Michelle Passerotti came to the University of South Carolina with a clear goal in mind. She knew she was destined to innovate the field of marine biology.

Now, she holds a doctorate in Biological Sciences, is a Breakthrough Graduate Scholar Award winner and will soon be working for the National Oceanic and Atmospheric Administration.  

The Office of the Vice President for Research's Breakthrough Graduate Scholar Award recognizes exceptional graduate students who demonstrate excellence in the classroom and make considerable contributions to research and scholarly activities in their field. Only 12 exceptional graduate students receive this award each spring.

Here, Michelle explains a little of her background and why her research is so important.  

Where are you from?  

Perry, Florida, which is a small town in the panhandle region of Florida, also known as the “Nature Coast.”  

What brought you to UofSC? 

I’m a military spouse, and the Air Force moved our family to Charleston, S.C., in 2016. I knew I wanted to pursue a Ph.D. and had a project in mind. Through networking, I connected with Dr. Joe Quattro here at UofSC. I met with him, and he agreed to take me on as a student and help me find funding for my project, which we were able to do during my first year.   

What drew you to your general area of study?  

I’ve always been fascinated with marine biology and fish in particular, driven mostly by my childhood experiences snorkeling in the seagrass beds of Apalachee Bay in the Gulf of Mexico. I was fortunate to attend an undergraduate program with a fantastic marine ecology program at Florida State University that facilitated an internship with the National Oceanic and Atmospheric Administration (NOAA) in my junior year. That internship opened many doors and set me on a path to research geared towards fisheries management.   

What would you describe as a "breakthrough" moment of your time at the University of South Carolina? Who helped make that moment possible? 

There have been several, but one that sticks out happened during my second year, when I was just starting to experiment with my study system. We had a question about whether our method would work to determine age of fish on a time scale of days rather than the annual time scale that had been previously demonstrated. Using what (little) I knew about spectroscopy up to that point, I was able to engineer a new kind of light aperture for use with our juvenile fish samples that greatly improved our age estimates and allowed us to predict age to within a few days of traditional methods, and I went on to publish those results as the first of their kind in my field. 

It was the first time I felt like I understood the system well enough to improve it, and I owe that to Dr. Michael Myrick in the chemistry department, who spent many hours of his time helping me, a complete novice, understand spectroscopy. I also owe so much to my advisor, Dr. Quattro, who invested an incredible amount of faith in my ideas and effort in procuring equipment and additional support to expand my opportunities.  

I also owe so much to my advisor Dr. Quattro, who invested an incredible amount of faith in my ideas and effort in procuring equipment and additional support to expand my opportunities. 

– Michelle Passerotti 
 

What is your specific area of research? What is the main question that you are exploring, and what kind of impact do you hope your research will have?  

My research focuses on age determination in fish, which is usually accomplished by counting growth bands in various calcified body parts, much like counting rings in a tree. Knowing a population’s age structure is critical to managing it, especially in the face of exploitation, but the process of age estimation is time consuming, expensive, and usually lethal. 

My dissertation work explores a new technique to estimate age using near-infrared spectroscopy (NIRS), which uses light to detect fine-scale chemical differences among specimens of different ages from a quick laser scan of calcified tissues, and will perhaps one day help reduce the time, cost, and lethality of age estimation. 

For now, my work has demonstrated that NIRS-predicted ages are mostly equivalent to traditional ages in my study species (red snapper), and I’ve been able to deduce some of the chemical changes potentially underlying the NIRS relationship with age. These initial steps will help us fine-tune the method and hopefully apply it more broadly to other species, as well as to other areas of research. I hope my work opens the door to using other next-gen technologies to improve fisheries management. The molecular detection technologies being developed now are truly groundbreaking, and it’s a field with many potential applications to fisheries research. 

What are some of the wider implications of your breakthrough research? Why is it important to your field? 

Overall, my work suggests that NIRS is a viable method for broad-scale age estimation in fish across different time scales (both daily ages and annual ages) and different life stages (larval through adult), which is quite transformative for fisheries research given the large role that age estimation plays in management and conservation. 

My work also provides the first empirical basis for the mechanism underlying the NIRS/age prediction capability, which had not been demonstrated previously. I was able to confirm that chemical signatures in otoliths, and not just physical characteristics varying with age, contribute to the NIRS prediction capability, which implies that NIRS could have other wide-ranging applications to fisheries research based on the lifetime of chemical signatures present in calcified tissues. In the future, we might be able to do a quick 30-second NIRS scan of an otolith or other tissue and gain information on age, migration history and diet, just to name a few aspects.  

How will your findings impact those of us outside of the world of marine ecology?  

The field of near-infrared spectroscopy is rather young in comparison to other analytical chemistry techniques, so any progress in terms of describing characteristics of new materials is insightful. Fish otoliths are also of broad interest across the fields of chemistry, physics and engineering because of their properties as biogenic carbonates with various crystal polymorphs, so aspects of my findings may be of interest across those disciplines as well. 

Where do you see yourself in five years? 

In five years, I hope to be in a full-time research position continuing my work on innovative fish life history methods. I have just accepted a position with the National Oceanic and Atmospheric Administration (NOAA) Fisheries Apex Predators Program in Narragansett, Rhode Island, where I will be the lead shark life history researcher contributing to stock assessment for Atlantic coast shark populations. We are just starting to elucidate a full understanding of how and where sharks live, eat, and reproduce, and I hope to apply these innovative techniques to helping us ensure healthy shark populations are maintained in the future.