Author: getwetprojectblog

Research by Oregon State University has shed new light on the hazards associated with harmful algal blooms such as one four years ago that fouled drinking water in Oregon’s capital city of Salem.

The study led by Theo Dreher, emeritus professor of microbiology, involved sampling of cyanobacterial blooms from 10 Oregon lakes including Detroit Reservoir, which provides drinking water for Salem.

Genome sequencing and toxin analyses enabled Dreher and collaborators in the OSU colleges of Science and Agricultural Sciences to identify the precise types of toxins produced by specific organisms.

“This information is important for protecting public health, both with regard to consumption of drinking water and exposure to toxins through recreation on lakes,” Dreher said. “Two toxin-producing Dolichospermum cyanobacteria were present in Detroit Reservoir, one producing a type of cylindrospermopsin and another producing an uncommon form of microcystin. Occurrences of toxins had been known previously, but now we know the precise toxin types and the organisms making them.”

Cyanobacteria, often referred to as blue-green algae, are microscopic organisms ubiquitous in all types of water around the globe. They use sunlight to make their own food and in warm, nutrient-rich environments and can quickly multiply, resulting in blooms that spread across the water’s surface.

These harmful algal blooms, often abbreviated to HABs and which are of concern when visible in lake water, can form at any time of the year but most often between spring and fall.

In 2007 a national survey by the Environmental Protection Agency found microcystin, a recognized liver toxin and potential liver carcinogen, in one out of every three lakes that were sampled. Some strains of cyanobacteria can also produce neurotoxins, while most of the toxin-producing algae can cause gastrointestinal illness and acute skin rashes.

“Cyanobacterial HABs affect many of Oregon’s lakes each year,” Dreher said. “Some, but not all, of the blooms are toxic. Potential exposure to cyanotoxins is of public health concern, and blooms particularly pose a threat to dogs entering lakes.”

Among the 10 bodies of water in the research by Dreher and OSU colleagues Ryan Mueller and Ed Davis II, toxigenic Dolichospermum cyanobacteria caused blooms in four of them: Detroit Reservoir and Odell Lake in the Cascades, Lake Billy Chinook (Metolius Arm) in central Oregon and Junipers Reservoir, a private reservoir west of Lakeview in southern Oregon.

Analysis verified the presence and type of toxin. Microcystin was present in Odell Lake, Lake Billy Chinook and Junipers Reservoir.

“In early summer of 2018, low concentrations of microcystin and cylindrospermopsin cyanotoxins were found in finished tap water in Salem,” Dreher said. “A do-not-drink advisory was issued for vulnerable members of the population, particularly infants and pregnant women. Our research establishes the cyanobacteria and toxins that were involved in that emergency.”

Dreher notes that the Salem scare, along with the death of more than 30 steers from drinking cyanotoxin from Junipers Reservoir in June 2017, raised awareness of the hazards of cyanobacterial blooms in the state. The Oregon Legislature has since provided funding to the Department of Environmental Quality in an effort to improve the state’s ability to detect blooms and respond to them, he said.

“The good news is that not every cyanobacterial bloom that occurs in our lakes is toxic, although it is always wise to follow the rule of avoiding contact when there’s green growth in the water,” Dreher said.

If a person or a pet comes in contact with water that may contain harmful bacteria, the Centers for Disease Control and Prevention advises immediate rinsing with fresh water. Dogs should not be allowed to lick the contaminated water off their fur, the CDC adds, and a veterinarian should be called right away.

Anyone swallowing water near a harmful algal bloom should immediately call a doctor or poison control center. 

Amanda Foss of GreenWater Laboratories in Palatka, Florida, also took part in this research. The findings were published in Harmful Algae.

FOR MORE INFORMATION: https://phys.org/news/2022-06-hazards-posed-algal-blooms.html

Following a devastating wildfire in 2018 that raged through Paradise, California, volatile organic compounds (VOCs) were found to be contaminating the town’s water—and scientists suggest this problem may be widespread in other fire-prone areas. A feature article in Chemical & Engineering News, an independent news outlet of the American Chemical Society, examines how plastic pipes may be a key source of contamination and explores what can be done to protect vulnerable communities.

