2018-2019 Science Planning Summaries
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2018-2019 USAP Field Season
Project Detail

Project Title

Diversity and ecological impacts of Antarctic mixotrophic phytoplankton

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B-303-L Research Location(s): Western Antarctic Peninsula


Event Number:
NSF/OPP Award 1744767

Program Manager:
Dr. Christian Fritsen

ASC POC/Implementer:
Rachel Shackelford / Jamee Johnson

Principal Investigator(s)

Dr. Robert Sanders
Central Michigan University
Biology Department
Philadelphia, Pennsylvania


Supporting Stations: ARSV Laurence M. Gould
Research Locations: Western Antarctic Peninsula


Traditional models of oceanic food chains have consisted of algae (phytoplankton) being ingested by small animals (zooplankton), which are ingested by larger animals (fish). These traditional models changed as new methods allowed recognition of the importance of bacteria and non-photosynthetic “protozoa” in more complex food webs. More recently, the widespread existence of mixotrophy (the ability to both photosynthesize and ingest food particles) has been recognized in numerous species and many oceanographic areas. Mixotrophs are now known to have a large impact as predators of microbes in oceanic systems, yet little is known about mixotrophs in Antarctic regions. This project will advance understanding of mixotroph diversity and their ecological impact within the Southern Ocean microbial food web.

Field Season Overview

A team of five participants will deploy to the Western Antarctic Peninsula (WAP) area on the ARSV Laurence M. Gould. Their aim is to determine the diversity and role of mixotrophs in the Southern Ocean. The team will conduct experiments to examine bacterial grazing, bacterial production, and primary production. They will share ship time with a group that will be diving during daylight hours so the team will collect water via conductivity-temperature-depth (CTD) rosette casts during the evenings when the ship is in transit to the next dive site.

Deploying Team Members

  • Rebecca Gast (Co-PI)
  • Wade Jeffrey (Co-PI)
  • Robert Sanders (PI)
  • Arianna Simmering