Duke Research Blog

Following the people and events that make up the research community at Duke.

Category: Environment/Sustainability Page 1 of 10

Don’t Drink the Tap

Have you ever questioned the quality of the water you drink every day? Or worried that cooking with tap water might be dangerous? For most of us, the answer to these questions is probably no. However, students from a Bass Connections team at Duke say we may want to think otherwise.

Image result for image of water

From bottle refilling stations to the tap, drinking water is so habitual and commonplace that we often take it for granted. Only in moments of crisis do we start worrying about what’s in the water we drink daily. The reality is that safe drinking water isn’t accessible for a lot of people.

Image result for pink hog farm water
Pig waste discoloring lagoon water

Images like this hog farm motivated the Bass Connections project team DECIPHER to take a closer look at the quality of water in North Carolina. On April 16 they presented their concerning findings from three case studies looking at lead contamination, coal ash impoundments, and aging infrastructure at the Motorco Music Hall.

Motorco in Durham. The talk was inside, though.

Nadratun Chowdhury, a Ph.D. student in Civil and Environmental Engineering, investigated lead contamination in water. Lead is an abundant and corrosion-resistant material, making it appealing for use in things like paint, batteries, faucets and pipes. While we’ve successfully removed lead from paint and gasoline, a lot of old water pipes in use today are still fashioned from lead. That’s not good – lead is very toxic and can leach into the water.

Just how toxic is it? Anything over a blood-lead level concentration of fifty parts per billion – fifty drops of water in a giant Olympic swimming pool – is considered dangerous. According to Duke graduate student Aaron Reuben, this much lead in one’s blood is correlated with downward social mobility, serious health concerns, diminished capacity to regulate thoughts and emotions, and hyperactivity. Lower income and minority areas are more at risk due to the higher likelihood of owning contaminated older homes.

Rupanjali Karthik, a Master of Laws student, conducted research on the intersection of water and aging infrastructure in Orange County. Breaks in water pipes are common and can result in serious consequences, like the loss of 9 million gallons of drinkable water. Sometimes it takes 8 or 9 months just to find the location of a broken pipe. In 2018, the UNC-Chapel Hill water main break caused a huge shortage on campus and at the medical center.

Excess fluoridation is also an issue caused by aging infrastructure. In February 2017, a combination of human and machine error caused an excessive fluoride concentration coming out of an Orange County Water Treatment Plant. People were advised not to use their water even to shower. A UNC basketball game had to move locations, and stores were completely swept of bottled water.

Another issue is that arsenic, a known carcinogen, is often used as the fluoridation agent. We definitely don’t want that in our drinking water. Fluoridation isn’t even that necessary these days when we have toothpaste and mouthwash that supports our dental health.

Tommy Lin, an undergraduate studying Chemistry and Computer Science, topped off the group’s presentation with findings surrounding coal ash in Belmont, NC. Coal ash, the residue after coal is burned in power plants, can pollute rivers and seep into ground water, affecting domestic wells of neighboring communities. This creates a cocktail of highly concentrated heavy metals and carcinogens. Drinking it can cause damage to your nervous system, cancer, and birth defects, among other things. Not so great.

The group’s presentation.

Forty-five plastic water bottles. That’s how much water it takes Laura, a Belmont resident, to cook her middle-sized family Thanksgiving. She knows that number because it’s been her family’s tradition the past three years. The Allen Plant Steam Station is a big culprit of polluting water with coal ash. Tons of homes nearby the station, like Laura’s, are told not to use the tap water. You can find these homes excessively stockpiled with cases on cases of plastic water bottles.

These issues aren’t that apparent to people unless they have been directly impacted. Lead, aging infrastructure, and coal ash all pose real threats but are also very invisible problems. Kathleen Burns, a Ph.D. student in English, notes that only in moments of crisis will people start to care, but by then it may be too late.

So, what can people do? Not much, according to the Bass Connections team. They noted that providing clean water is very much a structural issue which will require some complex steps to be solved. So, for now, you may want to go buy a Brita.

