Montana State scientists publish evidence for new groups of methane-producing organisms

MONTANA STATE UNIVERSITY

A team of scientists from Montana State University has provided the first experimental evidence that two new groups of microbes thriving in thermal features in Yellowstone National Park produce methane – a discovery that could one day contribute to the development of methods to mitigate climate change and provide insight into potential life elsewhere in our solar system.

The journal Nature this week published the findings from the laboratory of Roland Hatzenpichler, associate professor in MSU’s Department of Chemistry and Biochemistry in the College of Letters and Science and associate director of the university’s Thermal Biology Institute. The two scientific papers describe the MSU researchers’ verification of the first known examples of single-celled organisms that produce methane to exist outside the lineage Euryarchaeota, which is part of the larger branch of the tree of life called Archaea. 

Alison Harmon, MSU’s vice president for research and economic development, said she is excited that the findings with such far-reaching potential impact are receiving the attention they deserve.

“It’s a significant achievement for Montana State University to have not one but two papers published in one of the world’s leading scientific journals,” Harmon said.

The methane-producing single-celled organisms are called methanogens. While humans and other animals eat food, breathe oxygen and exhale carbon dioxide to survive, methanogens eat small molecules like carbon dioxide or methanol and exhale methane. Most methanogens are strict anaerobes, meaning they cannot survive in the presence of oxygen.

Scientists have known since the 1930s that many anaerobic organisms within the archaea are methanogens, and for decades they believed that all methanogens were in a single phylum: the Euryarchaeota. 

But about 10 years ago, microbes with genes for methanogenesis began to be discovered in other phyla, including one called Thermoproteota. That phylum contains two microbial groups called Methanomethylicia and Methanodesulfokora.

“All we knew about these organisms was their DNA,” Hatzenpichler said. “No one had ever seen a cell of these supposed methanogens; no one knew if they actually used their methanogenesis genes or if they were growing by some other means. 

Hatzenpichler and his researchers set out to test whether the organisms were living by methanogenesis, basing their work on the results of a study published last year by one of his former graduate students at MSU, Mackenzie Lynes. 

Samples were harvested from sediments in Yellowstone National Park hot springs ranging in temperature from 141 to 161 degrees Fahrenheit (61–72 degrees Celsius).

Through what Hatzenpichler described as “painstaking work,” MSU doctoral student Anthony Kohtz and postdoctoral researcher Viola Krukenberg grew the Yellowstone microbes in the lab. The microbes not only survived but thrived – and they produced methane. The team then worked to characterize the biology of the new microbes, involving staff scientist Zackary Jay and others at ETH Zurich.

At the same time, a research group led by Lei Cheng from China’s Biogas Institute of the Ministry of Agriculture and Rural Affairs and Diana Sousa from Wageningen University in the Netherlands successfully grew another one of these novel methanogens, a project they had worked on for six years. 

“Until our studies, no experimental work had been done on these microbes, aside from DNA sequencing,” said Hatzenpichler.

He said Cheng and Sousa offered to submit the studies together for publication, and Cheng’s paperreporting the isolation of another member of Methanomethylicia was published jointly with the two Hatzenpichler lab studies.

While one of the newly identified group of methanogens, Methanodesulfokora, seems to be confined to hot springs and deep-sea hydrothermal vents, Methanomethylicia, are widespread, Hatzenpichler said. They are sometimes found in wastewater treatment plants and the digestive tracts of ruminant animals, and in marine sediments, soils and wetlands. Hatzenpichler said that’s significant because methanogens produce 70% of the world’s methane, a gas 28 times more potent than carbon dioxide in trapping heat in the atmosphere, according to the U.S. Environmental Protection Agency. 

“Methane levels are increasing at a much higher rate than carbon dioxide, and humans are pumping methane at a higher rate into the atmosphere than ever before,” he said. 

Hatzenpichler said that while the experiments answered an important question, they generated many more that will fuel future work. For example, scientists don’t yet know whether Methanomethylicia that live in non-extreme environments rely on methanogenesis to grow or if they grow by other means. 

