Learn about the structure and function of streams and rivers. We will connect ecological principles to the structure and function of running waters, and explore how ecological processes in these dynamic ecosystems are affected by environmental change. This course includes lecture/discussion meetings as well as a lab/field component, during which students will conduct coordinated semester-long research projects. The final exam will include an oral presentation and write-up of project results in the format of a manuscript.
INSTRUCTOR: DR. ERIN R HOTCHKISS OFFICE: 2006B Derring Hall, ehotchkiss@vt.edu
COURSE MEETING TIMES: MW 10:10 to 11:25 am & W 1-3:50 pm
Today’s global problems, such as food security, clean water, and infectious disease, defy disciplinary silos and government jurisdictions.
That’s why approximately 70 members of Virginia Tech’s Global Systems Science Destination Area (GSS DA) and the Policy Strategic Growth Area (Policy SGA) met recently to identify areas for collaboration.
The all-day workshop, held Sept. 29 at the Inn at Virginia Tech, involved short talks in the morning by faculty-led research teams from science and policy areas.
Topics included freshwater resources, coastal resilience; safety, security, and safeguards in nuclear science and policy; renewable energy policy; smart farms as a global food shortage solution; environmental-human health in rural communities; and the disparities surrounding autism in rural America.
As Karen Roberto, director of the Institute for Society, Culture, and Environment, University Distinguished Professor in the College of Liberal Arts and Human Sciences, and faculty co-lead for the Policy SGA noted, “the complexity of each of these areas necessitates information from multiple disciplines and require collaborative efforts to analyze, understand, engage, and solve or mitigate.”
In the afternoon, attendees broke into small, mixed science-policy groups to brainstorm opportunities for collaboration, which they presented to the large group. Many groups called for support and enhanced opportunities for interaction through shared spaces or support to collaborate on interdisciplinary courses and research projects. One idea included co-locating faculty from different departments working on a shared topic for a certain period of time, but with a commitment to communicate and collaborate.
Todd Schenk, Assistant Professor, School of Public and International Affairs, served as workshop facilitator.
“The workshop underscored the desire among faculty to work on boundary-spanning, problem-oriented projects, but also highlighted some of the challenges that must be overcome,” said Todd Schenk, assistant professor in the College of Architecture and Urban Studies’ School of Public and International Affairs, member of the Policy SGA, and the day’s facilitator. “Faculty members need to know that they are going to be supported and rewarded for working across traditional disciplinary boundaries, given the challenges involved.”
“Science and policy form an important continuum, from discovery and innovative problem-solving to translational outcomes that improve the human condition and protect the environment,” said William A. Hopkins, one of the workshop co-organizers, a GSS stake holder, and director of the Global Change Center at Virginia Tech. “This workshop was the first step in bringing together diverse scientists, engineers, and social scientists to explore synergistic opportunities at the science-policy interface. The energy during the workshop was palpable, and some exciting ideas for collaboration are already emerging.”
GCC Director, Bill Hopkins, discusses ideas during the faculty workshop
“We hope this workshop is an exemplar for the development of collaborations across the DAs and SGAs at Virginia Tech for which all interested faculty have the opportunity to participate and contribute,” said Dennis Dean, director of the Fralin Life Science Institute at Virginia Tech, which funded the workshop.
Destination Areas combine Virginia Tech’s existing strengths into novel transdisciplinary teams, tools, and processes that empower students and faculty to tackle the world’s most pressing problems.
Strategic Growth Areas have been identified as critical areas for future growth and development, similar to Destination Areas in structure but of smaller scale and aim for regional or national leadership.
More information and a complete list of Destination Areas and Strategic Growth Areas can be found on the Office of the Executive Vice President and Provost’s website.
The BP oil spill in the Gulf of Mexico. Human health disparities in Appalachia. The Dan River coal ash spill in North Carolina. The water crisis in Flint, Michigan. Air pollution in urban industrialized areas around the world.
The list goes on.
Now more than ever, U.S. laws designed to protect and improve public health and the environment, such as the Clean Water Act, the Safe Drinking Water Act, and the Clean Air Act, require federal support and adequate revision.
With drought, pollution, rising temperatures, wildfires, increased severity and frequency of storms, invasive species, and emerging diseases, lawmakers need access to the most up-to-date, accurate scientific information to make informed decisions when revising and enforcing public policies. In other words, they need scientists.
