrointestinal symptoms among evacuees.

“Our study demonstrated the difficulty of quickly collecting objective assessment data from evacuation shelters during the acute phase of a massive disaster,” says Ishii. “It also shows the validity of quick visual assessments of resources by trained staff. Importantly, the study reveals the importance of rapidly restoring clean water supply and toilet hygiene in shelters to reduce environmental health risks among evacuees.”

Ishii and his team next plan to develop easy, reliable and quick assessment tools for evaluating resource damage and health status in evacuation shelters. He also stresses the importance of collaborating with local governments to set up effective supply chains that can rapidly deploy clean water and hygienic rescue toilets in the aftermath of natural disasters.

FOR MORE INFORMATION: Tohoku University

Water treatment: Removing hormones with sunlight

Water Treatment: Removing Hormones With Sunlight - WorldNewsEra

Micropollutants such as steroid hormones contaminate drinking water worldwide and pose a significant threat to human health and the environment even in smallest quantities. Until now, easily scalable water treatment technologies that remove them efficiently and sustainably have been lacking. Scientists at the Karlsruhe Institute of Technology (KIT) developed a new chemical process for removing hormones. It takes advantage of the mechanisms of photocatalysis and transforms the pollutants into potentially safe oxidation products. The team reports on this in the scientific journal Applied Catalysis B: Environmental.

Organic pollutants such as pharmaceuticals, pesticides, and hormones — even at nanoscale concentrations — contaminate drinking water in a way that poses significant risks to humans, animals, and the environment. In particular, the steroid hormones estrone, estradiol, progesterone, and testosterone can cause biological damage in humans and wildlife. The European Union has therefore set strict minimum quality standards for safe and clean drinking water, which must also be taken into account in the development of new technologies for water treatment. “The challenge for science is to develop more sensitive methods to target the hormone molecules,” says Professor Andrea Iris Schäfer, Head of the Institute for Advanced Membrane Technology (IAMT) at KIT. The main problem is that steroid hormones are very hard to detect in water. “There is one hormone molecule for every quintillion water molecules. This is an extremely low concentration,” explains the expert.

Detecting — and Removing — Micropollutants

With conventional water treatment technologies, wastewater treatment plants can neither find nor remove micropollutants. Researchers at the IAMT and the KIT Institute of Microstructure Technology (IMT) are therefore working on new methods to not only detect and measure micropollutants, but also remove them. A new, photocatalytic process proves to be promising. The scientists coated a commercially available large-pore polymer membrane with Pd(II)-porphyrin, a palladium-containing, light-sensitive molecule that can absorb visible radiation. Exposure to radiation with simulated sunlight initiates a chemical process that produces so-called singlet oxygen, a highly reactive oxygen species. The singlet oxygen specifically “attacks” the hormone molecules and converts them into potentially safe oxidation products. “It is crucial that we coat the surface of each pore with the photosensitizer molecule, increasing the surface area of attack,” explains Roman Lyubimenko, a scientist at IAMT and IMT.

Significant Reduction of the Estradiol Concentration

The chemical decomposition of steroid hormones and the filtration of other micropollutants can be realized in a single module. With this process, filtering of 60 to 600 liters of water per square meter of membrane is possible in one hour. The scientists were able to reduce the concentration of estradiol, the most biologically active steroid hormone, by 98 percent from 100 to 2 nanograms per liter. “This means that we are already very close to the EU target value of one nanogram per liter,” emphasizes Schäfer. The next goal of the research team is to further optimize the photocatalytic process and transfer it to a larger scale. Open issues are to find out how much light intensity and how much porphyrin will be needed and whether the costly palladium from the platinum group of metals can be replaced by other metals.

FOR MORE INFORMATION: Karlsruhe Institute of Technology

Solving a natural riddle of water filtration

Solving a Natural Riddle of Water Filtration | Lab Manager

For many engineers and scientists, nature is the world’s greatest muse. They seek to better understand natural processes that have evolved over millions of years, mimic them in ways that can benefit society and sometimes even improve on them.

An international, interdisciplinary team of researchers that includes engineers from The University of Austin has found a way to replicate a natural process that moves water between cells, with a goal of improving how we filter out salt and other elements and molecules to create clean water while consuming less energy.