“My best bet is that they sometimes grow by making methane, and sometimes they do something else entirely, but we don’t know when they grow, or how, or why.” Hatzenpichler said. “We now need to find out when they contribute to methane cycling and when not.”

Whereas most methanogens within the Euryarchaeota use CO2 or acetate to make methane, Methanomethylicia and Methanodesulfokora use compounds such as methanol. This property could help scientists learn how to alter conditions in the different environments where they are found so that less methane is emitted into the atmosphere, Hatzenpichler said.

His lab will begin collaborating this fall with MSU’s Bozeman Agricultural Research and Teaching Farm, which will provide samples for further research into the methanogens found in cattle. In addition, new graduate students joining Hatzenpichler’s lab in the fall will determine whether the newly found archaea produce methane in wastewater, soils and wetlands.

Methanomethylicia also have a fascinating cell architecture, Hatzenpichler said. He collaborated with two scientists at ETH Zurich, Martin Pilhofer and graduate student Nickolai Petrosian, to show that the microbe forms previously unknown cell-to-cell tubes that connect two or three cells with each other. 

“We have no idea why they are forming them. Structures like these have rarely been seen in microbes. Maybe they exchange DNA; maybe they exchange chemicals. We don't know yet,” said Hatzenpichler.

The newly published research was funded by NASA’s exobiology program. NASA is interested in methanogens because they may give insights into life on Earth more than 3 billion years ago and the potential for life on other planets and moons where methane has been detected, he said. 

Hatzenpichler has discussed the results of the two studies in an online lecture and on a recent Matters Microbial podcast, and produced this infographic on methane cycling. To learn more about his lab visit www.environmental-microbiology.com or send an email to roland.hatzenpichler@montana.edu. 

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JOURNAL

Nature

DOI

10.1038/s41586-024-07631-6 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Cultivation and visualization of a methanogen of the phylum Thermoproteota

ARTICLE PUBLICATION DATE

24-Jul-2024

 

Svalbard: Non-native species are threatening vulnerable plant life

Authorities need to act more aggressively to prevent the accidental introduction of non-native plant species to arctic ecosystems

NORWEGIAN UNIVERSITY OF SCIENCE AND TECHNOLOGY

 

IMAGE: 

THE ALKHORNET BIRD CLIFFS. NATURALLY OCCURRING NUTRIENT-RICH SOIL CAN BE FOUND DIRECTLY BELOW THE BIRD CLIFFS, AND RESEARCHERS ARE MONITORING WHETHER NON-NATIVE PLANTS HAVE SPREAD THERE.

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CREDIT: PHOTO: KRISTINE BAKKE WESTERGAARD, NTNU

New, non-native plant species are constantly being discovered in Svalbard, and researchers are working to ascertain what threat these species pose to the native plants.

So far, the Arctic has managed to avoid one of the most serious threats to biodiversity on Earth. This is also true for Svalbard, but things could change very quickly, and researchers want to find out how to counteract this threat.

“Increased human activity heightens the risk of new plant species being introduced. And climate change increases the risk of invasive species establishing themselves,” says Kristine Bakke Westergaard.

She is an associate professor at the Department of Natural History, which is part of the University Museum at the Norwegian University of Science and Technology (NTNU).

No checks on arrival to Svalbard

New species can outcompete the plants already present in Svalbard. Non-native species are spreading across large parts of the globe and can disrupt the established balance between species in a certain area.

Human activity is to blame for the spread of new, non-native species to new areas. Svalbard is particularly at risk because of its popularity as a destination for cruises and other tourist activities. However,  upon arrival in Svalbard, visitors are not checked to see if they are carrying any biological stowaways. For example, no one checks whether air passengers or cruise tourists have contaminated shoes, or whether imported soil contains seeds.

On the other side of the globe in Antarctica, there are much stricter requirements and checks to prevent these types of introductions. The lack of biosecurity routines in Svalbard worries researchers.

The warmer climate supports new species

Currently, only the hardiest species are able to survive in Svalbard. However, the archipelago has become much warmer in recent years, enabling more species to establish themselves.

“We have developed models to map 27 non-native plant species and their potential to find new habitats and suitable climates in Svalbard,” says James Speed, a professor at NTNU’s Department of Natural History.