To address this need, the Global Change Center at Virginia Tech created a summer fellowship program to send undergraduate science and engineering students to the nation’s capital to learn firsthand how science shapes policy.
“Science plays a prominent role in the policy deliberation process, but we need young scientists and engineers to pursue careers involving decision-making at all levels of government,” said Bill Hopkins, a professor of fish and wildlife conservation in the College of Natural Resources and Environment and director of the Global Change Center.
Now, the center’s goal is to send at least two students to Washington, D.C. next summer, which is why it recently launched a 30-day fundraising campaign that will be matched dollar per dollar by the center. During the program, students will earn six academic credits while spending 11 weeks fully immersed in challenging science policy issues that shape communities locally and nationally within agencies, such as the U.S. Fish and Wildlife Service, U.S. Department of Agriculture, The Nature Conservancy, American Red Cross, USAID, and the U.S. Environmental Protection Agency.
“With assets in the National Capital Region, Virginia Tech is uniquely positioned to nurture the important relationship between science and society, so by placing Hokies on the Hill, we can positively influence public policies that will improve quality of life and preserve the environment long into the future,” Hopkins said.
The Undergraduate Science Policy Fellowship Program, now in its third year, is designed to expose students to the role scientific knowledge plays in policy decisions on issues from human rights and health to water quality and endangered species. It is also designed to expose future scientists to the realities of policymaking, which is based on societal norms and values, economics, and politics in addition to scientific and technical knowledge.
Washington Semester 2016 interns met with Virginia Congressman Don Beyer, 8th District.
So far, four Virginia Tech students have been awarded fellowships. Kallie Peurifoy of Charleston, South Carolina, and Steven Hall of St. Paul, Virginia, were the two 2017 award recipients.
Peurifoy, a senior majoring in environmental science in the College of Agriculture and Life Sciences, interned at the U.S. EPA’s Enforcement Targeting and Data Division in the Office of Enforcement and Compliance Assurance. While there, she was introduced to environmental policies and legal terminology. In turn, she introduced policymakers to the “science side of things,” she said.
In the process, she reviewed water facilities that emitted certain contaminants and then located public systems with emissions above permissible legal thresholds. She was then able to inform local government authorities and the public about their water quality.
“I plan to apply to graduate school to pursue a career in environmental engineering focused on renewable energy and climate,” said Peurifoy, who is also a member of the Virginia Tech women’s soccer team. “I hope to one day return to the federal government in a position that allows me to protect the Earth and to serve the American people.”
“In Washington, D.C., itself, you’re surrounded by so much government and policy you start to build a connection, a link,” said Steven Hall, a junior majoring in mechanical engineering in the College of Engineering, who said this experience opened his eyes since hailing from a small Appalachian town. “A lot of people feel a disconnect from big government, especially now with politics. But from being there I’ve learned how much of an impact I can make through my career and how I can become a change-agent for society,” said Hall, who interned with the EPA’s Office of Enforcement and Compliance Assurance.
Fellowship recipients participate in the science policy track of the Washington Semester program, administered by the School of Public and International Affairs at Virginia Tech.
One fellowship ($7,000) fully funds tuition, living expenses, transit, and a stipend.
The fundraising campaign will run through Nov. 1. Supporters can send a #Hokie2Washington by donating at the project’s page and spreading the word through Facebook and Twitter.
The application deadline for Summer 2018 is Dec. 10, 2017.
Before cutting down forest, land managers in drought-prone areas might first consider the birds in the trees.
According to a new study by biologists at Virginia Tech and the Smithsonian Migratory Bird Center, the offspring of a certain songbird, the wood thrush, are more likely to survive drought in larger forest plots that offer plenty of shade and resources.
Wood thrush are common to the United States, but populations have declined by more than 60 percent since the 1960s. In addition, many species of songbirds, such as blue jays, robins, and cardinals, as well as wood thrush, face the highest risk of dying within the first five days of leaving their nests.
Ben Vernasco
A team of Smithsonian biologists led by Brandt Ryder worked closely with Ben Vernasco, a doctoral candidate in biology at Virginia Tech, on a study that aimed to identify characteristics that promote healthy wood thrush populations on U.S. Department of Defense land. Vernasco specifically worked to determine the factors affecting wood thrush survival during the post-fledgling period — the stage lasting about 21 days until baby birds become independent.