Testing revealed Paradise’s water contained VOCs (including benzene, naphthalene and toluene, among others) at levels exceeding U.S. Environmental Protection Agency standards, writes freelance contributor Robin Meadows. A team investigating the water contamination did not find VOCs in the treatment plants or mains but did detect them in the service lines, which are smaller pipes near or above ground typically made of plastics like polyvinyl chloride (PVC) and high-density polyethylene (HDPE). The researchers also found evidence that PVC and HDPE start to degrade and generate VOCs at high temperatures, but don’t need to burn to do so. Another study identified the VOCs in Paradise’s water and compared them to VOCs emitted from burned pipes and to other sources such as building materials. Their results suggest that the water sample was contaminated by a combination of plastic pipes and smoke.

While it is impractical and costly to eliminate plastic from service lines, experts say that some changes can help protect communities from their risks, such as burying them deeper to insulate them from the heat produced by fires. A network of isolation valves can help prevent contaminants from spreading throughout the water system in the event of a fire. In the future, sensors may be able to detect when pipes reach the threshold temperature for releasing VOCs. Beyond installing engineering systems, other strategies include managing vegetation, reducing the flammability of buildings and assessing individual community vulnerabilities. And after wildfires, water utility companies should act fast to test for contaminants in the water of burned homes and service lines, say experts.

FOR MORE INFORMATION: https://phys.org/news/2022-06-link-wildfires-contamination.html

The production of wild and farm-raised fish, shellfish and algae reached record levels in 2020, and future increases could be vital to fighting world hunger, the Food and Agriculture Organization said Wednesday.

Driven by sustained growth in aquaculture, global fisheries and aquatic farming together hauled in 214 million tonnes, the UN agency said in a report.

The total first-sale value of 2020 production topped $400 million, with $265 million coming from aquaculture, a sector poised for further expansion.

These trend lines are good news for a world facing price hikes and food shortages due to the war in Ukraine, disrupted supply chains, and inflation. 

“The growth of fisheries and aquaculture is vital in our efforts to end global hunger and malnutrition,” said FAO director Qu Dongyu. 

But overfished oceans, climate change and pollution—if left unaddressed—could threaten that potential, the UN agency warned.

“Aquaculture growth has often occurred at the expense of the environment,” Qu noted. 

Many shrimp farms in Vietnam, China and Cambodia, for example, have displaced mangrove forests that are nurseries for marine life and critical barriers against storm surges. 

Climate change poses additional challenges, experts say. 

“Warming waters will create environments where there’s more likelihood of bacterial disease,” said Josh Madeira, director of fisheries and aquaculture policy at the Monterey Bay Aquarium.

That means a sector already highly reliant on antibiotics will likely become even more so, he told AFP.

Production of aquatic animals in 2020—totalling 178 million tonnes—was evenly divided between fisheries and aquaculture, according to the FAO report.

The remaining 36 million tonnes was algae production.

Overfished stocks

Yields of fish, shrimp and other shellfish destined for human consumption are more than 60 percent higher than during the 1990s, far outpacing population growth, according to the report, released during the UN Ocean Conference in Lisbon.

On average, people worldwide consume over 20 kilos (44 pounds) of aquatic foods per year today, more than double the amount 50 years ago.

Globally, 17 percent of the protein consumed by humans comes from aquatic sources. In many Asian and African countries, that figure rises to more than 50 percent.

Wild and farmed food from the seas and inland waters are also a critical source of essential omega-3 fatty acids and micronutrients, recent research has shown.

“Aquatic foods are increasingly recognised for their key role in food security and nutrition,” Qu said. 

Nearly 90 percent of aquatic animal production is for human consumption, with the rest destined for non-food uses such as fishmeal and fish oil.