Will Sheehan
Post by Will Sheehan

Building a Mangrove Map

“Gap maps” are the latest technology when it comes to organizing data. Although they aren’t like traditional maps, they can help people navigate through dense resources of information and show scientists the unexplored areas of research.

A ‘gap map’ comparing conservation interventions and outcomes in tropical mangrove habitats around the world turns out to be a beautiful thing.

At Duke’s 2019 Master’s Projects Spring Symposium, Willa Brooks, Amy Manz, and Colyer Woolston presented the results of their year-long Masters Project to create this map.

You’d never know by looking at the simple, polished grid of information that it took 29 Ph.D. students, master’s students and undergraduates nearly a full year to create it. As a member of the Bass Connections team that has been helping to support this research, I can testify that gap maps take a lot of time and effort — but they’re worth it.

Amy Manz, Willa Brooks, and Colyer Woolston present their evidence map (or gap map) at the 2019 Master’s Projects Spring Symposium

When designing a research question, it’s important to recognize what is already known, so that you can clearly visualize and target the gaps in the knowledge.

But sifting through thousands of papers on tropical mangroves to find the one study you are looking for can be incredible overwhelming and time-intensive. This is purpose of a gap map: to neatly organize existing research into a comprehensive grid, effectively shining a light on the areas where research is lacking, and highlighting patterns in areas where the research exists.

In partnership with World Wildlife Fund, Willa, Amy, and Colyer’s team has been working under the direction of Nicholas School of the Environment professors Lisa Campbell and Brian Silliman to screen the abstracts of over 10,000 articles, 779 of which ended up being singled out for a second round of full-text screening. In the first round, we were looking for very specific inclusion criteria, and in the second, we were extracting data from each study to identify the outcomes of conservation interventions in tropical mangrove, seagrass, and coral reef habitats around the world.

Coastal Mangroves (Photo from WikiCommons: US National Oceanic and Atmospheric Administration)

While the overall project looked at all three habitats, Willa, Amy, and Colyer’s Master’s Project focused specifically on mangroves, which are salt-tolerant shrubs that grow along the coast in tropical and subtropical regions. These shrubs provide a rich nursery habitat to a diverse group of birds and aquatic species, and promote the stability of coastlines by trapping sediment runoff in their roots. However, mangrove forests are in dramatic decline.

According to World Wildlife Fund, 35 percent of mangrove ecosystems in the world are already gone. Those that remain are facing intense pressure from threats like forest clearing, overharvesting, overfishing, pollution, climate change, and human destruction of coral reefs. Now more than ever, it is so important to study the conservation of these habitats, and implement solutions that will save these coastal forests and all the life they support. The hope is that our gap map will help point future researchers towards these solutions, and aid in the fight to save the mangroves.

This year’s team built a gap map that successfully mapped linkages between interventions and outcomes, indicating which areas are lacking in research. However, the gap map is limited because it does not show the strength or nature of these relationships. Next year, another Bass Connections team will tackle this challenge of analyzing the results, and further explore the realm of tropical conservation research.

Post by Anne Littlewood, Trinity ’21

A How-To Guide for Climate-Proof Cities

Roughly 400 miles separate Memphis and New Orleans. Interstate 55 connects the two cities, snaking south parallel to the Mississippi River. The drive is dull. There are few cars. The trees are endless.

South of the Louisiana border, the land turns flat, low, and wet. The air grows warmer, and heavy with moisture. I-55 cuts through the center of Maurepas Swamp, a 100,000-plus acre tract of protected wetlands. Groves of gumball and oak are rare here—instead, thin swamps of bald cypress and tupelo trees surround the highway on either side. At night, only their skeletal silhouettes are visible. They rise from the low water, briefly illuminated by passing headlights. Even in the dark, the trees are unmistakably dead.

*  *  *

A healthy cypress swamp in Lake Martin, Louisiana (Source: U.S. Geological Survey)

Traditionally, Maurepas Swamp serves as a natural barrier against flooding that threatens New Orleans each year. Native flora soaks up the rainfall, spreading it across a network of cypress roots and cattail. But centuries of logging and canal construction have drastically altered the swamp’s ecological composition. The Mississippi levee system compounded the issue, isolating the swamp from vital sources of fresh water and nutrients. Flooded with saltwater, much of the existing cypress withered and died. Young trees, now, are few and scattered. 