From 2011-14, the team tracked the birds’ movements and their habitats during breeding from April to August across 12 locations in southern Indiana. The sites, including locations in the Crane Naval Surface and Warfare Center, Big Oaks National Wildlife Refuge, and state parks, varied in habitat size and form, ranging from small to large forest fragments with varying degrees of tree cover.
In 2012, during the team’s investigation, a summer drought hit the Midwest and Northern Plains. Agriculture in the region was impacted such that the U.S. Department of Agriculture declared more than 1,000 counties in 26 states natural disaster areas as rainfall dropped an average of roughly 26 inches down to just over 13. Minor winter storms the previous year contributed to less snowfall, drier soil, and recorded temperatures of more than 30 degrees Fahrenheit higher in some states than in summer 2011.
According to the recent study, first authored by Vernasco, post-fledgling wood thrush survival is highest in small forest fragments, a result supported by previous work that found nestlings grow faster closer to forest edges, which were also found to have dense vegetation that protects fledglings from predators. During the drought, however, the birds had lower survival. The dry conditions, the researchers suspect, reduce available food resources, leaving the young birds more susceptible to starvation and predation.
Birds in larger mature forest areas, on the other hand, were better able to withstand the dry conditions, since these areas offer more shade and resources. Forest cover helps maintain climatic conditions, including moist soil, which is an important factor for wood thrush food availability. These conditions ultimately make areas more resilient to drought.
“The research highlights the role that forest cover can play in buffering animals from stressful environmental conditions – in this case, promoting survival of young birds during drought conditions,” said Amanda Rodewald, professor and director of conservation science at the Cornell Lab of Ornithology, who was not involved with the research. “This finding is yet another that underscores the importance of maintaining forested landscape mosaics in strategies to conserve biodiversity.”
For ideal survival, then, Vernasco says fledglings do well with a “mosaic” of habitats made up of forests that differ in age and thus vegetation structure. However, wood thrush populations are sensitive to forest fragmentation, which tends to come from agriculture and clear cutting.
Wood thrush are a flagship species, meaning they are charismatic and often studied as representative of other species, so knowledge learned about them can likely apply to other forest songbirds, said Vernasco.
The post-fledgling period has historically been understudied since tracking movements and following fledgling songbirds over long periods of time and space is difficult. For this study, the biologists were able to track the birds’ movement by applying colored bands on their legs and outfitting them with tiny backpacks that emit radio signals yet weigh less than a paper clip.
Since the development of high-frequency radio transmitters, this study is one of the longest and also has one of the largest sample sizes, with 210 birds, focused on the post-fledgling stage.
Vernasco got involved in the project as a field technician just after receiving a degree in applied vertebrate ecology in 2013 from Humboldt State University. He is now co-advised by Ryder and Ignacio Moore, a professor of biological sciences in the College of Science at Virginia Tech.
It all started with a few phone calls to check in on friends at Texas A&M and the University of Florida.
After hurricanes Harvey and Irma battered the southern coastline, Kelsey Pieper called Extension faculty from the two universities — friends she’d met through her work as a U.S. Department of Agriculture National Institute of Food and Agriculture postdoctoral fellow at Virginia Tech.
“We just reached out and were like, ‘Hey, we’re thinking of you, do you need anything?’ And then that started the conversation of ‘what are you all doing after the flood?’” said Pieper.
Her next question: “How can we help?”
Now, backed by a $200,000 National Science Foundation RAPID grant and advisory support from civil and environmental engineering professors Marc Edwards and Amy Pruden, Pieper, postdoctoral researcher William Rhoads, civil and environmental engineering Ph.D. candidate Kristine Mapili, and a team of Virginia Tech students are helping reach well owners with vital information on well-water supply contamination, the likelihood of which increases following hurricanes.
The grant will fund the on-the-ground distribution of water sampling kits and educational training in Texas and Florida, which faculty from Texas A&M’s AgriLife Extension Service and University of Florida’s Institute of Food and Agricultural Sciences Extension program will lead. The Virginia Tech team will analyze the samples and distribute the results to well owners.