In a new paper published today in Nature Nanotechnology, researchers created a molecule-sized water transport channel that can carry water between cells while excluding protons and undesired molecules. These channels mimic the water transport functions of proteins in our bodies known as aquaporins. In our cells, uncontrolled transport of protons alongside water can be harmful because they can change the pH of cells, potentially disrupting or killing them.

This is the first instance of an artificial nanometer-sized channel that can truly emulate the key water transport features of these biological water channels. And it could improve the ability of membranes to efficiently filter out unwanted molecules and elements, while speeding up water transport, making it cheaper to create a clean supply.

“It copies nature, but it does so by breaking the rules nature has established,” said Manish Kumar, an assistant professor in the Cockrell School of Engineering’s Department of Civil, Architectural and Environmental Engineering. “These channels facilitate speedy transport of molecules you want, like water, and block those you don’t want, like salt.”

The research team’s artificial water channels can perform the same functions as aquaporins, which are crucial at a larger level for desalination, water purification and other processes for separating molecules. And they do so while transporting water 2.5 times faster compared to aquaporins.

The artificial channels are three nanometers in width by three nanometers in length. If densely packed into the correct size membrane, the channels can pass roughly 80 kilograms of water per second per square meter of membrane, while rejecting salts and protons at rates much higher than current commercial desalination membranes are capable of.

“These artificial channels in essence solve the critical technical challenges of only allowing water molecules to pass while excluding other solutes like salt and protons,” said professor Huaqiang Zeng of Department of Chemistry at Hainan University and the Institute of Advanced Synthesis at Northwestern Polytechnical University in China. “Their extraordinary water transportation speed and the fact that these channels allow for simpler membrane fabrication suggest they will become a crucial component of next-generation membranes for producing clean water to address severe scarcity facing human beings in this century.”

Aquaporin-based channels are so small that they only allow a single molecule of water through at a time, like a single-lane road. A unique structural feature in these new channels is a series of folds in the channels that create additional “lanes,” so to speak, allowing water molecules to be transported faster.

“You’re going from a country road to a highway in terms of water transport speed, while still keeping out other things by putting little bumps in the road,” said Aleksei Aksimentiev, a professor of biological physics at the University of Illinois at Urbana-Champaign who collaborated on the research.

Kumar took a class taught by Aksimentiev on the physics of nanomachines while studying for his Ph.D. in environmental engineering at the University of Illinois. The course, he said, was about as challenging as it comes, and he still refers back to his notes from the class years later.

They worked together on a paper when Kumar was a student. And then when he became a professor, Aksimentiev helped him with simulation work on another paper. For years now, they have been collaborating on the study of water transport channels.

The interdisciplinary team features faculty and researchers from around the world in physics, chemical engineering, pharmacology and more. Researchers come from UT Austin, University of Illinois, Harvard Medical School, Hainan University and Northwestern Polytechnical University in China and NanoBio Lab in Singapore.

Zeng is the corresponding author on the paper. Kumar led the testing portion of the project and Aksimentiev led the simulation work.

Earlier this year, Kumar teamed with Penn State University researchers on a discovery that shed new light on how traditional water desalination membranes work. They found that uniformity throughout the membrane speeds up transporting water and improves the process of filtering out salt.

This new work, Kumar says, takes that concept to another level. These channels can only be one size to fit the desired water molecules through while squeezing out other unwanted molecules.

Going forward, the team plans to use these artificial water channels to fabricate next-generation reverse-osmosis membranes to convert seawater to drinkable water.

FOR MORE INFORMATION: University of Texas at Austin

Pollutants rapidly seeping into drinking water

Pollutants rapidly seeping into drinking water, study finds

The entire ecosystem of the planet, including humans, depends on clean water. When carbonate rock weathers, karst areas are formed, from which around a quarter of the world’s population obtains its drinking water. Scientists have been studying how quickly pollutants can reach groundwater supplies in karst areas and how this could affect the quality of drinking water. An international team led by Junior Professor Dr. Andreas Hartmann of the Chair of Hydrological Modeling and Water Resources at the University of Freiburg compared the time it takes water to seep down from the surface to the subsurface with the time it takes for pollutants to decompose in carbonate rock regions in Europe, North Africa and the Middle East. The researchers published their results in the scientific journal Proceedings of the National Academy of Sciences (PNAS).