Currently, all of these species are only found in the inhabited parts of Svalbard. The researchers mapped out which areas of Svalbard have the optimal combination of temperature and precipitation for these species, both now and in the future.

“In relation to the current climate, we have identified three species that have particularly high potential to find new habitats in Svalbard. If they manage to spread to these areas, they could pose a threat,” says James Speed.

The three species that could spread the most are:

• Tufted hairgrass (Deschampsia cespitosa)
• A species of meadow buttercup (Ranunculus subborealis subsp. villosus)
• Alpine saw-wort (Saussurea alpina)

All areas of Svalbard could be at risk

The models show that almost all areas of Svalbard will develop a suitable climate for many of these non-native plants. The uninhabited islands of Edgeøya and Barentsøya to the east, as well as the island of Bjørnøya with its manned meteorological station to the south, are most at risk. However, things can change quickly.

“In the future, as the climate warms, most of the non-native species we investigated have the potential to spread throughout Svalbard. Many of the species that do not belong in Svalbard may be able to spread over a much wider area than they are currently able to do,” says Westergaard.

Factors other than temperature and climate also play a role in preventing new species from spreading. Among other things, limited access to nutrient-rich soil has kept their prevalence to a minimum. This, however, also seems to be changing.

Urgent intervention required

The researchers are of the opinion that the environmental authorities must act quickly if they are to limit and prevent these invasive non-native species from spreading beyond the areas where they already exist.

In addition, the researchers say society must prioritize preventing new non-native species from spreading to Svalbard before the threat to the Arctic ecosystem becomes too great and unmanageable.

This study is part of the Biodiversa project ASICS (ASsessing and mitigating the effects of climate change and biological Invasions on the spatial redistribution of biodiversity in Cold environmentS). The Norwegian team is funded by the Research Council of Norway. Other contributors include the South African National Research Foundation and the Millennium BASE Institute.

References: Speed JDM, Pertierra LR, Westergaard KB (2024) The potential area of occupancy of non-native plants across a warming high-Arctic archipelago: Implications for strategic biosecurity management. NeoBiota 93: 157-175. https://doi.org/10.3897/neobiota.93.114854

 

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JOURNAL

NeoBiota

DOI

10.3897/neobiota.93.114854 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

The potential area of occupancy of non-native plants across a warming high-Arctic archipelago: Implications for strategic biosecurity management

 

Outsourcing conservation in Africa

NGO park management reduces poaching and boosts tourism, but raises the risks for civilians in war-torn areas

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - SANTA BARBARA

 

IMAGE: 

AFRICAN PARKS’ MAP OF ANCHOR SITES ENABLED THE AUTHORS TO COMPARE PRIVATE AND GOVERNMENTAL CONSERVATION MANAGEMENT.

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CREDIT: DENNY ET AL.

(Santa Barbara, Calif.) — There’s an experiment going on in conservation in Africa. With biodiversity imperiled, and nations facing financial and political crises, some governments are transferring the management of protected areas to private, non-governmental organizations (NGOs).

This strategy seems to be paying off. NGOs can better manage corruption, making them attractive to large donors like the World Bank and European Union. Their capital can fund personnel, research and technology to more effectively manage protected areas and species. While these management changes appear to be working anecdotally, few if any studies have rigorously evaluated the results.

A team of researchers from institutions including UC Santa Barbara wanted to know how this trend affects wildlife and people. Surveying parks throughout the continent under private and government administration, they discovered that NGO management improves measures for wildlife, including by reducing elephant poaching, and increases tourism. Overall, management appears to improve under NGO control. However, they also discovered that in landscapes experiencing armed conflict, outsourcing park management also raises the risk of armed groups targeting civilians in and around protected areas. The team published their results in the Proceedings of the National Academy of Sciences.

“Protected areas, and conservation generally, do not exist in isolation from humans,” said lead author Sean Denny, a doctoral candidate at UC Santa Barbara’s Bren School of Environmental Science & Management. “In fact, conservation is, at its heart, about humans — it's about finding ways for humans and other species to coexist. This includes preventing extinctions caused by human activities like hunting and deforestation.” As a result, conservation often impacts people’s lives and livelihoods, outcomes that need to be taken into consideration.

