Cal Poly Grad Student Honored for Parrotfish Study
All parrotfish are not created equal, and biology graduate student Madelyn Roycroft has taken home multiple awards for discovering just how different they are. Her honors include first place in the Kevin Gurr Scholarship award at the American Academy of Underwater Sciences symposium; a scholarship for graduate student research from the Women Divers Hall of Fame; funding from the CSU Council on Ocean Affairs, Science and Technology; and a Baker/Koob grant from Cal Poly.
“Madelyn is hard working, intelligent, dedicated and creative,” said her advisor, biology Professor Ben Ruttenberg. “I know she's going to go on to do great things. She's already doing great things.”
Roycroft is currently channeling that creativity into figuring out which species of parrotfish — a type of tropical reef fish — most benefits the health of coral reefs in the waters around St. Croix, U.S. Virgin Islands. Parrotfish open up space for corals to grow when they eat algae. With multiple species in an ecosystem, though, it’s hard to know which ones are eating the algae.
Roycroft and Ruttenberg use a straightforward technique to answer this question: they follow individual fish. For 20 minutes, a diver stays with a fish, recording where it goes, what kind of food it eats, even how many bites it takes. Combining this data with overall fish counts and quantity of food, researchers can determine whether different species have different impacts on the coral reef.
Though data analysis is still in the early phases, it appears that each species has its own feeding niche in the ecosystem.
“We found that the six species of parrotfishes in St. Croix each play a unique functional role on the reefs,” Roycroft said. “This is consistent with other studies regarding Caribbean parrotfish behavior.”
Another question for Roycroft is how human activity, specifically fishing, influences these feeding patterns. Three parrotfish species previously found in St. Croix have been overfished and are likely no longer present in the area. By comparing her data with data collected in Florida — where these species still live — Roycroft has found that some species adapt and fill the empty feeding niches while others do not.
The next step in the research study is to determine how this shift in behavior affects coral reef health.
After graduation, Roycroft plans to take this Learn by Doing experience into the world of marine conservation and environmental consulting. “This research opportunity has strengthened my analytical and computational skills and helped me develop strong mentorship skills,” Roycroft said. “I feel confident that it gave me the necessary skills for future employment opportunities.”
