Growing up near Chesapeake Bay sparked Illinois Natural History Survey (INHS) graduate student Nicholas Iacaruso's early interest in aquatic ecosystems. Now he works with Mark Davis in the INHS Collaborative Ecological Genetics Laboratory (CEGL) to monitor freshwater fish populations using environmental DNA (eDNA).
Tell us a little bit about yourself and your role at INHS.
I grew up in Maryland and majored in environmental science at Saint Vincent College just outside of Pittsburgh. Most of my research focuses on monitoring freshwater fish populations using environmental DNA (eDNA) as an early detection tool for invasive species. Although my primary taxa of focus are freshwater fish, I am using eDNA across a broad range of species including freshwater invertebrates and even some terrestrial arthropods, such as ticks. I also have a strong passion for marine ecosystems and would like to pursue further research opportunities in marine environments.
What drew you to your particular area of study?
I grew up not far from the Chesapeake Bay and its tributaries which is where my interests in aquatic ecosystems and fish developed. I've always been interested in ecology and the natural world, so I knew I wanted to study environmental science, and early on in my undergraduate work I wanted to pursue research, however, the idea of pursuing eDNA and ecological genetics did not occur to me until a couple of years ago. Honestly, I thought I hated genetics and avoided taking any genetics classes as an undergraduate, but when I first heard about eDNA as a new tool to detect species in an environment without needing to see or catch them, I decided to incorporate it into my undergraduate thesis work. During that time I realized I really did like genetics, especially where it intersected with ecology and animal populations.
What tools are indispensable to your fieldwork?
My fieldwork primarily takes place near Duluth, MN on the St. Louis River and at Isle Royale National Park in the middle of Lake Superior. We survey fish species using a variety of conventional gears including fyke nets, ichthyoplankton nets, and an electrofishing boat. Environmental DNA does not involve much field gear other than a sample bottle which makes it an extremely efficient field technique. At our sites in the St. Louis River, we have a mobile eDNA lab nearby that is built out of a trailer where we can quickly filter out the DNA from our water samples and preserve them. This is a huge benefit as timely preservation of the DNA is crucial because DNA begins to degrade the moment we collect our samples from the river.
What question do you get asked most frequently about your career?
The biggest question I get asked is "What do you want to do after graduate school?" Everybody assumes that I either want to work for the Fish and Wildlife Service or become a university professor. So far, my answer is that I do want to pursue academia and become a professor where I can further pursue research as well as teach at an undergraduate or graduate level.
What do you wish more people understood about ecological genetics?
eDNA is a new and rapidly evolving field. It was not widely used in ecology or the conservation of species until a little over 10 years ago, so there are still many advancements and improvements ahead. The reliability of eDNA continues to be validated and recent studies are beginning to show that we might be able to generate a lot more important information about individual species than before. As this field continues to expand and become more accessible worldwide, eDNA has the chance to revolutionize how we study rare and endangered species or track invasive and heavily trafficked species around the world. However, I stress that eDNA will never replace conventional methods that allow you to get your hands on individuals and observe them in the field. The field of eDNA is heavily reliant on ecologists and taxonomists who can identify species and obtain physical specimens that are vital to our work. Both fields are going to continue to be crucially important to the future of environmental research.
What advice would you give to those who are considering going into this field?
Not only is there a very steep learning curve with eDNA, but ecological genetics and eDNA sit at the crossroads of many different fields. Ecological genetics researchers need to have just as much knowledge of the molecular genetic processes occurring inside an individual and a population as well as the ecology and dynamics of whole species and ecosystems. You need to be proficient with field sampling techniques as well as genetics procedures in the laboratory. Also, most ecologists primarily study a specific group of species, but researchers in the field of eDNA often work with a large variety of very different species. The broad nature of the field can make it very challenging for new students, but it's the main reason why I love it—you get so much diverse experience doing completely different tasks, so you can never get bored. For example, I'll be designing and testing PCR primers to detect species of ticks, and the next day I'm hauling fyke nets and measuring fish, and the day after that I'm working in GIS to build a species distribution model for a species. My advice to anyone entering the field of eDNA is not to be intimidated by the broad breadth of knowledge and experience that is seemingly required. Nobody is expected to be an expert at everything, so collaborate with others, ask questions, and always be open to learning as much as you can. You'll be surprised how fast you pick up new techniques in graduate school!