Rhoads, a postdoctoral researcher in the College of Engineering, is leading the microbial analysis. He said the team is not only conducting microbial testing and providing an evaluation of water treatment options for well owners, they will also document the presence of any pathogens in the water.
“These pathogens are known to cause health issues, mainly in large buildings with immunocompromised inhabitants like hospitals, but no one has really looked for them in private well systems yet,” Rhoads said.
Taking it one step further, the team will build upon research on risk communication strategies with well owners that began earlier this year with collaborator Adrienne Katner, a faculty member of the Louisiana State University Health Sciences Center’s School of Public Health-New Orleans.
Lauren Buttling, a senior in environmental policy and planning, isolates E. coli samples for further study in a pathogen ecology lab led by civil and environmental engineering professors Marc Edwards and Amy Pruden.
Using funding from a separate National Science Foundation RAPID grant earned last year, Katner, Pieper, Rhoads, and other Virginia Tech students conducted testing for inorganics, bacteria, and pathogens in well water samples from 113 parish residences in Louisiana impacted by a major flood.
“This is an exciting opportunity for AgriLife Extension to work with Virginia Tech and the other universities to respond to the effects of Hurricane Harvey,” said Diane Boellstorff, AgriLife Extension water resource specialist and associate professor in the Texas A&M Department of Soil and Crop Sciences. “With its expertise in responding to similar situations in Louisiana, the team was able to share its strategies to quickly bring needed information and help to Texas well owners affected by Harvey.”
Beyond the testing, they evaluated and developed communication strategies for natural disaster response — desperately needed, considering the oftentimes hard-to-find information on what well owners should do to ensure they have potable water following a natural disaster.
“How are people looking for information? Are they reading the newspaper, watching the news, or are they going online? And how can we help better equip the first responders, FEMA, [and] state health officials to get that information to the people?” Pieper said.
With no federal regulation on well-water supply quality, private well owners can be left in the dark on vital information after a flooding, which often leads to contamination of well water.
Well owners should assume water has been compromised by bacteria until proven otherwise, according to Andrea Albertin, a regional water resources agent for the University of Florida’s Institute of Food and Agricultural Sciences Extension program.
“Water from a flooded well should not be used for drinking, cooking, making ice, brushing teeth, or even washing areas of the skin that have been cut or injured until it is tested,” Albertin said.
But the knowledge is useless unless it’s accessible to the well owners who need it, leading Pieper and Katner to tack on the expansion of their previous work to the most recent RAPID grant award. The team hopes to create a comprehensive guide to communicating with well-water owners now and in the future to keep them informed and healthy when natural disasters strike.
“We found in Louisiana that the majority of people wanted to do testing; they understood the need to do testing, but they didn’t know where to go get testing,” Pieper said. “So the information was available, but it wasn’t necessarily accessible.”
Over the course of the next year, Pieper, Rhoads, Mapili, and the students on the project will also compile a comprehensive data analysis using samples collected in Louisiana, Texas, Florida, and Virginia, where the team has also worked on sampling well water. They’re aiming for 2,000 samples.
Ultimately, the team hopes the compiled data will help illustrate the similarities and differences in the impacts across the United States of hurricanes and major rain events.
Is overcrowding in cities bad for your brain? Do children in preschool learn better because of the social enrichment? Are animals at zoos learning and behaving the way they would in the wild even if they aren’t in normal group sizes?
These are the types of questions behind the research of a Virginia Tech neurobiologist who studies the impacts of the social environment on the brain.
Kendra Sewall, an assistant professor of biological sciences in the College of Science and an affiliated faculty member of the School of Neuroscience, recently received a National Science Foundation CAREER grant to expand her studies of the “sweet” spot of optimum social interaction — the point at which brain function is improved.
Neurobiologist Kendra Sewall (right) works with graduate student Tre Mills to prepare samples for an immunohistochemistry assay.
The research uses zebra finches, a songbird that shows social relationships and vocal learning that is surprisingly similar to humans. Prior research has shown that social birds living in larger flocks have super cognitive abilities and greater neuron growth. But if socializing becomes stressful over time, perhaps due to overcrowding or competition, the birds produce stress hormones called glucocorticoids that, in high amounts, are known to impair neural plasticity and compromise learning.
The new funding will allow Sewall to continue this line of research, as well as increase education and outreach in the field.
