Students
(Past and Present)
Samuel Priester (M.S. advisor, 2025-Present)
Samuel is currently working on coral samples from Weligama, Sri Lanka, in order to create the first nitrogen isotope record of interannual variability in the northwestern Indian Ocean. Samuel is also analyzing fossil corals from the region in order to understand how the region may have changed since the late Holocene.​​
Eleanor Percy-Rouhad (M.S. advisor, 2024-2025)
Eleanor analyzed µ-CT scans of the corals we have collected on our expeditions to the Eastern Tropical Pacific and Indian Ocean to better understand how coral calcification rates may be changing as the oceans are warming and acidifying. Eleanor also quantified the degree of macrobioerosion that these corals experienced to help better define how coral loss may change in the future.
Cornelia Hermann (M.S. advisor, 2023-2024)
Conni analyzed the coral and water samples we collected at Clipperton Atoll to try to better understand how the southern boundary of the Oxygen Deficient Zone in the Eastern Tropical North Pacific evolved over the last 40 years. Her work directly adds to our growing understanding of the role of decadal climate variability of the Eastern Tropical Pacific in governing the size of its Oxygen Deficient Zones.
Camino Eck (M.S. advisor, 2022-2023)
Using corals collected by Jens Zinke, Mireille Guillaume, Heinrich Bruggeman and others, Camino reconstructed the nitrogen isotopic history of the Mozambique Channel across the 20th century. Ultimately this work is the first evidence that the Indian Ocean subtropical gyre expanded across the 20th century. Camino is currently a Ph.D. student studying coral reefs and public policy in the Dipartimento di Scienze dell’Ambiente e della Terra (DISAT) at the University of Milan.
Alina Jaeger (M.S. co-advisor with N. Duprey, 2022)
For her M.S. thesis, Alina analyzed the carbon and nitrogen isotopic composition of coral tissue and of the symbionts that corals host to examine how different genera of corals in the Eastern Tropical Pacific partition resources in the coral holobiont. Alina produced very interesting results regarding the feeding behavior of Porites sp. compared with Pocillopora sp. that have implications for the nitrogen isotopic information recorded in the coral skeleton of each genera. Alina will soon defend her Ph.D. (Expected in Summer 2026) as part of joint collaboration between IUEM-LEMAR and MPIC.
Robyn Granger (Ph.D. committee member, 2020-2023)
Robyn's work focuses on characterizing nutrient cycling in the Southeastern Atlantic Ocean and Southwestern Indian Ocean. The results from the modern groundtruthing studies Robyn conducted during her Ph.D. provide key insights as we try to characterize and interpret changes in the nitrogen isotopic composition of the fossil foraminifera collected from sediment cores in the Agulhas region and in the Southeastern Atlantic.
Jonathan Jung (M.S. co-advisor with N. Duprey, 2020-2021)
Jonathan's masters work focused on understanding the nitrogen isotopic changes in a Siderastrea siderea coral core from the Caribbean coastline of Costa Rica. Jonathan's work ultimately led him to characterize the nitrogen isotopic history of the entire Caribbean, which he has since published in Nature Geoscience. Jonathan is expected to defend his Ph.D. in March 2026 - Congratulations Jonny!
Ongoing Collaborations:
Mark and Rachel Rohr Foundation and the S/Y Acadia
I have been fortunate to work closely with the Mark and Rachel Rohr Foundation and the crew of the S/Y Acadia since 2020 to make many of these field expeditions possible. The S/Y Acadia and the Rohr Foundation support many ocean conservation projects documenting the health of marine ecosystems and the impacts of climate change on these complex environments. The S/Y Acadia aims also to document the diversity of marine life on their voyages to remote locations around the globe and to help connect communities and scientists by fostering public discussion about marine conservation.
SPP 2299 Priority Program: Tropical Climate Variability & Coral Reefs
I recently received a DFG Eigenestelle Principal Investigator position as part of the SPP 2299 Program. SPP 2299, funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) for six years (2022-2028), aims to improve our understanding of tropical marine climate variability and its impacts on coral reef ecosystems in a warming world. This is being done by quantifying climate and environmental changes both during the current warming and during past warm periods on time scales relevant to society. My work focuses on understanding the evolution of oxygen minimum zones over some of these periods.
Smithsonian Tropical Research Institute
I work together with many researchers at the Smithsonian Tropical Research Institute in Panama to better characterize the variability in the Nitrogen cycle in the Eastern Tropical Pacific. We have several ongoing projects, which include: characterizing the upwelling history of the region; better understanding N cycling in the coral Holobiont across different coral genera; and documenting modern oceanographic in the ETP onboard the S/Y Eugen Seibold. Collaborators at STRI include Matthieu Leray, Sean Connolly, Andrew Sellers-Lara, Jonathan Cybulski, and Aaron O'Dea.
University of Costa Rica - CIMAR
Together with researchers at CIMAR, we have worked to build a climatic history of the ETP using coral cores from Cocos National Park. As part of a larger collaboration with STRI and the S/Y Acadia, I worked with CIMAR researchers to characterize Nitrogen cycling on the reefs of Cocos, and to better understand how the nutrient supply at Cocos may have changed over the last 50-100 years. We are continuing to build a better understanding of the region through oceanographic cruises onboard the S/Y Eugen Seibold. Collaborators at CIMAR include: Juan José Alvarado, Cindy Fernández-García, and Celeste Sanchez-Noguera.
Galapagos National Park and the Charles Darwin Foundation
I collected coral cores and seawater samples from islands around the Galapagos, with the goal of understanding changes in coral reef health across the archipelago over the last 50-100 years. Together with researchers from the Galapagos National Park and the Charles Darwin Foundation, we completed a 22 day research cruise that sampled at 7 different islands.
Save our Seas Foundation
We were able to work with researchers at d'Arros and St. Joseph Atoll to collect coral cores from around the two atolls. In combination with existing measurements that I have made on an older coral core, these samples will help characterize changes in the Indian Ocean over the last 100 years at monthly resolution. The Save Our Seas foundation focuses on conservation of sharks and rays in the world's ocean's as climate change and overfishing continue to threaten their populations; we hope to contribute an understanding of the natural cliamte variability at St. Joseph Atoll over the 20th and 21st centuries. We worked very closely with Henriette Grimmel and Robert Bullock on this project.
