Project Title

Diversity and ecological impacts of Antarctic mixotrophic phytoplankton

Summary

Event Number:
B-303-N

Program Director:
Dr. Karla Heidelberg

ASC POC/Implementer:
Rachel Shackelford / Jamee Johnson

Principal Investigator(s)

Dr. Robert Sanders
robert.sanders@temple.edu
Temple University
Biology Department
Philadelphia, Pennsylvania

Location

Supporting Stations: RV/IB Nathaniel B. Palmer
Research Locations: Western Antarctic Peninsula

Description

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

Five participants will deploy to the Western Antarctic Peninsula (WAP) area on the ARSV Laurence M. Gould to sample approximately ten stations, including one in the Gerlache Strait on the way to Palmer Station, one in the Palmer Deep, and several to the south, as far as Marguerite Bay. The team will conduct experiments to examine bacterial grazing, bacterial production, primary production and microbial diversity (prokaryotic and eukaryotic). The team will collect water samples from the surface and the deep chlorophyll maximum early in the morning every two to three days.

Deploying Team Members