Asian countries were the source of 70 percent of the world’s fisheries and aquaculture of aquatic animals in 2020.

China remaines by far the top fisheries producer, followed by Indonesia, Peru, Russia, the United States and Vietnam.

So-called capture fisheries of commercial species in the wild—including tuna, cod, salmon and especially anchoveta—dropped by four percent in 2020 compared to the average of the previous three years.

Part of the drop can be attributed to COVID-related disruptions, but long-term decline is due to the pressures of overfishing, experts say. 

Catch levels peaked in the mid-1990s, and have—with fluctuations—stagnated since then.

“The FAO estimates that 34 percent of caught fish come from overfished stocks,” University of British Columbia economist and fisheries expert Rashid Sumaila told AFP.

“But they are very conservative,” he added. “Independent studies put that figure at 50 percent.”

Aggravating the problem is some $34 billion dollars annually in government subsidies. 

Earlier this month, the World Trade Organization (WTO) took preliminary steps to reduce these handouts to industry, but experts say the measures will have limited effect and take years to implement.

FOR MORE INFORMATION: https://phys.org/news/2022-06-aquaculture-aquatic-food-yields-high.html

New research, published in Scientific Reports by Smithsonian Tropical Research Institute (STRI) postdoctoral fellow Karina Chavarria and colleagues, shows that bacterial communities in streams adjacent to young secondary forests recover to resemble those of mature forest streams in as little as a decade after cattle has been removed from the land, and that these communities are robust throughout the year.

These results come at a critical time. 2021 marks the beginning of the United Nations Decade on Ecosystem Restoration, which aims to prevent, halt and reverse the degradation of ecosystems worldwide. The Agua Salud Project, a collaboration with the Panama Canal Authority and the Ministry of the Environment in Panama, and where this research took place, is one of the many initiatives at STRI aimed at understanding the drivers and consequences of environmental change.

Lessons learned from long term studies of forest ecosystems across different land uses and extreme weather events at Agua Salud inform our ability to restore and maintain tropical forests. With its various streams and rivers distributed throughout hundreds of hectares, Agua Salud also offers a unique platform for hydrological studies.

Water is a key resource for life on earth. People rely on streams and lakes for food and recreation. Microbes are less appreciated constituents of aquatic systems but are behind-the-scenes engineers that ensure water quality by cycling nutrients and energy. When streams become polluted or surrounding landscapes are degraded, microbial communities shift, risking their ability to help maintain natural processes and often allowing harmful bacteria to flourish. 

Chavarria and colleagues took weekly samples from streams surrounded by mature forest, young secondary forest, silvo- and traditional pasture over a two-year period at STRI’s Agua Salud site. They measured different aspects of water quality, and filtered water samples to extract and sequence the bacterial DNA in these streams.

They found similar communities in streams surrounded by young secondary and mature forests but different, less diverse communities in the cattle pasture stream. Notably, the bacterial community in the silvopasture stream shifted seasonally, with the wet season bacterial community being like the forests and the dry season community similar to the traditional pasture.

“Riparian forest helps to protect the silvopasture stream from the impacts of cattle in the wet season but in the dry season, when cows congregate in the stream to drink and seek shade as a way of avoiding the scorching sun, increased disturbance and fecal inputs make the bacterial community in the water more like that of traditional cattle pastures,” said STRI staff scientist Kristin Saltonstall, Chavarria’s advisor and collaborator on the project.

“It is important that cattle not access the streams, and that their drinking water is provided up slope during the dry season to ensure year-round water quality,” said Jefferson Hall, the director of Agua Salud and a collaborator on the project.

Silvopasture systems, where trees are planted on traditional cattle pastures and forest corridors are often maintained along streams, have gained a lot of attention in recent years. While the jury may still be out as to whether these systems provide all the environmental benefits claimed by promoters, it is clear that having a forest buffer around the stream is beneficial with respect to water quality and stream water bacterial communities.

