CELS Ph.D. Student Aids Rhode Island Waterways By Studying Invasive Plant That Smothers Them

By Gabriella Placido, CELS Communications Fellow

As she cruises through Rhode Island’s wetlands in a kayak, College of the Environment and Life Sciences (CELS) Ph.D. student Lynde Dodd has a mission: study the invasive water chestnut to help identify the most effective methods for its management. Dodd, a research biologist with the U.S. Army Corps of Engineers, has traveled all over the country studying some of the most difficult and destructive invasive aquatic plants. She is based out of the Lewisville Aquatic Ecosystem Research Facility in Texas with the Engineer Research and Development Center but is on assignment in Rhode Island conducting research on this devastating plant as part of her Ph.D. program.

Dodd studies invasive plants: non-native species introduced from outside an ecosystem that cause significant harm to the environment, economy, and/or human health. She specializes in invasion ecology, an important discipline of study that aims to better understand invasion processes and how to prevent, manage, and mitigate them. “Invasive species can disrupt natural processes and food webs, and reduce species diversity by outcompeting and displacing natives,” states Dodd.

Throughout her career, Dodd has focused her research on aquatic invasive plants. These plants can cause significant damage to infrastructures like water intakes and dams by causing impediments due to extensive growth. “Many invasives like water chestnut can impede navigation, whether you’re on a large boat or a kayak,” she says. “If you have lakefront property, you may not be able to get in and out of your boat dock. And if you have invasives in your reservoir, it can impact the ability to get water out of your tap.” In addition to these challenges, Dodd emphasizes that these invasives are often very difficult and expensive to control. “Millions of dollars are regularly spent by federal, state, and local governments to control such invasives,” she says. “We must manage them to reduce impacts on the environment and our everyday lives.” This is where her Ph.D. comes in.

Dodd has been studying an invasive aquatic plant known as the European water chestnut since 2016. This aggressive invader can almost completely enshroud pond surfaces, wreaking havoc on freshwater ecosystems. “Water chestnut can reduce water quality by acting as a barrier to sunlight, starving plant life below the surface of light,” explains Dodd. She says the plant can form dense mats of vegetation on the surface that reduce oxygen, compete with native plants for resources, and threaten fish and other wildlife.

Dodd is conducting her research with the aid of her advisor, CELS professor, and researcher Dr. Laura Meyerson. “I was attracted to the University of Rhode Island (URI) because I get to work with an internationally-known invasion ecologist,” says Dodd of Meyerson’s recent recognition as a fellow of the Ecological Society of America. “The work I’m doing here in CELS has molded me into a better researcher by providing me the needed tools, connections, facilities, guidance, and collaborations,” she states. “I will use what I have learned in my role as a research biologist and team leader for the U.S. Army Corps of Engineers.”

Dodd is also studying the complex interactions between plants and their environment in relation to a new, potentially invasive water chestnut species. This plant is currently spreading in the Potomac River watershed of Virginia and could pose a threat to Rhode Island. The mysterious species has long been mistaken for European water chestnut and has shown some of the same aggressive traits, such as invading, spreading, crowding out native species, and blocking sunlight. There is also concern that this new species will interbreed with the previously introduced water chestnut in the United States – potentially creating a more robust hybrid.

One of the goals of Dodd’s research is to gain more baseline information on this new species to better inform management and control methods through science in Rhode Island and beyond. “Rhode Islanders do not want this species to show up in Rhode Island!” she states. “My research will result in sound scientific evidence to better understand both species of water chestnut introduced to North America.”

Dodd plans to return to the U.S. Army Corps of Engineers research facility in Texas, when she completes her current experiments and course work at URI in August, to continue her Ph.D. dissertation. “I hope to ultimately transfer this knowledge to a broader audience, especially the agencies and groups that manage water chestnut and craft policy for it,” says Dodd. “By reducing invasives, we create sustainable, healthy aquatic ecosystems.”