Previous continental or global hydrologic model applications have focused mainly on the occurrence of floods or droughts and the general availability of drinking water. However, scientists have predominantly neglected water quality as an important factor for the potability of water on these large scales, in particular how quickly pollutants can seep from the earth’s surface into the groundwater through cracks or fissures.

The current research results of Hartmann and his team show that in karst regions, which are characterized by an increased occurrence of cracks or fissures, the risk of pollution by degradable pollutants such as pesticides, pharmaceuticals or pathogens is significantly higher than previously expected. Although pollutants are considered short-lived, up to 50 percent of them can still reach groundwater, depending on the period of their decomposition. The main reason for this, the researchers show, is rapid seepage pathways that allow large amounts of infiltrating water to reach groundwater in a short time. Particularly in regions with thin soils, such as the Mediterranean region, pollutants on the surface can thus seep quickly and in high concentrations into the subsurface during large rain events. Hartmann’s researchers demonstrated the consequences using the example of the degradable pesticide Glyphosate. According to their calculations, the rapid transport of Glyphosate into the groundwater can cause it to exceed its permissive values by a factor of up to 19. The increased risk of pollution for drinking water or ecosystems that depend on groundwater is particularly relevant for regions where agriculture depends on degradable fertilizers and pesticides.

FOR MORE INFORMATION: University of Freiburg

Airborne radar reveals groundwater beneath glacier

Airborne radar reveals groundwater beneath glacier | EurekAlert! Science  News

Melting glaciers and polar ice sheets are among the dominant sources of sea-level rise, yet until now, the water beneath them has remained hidden from airborne ice-penetrating radar.

With the detection of groundwater beneath Hiawatha Glacier in Greenland, researchers have opened the possibility that water can be identified under other glaciers from the air at a continental scale and help improve sea-level rise projections. The presence of water beneath ice sheets is a critical component currently missing from glacial melt scenarios that may greatly impact how quickly seas rise — for example, by enabling big chunks of ice to calve from glaciers vs. stay intact and slowly melt. The findings, published in Geophysical Research Letters May 20, could drastically increase the magnitude and quality of information on groundwater flowing through the Earth’s poles, which had historically been limited to ground-based surveys over small distances.

“If we could potentially map water underneath the ice of other glaciers using radar from the air, that’s a game-changer,” said senior study author Dustin Schroeder, an assistant professor of geophysics at Stanford’s School of Earth, Energy & Environmental Sciences (Stanford Earth).

The data was collected in 2016 as part of NASA’s Operation IceBridge using a wide-bandwidth radar system, a newer technique that has only started being used in surveys in the last few years. Increasing the range of radio frequencies used for detection allowed the study authors to separate two radar echoes — from the bottom of the ice sheet and the water table — that would have been blurred together by other systems. While the team suspected groundwater existed beneath the glacier, it was still surprising to see their hunch confirmed in the analyses.

“When you see these anomalies, most of the time they don’t pan out,” said lead study author Jonathan Bessette, a graduate student at the Massachusetts Institute of Technology who conducted the research as a SUNY Buffalo undergraduate through the Stanford Summer Undergraduate Research in Geoscience and Engineering Program (SURGE).

Based on the radar signal, the study team constructed two possible models to describe Hiawatha Glacier’s geology: Frozen land with thawed ice below it or porous rock that enables drainage, like when water flows to the bottom of a vase filled with marbles. These hypotheses have different implications for how Hiawatha Glacier may respond to a warming climate.

Groundwater systems may play a more significant role than what researchers currently model in ice sheets for sea-level-rise projections, according to Schroeder. The researchers hope their findings will prompt further investigation of the possibility for additional groundwater detection using airborne radar, which could potentially be deployed on a grand scale to collect hundreds of miles of data per day.