“Our results add an important dimension to the growing body of research on the ability of biodiversity associated with young tropical secondary forests to recover rapidly, with implications for human health as well as a healthy environment,” said Chavarria.

Mitigation efforts taken during this Decade of Ecosystem Restoration will determine our quality of life for generations to come. Chavarria’s research provides hope, showing that passive reforestation, where forests are allowed to recover after cattle are removed, can restore many aspects of water quality in a matter of years. Studies such as this provide much needed data and demonstrate how science can inform policy and practice, contributing to a sustainable planet.

The Smithsonian Tropical Research Institute, headquartered in Panama City, Panama, is part of the Smithsonian Institution. The Institute furthers the understanding of tropical nature and its importance to human welfare, trains students to conduct research in the tropics and promotes conservation by increasing public awareness of the beauty and importance of tropical ecosystems.

FOR MORE INFORMATION: https://phys.org/news/2021-11-secondary-forests-fresh-sources-degraded.html

In an in-depth cross-country analysis considering the impacts of large-scale agriculture and industry on the human right to drinking water, Dr. Naho Mirumachi, Reader in Environmental Politics, from King’s College London has called for renewed political commitment to ensure everyone can enjoy access to clean, drinkable water.

There are Currently 2.2 billion people, or nearly a third of the global population, who lack safely managed drinking water. Of this figure, 450 million children face poor drinking water servicesand water scarcity, putting them in situations of high or extreme water vulnerability. The labor costs of water collection, including that of time spent to collect water and associated security risks, disproportionately fall on women and girls, affecting 8 out of 10 households without water.

Businesses from the food, textile, energy, industry, chemicals, pharmaceutical and mining sectors contribute to the majority of water use and pollution, which are often facilitated by foreign investment. These sectors are continuing to undertake activities, such as water intensive crop production, and withdraw from fresh water sources in areas where water access is already unreliable at a human cost. 

Consumption of one country can have an impact on another because of the global food trade. The water embedded in that food trade or, virtual water ‘trade’ means that countries are interdependent and have a high water footprint. The UK is the sixth largest net importer of virtual water in the world. Over half of that water footprint comes from countries facing water scarcity. The study, commissioned by the European Parliament’s Subcommittee on Human Rights, further highlights:

• It is estimated that global meat consumption will increase by 14% in the next decade as the population increases and income rises. Accordingly, a further 50% increase in food production is required by 2050 to feed the population. This growth in demand for agricultural products will strain the already unsustainable levels of water use.
• Temperature and precipitation changes resulting from climate change will contribute to the uncertainty of water availability and instances of drought and flooding. Water quality will be exacerbated by climate-induced algae blooms
• By 2040, water consumption in the energy sector will increase by about 60%.
• The demand for biofuels is underpinned by global shifts towards cleaner forms of energy. Biofuels impact other water uses, especially when these crops are irrigated for commercial production. There are concerns this will drive up prices and make food less affordable, in particular, for people below the poverty line.

Whilst behavior changes such as eating less red meat would ease pressure on production elsewhere, reduce virtual water ‘flows’ and relieve water stress, this alone is not enough. It is necessary to strengthen corporate due diligence and corporate accounting. Voluntary mechanisms will only go so far in addressing the impact of businesses on human rights. States need to put in place mandatory measures for corporate accountability.

The analysis was requested by the European Parliament’s Subcommittee on Human Rights, funded by the European Parliament, and the copyright is with them. The content of study is the sole responsibility of the authors, and any opinions expressed herein do not necessarily represent the official position of the European Parliament.

for more information: https://phys.org/news/2021-11-human-rights-millions-endangered-large-scale.html

Years ago, there was a time that kids from a rural village in South Africa still wanted to swim in the rivers nearby. But when they got out of the water, those with sensitive skin would have the worst rash ever, says Professor Philiswa Nomngongo from the University of Johannesburg’s (UJ) campus in the CBD. Nomngongo is the DSI/NRF SARChI Chair: Nanotechnology for Water, within the UJ Department of Chemical Sciences.