Maurepas Swamp highlights the danger of even the most well-intentioned changes to the  environment. This problem is hardly unique to the wetlands. “Many of the issues that we are experiencing today were seen as solutions in the past,” says Nancy Grimm, a professor of ecology at Arizona State University. “What we want to do now is to think about the future, so that the solutions of today don’t become the problems of tomorrow.”

Nancy Grimm addresses urban sustainability at the 2019 Henry J. Oosting Memorial Lecture in Ecology. (Source: Nicholas School of the Environment)

Grimm is the co-director of the UREx Sustainability Research Network. UREx aims to climate-proof urban municipalities without sacrificing environmental stability. To do so, UREx has partnered with several cities across the United States and Latin America. Each city hosts a workshop geared towards municipal decision makers, such as government officials,  environmental NGOS, and more. Together, these participants design different “futures” addressing their cities’ most pressing concerns. 

Phoenix, Arizona is one of the nine initial cities partnering with UREx. One of the hottest cities in the United States, Phoenix is already plagued with extreme heat and drought. By 2060, Phoenix is projected to have 132 days above 100°F—a 44 percent increase from data collected in 2010.  

UREx doesn’t dwell too much on these statistics.  “We’re bombarded constantly by dystopian narratives of tomorrow,” says Grimm, with a slight smile. “Instead, what we want to think about are ways we can envision a more positive future.”

The Phoenix workshop produced five distinct visions of what the city could look like in sixty years. Some scenarios are more ambitious than others—“The Right Kind of Green,” for example, imagines a vastly transformed city defined by urban gardens and lush vegetation. But each vision of Phoenix contains a common goal: a greener, cooler city that retains its soul. 

A visualization accompanies each scenario. In one, a family walks about a small orchard. The sky is blue, and the sun is out. But no one seems bothered by the heat. The oranges are vibrant; the trees thick, and full. It’s an idyllic future. But it’s one within grasp.  

Post by Jeremy Jacobs

Science Gets By With a Little Help From Its Friends

There are many things in life that are a little easier if one recruits the help of friends. As it turns out, this is also the case with scientific research.

Lilly Chiou, a senior majoring in biology, and Daniele Armaleo, a professor in the Biology Department had a problem. Lilly needed more funding before graduation to initiate a new direction for her project, but traditional funding can sometimes take a year or more.

So they turned to their friends and sought crowdfunding.

Chiou and Armaleo are interested in lichens, low-profile organisms that you may have seen but not really noticed. Often looking like crusty leaves stuck to rocks or to the bark of trees, they — like most other living beings — need water to grow. But, while a rock and its resident lichens might get wet after it rains, it’s bound to dry up.

If you’re likin’ these lichens, perhaps you’d like to support some research…

This is where the power of lichens comes in: they are able to dry to a crisp but still remain in a suspended state of living, so that when water becomes available again, they resume life as usual. Few organisms are able to accomplish such a feat, termed desiccation tolerance.

Chiou and Armaleo are trying to understand how lichens manage to survive getting dried and come out the other end with minimal scars. Knowing this could have important implications for our food crops, which cannot survive becoming completely parched. This knowledge is ever more important as climate becomes warmer and more unpredictable in the future. Some farmers may no longer be able to rely on regular seasonal rainfall.

They are using genetic tools to figure out the mechanisms behind the lichen’s desiccation tolerance[. Their first breakthrough came when they discovered that extra DNA sequences present in lichen ribosomal DNA may allow cells to survive extreme desiccation. Now they want to know how this works. They hope that by comparing RNA expression between desiccation tolerant and non-tolerant cells they can identify genes that protect against desiccation damage.  

As with most things, you need money to carry out your plans. Traditionally, scientists obtain money from federal agencies such as the National Science Foundation or the National Institutes of Health, or sometimes from large organizations such as the National Geographic Society, to fund their work. But applying for money involves a heavy layer of bureaucracy and long wait times while the grant is being reviewed (often, grants are only reviewed once a year). But Chiou is in her last semester, so they resorted to crowdfunding their experiment.

