Date Thesis Awarded


Access Type

Honors Thesis -- Open Access

Degree Name

Bachelors of Science (BS)




Randolph Chambers

Committee Members

Deborah Steinberg

Orissa Moulton

Christopher Hein


Fecal pellet carbon (FPC) production by zooplankton is a significant component of the ocean’s biological carbon pump: the suite of biological processes that mediate export of carbon to the deep ocean, ultimately leading to the sequestration of atmospheric carbon dioxide in the ocean. In this study, mesozooplankton (zooplankton 0.2 mm to ~2 cm) were collected from the epipelagic zone in the temperate North Atlantic Ocean during day and night in May 2021. Zooplankton were live separated into five size fractions and incubated on board ship in natural surface seawater to measure fecal pellet production rate of the mixed mesozooplankton community. Individual animals in each size class used in experiments were counted and identified by major taxonomic groups, and fecal pellets were counted, measured, and analyzed by CHN analysis to determine amount of particulate organic carbon and nitrogen produced as fecal pellets. Despite having a small contribution to dry-weight biomass relative to individual abundance, zooplankton in the smallest size class (200-500 µm) contributed the most to FPC production. When normalized for total dry weight biomass of animals collected throughout the May 2021 cruise, FPC production was higher during the night than day, but this difference was not significant. This research is important to our understanding of the ocean’s biological pump, allowing us to more accurately model the impact of the open oceans – the largest ecosystem on earth – on long-term climate regulation.