She grew up in the village of Flagstaff in the Wild Coast region of the Eastern Cape of South Africa. “In my village, there are streams and rivers. What happens is, those who do not have money to buy a tank for rainwater harvesting, they depend on the stream or river,” she says.

The people who have tanks will do their bathing, dishes and laundry with the convenient and relatively safe rainwater. Then they release their wastewater into the river nearby. “Downstream, someone else is drinking water from that river,” she adds.

Most rivers in South Africa may only be a few meters across, and about waist deep most of the year until flash floods arrive. And it’s not just people affecting water quality in such a village, it is livestock also. “When the cows walk in the water and it looks dirty, the villagers wait for the water to clear again, but the question is, is it clean? The challenge is, we always look to see if water is clear, rather than looking at the quality of that particular water,” she says.

Upstream from the city

People who live in large towns and cities may think that upstream contamination doesn’t affect them. After all, water treatment plants protect them, removing heavy metals, bacteria, viruses and more from their tap water. But the tap water in large towns and cities often come from rivers upstream. And there is another type of contamination that slips right through almost all water treatment plants—the medicines other people use upstream. They are not filtered by their wastewater treatment plants; the medicines end up in the rivers supplying drinking water to cities and towns downstream.

Pharma in our own taps

“What I can say to a city person is, not all clear water means clean. As researchers, we know the challenges with pollutants. Water treatment plants cannot remove pharmaceuticals. But we release pharmaceuticals ourselves into wastewater on a daily basis,” says Nomngongo.”In the cities, we get medications because we have medical aids (health insurance). Sometimes, we don’t care and say, “I am healed now’ and throw our medicines away. The easiest way to do it is to flush it down the toilet. We don’t think that this might come back to us through our own tap.”

Treatment plants only do so much

“The technologies at wastewater plants remove some pollutants, but not everything,” says Dr. Mpingana Akawa. She lives near the Orange River in Namibia. Dr. Akawa conducted the experimental work for the research as part of her Ph.D. studies at the university of Johannesburg.

“Pharmaceuticals are regarded as emerging organic pollutants. We need to remember that most pharmaceuticals are not regulated. Hence, there are no limits on how much should be in the effluent of a wastewater treatment plant before it is discharged into the environment. Because they are not regulated, people are not really monitoring these things before releasing the treated wastewater. I think that is where the whole problem is,” adds Akawa.

Stuck between need and pollution

One of the reasons pharmaceuticals in wastewater are not yet regulated, is because a ‘cocktail’ of many of these are released daily into rivers. Sometimes, this makes it very difficult to make rules about this, says Nomngongo. One reason water treatment plants are not designed to remove pharmaceuticals is because they are present in water at very low concentrations, she adds.

There is also the tension between individual medical treatment and collective water management. “Mothers living with HIV have to use Nevirapine to prevent transmitting the virus to their babies. If you started regulating ARVs, how would you regulate Nevirapine in wastewater? We are stuck between a need and pollution.”

Nevirapine is also used as part of combination therapy for people who are on antiretroviral treatments. “The wastewater from our homes goes to a wastewater treatment plant. There it is treated in multiple stages. In the end, the treated water is released into the nearest river. That is why most of these plantsare built close to a river or stream. And if that water is not treated well, it means that the river close by will be contaminated by some of the pollutants of the treatment plant,” she adds.

FOR MORE INFORMATION: https://phys.org/news/2021-11-hiv-drugs.html

Scientists are inching closer to revealing the elusive mechanisms that tiny marine species activate to transform organic contaminants in water into less toxic chemicals

Cup sea water in your hands and you will be holding a bustling world of single-cell organisms—thousands of them. 

Much like creatures of an undersea metropolis, microscopic photosynthetic microbes—phytoplankton—quietly float through the ocean, enhancing water quality. As the foundation for the ocean ecosystem, phytoplankton work tirelessly to fuel marine food webs and consume large amounts of carbon dioxide on scales equivalent to forests. But this is not all they can do. These tiny plants may turn organic contaminants into less toxic chemicals. 