This is not the first instance of crowdfunded science in the Biology Department at Duke. In 2014, Fay-Wei Li and Kathleen Pryer crowdfunded the sequencing of the first fern genome, that of tiny Azolla. In fact, it was Pryer who suggested crowdfunding to Armaleo.

Chiou (left) and Armaleo in a video.

Chiou was skeptical that this approach would work. Why would somebody spend their hard-earned money on research entirely unrelated to them? To make their sales pitch, Chiou and Armaleo had to consider the wider impact of the project, rather than the approach taken in traditional grants where the focus is on the ways in which a narrow field is being advanced.

What they were not expecting was that fostering relationships would be important too; they were surprised to find that the biggest source of funding was their friends. Armaleo commented on how “having a long life of relationships with people” really shone through in this time of need — contributions to the fund, however small, “highlight people’s connection with you.” That network of connections paid off: with 18 days left in the allotted time, they had reached their goal.

After their experience, they would recommend crowdfunding as an option for other scientists. Having to create widely understood, engaging explanations of their work, and earning the support and encouragement of friends was a very positive experience.

“It beats writing a grant!” Armaleo said.

Guest Post by Karla Sosa, Biology graduate student


Alex Dehgan and The Snow Leopard Project

Traveling through war-torn areas at risk of encountering landmines, militia, and difficult terrain, Alex Dehgan was protected only by a borrowed Toyota Corolla. Dehgan, the Chanler Innovator in Residence at Duke, has spent much of his life overseas addressing conflict in Afghanistan through promoting wildlife conservation.

As a result, Dehgan has served in multiple positions within the U.S. Department of State, including the office of the secretary, and the bureau of Near Eastern affairs. There, he aided in addressing foreign policy issues in Iran, Iraq, and Egypt and contributed to the improvement of science diplomacy. Recently, he founded the Office of Science and Technology as the Chief Scientist at the U.S. Agency for International Development.

Dehgan Speaking at Duke

Dehgan recently gave a talk at Duke on the snow leopard project, an effort he spearheaded focusing on snow leopard (Panthera uncia)  and other wildlife conservation in Afghanistan. Because of the conflict, most people are not aware of the incredible wildlife and natural beauty within the country’s borders.

Snow Leopard Project Gallery Photo

In his conservation efforts, Dehgan visited the Pamir, Karakoram, Hindu Kush, and Tien Shian mountain ranges hoping to learn more about the wildlife that lived there and the best way to promote their conservation. He used camera traps and collected scat to figure out species were in the area.

He began by talking about the Pamir mountains. Despite the fact that this is a very dangerous region to be, Dehgan ventured in ready to work with locals and discover the wildlife there. Once,  a member of his team asked if they could forgo checking the camera traps for the day because they were being bombed by the U.S. Army. However, it was worth it because Dehgan had the opportunity to work with locals and collect images as well as data on several unique species.

This included the Marco Polo sheep (Ovis ammon polii), enormous sheep that live in single-sex groups for most of the year. They only come together to mate and when they do, the males clash heads with one another for the ability to procreate. He was also able to find a markhor (Capra falconeri), which he prefers to call a “Twin-horn unicorn.” Markhor means snake eater, but the animal does not actually eat snakes. These animals are so valuable that a hunter once paid $110,000 to shoot one. Dehgan and his team were able to collect hair and genetic samples of musk deer (Moschus), which can be found in very steep areas of the Pamir mountains. These animals derive their name from the musk they produce which is often used in perfumes.

