Hannah Baker holding the Tamanend's bottlenose dolphin tooth samples that she used for her internship. She cut the teeth in half with a saw and used a half section to scan using scanning electron microscopy. In the cabinet behind her is 30 years of dolphin teeth samples! (Image credit: Bonnie Ertel)
Hi everyone! My name is Hannah Baker and I’m a 2025 Ernest F. Hollings Scholarship student studying Earth and Environmental Sciences with a minor in Climate and Space Sciences and Engineering at the University of Michigan. For my summer internship, I worked at the National Coastal Centers for Ocean Science (NCCOS) Hollings Marine Laboratory in Charleston, South Carolina, studying Tamanend’s bottlenose dolphin teeth as a biomarker of freshwater exposure.
Tamanend’s bottlenose dolphins (Tursiops erebennus) in the Charleston Estuarine System have faced an increased exposure to freshwater, which is harmful to their skin, often resulting in lesions and other maladies. We looked at barium incorporation in the dolphins’ teeth as a signature of freshwater exposure. Tamanend’s bottlenose dolphins incorporate chemicals into their teeth throughout their lifespan, relaying information about their diets, habitat, and environmental conditions. We chose barium because it is naturally found in freshwater.
I used teeth that were previously collected from stranded dolphins. I scanned them using SEM-EDS (scanning electron microscopy energy dispersive x-ray spectroscopy) to measure barium exposure. During my internship, I scanned about 30 bottlenose dolphin teeth and one pygmy sperm whale (Kogia breviceps) tooth. Working with marine mammal specimens was new for me, so it was a highlight of this project to be able to use dolphin teeth for conservation efforts!
Working in Charleston was such a great experience! As somebody interested in pursuing marine science, the Hollings Marine Laboratory was a perfect fit for my summer internship. Some highlights of my project were assisting in photo IDing dolphins in the Kiawah River, attending necropsies of a loggerhead sea turtle, bottlenose dolphin, and a dwarf sperm whale, and having the opportunity to tour the Nancy Foster Research Vessel with a NOAA Corps officer. This experience has helped shape my path for the next years to come!
Hannah Baker, 2025 Hollings scholar
Hannah is a class of 2025 Hollings scholar and is studying Earth and Environmental Sciences with a minor in Climate and Space Sciences and Engineering at the University of Michigan.