African Parks as a case study

Denny and his two co-authors focused on the organization African Parks (AP) as a case study. AP is the largest NGO partnering with governments in Africa to administer protected areas. The South Africa-based non-profit is given complete authority to manage, staff and fund the parks.

AP’s primary mission is to conserve and restore wildlife populations in Africa, but they also seek to make protected areas benefit people through tourism and development projects, like building schools and hospitals for local communities. Due to their focus on restoration, they sometimes work in areas experiencing armed conflict, where wildlife is especially prone to being over-hunted and faces extreme pressure from hunting. But protecting wildlife in these landscapes can require high levels of security and enforcement, which could have unintended impacts on people and result in tradeoffs between wildlife conservation and human well-being. The authors were interested in exploring these trade-offs; and, because AP operates in conflict zones, they suspected AP’s activities might capture them.

But running a study at such a large scale presented a challenge: The authors had to compare outcomes in areas under AP’s management to what would have happened if AP were never given the reins. To do so, they ran a quasi-experiment in which researchers make use of real-world events to create treatment and control groups. In real experiments, researchers randomly assign subjects to one of these groups to ensure that their findings are due to the treatment and not simply down to prior differences. But Denny and company didn’t have this luxury.

Fortunately, AP published a map of protected areas in Africa that they believe are key to safeguarding the continent’s biodiversity and ultimately meet their criteria for future management. These “anchor sites” share key characteristics like a large size, strong legal status, limited agricultural activity and the potential to sustain large wildlife populations. Twenty-two of these anchor sites are already managed by AP, but the rest are managed by governments and in very few cases, by other NGOs.

The research team formed a treatment group from anchor sites that AP already administers. Their control group consisted of anchor sites not managed by AP or another NGO. “African Parks essentially created our control group for us,” Denny said.

Deciding what to look for

The team used a variety of metrics to measure the effects of private management on wildlife and people. They needed metrics for which data was available at a continental scale. For wildlife, they focused on elephant poaching and bird abundances. On the human side, they looked at tourism, wealth and armed conflict. To measure these outcomes, they drew on diverse datasets and platforms, including a dataset called MIKE that monitors elephant poaching; the citizen science platforms eBird and iNaturalist; Atlas AI, which measures wealth; and the Armed Conflict Location & Event Data Project, which measures incidences of armed conflict.

The researchers also used the Management Effectiveness Tracking Tool (METT) to look under the hood at how AP affects management practices themselves. Developed by the International Union for Conservation of Nature, this standardized questionnaire quantifies how well protected areas are managed. It reports data on planning, financial resources, law enforcement and stakeholder involvement. The METT can shed light on the mechanisms behind the outcomes observed in the other datasets.

Following the results

Denny and his co-authors were impressed by the results private management had for wildlife. It reduced elephant poaching by 35%, and increased bird abundance by 37%. “African Parks really appears to work for wildlife,” Denny said. “The fact that they can reduce elephant poaching in protected areas that are threatened by armed groups is really quite extraordinary.” NGO administration also increased tourism, but the effects on wealth were less conclusive.

The authors also found some important drawbacks, though. In areas already experiencing armed conflict, these changes can increase the probability that armed groups target civilians living in areas bordering those overseen by AP. They think this could be a result of armed groups redirecting their activity toward exploiting civilians when AP prevents them from operating in or extracting resources from protected areas.

“While the outcomes for wildlife were even stronger than we expected,” Denny said, “we were concerned by the conflict results, especially when combined with the potential decrease in decision-making inclusiveness that comes with private management.”

Looking under the hood

The Management Effectiveness Tracking Tool provided insights on the mechanisms behind these outcomes. African Parks is a juggernaut compared to many cash-strapped national governments. Results from the METT revealed that AP increased capacity and resources (in terms of budget and staffing), as well as design and planning. “In some management criteria, they really do seem to manage more effectively,” Denny said.

