Catharine Leahy ’18



Project Title

Fish Ecology from Ear Bones (Otoliths) Past and Present

Over the course of the summer, I created a compilation of stable isotope data from over 150 papers studying a variety of aquatic species, including invertebrates, teleost fish, and zooplankton. This database will allow for comparison of species’ stable isotope ratios of carbon, nitrogen, and sulfur, over time, environment, and location, and can be used as a tool for analyzing human impact on marine, estuarine, and other ecosystems. In addition to the database project, I worked on a time series (from 1984 to 2014) of the nitrogen isotopic signatures present in calcium carbonate structures in the inner ears of winter flounder and butterfish. I also performed some fish dissections at the beginning of the summer. This internship offered incredible insight into the complexity of aquatic ecosystems and provided opportunity to improve my skills both in the lab and using statistical software like R. As a result of this experience, I hope to continue studying the impact humanity has on the environment.

Internship Year


Project Category



Ward Group, Geosciences Department, Princeton University, Princeton, NJ


Bess Ward, Professor, Geosciences and the Princeton Environmental Institute