She will teach a new course titled Animal Cognition through the Department of Biological Sciences in the College of Science. The course, available to undergraduate and graduate students, will involve working with local high school classes interested in animal cognition research, and will be available beginning in fall 2018.
Sewall will also work with K-12 teachers to develop an animal cognition module in line with the Virginia Standards of Learning for regional high school classes to use. Four teachers will visit Sewall’s lab in summer 2018 to develop a one-week module that they can take back to their classrooms.
Sewall, who is also affiliated with the Global Change Center at Virginia Tech, an arm of the Fralin Life Science Institute, said the research is important for understanding how changes in resource availability due to climate change or habitat degradation could impact bird social dynamics and ultimately, individuals’ learning and brain function.
But, because zebra finches are a model for human language learning, the research also shines a light on how lifestyle impacts human cognition.
“With the incidence of brain-related disorders, such as anxiety, depression, and autism, on the rise, understanding the brain’s reaction to environmental factors is incredibly important,” said Sewall.
The project is funded for five years by NSF’s Division of Integrative Organismal Systems with grant IOS-1652496.
“This research project is an example of science focused on a single organism and topic — here, a common songbird and how stress impacts it — with the potential to produce results that tell us more about vast groups of creatures, including humans,” said Jodie Jawor, program director for the Behavioral Systems Cluster at the National Science Foundation. “The National Science Foundation’s animal behavior program supports integrative work, such as this, that can help us piece together the rules governing all life.”
The CAREER grant is the National Science Foundation’s most prestigious award, given to creative junior faculty considered likely to become academic leaders of the future. Sewall is one of three College of Science faculty to receive a CAREER Award this year, the first time that three faculty have won such funding in more than 10 years. The other two faculty members are Julianne Chung, of the Department of Mathematics, and F. Marc Michel, of the Department of Geosciences.
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Story by Lindsay Key, Fralin Life Science Institute
Four floors above a dull cinder-block lobby in a nondescript building at the Ohio State University, the doors of a slow-moving elevator open on an unexpectedly futuristic 10,000-square-foot laboratory bristling with technology. It’s a reveal reminiscent of a James Bond movie. In fact, the researchers who run this year-old, $750,000 lab at OSU’s Spine Research Institute resort often to Hollywood comparisons.
Thin beams of blue light shoot from 36 of the same kind of infrared motion cameras used to create lifelike characters for films like Avatar. In this case, the researchers are studying the movements of a volunteer fitted with sensors that track his skeleton and muscles as he bends and lifts. Among other things, they say, their work could lead to the kind of robotic exoskeletons imagined in the movie Aliens.
The cutting-edge research here combines the expertise of the university’s medical and engineering faculties to study something decidedly commonplace: back pain, which affects as many as eight out of every 10 Americans, accounts for more than 100 million annual lost workdays in the United States alone, and has accelerated the opioid addiction crisis.
“The growth of the technology around us has become so familiar that we don’t question where it comes from,” says Bruce McPheron, an entomologist and the university’s executive vice president and provost, looking on. “And where it happens consistently is at a university.”
But university research is in trouble, and so is an economy more dependent on it than many people understand. Federal funding for basic research—more than half of it conducted on university campuses like this one—has effectively declined since 2008, failing to keep pace with inflation. This is before taking into account Trump administration proposals to slash the National Science Foundation (NSF) and National Institutes of Health (NIH) budgets by billions of dollars more.
Trump’s cuts would affect all research universities, but not equally. The problem is more pronounced at public universities than private ones, and especially at public institutions in the Midwest, which have historically conducted some of the nation’s most important research. These schools are desperately needed to diversify economies that rely disproportionately on manufacturing and agriculture and lack the wealthy private institutions that fuel the knowledge industries found in Silicon Valley or along Boston’s 128/I-95 corridor. Yet many flagship Midwestern research universities are being weakened by deep state budget cuts. Threats to pensions (in Illinois) and tenure (in Wisconsin) portend an exodus of faculty and their all-important research funding, and have already resulted in a frenzy of poaching by better-funded and higher-paying private institutions, industry, and international competitors.