Snow Leopard Project Gallery Photo

The area is known as Nuristan, the land of the enlightened, and is unique in that each valley has its own tradition, crafts, and even dialect. Dehgan and his team worked with people from the region and trained them to look for the specific animals

One of the most remarkable places Dehgan visited was Band-e Amir, which he described as looking like the grand canyon. The most unique natural aspect is a system of six lakes formed by the same process that creates stalactites and stalagmites. Above the lakes is an incredible mountain range and on top of the mountains are marine fossils because it used to be at the bottom of the sea. Here, Dehgan was able to use camera traps to collect images of ibexes (Capra ibex), Persian leopards (Panthera pardus saxicolor), and poachers. Poaching would eventually become one of Dehgan’s key focuses. Dehgan and his team also discovered Asiatic wild asses and assumed the presence of Asiatic leopards after finding their skins in the nearby villages.

Dehgan discovered that there was a massive trade in wildlife driven by the U.S. military. Skins of snow leopards and Persian leopards could be found all over Afghanistan as a part of illegal wildlife trade and other wildlife like Saker Falcons could be sold for up to $1 million.

As a result, Dehgan started a program around wildlife trafficking. A major part of his effort took place on Chicken Street, a busy shopping area where illegal animal skins could frequently be found. Dehgan worked closely with U.S. Military police, training them on how to identify furs.

Dehgan also worked with Afghani airport employees on how to inspect baggage for illegal furs. This resulted in the shut down of nearly all illegal fur trade, which Dehgan said was one of his biggest successes. In fact, one day while in Afghanistan, Dehgan received word that a fur trader wished to speak with him. Assuming they were angry at him for reducing their business Dehgan said that he actually feared for his life. However, it turned out that the fur trader simply wanted to be trained to identify illegal furs because they too wanted to protect Afghanistan’s wildlife.

Dehgan explained that Afghanistan was one of the easiest places he ever did conservation. This is because 80 percent of the human population is dependent on natural resources and thus when the wildlife fails, they fail. Because of this, they are eager to help aid in promoting conservation efforts.

Additionally, Dehgan was able to create the Wildlife Conservation Society’s Afghanistan Program which resulted in Afghanistan’s first and second national parks. Villages held local elections to set up a committee and to set up rules to govern the national parks.

Ultimately, his conservation work not only helped wildlife, but supported democracy by empowering, working with and training local communities.

To learn more, check out Dehgan’s recently published book, “The Snow Leopard Project” as well as his twitter, @lemurwrangler.

By Anna Gotskind

Meet New Blogger Anna Gotskind: Science and Gilmore Girls

Hello! My name is Anna Gotskind. I’m a first year originally from Chicago. I plan to double major in biochemistry and environmental science and policy with a certificate in innovation and entrepreneurship (I know it’s a mouthful).

I fell in love with science in seventh grade, inspired by a great teacher named Mark A. Klein. He wore a different tie every day of the year, had tarantulas as pets and frequently refused to say anything but “9” until 9:00 am. He also taught me to appreciate research and discovery, guiding me as I conducted my first independent experiment on the caffeine content in tea which helped me win my middle school science fair.

One of my other role models is Rory Gilmore from the T.V. show Gilmore Girls (yes, I am aware that she is a fictional character). Inspired by watching her write for the Yale Daily News I decided to join the Duke Chronicle when I got to campus. I quickly learned that I loved writing for a publication but more specifically that I loved writing about science. It was incredibly exciting for me to read a study, interview the researchers who conducted it and then translate the information into a story that was understandable to the public. Beyond this, it was also incredible to be exposed to groundbreaking research that had real-world impacts. Essentially, it made me feel like a “Big Girl” and when you’re only 5’0” tall, sometimes that’s necessary.

Rory Gilmore

My love for science does not end in the classroom. My greatest passion is travel and I’ve been fortunate enough to travel around the world with my family exploring some of nature’s greatest wonders. We’ve hiked Bryce Canyon in Utah, Ali San in Taiwan and Masada in Israel. In December 2018 we ventured to the Galapagos, which as an aspiring environmentalist was an incredible experience. We go to see tortoises, iguanas, penguins, sharks and sea lions mere feet away. Right now I’m working with Duke Professor Stuart Pimm on a Big Cats Conservation Initiative sponsored by SavingSpecies, analyzing camera trap data of species in Sumatra, Brazil, and Ecuador. So who knows, I may be off there next. For more pictures check out my Instagram page @annagotskind (shameless plug).

