2002-2003 Science Planning Summary

Biology & Medicine

Dr. Polly Penhale
Program Manager

BO-034-E

NSF/OPP 99-09274
Station: Not based at a station
RPSC POC: John Evans
Research Site(s): Seymour Island and other peninsula locations

Abandoned penguin colonies in Antarctica
Dr. Steven D. Emslie
University of North Carolina
Department of Biological Sciences
emslies@uncwil.edu
http://www.uncwil.edu/people/emslies

Deploying Team Members: Manuela Campo . Steven D Emslie . Rodney Hayward
Research Objectives: Climate change is assumed to be a pivotal factor in the success of many species. This project will investigate the history of Adélie penguins in late Holocene Antarctica. By locating and examining the fossil remains of former colonies, scientists hope to develop a model of when they thrived and when colonies were abandoned, and thus their success relative to climate change. This model could inform current science on the relationship between climate and population dynamics.

This study will integrate data from the ecological, geological and paleobiological records with satellite-imagery analyses. The climate factor will be inferred by data contemporaneous with the fossil evidence, in particular the extent of the sea ice and marine productivity. The population factor will be developed through field and laboratory investigations of abandoned colonies along coastal Antarctica.

Researchers will first collect surface and subsurface bones, feathers, and eggshell fragments preserved at these sites. Later in the lab, they can reconstruct the occupation history of each abandoned colony, through standard and radiocarbon analyses. Sediments from each site will be sifted to recover organic remains (such as squid beaks and fish otoliths) believed to be staples of the penguin diet. Statistical analysis of such indicators can trace the changing size of the colony at specific prehistoric times, and thus prey consumption becomes a proxy for population success. This timeline can then be matched to past episodes of climate change, which are well documented for the late Pleistocene and Holocene in ice-core and marine sediment records.

Researchers expect these ancient responses by penguins to climate change (as indicated by the paleoecological record) to parallel those observed in Antarctica today, where regional warming has been documented over the past 20 to 50 years. Ultimately they will be able to test the hypothesis that Adélie penguins - for decades and centuries - have been responding to climate change in a predictable manner and that those responses can be anticipated, relative to fluctuations in sea-ice extent and marine productivity.


Field Season Overview:
The researcher will be joining a team from the Swedish Antarctic program, receiving logistical support through the Argentine Antarctic program. Dr. Emslie will travel from Argentina to Seymour Island in an Argentinean C-130 to:

- Locate and excavate abandoned penguin colonies on ice-free terrain,

- Collect organic remains (penguin bones, eggshell, fish bones, and otoliths) from ornithogenic sediments,

- Obtain radiocarbon dates on penguin bones and tissue to determine an occupation history for penguins in the Antarctic Peninsula,

- Sample active colonies of Adelie and chinstrap penguins to obtain similar information on occupation history and dietary remains from guano.

The sediments will be screened and washed in the field, coarse fractions will be sorted in the field, and fine sediments will be shipped back to the U.S. for further study.