The authors also found that monitoring and enforcement within parks rose under AP. The organization uses sophisticated equipment — like aircraft, drones and remote sensing — to monitor illegal activity in their parks and enforce wildlife protection. This likely contributes to the benefits of AP management for wildlife, as well as the rise in likelihood that armed groups target civilians.

Notably, only one of the four categories measured by the METT appeared to fall under private park management: decision-making inclusiveness. The slight drop in this category didn’t surprise Denny and his colleagues since AP maintains tight control over its work. It does, however, point to an opportunity for improvement.

Managing more effectively

African wildlife is threatened, and NGOs are offering a potential solution. But it’s crucial to investigate the impacts of private conservation management to understand its strengths, weaknesses and opportunities for improvement. Outsourcing conservation appears to provide a path for protecting wildlife, but the accompanying increased enforcement can lead to problems for people.

One way to ensure that protected areas work for people, according to the researchers, is to include local communities in stewardship. In Denny’s opinion, ethical conservation requires compensating local communities for the costs they bear and including them in policy decisions.

“If, in conflict regions, civilians are bearing some unexpected costs of private protected area management, then it is especially important that they are involved in decision making,” he said. Another avenue is to make sure that conservationists, park managers and governments monitor the impacts of private management, not just on wildlife but also on people, and adapt when necessary.

Additionally, many national parks in Africa were created by colonial administrations, so they have deep colonial histories and legacies. Denny and his co-authors are eager to partner with African researchers to explore how this history affects local people’s perceptions of parks, and their preferences for how they’re managed and by whom. “By elevating local voices, perspectives and experiences, we can develop more meaningful research and support management practices that benefit both wildlife and local communities,” he said.

An elephant ambles through the savannas of Tarangire National Park, one of AP’s anchor sites currently managed Tanzanian government.

CREDIT

Sean Denny

JOURNAL

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2401814121 

ARTICLE TITLE

Private management of African protected areas improves wildlife and tourism outcomes but with security concerns in conflict regions

GUNS OR BUTTER

Study: When allocating scarce resources with AI, randomization can improve fairness

Introducing structured randomization into decisions based on machine-learning model predictions can address inherent uncertainties while maintaining efficiency.

MASSACHUSETTS INSTITUTE OF TECHNOLOGY

CAMBRIDGE, MA – Organizations are increasingly utilizing machine-learning models to allocate scarce resources or opportunities. For instance, such models can help companies screen resumes to choose job interview candidates or aid hospitals in ranking kidney transplant patients based on their likelihood of survival.

When deploying a model, users typically strive to ensure its predictions are fair by reducing bias. This often involves techniques like adjusting the features a model uses to make decisions or calibrating the scores it generates.

However, researchers from MIT and Northeastern University argue that these fairness methods are not sufficient to address structural injustices and inherent uncertainties. In a new paper, they show how randomizing a model’s decisions in a structured way can improve fairness in certain situations.

For example, if multiple companies use the same machine-learning model to rank job interview candidates deterministically — without any randomization — then one deserving individual could be the bottom-ranked candidate for every job, perhaps due to how the model weighs answers provided in an online form. Introducing randomization into a model’s decisions could prevent one worthy person or group from always being denied a scarce resource, like a job interview.

Through their analysis, the researchers found that randomization can be especially beneficial when a model’s decisions involve uncertainty or when the same group consistently receives negative decisions.

They present a framework one could use to introduce a specific amount of randomization into a model’s decisions by allocating resources through a weighted lottery. This method, which an individual can tailor to fit their situation, can improve fairness without hurting the efficiency or accuracy of a model.

“Even if you could make fair predictions, should you be deciding these social allocations of scarce resources or opportunities strictly off scores or rankings? As things scale, and we see more and more opportunities being decided by these algorithms, the inherent uncertainties in these scores can be amplified. We show that fairness may require some sort of randomization,” says Shomik Jain, a graduate student in the Institute for Data, Systems, and Society (IDSS) and lead author of the paper.

Jain is joined on the paper by Kathleen Creel, assistant professor of philosophy and computer science at Northeastern University; and senior author Ashia Wilson, the Lister Brothers Career Development Professor in the Department of Electrical Engineering and Computer Science and a principal investigator in the Laboratory for Information and Decision Systems (LIDS). The research will be presented at the International Conference on Machine Learning.