While private institutions are better shielded from funding cuts by huge endowments, Midwestern public universities have much thinner buffers. The endowments of the universities of Iowa, Wisconsin, and Illinois and Ohio State, which together enroll nearly 190,000 students, add up to about $11 billion—less than a third of Harvard’s $37.6 billion. Together, Harvard, MIT, and Stanford, which enroll about 50,000 students combined, have more than $73 billion in the bank to help during lean times. They also have robust revenues from high tuitions, wealthy alumni donors, strong credit, and other support to fall back on. Compare that to the public university system in Illinois, which has cut its higher-education budget so deeply that Moody’s downgraded seven universities, including five to junk-bond status.
This ominous reality could widen regional inequality, as brainpower, talent, and jobs leave the Midwest and the Rust Belt—where existing economic decline may have contributed to the decisive shift of voters toward Donald Trump—for places with well-endowed private and better-funded public universities. Already, some Midwestern universities have had to spend millions from their battered budgets to hang on to research faculty being lured away by wealthier schools. A handful of faculty have already left, taking with them most if not all of their outside funding.
In Ghana, experts suspect that some fish farmers have started to raise unapproved, controversial strains of the Nile tilapia Oreochromis niloticus that have the ability to grow quickly on their farms.
A Virginia Tech graduate student seeks to establish which strains farmers are growing in the country, and whether these include the unapproved strains of genetically improved farm tilapia (GIFT).
Gifty Anane-Taabeah
“If it is confirmed that the GIFT strains are on the farms in Ghana, it is only a matter of time for these strains to escape into the wild,” said Gifty Anane-Taabeah of Accra, Ghana, a doctoral student in the Department of Fish and Wildlife Conservation in the College of Natural Resources and Environment. “If it is confirmed that the GIFT strains are being farmed and mixing in with wild tilapia, this could reduce the genetic diversity of the natural population and compromise their adaptation to the local environment.”
The escape of farm fish into nearby rivers and streams is a common phenomenon due to poorly secured fish holding facilities and frequent storms.
Farmed fish can be as much as 50 percent less genetically diverse than wild fish, according to Anane-Taabeah. A genetically diverse fish population is an enduring one, able to withstand environmental stressors like disease, climate change, and pollution.
“We want to know if there is significant mixing going on, and if so, how we can lessen the impact and protect the environmental while also growing the aquaculture industry,” said Anane-Taabeah.
Tilapia is a potential umbrella species in Ghana, serving as one of the country’s primary food sources. A popular way to raise fish is through cage farming, a technique that involves placing floating cages in public freshwater bodies.
In the Volta Lake region of Ghana, cage farming of tilapia developed quickly between 2010 and 2014 as a commercial activity, with an average annual growth rate of 50 percent.
To assess the effect of aquaculture on the genetic diversity of natural tilapia populations, Anane-Taabeah is conducting a pilot study with selected hatcheries and cage farms in the Volta Lake region of Ghana.
Between March 2015 and July 2017, she sampled the Volta River basin in Ghana to obtain fin clips from wild and farmed tilapia. Using DNA extracted from the fish samples, Anane-Taabeah will employ highly variable molecular markers including nuclear microsatellite DNA and mtDNA sequences from the D-loop region and the ND1 gene to characterize the fish populations and assess the level of genetic mixing between farmed tilapia and natural populations.
In May 2018, she will share her findings with stakeholders including the Ghanaian Fisheries Commission, the Ministry of Fisheries and Aquaculture Development, and the Ghanaian Environmental Protection Agency.
In addition to the threat of aquaculture species introduction, wild tilapia populations also face threats from climate change, unregulated inland fisheries, and habitat destruction from the activities of illegal gold mining commonly referred to as “galamsey,” Anane-Taabeah said.
Anane-Taabeah is an Assistant Lecturer in the Department of Fisheries and Watershed Management at the Kwame Nkrumah University of Science and Technology in Ghana, and currently on study leave for doctoral studies. She was a master’s student in the Department of Fish and Wildlife Conservation at Virginia Tech from 2010 to 2012 and returned to start her doctoral studies in 2015.
“Of the many aquaculture development constraints in sub-Saharan Africa, a lack of appreciation for genetic resources management and weak biosecurity policies among countries is most critical in the face of the compounding problem of changing climate,” said Emmanuel Frimpong, Anane-Taabeah’s advisor and an associate professor of fisheries in the College of Natural Resources and Environment. “Gifty’s research will not only fill a current void in our understanding of aquaculture impacts and tilapia conservation needs, but also her training in modern genetics technology at Virginia Tech is a real boost of expertise for aquaculture and conservation management in Ghana and the sub-Saharan Africa region.”
