Environmental Internship Program - 2022 Booklet

Kenya Ripley-Dunlap ’24
ECOLOGY AND EVOLUTIONARY BIOLOGY
Certificates: Chinese Language and Culture,
Gender and Sexuality Studies
CLIMATE AND
ENVIRONMENTAL SCIENCE
PROJECT TITLE
Fish Ecology From Ear
Stones (Otoliths) and Coral
Skeletal Material Past and
Present
ORGANIZATION(S)
Sigman Research
Laboratory and The Ward
Lab, Department of
Geosciences, Princeton
University
LOCATION(S)
Princeton, New Jersey
MENTOR(S)
Daniel Sigman, Dusenbury
Professor of Geological
and Geophysical
Sciences, Professor of
Geosciences; Bess Ward,
William J. Sinclair
Professor of Geosciences
and the High Meadows
Environmental Institute;
Jessica Lueders-Dumont,
Postdoctoral Research
Fellow, Geosciences
I focused on two topics in marine ecology: cod
trophic level changes over the past few centuries
and humpback whale migration patterns.
Nitrogen isotope contents can relay information
about an individual’s place in the food web, with
a higher concentration of nitrogen-15 signifying
a higher trophic level. To understand changes
in cod trophic levels, I analyzed modern and
archeological cod otoliths — fish ear bones —
using a denitrifier method. This method converts
organic bound nitrogen to nitrous oxide using
processes including oxidation, pH adjustments,
and bacteria sparging, which is quantified by
nitrous oxide spectroscopy. I used the same
method to analyze coronulid barnacles, which
grow on humpback whales. The nitrogen isotopic
content of the coronulid at different locations
is related to where the humpback whale was at
the coronulid’s time of growth, which allows the
whale’s migration pattern to be mapped. I am
thankful to have had the opportunity to carry out
the method from the first step of drilling samples
all the way to the last step of spectroscopy data
retrieval. Working with so many amazing people
and understanding the interconnectedness
of research has inspired me to seek out more
environmental research opportunities in the
future.
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