Phytoplankton Research

Amy Shields, a graduate student with Dr. Kam Tang of William and Mary College, showed me around her lab and told me about her research with a particular type of phytoplankton called Phaeocystis antarctica. This tiny one-celled plant is at the bottom of the marine Antarctic food chain, but not much is known about this particular species. This organism has a period where it wanders around as a single cell, but later it seems to clump together with others of its species into a colony and secrete mucous to hold the colony together. The colonies are yellowish. They take up carbon and produce volatile organic sulfur into the water.

The group is looking at whether the solitary forms differ from the group forms in growth, composition or photosynthetic rates. They also are looking at how the zooplankton that feed on these phytoplankton and the nutrients available affect the colonies.

To do these studies, they have a dive hole on the sea ice behind Crary Lab where they bring up water samples with the phytoplankton. They then filter out specific amounts of the organism and put it into sample bottles which they keep in an environmental chamber that keeps the water at just the right temperature. They can change the nutrient levels and the number of grazers (zooplankton) in each sample bottle, as well as control light levels and turbulence within the bottles. Amy does some work with radioisotopes to trace the carbon uptake and emissions from these tiny critters. It is a complex and interesting piece of work they are doing. This is Amy’s fifth season at McMurdo.

This is just one example of the many types of biological research that go on in Antarctica.

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