Considering claims

This work builds off a previous paper in which the researchers explored harms that can occur when one uses deterministic systems at scale. They found that using a machine-learning model to deterministically allocate resources can amplify inequalities that exist in training data, which can reinforce bias and systemic inequality.  

“Randomization is a very useful concept in statistics, and to our delight, satisfies the fairness demands coming from both a systemic and individual point of view,” Wilson says.

In this paper, they explored the question of when randomization can improve fairness. They framed their analysis around the ideas of philosopher John Broome, who wrote about the value of using lotteries to award scarce resources in a way that honors all claims of individuals.

A person’s claim to a scarce resource, like a kidney transplant, can stem from merit, deservingness, or need. For instance, everyone has a right to life, and their claims on a kidney transplant may stem from that right, Wilson explains.

“When you acknowledge that people have different claims to these scarce resources, fairness is going to require that we respect all claims of individuals. If we always give someone with a stronger claim the resource, is that fair?” Jain says.

That sort of deterministic allocation could cause systemic exclusion or exacerbate patterned inequality, which occurs when receiving one allocation increases an individual’s likelihood of receiving future allocations. In addition, machine-learning models can make mistakes, and a deterministic approach could cause the same mistake to be repeated.

Randomization can overcome these problems, but that doesn’t mean all decisions a model makes should be randomized equally.

Structured randomization

The researchers use a weighted lottery to adjust the level of randomization based on the amount of uncertainty involved in the model’s decision-making. A decision that is less certain should incorporate more randomization.

“In kidney allocation, usually the planning is around projected lifespan, and that is deeply uncertain. If two patients are only five years apart, it becomes a lot harder to measure. We want to leverage that level of uncertainty to tailor the randomization,” Wilson says.

The researchers used statistical uncertainty quantification methods to determine how much randomization is needed in different situations. They show that calibrated randomization can lead to fairer outcomes for individuals without significantly affecting the utility, or effectiveness, of the model.

“There is a balance to be had between overall utility and respecting the rights of the individuals who are receiving a scarce resource, but oftentimes the tradeoff is relatively small,” says Wilson. 

However, the researchers emphasize there are situations where randomizing decisions would not improve fairness and could harm individuals, such as in criminal justice contexts.

But there could be other areas where randomization can improve fairness, such as college admissions, and the researchers plan to study other use-cases in future work. They also want to explore how randomization can affect other factors, such as competition or prices, and how it could be used to improve the robustness of machine-learning models.

“We are hoping our paper is a first move toward illustrating that there might be a benefit to randomization. We are offering randomization as a tool. How much you are going to want to do it is going to be up to all the stakeholders in the allocation to decide. And, of course, how they decide is another research question all together,” says Wilson.

 

 

ISU studies explore win-win potential of grass-powered energy production

IOWA STATE UNIVERSITY

 

IMAGE: 

AN ANAEROBIC DIGESTER USED BY THE CITY OF AMES' WATER POLLUTION CONTROL FACILITY. ONE OF TWO RECENT FEASIBILITY STUDIES BY AN IOWA STATE UNIVERSITY RESEARCH TEAM EXPLORING USING PRAIRIE GRASS TO MAKE BIOFUELS MODELED AN EXPANDED NETWORK OF ANAEROBIC DIGESTERS IN AMES.

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CREDIT: LISA SCHULTE MOORE

AMES, Iowa – Strategically planting perennial grass throughout corn and soybean fields helps address the unintended environmental consequences of growing the dominant row crops, including soil erosion, fertilizer runoff and greenhouse gas emissions.

But converting portions of farmland back to prairie has to make financial sense for farmers, which is why a research team led by Iowa State University landscape ecologist Lisa Schulte Moore has spent the past six years studying how to efficiently turn harvested grass into lucrative renewable natural gas.

“We’re looking at existing markets where there is already a demand, use existing infrastructure to reduce costs of the energy transition and create wins in multiple categories. We want wins for farmers, wins for businesses, wins for municipalities and wins for society,” said Schulte Moore, professor of natural resource ecology and management and director of the Consortium for Cultivating Human And Naturally reGenerative Enterprises (C-CHANGE). “We can have great conversations about what could be, but unless it benefits everyone along these supply chains, it won’t happen.”

