January 7, 2019 – Growing up, Natalie Griffiths dreamed of playing shortstop for the Toronto Blue Jays. With a stint on the Canadian national women’s baseball team under her belt, Griffiths has retired her glove and now fields scientific questions about carbon and nutrient cycling and water quality as an aquatic ecologist at Oak Ridge National Laboratory.
Griffiths is the science lead for Aquatic Ecosystem Dynamics within the Aquatic Ecology Group, examining how changes in the environment affect the health and functioning of streams and other aquatic systems.
“The environment, whether it’s a stream, a wetland, or a forest, is complex,” said Griffiths. “When you do field research, you can’t control all of the variables, so you are trying to understand processes and responses on an ever-changing background.”
Griffiths’ work at ORNL has taken her to Minnesota peatlands, South Carolina forests, and down the road to the Walker Branch watershed in Oak Ridge. She contributes to the Spruce and Peatland Responses Under Changing Environments or SPRUCE experiment that ORNL operates in the Marcell Experimental Forest in northern Minnesota. There Griffiths measures changes in water chemistry inside what she calls the ‘mini peatlands’ created by 10 specially-designed enclosures that maintain elevated temperatures and carbon dioxide levels.
SPRUCE offers a unique chance to measure the effects of warming temperatures on water quality within the peatland, which is hydrologically connected to the Mississippi River. Griffiths especially enjoys collaborating with experts in other disciplines who are measuring changes in the soil and vegetation and often finding similar trends.
“These large-scale, collaborative experiments really strengthen our science,” said Griffiths. “You get a more complete understanding of what the entire system responses are compared to individual studies. It is not just a sum of its parts, but something greater.”
Teaming up with the US Forest Service and several university partners, she recently completed an 8-year study of the effects of growing pine trees for bioenergy on several South Carolina watersheds. The project examined whether applying additional fertilizer and pesticides to speed the growth of the loblolly pines would affect soil and water quality. The team found that forestry best management practices resulted in little effect on stream water quality, though they did note an increase in the nitrogen concentration of the groundwater.
In one of her newest projects, Griffiths is working with ORNL experts in the Sensors and Embedded Systems Group to equip a surface water drone to measure nitrate concentrations in streams to examine spatial patterns. Current methods of measurement typically involve researchers collecting multiple water samples up and down a stream and carrying them to the lab for analysis. The drone system, which is in the early stages of development, would take measurements while traveling up and down the stream, in real-time and with GPS coordinates. If successful, the drone will be deployed as part of a project in Iowa investigating the environmental sustainability of growing bioenergy crops.
Stepping up for the home team
Studying water quality and aquatic environments comes naturally to Griffiths, who grew up in a family of scientists—all focused on water research. Her dad was a fisheries biologist, and her mom worked for Ontario’s Ministry of the Environment on water quality in the Great Lakes. Her sister is a paleo limnologist who reconstructs the history of lakes by studying sediments, and Griffiths’ wife is an oceanographer.
Even so, when Griffiths arrived at the University of Toronto to pursue her bachelor’s degree, she intended to meld her interest in science and her lifelong love of baseball into a career in medicine or sports physiology. She had played baseball from sixth grade until the beginning of college, putting her agility and accuracy to work as a pitcher and fielder for the provincial Ontario team and then for the national team. She had the opportunity to play in a tournament against Japan, Australia, and the US before a shoulder injury put her on the bench, and she refocused her energies on college.
At the University of Toronto, all first-year science majors take a year of ecology and evolution. Griffiths had some fantastic professors and credits her work with them in class and as a summer intern with sparking her love of ecology. The summer after her sophomore year, she worked on a project at the University of Notre Dame in collaboration with researchers across the US focused on nutrient cycling in streams and found her true passion, aquatic ecosystem dynamics.
A world-renowned aquatic biogeochemist, the late Pat Mulholland of Oak Ridge National Laboratory, was the lead scientist on that project, though Griffiths did not meet him until the following summer. After securing her doctorate at Notre Dame, Griffiths came to ORNL as a postdoctoral researcher, drawn by Mulholland and the opportunity to work at the Walker Branch watershed. The area provides a unique long-term study of aquatic biogeochemistry and ecology and is among the most studied watersheds in the world.
Griffiths’ innovative biogeochemical research recently garnered her the Stanley I. Auerbach Award, one of the longest-standing honors at ORNL. Past winners include her mentor, Mulholland. “Pat’s mentorship and his research inspired me as an undergraduate and continue to inspire me today,” said Griffiths. “I have been really fortunate to be involved with so many exciting research projects and to have the opportunity to learn from so many excellent scientists at ORNL.”
When she’s not researching in the field, Griffiths enjoys rock climbing, triathlons, and hiking with her family. She is passing on her love of the outdoors to her young son. She and her wife set a goal of hiking 100 miles in the Great Smoky Mountains in their son’s first year and celebrated his birthday in the mountains completing the last two miles. Griffiths’ natural curiosity drives her explorations outdoors and at work.
“I’m always really excited to learn new things,” she said. “That might be the best part about being a scientist; you learn something new every day.”
ORNL is managed by UT-Battelle for the Department of Energy's Office of Science, the single largest supporter of basic research in the physical sciences in the United States. DOE’s Office of Science is working to address some of the most pressing challenges of our time. For more information, please visit https://energy.gov/science.