A Parrot my little brother Avi photographed in the Amazon Rainforest in Ecuador

I’m very excited to continue exploring and writing about the research being done on Duke’s campus!

By Anna Gotskind

The Importance of Evidence in Environmental Conservation

What counts as good evidence?

In medical research, a professional might answer this question as you would expect: evidence can be trusted if it is the result of a randomized, controlled, double-blind experiment, meaning the evidence is only as strong as the experiment design. And in medicine, it’s possible (and important) to procure this kind of strong evidence.

But when it comes to conservation, it’s a whole different story.

Dr. David Gill (photo from The Nicholas School)

The natural world is complicated, and far beyond our control. When studying the implications of conservation, it’s not so easy to design the kind of experiment that will produce “good” evidence.

David Gill, a professor in Duke’s Nicholas School for the Environment, recently led a study featured in the journal Nature that needed to  define what constitutes good evidence in the realm of marine conservation. Last Wednesday, he made a guest appearance in my Bass Connections meeting to share his work and a perspective on the importance of quality evidence.

Gill’s research has been centered around evaluating the effectiveness of Marine Protected Areas (or MPAs) as a way of protecting marine life. Seven percent of the world’s oceans are currently designated as MPAs, and by 2020, the goal is to increase this number to 10 percent. MPAs arguably have massive effects on ecosystem health and coastal community functioning, but where is the evidence for this claim?

Although past investigations have provided support for creating MPAs,  Gill and his team were concerned with the quality of this evidence, and the link between how MPAs are managed and how well they work. There have historically been acute gaps in study design when researching the effects of MPAs. Few experiments have included pre-MPA conditions or an attempt to control for other factors. Most of these studies have been done in hindsight, and have looked only at the ecological effects within the boundaries of MPAs, without any useful baseline data or control sites to compare them to.

As a result of these limitations, the evidence base is weak. Generating good evidence is a massive undertaking when you are attempting to validate a claim by counting several thousand moving fish.

Gill’s measure of ecosystem health includes counting fish. (Photo from Avoini)

So is there no way to understand the impacts of MPAs? Should conservation scientists just give up? The answer is no, absolutely not.

To produce better evidence, Gill and his team needed to design a study that would isolate the effects of MPAs. To do this, they needed to account for location biases and other confounding variables such as the biophysical conditions of the environment, the population density of nearby human communities, and the national regulations in each place.

The solution they came up with was to compare observations of current conditions within MPAs to “counterfactual” evidence, which is defined as what would have happened had the MPA not been there. Using statistical matching of MPAs to nearby non-MPA and pre-MPA sites, they were able to obtain high-quality results.

A happy sea turtle pictured in a marine protected area (photo from English Foreign and Commonwealth Office.)

The research showed that across 16,000 sampled sites, MPAs had positive ecological impacts on fish biomass in 71 percent of sites. They also discovered that MPAs with adequate staffing had far greater ecological impacts than those without, which is a pretty interesting piece of feedback when it comes to future development. It’s probably not worth it to create MPAs before there is sufficient funding in place to maintain them.

Gill doesn’t claim that his evidence is flawless; he fully admits to the shortcomings in this study, such as the fact that there is very little data on temperate, coldwater regions — mostly because there are few MPAs in these regions.

The field is ripe for improvement, and he suggests that future research look into the social impacts of MPAs and the implications of these interventions for different species. As the evidence continues to improve, it will be increasingly possible to maximize the win-wins when designing MPAs.

Conservation science isn’t perfect, but neither is medicine. We’ll get there.

The Complicated Balance of Predators and Prey

If you knew there was a grizzly bear sitting outside the door, you might wait a while before going to fill up your water bottle, or you might change the way you are communicating with their other people in the room based on your knowledge of the threat.

Ecologists call this “predation risk,” in which animals that could potentially fall prey to a carnivore know this risk is present, and alter their habits and actions accordingly.

A yellow slider turtle.

A yellow slider turtle.

One way in which animals do this is through habitat use, such as a pod of dolphins that changes where they spend most of their time depending on the presence or absence of predators. Animals might also change their feeding habits and diving behavior because of predation risk.