A pair of recently published peer-reviewed articles by Schulte-Moore’s research group modeled the economic feasibility of grass-to-gas production in different settings and from varying perspectives, analysis that helps flesh out the system’s win-win potential. 

“To replace natural gas with resources that revitalize sustainable agriculture, we have to be able to quantify how much energy we can produce and show it can be cost effective and environmentally friendly,” said associate professor of mechanical engineering Mark Mba-Wright, co-author of the studies. 

City-based scenarios

The ongoing research is funded in part by a $10 million federal grant in 2020, another $10 million in federal support in 2022 and about $650,000 from the Walton Family Foundation. The work centers on optimizing and expanding the use of anaerobic digesters. Biogas is released in anaerobic digestion, the natural process of organic matter biodegrading without oxygen. Captured in tank-like digesters, biogas can be processed into a fuel that easily swaps in for petroleum-based natural gas. It also can power electrical generators and produce fertilizer.

In a study published in BioEnergy Research, the Iowa State researchers modeled how a network of digesters in and around Ames could supply the city’s heat and power demands. Livestock manure, biofuel byproducts, food waste and wastewater would join grassy biomass as the feedstock supplies for up to 10 digesters. The locations, size and number of facilities depended on whether the network was designed primarily to produce natural gas or power. 

The analysis found renewable natural gas was the most economically practical focus, with a levelized cost roughly twice the historical average price of traditional natural gas. Incentives supporting clean energy production could provide a boost to make pricing competitive. Regardless, seeing how digester supply chains would work to serve municipal needs helps city leaders envision possibilities, Mba-Wright said. 

“We wanted to consider the seasonality of the supply and demand over a year to give a mayor, for instance, scenarios to look at and strategize around,” he said. 

Researchers have discussed anaerobic digestion with municipal wastewater officials in several cities in Iowa, and generally they’ve been curious, said Schulte Moore, co-director of the Bioeconomy Institute and a 2021 MacArthur Fellow.

“Their immediate need is to provide a service to their customers 24-7. But they work on 15- to 30-year planning horizons, so they’re also thinking about the future,” she said. 

A grass-to-gas road map

A study published in Global Change Biology Bioenergy modeled the economic and environmental impact of two hypothetical digesters processing grassy biomass in the Grand River Basin in northwest Missouri and southwest Iowa.

Over their expected 20-year lifespan, the digesters would produce a combined profit of more than $400 million under the best conditions, based on the researchers’ analysis. The 45 million gigajoules of renewable natural gas created over two decades – equal to about 12.5 billion kilowatt hours – would have a carbon footprint 83% lower than natural gas derived from fossil fuels. Emissions also project to be lower than those from corn-based ethanol or soybean-based biodiesel. 

Most existing anaerobic digesters that produce renewable natural gas have run on dairy manure, so it’s essential to pencil out how they would perform on a grass diet, Mba-Wright said.

“This is dotting our ‘i’s and crossing our ‘t’s to confirm the benefits are what we’d expect. We’re providing a road map to help build infrastructure, which will in turn reduce future costs,” he said. 

The profitable scenarios examined in the study rely on existing carbon credit programs, including the California Low Carbon Fuel Standard and federal Renewable Fuel Standard. The most valuable outcomes also require high-yield grass and prairie restoration on some of the least-productive farmland.

Researchers aimed to be as realistic as possible in both studies, accounting for all known costs – including capital expenses. But they’ll be even more accurate in the coming years, as methods improve and new research results roll in, Schulte Moore said.

“In the future, we will refine our models by plugging in data our research teams have collected right here in Iowa,” she said. 

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JOURNAL

GCB Bioenergy

DOI

10.1111/gcbb.13164 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Techno-economic and life cycle analysis of renewable natural gas derived from anaerobic digestion of grassy biomass: A US Corn Belt watershed case study,

 

Two shark species documented in Puget Sound for first time by Oregon State researchers

OREGON STATE UNIVERSITY

 

IMAGE: 

LISA HILLIER OF THE WASHINGTON DEPARTMENT OF FISH AND WILDLIFE WITH A BROADNOSE SEVENGILL SHARK.

