“I believe that we have been doing this not primarily to achieve riches or even honor, but rather because we were interested in the work, enjoyed doing it and felt very strongly that it was worthwhile. Scientific research is one of the most exciting and rewarding of occupations.” -Dr. Frederick Sanger said this during his 1980 Nobel Banquet speech. He (along with his colleagues Peter Berg and Walter Gilbert) was awarded the prize in chemistry for their work on the first DNA sequencing technique. Dr. Sanger’s words resonate particularly within me. After all, his work laid the foundation for my senior summer research project: biomonitoring of zebra mussels via environmental DNA (eDNA).
In April 2021, Zebra mussels (Dreissena polymorpha)were discovered on a boat destined for Lake Lanier; the Georgia DNR was contacted and positively identified the zebra mussels. First found in the U.S. in the Great Lakes region during the mid-1980’s, these fingernail sized mussels have been transported through the U.S. at an alarming pace and can now be found within many of our freshwater systems. They catch a ride quite easily: juvenile veligers swimming freely in the environment can be uptaken into ballast water and released in novel locations, while the resilient adults can attach to surfaces (i.e. submerged boat surfaces) and survive out of water for several days if provided moist conditions. Population densities may reach 100,000 per square meter. Individuals can filter up to a liter of water per day, increasing water clarity (encouraging algal blooms) while competing with native organisms for food. They can attach to nearly any solid surface, frequently clogging water treatment facility intake pipes. They devastate native ecology and create millions of dollars in economic damage annually. They are now as close as the Tennessee River, and our region is in the hot zone for potential introduction.
My professors took note of this news and designed an experiment to detect a possible population of the zebra mussels within Lake Lanier using eDNA. In eDNA techniques, samples are collected from the environment and tested for the presence of highly specific DNA fragments. While DNA amplification and detection are well established techniques, environmental applications have only been developed within about the last 5 years. We received a grant from the University of North Georgia’s Faculty Undergraduate Summer Engagement program, covering supplies and 8 weeks of pay for student researchers. In the summer before my senior year (B.S. Biology), I got paid to do research focused on three of my favorite subjects: aquatic ecology, DNA, and invasive species. How amazing is that!?! And so, my research partner and I spent 1-2 days per week collecting, filtering, and testing samples to detect eDNA fragments.
As I’m writing this piece, we have detected no positive samples from Lake Lanier (thankfully). Instead of finding zebra mussels in our lake, I found those things that Dr. Sanger spoke of: the reward of doing what I’m interested in, what I enjoy, and what I find worthwhile. I observed the process of research from conception to presentation. I took part in experimental design, field collections, lab work, and troubleshooting. I observed the power of collaboration as the DNR assisted us with our inquiries. I presented our work as a poster presentation to fellow FUSE participants and faculty. On several occasions we had the opportunity to speak with locals and lake-goers, and we found that most didn’t know about the near-miss incident. However, every patron we spoke with expressed concern for the watershed’s ecology and asked what they could do to help. The interest and concern of the public gives me hope that by pursuing my chosen intended profession, ecological research and education, I can have a positive impact on my community and the larger scientific world.