Animals do this all of the time in the wild, but when predators are removed from ecosystems by hunting or over-fishing, the effect of their absence is felt all the way down the food chain.

For example, large amounts of algae growth on coral reefs can be traced back to over-fishing of large ocean predators such as sharks, who then don’t hunt smaller marine mammals like seals. As seal numbers increase, there are more of them to hunt smaller fish that feed on vegetation, which means fewer smaller fish or plankton to keep algal growth in check, and algae begins to grow unchecked.

Meagan Dunphy-Daly

Meagan Dunphy-Daly

This is a “trophic cascade” and it has large effects on ecosystems, Duke Marine Lab instructor Meagan Dunphy-Daly  t0ld the Sustainable Oceans Alliance last Thursday. She has performed research both in labs and in the field to study the effects that removing large predators have on marine ecosystems.

Dunphy-Daly discussed one lab experiment where 10 yellow-bellied slider turtle hatchlings were kept in tanks where they couldn’t see people or anything else on the outside. In real life, blue herons and other large birds prey on these turtle hatchlings, so the researchers made a model skull of a blue heron that they painted and covered with feathers.

Turtles are air-breathing, so each hatchling was given the option to sit where they could be at the surface of their tank and breathe, but this spot was also where the turtle hatchlings thought the bird beak might shoot down at any time to try to “eat” them.

Their options were to get air and risk getting hit by the bird beak, or diving down to the bottom of the tank to get food. During this experiment, Dunphy-Daly found that turtle hatchlings actually decreased their dive time and spent more time at the surface. If the turtles are continuously diving, they are expending lots of energy swimming back and forth between the surface and the bottom, she said, which means if the predator were to actually attack, they would have less energy left to use for a rapid escape.

Even when there is food at the bottom, when a predator is present, these turtles alter their activity by taking deep dives less frequently so as to not max out their aerobic limit before they actually need to escape a predator.

This is one way in which animals alter their behavior due to predation risk.

But let’s say that predators were disappearing in their real habitats, so turtles didn’t feel the need to build up these emergency energy reserves to escape them. They might dive down and feed more frequently, which would then decrease the amount of the vegetation they eat.

This in turn could have an effect on oxygen levels in the water because there would be fewer plants photosynthesizing. Or another species that feeds on the same plant could be out-competed by turtles and run out of food for their own populations.

The absence of large or small predators can have large impacts on ocean ecosystems through these complicated trophic cascades.

Victoria PriesterPost by Victoria Priester

Heating Up the Summer, 3D Style

While some students like to spend their summer recovering from a long year of school work, others are working diligently in the Innovation Co-Lab in the Telcom building on West Campus.

They’re working on the impacts of dust and particulate matter (PM) pollution on solar panel performance, and discovering new technologies that map out the 3D volume of the ocean.

The Co-Lab is one of three 3D printing labs located on campus. It allows students and faculty the opportunity to creatively explore research through the use of new and emerging technologies.

Third-year PhD candidate Michael Valerino said his long term research project focuses on how dust and air pollution impacts the performance of solar panels.

“I’ve been designing a low-cost prototype which will monitor the impact of dust and air pollution on solar panels,” said Valerino. “The device is going to be used to monitor the impacts of dust and particulate matter (PM) pollution on solar panel performance. This processis known as soiling. This is going to be a low-cost alternative (~$200 ) to other monitoring options that are at least $5,000.”

Most of the 3D printers come with standard Polylactic acid (PLA) material for printing. However, because his first prototype completely melted in India’s heat, Valerino decided to switch to black carbon fiber and infused nylon.

“It really is a good fit for what I want to do,” he said. “These low-cost prototypes will be deployed in China, India, and the Arabian Peninsula to study global soiling impacts.”

In a step-by-step process, he applied acid-free glue to the base plate that holds the black carbon fiber and infused nylon. He then placed the glass plate into the printer and closely examined how the thick carbon fiber holds his project together.