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CREDIT: JESSICA SCHULTE

CORVALLIS, Oregon – Oregon State University researchers have made the first scientific confirmation in Puget Sound of two distinct shark species, one of them critically endangered.

The presence of the broadnose sevengill shark and endangered soupfin shark in the sound, the southern portion of the Salish Sea, may indicate changes in what biologists in OSU’s Big Fish Lab describe as an economically, culturally and ecologically valuable inland waterway.

The Salish Sea separates northwest Washington from British Columbia’s Vancouver Island. The 6,500-square-mile body of water stretches into Washington as Puget Sound, and the sharks were caught close to Olympia near the sound’s southernmost point.

Taylor Chapple, an assistant professor in Oregon State’s College of Agricultural Sciences, and graduate students Jessica Schulte and Ethan Personius report the broadnose sevengill and soupfin documentations in papers published in Frontiers in Marine Science.

The authors collaborated with partners at NOAA’s National Marine Fisheries Service and the Washington Department of Fish and Wildlife to confirm that the broadnose sevengill, an apex predator that can grow to nearly 10 feet, is now inhabiting heavily urbanized South Puget Sound.

“Understanding the sevengill presence in this new habitat is crucial for understanding the food webs of the Salish Sea, and it highlights the need for continued monitoring and research – including their relationship with other species of conservation concern, such as salmon,” said Schulte, the lead author on the sevengill paper.

Broadnose sevengill sharks – so named because they have two more gill slits than most shark species – eat a wide variety of prey: fishes (including rays and other sharks), crustaceans and marine mammals. They live in temperate waters worldwide, and off the west coast of North America they range from southern Alaska to Baja California.

Prior to 2021, only one sevengill shark had ever been confirmed in the Salish Sea, at Point Roberts, Washington, near the Canadian border. In August 2021, however, anecdotal reports indicated several of them had been caught in South Puget Sound.

During 10 days of field work in 2022 and 2023, the scientists caught nine sevengills, more than 190 miles away from their previously documented range. Eight of them were males – the largest measured just under 7 feet – and the female was about 4 feet, 6 inches.

“Our continued research on this species in Oregon and Washington waters will allow us to have a better handle on its role in our valuable marine ecosystems,” Schulte said.

The same holds for the soupfin shark, said Personius, the lead author on that paper. It is the largest species of hound shark, can be as big as 6 1/2 feet and got its name because of its use as the key ingredient in shark fin soup.

“Soupfin sharks were relentlessly exploited during the 1930s and 1940s, including for their livers, which are rich in vitamin A,” Personius said. “Despite lower fishing pressure the species has not been able to recover and is currently under consideration for federal protection under the Endangered Species Act.”

Like the broadnose sevengill shark, the soupfin shark is found in temperate waters around the globe and is a top predator in any ecosystem it inhabits, eating cephalopods as well as a variety of fishes. Soupfin sharks are known as strong swimmers whose migrations can exceed 1,000 miles.

In field work concurrent with the sevengill project, the scientists caught one soupfin shark, a male that measured just over 5 feet.

“The Salish Sea has experienced pervasive shifts in species abundance and composition along with industrialization and significant habitat degradation,” Personius said. “The appearance of soupfin sharks may be a result of climate change and changes in prey availability.”

Following the 2014-15 extreme marine heat wave event known as “The Blob,” he explained, anchovies emerged as a dominant forage fish species in the Salish Sea after having been historically uncommon there. Soupfin sharks are a known predator of anchovies.

Graduate student Maddie English is a co-author of the soupfin shark paper, along with scientists from the NOAA Marine Fisheries Service and the Washington Department of Fish and Wildlife. Research associate Alexandra McInturf contributed to the sevengill study.

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JOURNAL

Frontiers in Marine Science

DOI

10.3389/fmars.2024.1430962 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Observation of the Critically Endangered Soupfin Shark (Galeorhinus galeus) in the Changing Salish Sea