2002-2003 Science Planning Summary

Biology & Medicine

Dr. Polly Penhale
Program Manager

BO-043-O

NSF/OPP 00-03639
Station: McMurdo Station
RPSC POC: Rob Robbins
Research Site(s): Explorers Cove

Seasonal dynamics of giant agglutinated foraminifera
Dr. Samuel S. Bowser
New York State Department of Health
Division of Molecular Medicine
bowser@wadsworth.org
http://www.bowserlab.org

Deploying Team Members: Samuel S Bowser . Douglas H Coons . Philip E Forte . Steven D Hanes . Jan W Pawlowski . Karen H Sterling . Joseph G Tyson
Research Objectives: Found in all marine environments, foraminifera ("forams") are single-celled, shelled (agglutinated) creatures with a key role in the ocean food web. They may be planktonic (floating) or benthic (bottom-dwelling), living on shells, rock, seaweed, or in sand or mud at the bottom of the ocean. Their characteristic habitats, and the chemistry of their shells (which reflects qualities of the local water they live in) make them very useful to scientists as an indicator of when and under what conditions they lived. Antarctica and the Southern Ocean ecology is no exception.

Previous studies have shown that the forams assemblage in Explorers Cove in McMurdo Sound consume a wide variety of prey, ranging from bacteria through a taxonomically diverse group of metazoans, including juvenile invertebrates. These studies have been restricted to specimens collected from October through early December, immediately following the austral winter. In the succeeding months, the austral summer shows a burst of biological productivity, both under the ice and in the benthos. Lacking studies during this period, scientists do not know how the forams might be responding to this summer food pulse. This project's goal is to document changes in relevant abiotic and biotic factors in the Explorers Cove benthos from austral spring to late summer and to characterize how the agglutinated foram community structure responds, looking at such indices as species composition, densities, size distribution, and others. To accomplish these analyses project team members will use sediment cores, underwater microscopy, molecular tools, isotope analysis of lipids, and some other newly refined methods.

Researchers expect these combined approaches to elucidate the roles played by larger agglutinated forams in the Explorers Cove benthic food web, especially how these roles may change consequent to the summer food pulse. Further, the results of these studies should have wider significance in the ocean sciences because Explorers Cove and its agglutinated foram assemblage are comparable to many bathyal and abyssal deep-sea localities.

To enhance insight into marine processes associated with global climate change, this group collaborates with investigators from Russia to

Test the universality of meltwater turbidity impacts documented in the Arctic,

Assess changes (by adapting modern biochemical and molecular assays) in the living foraminiferal assemblage in response to glacial meltwater, and

Explore ways of revealing the imprint of glacial proximity in the antarctic fossil record.


Field Season Overview:
Project team members will travel by helicopter to Explorer's Cove and Marble Point and by snowmobile to the Ferrar Glacier fjord. Using a small box corer, divers will obtain undisturbed bottom samples to collect foraminifera.