“What society wants from us are predictions of sea level — not only now, but in futures with different greenhouse gas emission scenarios and different warming scenarios — and it is not practical to survey an entire continent with small ground crews,” Schroeder said. “Groundwater is an important player, and we need to survey at the continental scale so that we can make continental-scale projections.”

FOR MORE INFORMATION:  Stanford University

Groundwater monitoring with seismic instruments

Groundwater monitoring with seismic instruments

Water in the high-mountain regions has many faces. Frozen in the ground, it is like a cement foundation that keeps slopes stable. Glacial ice and snow supply the rivers and thus the foothills with water for drinking and agriculture during the melt season. Intense downpours with flash floods and landslides, on the other hand, pose a life-threatening risk to people in the valleys. The subsoil with its ability to store water therefore plays an existential role in mountainous regions.

But how can we determine how empty or full the soil reservoir is in areas that are difficult to access? Researchers at the German Research Centre for Geosciences (GFZ), together with colleagues from Nepal, have now demonstrated an elegant method to track groundwater dynamics in high mountains: They use seismic waves, such as those generated by ground vibrations, which they record with highly sensitive instruments. Similar to medical ultrasound, they exploit the fact that the waves propagate differently in different subsurface conditions. The researchers led by Luc Illien, Christoph Sens-Schönfelder and Christoff Andermann from GFZ report on this in the journal AGU Advances.

Seismic waves well-known from earthquakes. After a rupture in the subsurface, they propagate rapidly and unleash destructive forces. However, there are also much smaller waves caused, for example, by trucks, streetcars or — in the mountains — by falling rock. The ground is actually vibrating all the time. In geoscience, this is referred to as “seismic noise.” What has to be laboriously extracted from the measured data of seismometers in earthquake detection turns out to be a valuable source of information when looking into the subsurface. This is because seismic waves propagate differently in the water-saturated zone than in the unsaturated zone, also called vadose zone.

Luc Illien, a PhD student at GFZ, and his colleagues used two Nepalese seismic stations at 1,200 and 2,300 meters above sea level. Luc Illien says: “The Nepalese Himalayas provide vital water resources to a large part of the population of South Asia. Most of this water drains through mountain groundwater reservoirs that we can poorly delineate.” The study area comprised the catchment area of a small tributary to the Bothe Koshi, a border river between China and Nepal. Using several weather stations and level gauges, the team collected data, sometimes every minute, over three monsoon seasons. From this, they established a groundwater model that they could compare with the seismic records. The result: runoff to the Bothe Koshi is fed mainly from the deep aquifer. In the dry season, little water flows down the valley. In the monsoon, levels rise, but two distinct phases can be identified. First, it rains without increasing the discharge, but later a clear correlation between rainfall and river level becomes apparent. Christoff Andermann, co-author of the study, explains, “The first rainfall initially replenishes reservoirs in the soil near the surface. Once the soil is saturated with water, the deep groundwater reservoir, which is directly linked to the rivers, fills up. An increase in groundwater is then immediately reflected in rising river water levels.”

The comparison with the data from seismometers showed that the saturation of the vadose zone can be well deduced from the seismic noise. “Only by merging the hydrological observations with the seismic measurements we could analyze the function of the vadose zone as a link between precipitation and groundwater reservoir,” says Christoph Sens-Schönfelder. First author Luc Illien: “Understanding how the reservoir fills and drains is crucial for assessing its sustainability. From this, we can not only make predictions for runoff, but also warn of increased risk of landslides and flash floods.” For example, if the soil is already saturated with water, rainfall will run off more superficially and can carry away slopes. Climate change is exacerbating the situation by contributing to changes in large-scale weather patterns and destabilizing the mountain environment. GFZ Scientific Director Niels Hovius, who contributed to the study, says: “Our work in Nepal and its results show how important it is to monitor numerous influencing factors. These include groundwater storage, changes in land use, land cover and precipitation regimes. Capturing and anticipating such changes will help us better predict the future of freshwater resources and mountain landscapes, especially as glaciers continue to melt.”

FOR MORE INFORMATION: https://www.gfz-potsdam.de/en/media-and-communication/news/details/article/lifeline-and-mortal-danger/

Only 17 percent of free-flowing rivers are protected

Only 17 percent of free-flowing rivers are protected, new research shows

New science about the fate of freshwater ecosystems released today by the journal Sustainability finds that only 17 percent of rivers globally are both free-flowing and within protected areas, leaving many of these highly-threatened systems¬ — and the species that rely on them — at risk.