Sounds simple, but it’s not. The processes involved remain elusive. 

Synthetic chemicals in the environment

Water pollution, once an invisible, silent threat, is now a top environmental concern worldwide. 

“Millions of tons of synthetic organic chemicals are used for industrial, agricultural and consumers’ purposes annually. These compounds partially find their way to the aquatic environment, impairing water quality and undermining aquatic life,” said Giulia Cheloni, an environmental scientist studying phytoplankton’s responses to carbon-based contaminants. 

These pollutants are described as contaminants of emerging concern because of their potential risk to human health and ecological impacts. They can be found in personal care products like fragrances, disinfectants and sunscreen agents, as well as household items such as solvents, fabric protectors and flame retardants. 

Can powerful phytoplankton clean up contaminants?

Scientists are studying how organic contaminants affect phytoplankton.

FOR MORE INFORMATION: https://phys.org/news/2021-11-smaller-grain-sand-phytoplankton-key.html

For more than a decade, fertilizer leaching and associated stormwater runoff were thought to be the major drivers of harmful algal blooms in Florida’s Indian River Lagoon. Despite the numerous residential fertilizer ordinances passed since 2011, water quality, harmful algal blooms, and seagrass loss, which has resulted in mass deaths of the threatened Florida manatee, have continued to worsen.

There are more than 300,000 septic systems permitted in six counties adjacent to the 156-mile-long Indian River Lagoon, which makes up 40 percent of Florida’s eastern coast, and in Indian River and Martin counties, septic systems represent more than 50 percent of wastewater disposal. Five inlets allow the lagoon’s waters to drain into the ocean, potentially impacting another important Florida ecosystem.    

To determine if septic systems in Indian River County contribute to nutrient enrichment of groundwaters and surface waters that discharge into the central Indian River Lagoon, researchers from Florida Atlantic University’s Harbor Branch Oceanographic Institute assessed water quality at 20 sites in four Indian River County sub-drainage basins.

For the study, published in the journal Marine Pollution Bulletin, they measured stable nitrogen isotopes in groundwater, surface water, and macrophyte tissue to identify nitrogen sources impacting the Indian River Lagoon. Sucralose, an artificial sweetener that is not completely broken down by septic systems or wastewater treatment plants, was used as a human wastewater tracer, and fecal indicator bacteria density was used as an indicator of wastewater pollution.

Results reveal that nitrogen enrichment of all sub-drainage basins in this study supports that even “properly functioning” septic systems contribute nitrogen to surficial (shallow) groundwater. Furthermore, shallow ecosystems without a significant source of flushing and dilution, such as the central Indian River Lagoon are more susceptible to inputs from contaminated groundwater. Evidence shows that this issue is likely widespread in the Indian River Lagoon, including its canals, tributaries and rivers.

Groundwater had significantly higher dissolved nutrient concentrations, nutrient ratios and more enriched stable nitrate isotopes than surface waters, indicating septic system-enriched groundwater as a nitrogen source to adjacent surface waters. This finding has implications for nutrient loading and pollution, as submarine groundwater discharge is a primary mechanism for nutrient and microbial transport to coastal waters.

FOR MORE INFORMATION: https://phys.org/news/2021-12-septic-pervasive-florida-indian-river.html

Human wastewater poses a global threat to seafood safety and the financial stability of the aquaculture industry. A recent study by researchers at the Dauphin Island Sea Lab and the University of South Alabama, in collaboration with the U.S. Food and Drug Administration, tested multiple indicators of wastewater contamination to identify potential sources of contamination to local shellfish farms and aid management efforts.

Successful management of wastewater contamination relies on understanding the sources of wastewater to a system. Established metrics to assess water quality and wastewater sources include bacterial and viral indicators, nutrient concentrations, and stable isotope ratios. 