Michael Bergin, a professor of civil and environmental engineering professor at Duke collaborated with the Indian Institute of Technology-Gandhinagar and the University of Wisconsin last summer to work on a study about soiling.

The study indicated that there was a decrease in solar energy as the panels became dirtier over time. The solar cells jumped 50 percent in efficiency after being cleaned for the first time in several weeks. Valerino’s device will be used to expand Bergin’s work.

As Valerino tackles his project, Duke student volunteers and high school interns are in another part of the Co-Lab developing technology to map the ocean floor.

The Blue Devil Ocean Engineering team will be competing in the Shell Ocean Discovery XPRIZE, a global technology competition challenging teams to advance deep-sea technologies for autonomous, fast and high-resolution ocean exploration. (Their mentor, Martin Brooke, was recently featured on Science Friday.)

The team is developing large, highly redundant carbon drones that are eight feet across. The drones will fly over the ocean and drop pods into the water that will sink to collect sonar data.

Tyler Bletsch, a professor of the practice in electrical and computer engineering, is working alongside the team. He describes the team as having the most creative approach in the competition.

“We have many parts of this working, but this summer is really when it needs to come together,” Bletsch said. “Last year, we made it through round one of the competition and secured $100,000 for the university. We’re now using that money for the final phase of the competition.”

The final phase of the competition is scheduled to be held fall 2018.
Though campus is slow this summer, the Innovation Co-Lab is keeping busy. You can keep up-to-date with their latest projects here.

Post by Alexis Owens

 

Becoming the First: Erika Weinthal

Editor’s Note: In the “Becoming the First” series,  first-generation college student and Rubenstein Scholar Lydia Goff explores the experiences of Duke researchers who were the first in their families to attend college.

A portrait of Erika Weinthal

Erika Weinthal

In her corner office with a wall of windows and stuffed bookshelves, Erika Weinthal keeps a photo of her father. He came to the United States from Germany in 1940. And for a German Jew, that was extremely late. According to the family stories, Weinthal’s father left on the second to last boat from Italy. It is no surprise that he was never a big traveler after his arrival to America. As Weinthal describes it, “America…was the country that saved him.” Not only did it protect him, but it also gave his children opportunities that he did not have, such as going to college.

Weinthal, Lee Hill Snowdon Professor of Environmental Policy in Duke’s Nicholas School of the Environment, took this opportunity to become the first in her family to attend college, launching her career researching environmental policy and water security in areas including the former Soviet Union, Middle East, East Africa, India and the United States.

In high school, Weinthal traveled as an exchange student to Germany, a country her relatives could never understand her desire to visit. “As a child of a refugee, you didn’t talk about the war,” she explains as she describes how this silence created her curiosity about what happened. That journey to Bremen marked only the first of many trips around the world. In the Middle East, she examines environmental policy between countries that share water. In India, she has researched the relationship between wildlife and humans near protected areas. “What do you do when protected wildlife destroys crops and threatens livelihoods?” she asks, proving that since her curiosity about the war, she has not stopped asking questions.

However, her specific interest in environmental science and policy came straight from a different war: the Cold War. She became obsessed with everything Russian partly thanks to a high school teacher who agreed to teach her Russian one-on-one. The teacher introduced Weinthal to Russian literature and poetry. While her parents, like many parents, would have loved for her to become a doctor or a lawyer, they still trusted her when she enrolled in Oberlin College intent on studying Soviet politics. A class on Soviet environment politics further increased her interest in water security.

Currently, her work contends that water should be viewed as a basic human need separate from the political conflicts in Palestine and Israel. She has studied how protracted conflict in the region has led to the deterioration of water quality in the Gaza Strip, creating a situation in which water is now unfit for human consumption. Weinthal argues that these regions should not view water as property to be secured but rather as a human right they should guarantee.

Erika Weinthal’s father in 1940

As a child of a refugee and a first-generation college student, Weinthal says “you grow up essentially so grateful for what others have sacrificed for you.” Her dad believed in giving back to the next generation. He accomplished that goal and, in the process, gave the world a researcher who’s invested in environmental policy and human rights.

Post by Lydia Goff

 

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