“Populations of freshwater species have already declined by 84 percent on average since 1970, with degradation of rivers a leading cause of this decline. As a critical food source for hundreds of millions of people, we need to reverse this trend,” said Ian Harrison, freshwater specialist at Conservation International, adjunct professor at Northern Arizona University and co-editor of the journal issue.

As the world looks to establish new conservation targets at the UN Convention on Biological Diversity meeting later this year, scientists are calling on policymakers to prioritize increasing protection of freshwater ecosystems and species and to better integrate land and water conservation.

Free-flowing rivers and other naturally functioning freshwater ecosystems sustain biodiversity and the food supply chain, drinking water, economies and cultures for billions of people worldwide. Therefore, their protection is critical to sustain these values,” said Jonathan Higgins, senior freshwater science advisor at The Nature Conservancy.

A newly formed coalition of water resource experts — including representatives from academia as well as the World Wildlife Fund (WWF), Conservation International and The Nature Conservancy, among other entities — coordinated this first-of-its-kind collection of papers focused exclusively on durable protections for free-flowing rivers, with the aim of offering a blueprint to policymakers so they can integrate the best available science into environmental action plans. There is no global framework focused specifically on river protection, and freshwater protection receives less attention and funding than comparable efforts for marine and terrestrial systems.

The collection of 15 studies with authors from throughout the world offers examples of free-flowing river protections through the application of scientific research, law, policy and on-the-ground implementation of restoration and management strategies.

It is co-edited by Denielle Perry, a water resource geographer who leads the Free-flowing Rivers Lab in the School of Earth and Sustainability at NAU, and Harrison, who also is co-chair of the Freshwater Conservation Committee of IUCN’s Species Survival Commission. Both are founding members of the Durable River Protection Coalition, which is working to enable scientific research and policy proposals to help local communities, national governments, international institutions and private and public investors better protect these valuable but vulnerable resources.

“These ecosystems are among the most understudied and under-protected in the world, and they are at risk from further severe alteration and degradation by a range of threats, including poorly sited dam construction, overfishing, excessive water extraction and pollution,” Perry said. “This first-of-its-kind collection addresses growing calls to protect rivers as corridors in a changing climate and for the important role they play in providing ecosystem services and livelihoods around the world. We are at a moment when climate change and policy will shape the path of development, and the management of our riverine resources. We must act to protect rivers now because failing to do so will have lasting consequences for decades to come.”

The article topics range from global assessments to local case studies, including discussion of a framework that defines durable river protection, safeguarding free-flowing rivers through various policy mechanisms, adaptive management of the Malkumba-Coongie Lakes Ramsar site in Australia, the biological and cultural importance of sustainable floodplains in North Africa and more. The issue also features rivers in India, Mongolia, Mexico, China and the United States. Several articles take an in-depth look at a specific freshwater ecosystems and offer insights that can be applied elsewhere.

“The recommendations made in this special issue for more forward-thinking protections and wise use of our inland aquatic resources are timely. Wetlands are a powerful nature-based solution to the many challenges the world is facing. Taking action now for wetlands is foundational for creating the future we want,” said Martha Rojas Urrego, Secretary General of the Ramsar Convention on Wetlands.

As policymakers gather virtually this month to develop new global conservation goals, experts are calling for improved global targets for river protection. There is clear scientific evidence for the value of free-flowing rivers, including their ability to sustain migratory fish and to deliver the sediment needed to maintain river deltas — home to 500 million people and some of the most productive agricultural land on the planet — and prevent them from sinking and shrinking. Due to these values, researchers are calling for increased protections for free-flowing rivers as part of river basin management strategies.

“While 17 percent of all free-flowing rivers are within protected areas, in most countries the level of protection for large rivers is far lower,” said Jeff Opperman, WWF’s global lead freshwater scientist. “It’s these large rivers that are most crucial for supporting fisheries that support rural communities.”

FOR MORE INFORMATION:  Northern Arizona University