BEAUFORT, N.C. — On a sun-streaked day in early November, several dozen faculty and staff from the Nicholas School of the Environment gathered at the Duke Marine Lab in Beaufort, North Carolina, for the school’s now-annual fall symposium. Showcasing 14 scientific talks, the event was an opportunity for new and established faculty to meet and discuss their research.

From glaciers to barnacles, topics spanned the school’s four divisions and associated research areas. Together the talks illustrated the Nicholas School’s expansive research portfolio, and the faculty’s commitment to addressing important environmental questions for the sake of ecological and human health.

The symposium also opened the door to potential new collaborations.

“By bringing together researchers from different departments, faculty had a chance to hear from others they might not typically work with,” said event organizer Prasad Kasibhatla, senior associate dean of research and doctoral programs. “Hopefully this experience will lead to new interdisciplinary projects and partnerships.”

Bird’s-Eye Views and Chemical Clues

Featured speakers from the Earth and Climate Sciences Division: Sarah Cooley, Jonathan (Johnny) Ryan and Avner Vengosh

Northern climes featured prominently in talks by new faculty members Johnny Ryan and Sarah Cooley, who use lofty tools — namely, drones and satellites — to study earthly processes.

Ryan studies water-filled cracks in glacial ice called ponded crevasses. These features can drain underneath glaciers, exerting pressure that can “jack the ice sheet up,” potentially pushing ice toward the margins where it’s more likely to melt, he explained.

To investigate this process, Ryan built a drone system dubbed Skywalker X8 — an homage to a certain Jedi — designed to collect data over harsh terrain in Greenland. For about 10 weeks in 2014, “we would get up, have breakfast, check the drone one last time, and then launch it,” Ryan said. “There’s no subtle way of doing it, really. You just have to chuck it off a cliff.”

Fortunately, Skywalker X8 lived up to its name, gathering tens of thousands of aerial images that Ryan stitched together into a cohesive whole. However, traditional image analysis was insufficient to discriminate ponded crevasses from other features, Ryan said. For help, he turned to an A.I. tool called Segment Anything, which can be used to discern objects and borders in images. 

“It made a practically impossible task much more possible,” Ryan said. Now, his team is using the images to document where ponded crevasses form, and how they drain, to better understand the role of meltwater on glacier ice flow.

Cooley also relies on aerial imagery for her work studying Arctic lakes. Thawing permafrost in the rapidly warming Arctic can cause these lakes to expand or shrink through complex processes, she explained. The waxing and waning of these polar water bodies could affect the carbon cycle, with potential climate effects.

To better understand lake variability, Cooley gathered more than 75,000 images from a vast network of shoebox-sized satellites called CubeSats deployed by a company called Planet. Using that data, Cooley and colleagues developed a method for tracking variability in more than 85,000 Arctic lakes. They found that, overall, total lake area is declining.

Building on that work, Cooley’s team is now using a sophisticated NASA satellite called SWOT — for Surface Water Ocean Topography — to map more Arctic lakes, as well as study trends in lake variability and the factors driving them. “I’m hoping SWOT will give us a really good picture of the dynamism of water bodies over space and time,” she said. 

Water is also an important subject for Avner Vengosh, who discussed research into how the energy sector affects water quality and use.

“One of the things that makes our lab proud is not only being able to detect contamination, but to elucidate what are the sources of contamination,” he said, referencing a pollutant-tracking technique used by his lab.

Like detectives searching for fingerprints, his team tests water for clues such as isotopes — atoms with distinctive chemical properties — to track water pollutants to their source. Using these isotopic tracers, Vengosh and colleagues have analyzed the water quality impact of coal burning and hydraulic fracturing for oil and gas. In one study, for example, they reported evidence of contamination from coal ash — a byproduct of coal burning — in fish.

Vengosh also highlighted current work investigating the electric vehicle industry’s reliance on water. Initial findings suggest that manufacturing an electric car requires four times the amount of water relative to a combustion car, in large part because electric cars require water-intensive mining for critical minerals like lithium, cobalt and copper, he explained.