“Gifty’s work will open our eyes to the patterns of natural genetic variation among Ghanaian tilapia populations and to any threats to local adaption due to poorly confined aquaculture activities,” said Eric Hallerman, Anane-Taabeah’s co-advisor and a professor of fisheries in the College of Natural Resources and Environment.
The Rufford Foundation, a U.K.-based charity that funds nature conservation projects across the developing world, recently provided a grant to support Anane-Taabeah’s project, and she continues to partner with the Fisheries Commission in Ghana.
Aquatic invertebrates found in mountain streams — crayfish, stoneflies and mayflies, among others — are important to ecosystems because they are part of the natural food web and are often used by state agencies as indicators of freshwater health.
Soon, land managers will be able to track the behaviors of these invertebrates using a computer model developed by a research team that includes Virginia Tech aquatic ecologist, Bryan Brown.
The model, supported by a National Science Foundation grant, will simulate different possible natural responses to environmental changes by considering the location and shape of a river network and the types and behavior of invertebrate species within it. Land managers will then be able to use it when deciding how to restore watersheds after a disturbance, such as a flood.
“We’re thinking about this in terms of river networks, but the model would really apply to any set of populations or communities on the landscape,” said Bryan Brown, an associate professor of biological sciences in the College of Science and a Global Change Center at Virginia Tech affiliate. “What we envision is for land managers to plug in their scenarios and tweak the parameters so the model responds like nature.”
To develop the model, the team will first perform a large-scale analysis of past research that explores how communities of freshwater invertebrates change and disperse over time around rivers and streams. These aquatic communities are made of different species, each with their own distinct life cycles and movement patterns that tie them to the landscape. Mayflies, for example, begin life in headwater streams where they live as larvae for up to two years in stream-bottom sediment. During this stage of their life cycle, they feed on algae and move downstream by drifting. Once larvae complete metamorphoses, the winged adults fly back upstream to lay eggs.
These movement patterns are affected by the shapes of rivers and tributaries within watersheds, connections between forest fragments, and environmental conditions, such as prevailing winds. Taken together, these invertebrate movements and landscape conditions will be used to create models or “networks” to predict how ecological systems respond to human and natural disturbances. The model will also be used to identify what areas may be most sensitive to those disturbances.
Beginning in the spring, Brown will lead a series of field experiments at the Coweeta Long-Term Ecological Research site in Franklin, North Carolina. There, he and lab members, including new biology Ph.D. student and Interfaces of Global Change Fellow Sara Cathey, will set up artificial streams to compare invertebrate abundance in headwaters to larger intermediate zones. In the process, they will induce natural disturbances to see how invertebrates respond and in what locations the species communities are the most stable.
Dr. Bryan Brown inspects a crayfish at Sinking Creek in Newport, VA
In a study published in July, Brown and collaborator Chris Swan at the University of Maryland found that the most effective areas to restore are the headwaters, likely because these are isolated sections of watersheds. Although these areas tend to be the most vulnerable to environmental change, they are more likely to sustain stable communities when restored compared to intermediate zones – larger streams that have more well-connected populations of species.
The Coweeta field experiments and initial meta-analysis will then be merged and computerized, making one “grand synthetic model,” said Brown.
Along with three collaborators, including Virginia Tech alumnus Eric Sokol, now at the University of Colorado-Boulder, Brown will simulate networks of hundreds of species communities continuously. The computer model will then allow users to explore possible scenarios based on different watershed shapes, organism types, and novel disturbances that cannot be studied with current research. Users will also be able to consider different parameters, such as temperature and rainfall.
“Understanding how things are responding in different areas or how different shapes of networks respond to different sorts of disturbances, such as increased precipitation, also helps us get a handle as climate starts to fluctuate more and more,” Brown said. “Hopefully this [model] can help us predict what areas are going to be more sensitive than others as the climate changes.”
The project is funded for three years by NSF’s Division of Environmental Biology with grant DEB-1655927.
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Written by Cassandra Hockman; Photos by Cassandra Hockman