Along with these sources, the team tested artificial sweetenersas a wastewater indicator. The analysis of artificial sweeteners emerged recently as a method to better trace human-specific wastewater sources. Artificial sweeteners, such as acesulfame and sucralose, are slow to degrade and are not found in nature. They are also rarely found in commonly used fertilizers or livestock feed. 

Individually, these water quality indicators provide some evidence of the presence of wastewater and associated microbes of human concern. The research team found that using multiple indicators in combination provided a greater potential for source identification and detected seasonal variation in contamination risk. 

The study focused on shellfish farms in Portersville Bay, Alabama, in Mississippi Sound on the northern Gulf of Mexico coast, but has implications for shellfish farms in any system potentially affected by multiple sources of wastewater contamination. Potential wastewater sources sampled for the study included a wastewater treatment plant outfall and industrial, residential, and agricultural areas near the shellfish farms. To understand how environmental conditions may affect wastewater source contributions, samples were collected in wet and dry conditions and during warm and cold periods. 

Overall, indicator source dominance depended on environmental conditions, with wastewater treatment plant outfall and residential sources conveying human-specific indicators to farms year-round, while agricultural and industrial sites contributed additional fecal coliforms during cold wet periods. The study additionally found evidence that disturbance such as some types of construction activity may contribute fecal indicators to adjacent waters.

The use of multiple indicators will aid managers to detect and define wastewater sources, identify targets for monitoring or remediation, and manage shellfish areas in estuaries with a mosaic of land-derived wastewater sources.

FOR MORE INFORMATION: https://phys.org/news/2021-12-multiple-indicators-wastewater-contamination-shellfish.html

Beavers could make an important contribution to improving the condition of Scotland’s rivers, including helping to improve water quality and limiting the effects of drought.

The positive role they can play in water resource management, as well as in creating habitat, carbon sequestrationand river restoration, is highlighted in a report produced by scientists at the University of Aberdeen and the James Hutton Institute. They have collated evidence from 120 studies of beaver populations worldwide, as part of a large-scale review of their effects on streams and rivers.

In Scotland, beavers have already taken up residence in a few areas, including Tayside and Knapdale. While sometimes their presence has been welcomed, in other situations there has been conflict, for example where their activity affected intensively managed landscapes.

Until now, evidence of the role of beavers in helping to manage river ecosystems in Scotland has been minimal. But by identifying trends associated with the effects of beaver dam building on water quantity and quality—while factoring in the characteristics of Scottish rivers—the scientists who produced the report have provided detailed evidence to help policymakers consider the benefits and limitations of beaver expansion in Scotland, including where trade-offs are required.

In November last year the Scottish Government announced a revised beaver policy which included the development of a new national strategy for beavers. The research leading to the publication of the report was requested by NatureScot and funded by the Scottish Government via the Centre of Expertise for Waters.

Dr. Josie Geris, from the University’s School of Geosciences, led the study. She said: “We found that, by modifying physical processes in streams and rivers, beaver dam building could help to address several important water management challenges in Scotland, including water supply and, by trapping sediment and contaminants, water quality.

“Locally, beaver activity may also limit the effect of extreme events such as drought, which is expected to increase with climate change and can carry an economic impact—for example during the dry summer of 2018 when numerous private water supplies to communities and businesses were affected.

“Achieving the potential of the positive effects of beaver activity may involve some challenges and the need to find solutions. And while most of the evidence points to positive contributions to river ecosystems locally, the report recommends that more work is needed on understanding how the effects of beavers across multiple sites sum up to affect rivers at larger scales.”

Angus Tree from NatureScot said: “This is a significant study that clearly demonstrates the unique ways in which beavers engineer ecosystems. It backs up evidence we’ve gathered over the years and will help our work with stakeholders as we develop the best ways to live with, and benefit from, beavers. We are committed to continuing work to restore and manage beavers, as one important way to protect Scotland’s environment and respond to the climate emergency.”

FOR MORE INFORMATION:https://phys.org/news/2022-01-major-role-beavers-scotland-rivers.html