On the road, however, electric cars use half as much water as their combustion-engine counterparts, according to Vengosh. “Right now, it takes about seven to eight years” to break even, he said. However, that window will shrink as electricity suppliers in the U.S. rely more heavily on wind and solar sources, he added.

Providing parts for electric vehicles depends on another natural resource: lithium. To that end, Vengosh and Ph.D. student Gordon Williams recently reported results from a water quality study involving a historic lithium mine in North Carolina (read more).

Vengosh’s team is also investigating the effects of lithium mining in South America’s “Lithium Triangle,” home to the world’s largest lithium reserves. The research has multiple objectives, including understanding how wastewater from the mining might affect the surrounding environment and how sustainable lithium mining can be, given extensive water scarcity in the region.

Human Health, Forest Health

Featured speakers from the Environmental Natural Sciences Division: Joel Meyer, Yan Lin, Jim Clark, Tong Qiu and Sari Palmroth

Joel Meyer shared a window into his work on mitochondria — cellular structures often called “powerhouses” for their role turning nutrients into energy. They’re also vital to other processes, such as apoptosis — cellular self-destruction — and immune response.

Exposure to ultraviolet radiation, chemicals in air pollution or other contaminants can affect mitochondrial health, causing conditions like oxidative stress or DNA damage, Meyer explained. And “when [mitochondria] don’t work well...we see all sorts of diseases,” he said.

Using Caenorhabditis elegans, a see-through worm commonly used in biological studies, Meyer’s team has found that oxidative stress in mitochondria promotes nerve degeneration, like what occurs in Parkinson’s disease. Understanding the underlying mechanisms could inform efforts to predict how various chemicals in the environment might affect mitochondria and human health, he said.

Like Meyer, new faculty member Yan Lin also studies how the body responds to environmental exposures. Lin described his efforts to find biomarkers, or biological clues, that can be used to identify various sources of contaminants in the body.

For example, air pollution can contain toxic chemicals called polycyclic aromatic hydrocarbons, or PAHs. Some of those PAHs may come from combustion — think vehicle exhaust or coal burning — while others may stem from non-combustion sources, like fossil fuel production or oil refining. If inhaled, PAHs break down into other molecules in the body that can provide clues into the initial source of exposure.

Several years ago, Lin’s team investigated potential biomarkers of exposure to PAHs. The team analyzed urine samples collected from participants exposed to air pollution and found an association between PAHs tied to non-combustion sources and increased levels of a molecule called 2-PHECA (phenanthrene-2-carboxylic acid). The findings provided the first direct evidence that 2-PHECA could be a biomarker of exposure to PAHs with non-combustion origins.

This year, Lin’s team identified a promising biomarker related to exposure to wood smoke from campfires. Although camping is “pretty popular here” in the U.S., Lin noted, the study has implications for individuals beyond outdoor adventurers — essentially, anyone exposed to wildfires, which could increase in frequency and severity as the climate changes.

Pivoting from environmental exposures, Jim Clark discussed efforts to monitor forest health. In the western U.S., warming temperatures and dry conditions are contributing to forest diebacks, the gradual death of trees from the tips of twigs and branches inward. The ability of a forest to rejuvenate after a dieback “really depends on tree fecundity,” or how much seed can be produced in a year, Clark explained.

Until a few years ago, however, models of vegetation change couldn’t factor in fecundity, according to Clark. To address that challenge, Clark’s team developed MASTIF (Masting Inference and Forecasting), a modeling tool that crowdsources field data on seed mass to estimate fecundity. 

“MASTIF gives us a way to actually measure what’s being supplied to landscapes for forest recovery and food webs” in the way of seeds, Clark explained.

MASTIF is one of the modeling tools also employed by new faculty member Tong Qiu, a former postdoc in Clark’s lab. Qiu now runs the SEED Lab, where his team combines data from remote-sensing tools, field studies and statistical models to explore how a warming climate might affect biodiversity and regeneration of forests.

