Hi everyone! My name is Maddie Lausted (she/her) and I’m a rising sophomore from Seattle, WA. I plan on concentrating in Ecology & Evolutionary Biology with certificates in French and Global Health and Health Policy. I’m also pre-vet, and spent the first part of my summer at a mixed-practice veterinary clinic watching surgeries, learning hands-on skills, and (once, unfortunately) getting stepped on by a dairy cow. At Princeton, I write for the Daily Princetonian and its Daybreak podcast, and was a participant on Bridge Year Senegal 2019-2020. This summer, I interned with the Sigman Research Laboratory as a part of the High Meadows Environmental Institute Internship Program, where I got a crash course in paleogeology and set up a mini-laboratory in my living room!
The goal of the Sigman Lab is to study how the cycles of significant biological elements are affected by changes in the Earth’s environmental conditions. The project I am working on specifically aims to track the extent of water column denitrification in the Eastern Tropical North Pacific from glacial to our current interglacial time periods. The main goal of my internship is to use the nitrogen in the preserved shells of foraminifera that lived at different points in these time periods to generate a continuous nitrogen isotope record. Because Nitrogen-14 is preferentially lost to the atmosphere during water column denitrification, a larger Nitrogen-15/Nitrogen-14 ratio within the foraminifera shells would indicate a greater degree of water column denitrification while those particular foraminifera were alive and incorporating nitrogen into their shells. The extent of water column denitrification is important for a number of reasons, including its role as a major mechanism for the ocean to lose nitrogen to the atmosphere and how it can inform us about the size of oxygen minimum zones where it is taking place. While past bulk sediment records have indicated that water column denitrification has changed as the world has warmed in the past, the foraminifera record is hypothesized to be more accurate and early research has contradicted the bulk sediment record. I hope that the record I create during this internship will provide important evidence supporting or contradicting this early research.
My day-to-day work mostly revolves around the microscope the Sigman Lab sent me, as I identify different foraminifera species and prepare slides of them that I will send back to Princeton to be processed with methods developed in the Sigman Lab and run through a mass spectrometer. In the next few weeks I’m excited to learn more about this process, and to get the results back! In the fall, I’ll present my work and the results at the HMEI Summer of Learning Symposium.
Looking at how the ocean’s nitrogen cycling, circulation, and ecology has changed or stayed constant as the climate warmed has important implications for the climate crisis now. The papers I have read and discussions I have had with my advisor as part of this internship have given me a much deeper understanding of our climate and the fields of paleontology and biogeochemistry. In the past, documentary films I worked on and experiences I had on Bridge Year gave me firsthand experience in the ways changes to our environment can directly harm communities at home and abroad, and I greatly appreciate my time with the Sigman Lab for the education it has given me in climate science and the research process. I am sure that as my internship continues and eventually wraps up I will have learned even more, and am looking forward to the opportunity to visit the lab in person in the fall!