For example, Qiu and team have been studying trends in spring green-up, or the time when leaves form and flowers blossom, within the North American continent. They have found that, budburst — when buds start to form — arrived a day earlier each year, on average, from 2000 to 2020, due to climate warming. That shift translates to 0.05 kilogram per hectare of increased seed production a year for some species, or 1 kilogram per hectare over the 20-year period if only marginal effects of such shifts are considered, according to the team’s findings.

“This [work] can help us identify species that are more likely, or fail to, regenerate under a warming climate,” Qiu explained in an email. “We can anticipate community composition changes and then identify the species that are more vulnerable to global change.”

In related work, Qiu and colleagues have been exploring connections between climate change, habitat and animal characteristics, such as diet. According to research in progress, a warming climate appears to favor large granivores, or mammals that nosh on seeds. The findings have direct applications to conservation management, Qiu said.

Sari Palmroth also studies interactions between forests and climate. Palmroth shared findings from a 2024 paper investigating the influence of branch turnover — the amount of dead branches replaced yearly by new growth — on carbon flux, or the movement of carbon through forest ecosystems.

“Branches die, they remain attached, sometimes decades, and they decompose in place,” releasing carbon into the atmosphere, Palmroth explained. However, most models of carbon cycling neglect the carbon loss from those dying branches, as well as the intake of carbon associated with replacement growth, according to Palmroth.

Synthesizing data from nearly 190,000 trees in boreal, temperate and tropical forests, Palmroth and team calculated how branch turnover contributes to aboveground woody biomass — trunks, branches, bark and the like.

They found that global annual wood production increased approximately 16% when branch turnover was factored in. Meanwhile, estimates of stem biomass — important for calculating long-term carbon storage capacity — declined by about 17% when branch turnover was considered. The findings have implications for carbon flux and storage estimates, according to the study. 

Insurance Against Disaster

Featured speakers from the Environmental Social Systems Division: Anaís Roque, and Elizabeth (Betsy) Albright

New faculty member Anaís Roque shared findings from a project conducted in collaboration with residents of Corcovada, a small rural community on Puerto Rico’s west coast. In recent years, the community has experienced landslides, hurricanes and flooding, which caused a cascade of impacts such as power outages, limited access to resources and water shortages. 

Building on earlier work with community leaders, Roque’s team engaged a group of residents to lead a participatory budget exercise, “a democratic process in which residents have a direct decision-making role in the making of a budget,” Roque explained. The aim was to solicit ideas on ways to address food, energy or water insecurities and public health risks during disasters. Community residents then got to vote on their three favorite suggestions.

Twenty-two percent of residents voted and chose installing solar-powered security cameras in key locations, such as the community aqueduct; adding solar streetlights in important gathering spots; and introducing workshops on food, water, energy security, public health and emergency preparedness, which a community resident is coordinating.

The project also achieved another goal: “We see [residents] now wanting to be more involved in community activities,” Roque said. “This is important because social interactions (including new leadership) in the community are crucial to responding to disasters and events like COVID-19 that had eroded relationships in the community,” she added in an email.

Betsy Albright also described work with individuals experiencing disaster — specifically, residents in the Boulder, Colorado, area. In late December 2021, what began as a grass fire morphed into a conflagration that destroyed more than a thousand homes and several commercial properties in the Boulder County communities of Louisville and Superior.

The wildfire raised an important question: When it comes to rebuilding post-disaster, do households support resilience policies — which can be more costly — or is the bottom line more important as they recover from the devastation?

In the case of the Marshall Fire, under-insurance was a concern, Albright said. “After the fire, there was pushback among residents for changes or loosening of energy efficiency standards,” because rebuilding to higher energy efficiency standards would have been more expensive, Albright explained.

Albright is also part of a Duke Bass Connections project to explore new approaches to climate risk analysis, as well as alternative insurance products that could support improved resilience in North Carolina communities vulnerable to disasters.

Water, Water, Everywhere

Featured speakers from the Marine Science and Conservation Division: Juliet Wong, Daniel (Dan) Rittschof, Dana Hunt and Zackary Johnson

Juliet Wong shared insights from her work in Biscayne Bay, a popular lagoon near Miami that draws millions of visitors a year. Covering 400 square miles, the bay includes two state aquatic preserves, a critical wildlife area, a national park and a national marine sanctuary.

Wong sought to establish a baseline assessment of vertebrate biodiversity in bay waters amid ongoing environmental threats, such as pollution, and restoration efforts. The team first collected samples of environmental DNA, or eDNA, from lagoon waters. “Organisms are constantly shedding their DNA into the environment…essentially leaving their biological signature behind,” she explained.

Back in the lab, Wong’s team analyzed the samples specifically for DNA from vertebrates, which comprise a variety of species of conservation or commercial interest. Reporting in November, they detected 145 different vertebrate taxa, or groups, including fish species targeted for the aquarium trade and from commercial and recreational fisheries, as well species of conservation concern, including the West Indian manatee.

The findings highlight the potential of eDNA analyses to support other monitoring techniques, especially in areas where visual methods are challenging to conduct, according to Wong. The study also provides baseline data for future biodiversity studies of the bay, she added.

Pivoting from marine vertebrates, Dan Rittschof discussed his lab’s work on certain spineless aquatic organisms: barnacles.

Barnacles have evolved an impressive ability to generate and cure adhesives that allow them to stick to many kinds of surfaces, from whale skin to boat hulls. Rittschof’s lab has refined the science of culturing, or growing, barnacles to study their stickiness. Over time, his team has learned that epoxy — used as a watertight sealant on ships — disrupts proper endocrine functioning in barnacles, causing them to grow larger.

Rittschof and colleagues are now exploring nontoxic coatings that prevent barnacles from hitchhiking on ships. It costs more money and takes more fossil fuel “to push a ship through water if it’s got barnacles on it,” Rittschof said.

Small things — particularly of the microscopic variety — also fascinate Dana Hunt, who heralded the outsize role that microbes play in nature. “If we don’t study microbes, we’re missing the vast majority of life on earth,” she said.

Researchers can use microbes to study the effects of changes in the environment in real time, Hunt explained, because microbes divide quickly — sometimes multiple times a day. For example, in one study, Hunt and team found that the composition of marine bacteria changed with experimental warming. The findings suggest that a warming ocean will alter the structure and function of marine ecosystems, the researchers concluded.

For his part, Zackary Johnson discussed a project to develop a device built by teammates at partner company MoleculeWorks that selectively harvests carbon dioxide (CO2) from the atmosphere for storage or sustainable production of goods. Through this technology, called direct air capture, CO2 could then be converted into a durable form for marine storage, for instance, or fed to organisms such as algae. In turn, those algae could be made into a sustainable fishmeal replacement or other food products, Johnson explained.

Prototype testing has identified several areas for improvement for the second-generation unit, according to Johnson. Nevertheless, the team is on track to remove 1 ton of CO2 from the air for less than $100, at less than 1 megawatt-hour of energy input — a feat that aligns with the International Energy Agency’s roadmap to net-zero carbon emissions, according to Johnson. Yet, “priority number one” should still be reducing emissions, he noted.

Fresh Perspectives

As the balmy day gave way to dusk, symposium participants filed onto the bus back to Duke’s main campus in Durham. Some faculty members reflected on the experience a few weeks later.  

“I loved the chance to learn what my colleagues are excited about and discovering, which I think will not just lead to collaborations but improve my ability to advise students and incorporate broad material in classes,” Joel Meyer said. “I also really valued the chance to get to know them better as people.”

Tong Qiu echoed the sentiment: “I really enjoyed the symposium for the engaging conversations that bridged diverse, interdisciplinary fields. It was inspiring to see senior and junior faculty coming together to share ideas and explore connections across our research areas,” he said.

In fact, Qiu is planning to collaborate with another colleague who attended the event.

“Richard [Bin] Mei and I have put together a proposal to combine forest digital twins (a digital and three-dimensional representation of forest, like virtual reality) with resource economic theory to develop mitigation strategies for wildfire impacts in southeastern forests,” Qiu said.

 

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