PROGRAM TITLE:	Antarctic Ecosystems
ACTIVITY STREAM:	Process, Observe
SCIENCE ELEMENT:	Ecosystem Dynamics


SCIENTIFIC MERIT:  The Office of Polar Programs has supported global 
change research in the form of interdisciplinary investigations of terrestrial, 
limnetic, and marine ecosystems in Antarctica.  Antarctic Ecosystems is 
focused directly on ecosystem monitoring and long-term ecological response 
to global climate change to answer questions such as how climate variability 
and change in a fragile polar environment affect the food chain.  The 
Antarctic LTER (Long Term Ecological Research) activities at Palmer Station 
provide a focal point for ecosystem studies which will include measurement 
of both physical and biological parameters.  LTER's main goal is the effect of 
the interannual variation of sea ice cover on the structure of the marine 
ecosystem of the Antarctic Peninsula.  Sea ice varies widely from season to 
season in the Antarctic and its maximum and minimum extent varies 
considerably from year to year.  As many components of the marine food web, 
ranging from algae to penguins and seals, are dependent on the sea ice, 
changes in its extent can have a significant impact on marine life and the 
structure of the food web.  Some of the changes in these extents may be 
complex periodicities; others may be associated with overall trends in global 
change.  The ongoing studies at the site include environmental monitoring, 
satellite observations, and short term experimental process studies.  A 
periodicity in annual sea-ice has been observed resulting in penguin 
population oscillations.  The major advantages of this site include a relatively 
pristine environment, a simple food chain, (phytoplankton-krill-fish-
mammals/birds), a fragile ecosystem balance in a harsh climate and limited 
interference by humans, i.e., minimal commercial interests.  On the other 
hand, events such as the grounding of the Bahia Paraiso, and subsequent oil 
spill, can introduce major uncertainties in localized areas.  This work would 
clearly have relevance to USGCRP if global warming were responsible for a 
long term reduction in sea-ice.
STAKEHOLDERS:  The Antarctic LTER at Palmer is funded and administered 
by the Office of Polar Programs, but jointly reviewed by the NSF LTER 
program, which includes sites located throughout the US, the Antarctic and 
its territories.  The Palmer site is part of the LTER network.  NASA 
participates peripherally in this program through MOU agreements regarding 
satellite coverage at the sites.  The LTER program is not a part of the 
Long-Term Ecological Monitoring (LTEM) component of the Global Change 
in the Terrestrial Environment (GCTE) project of the International Geosphere 
Biosphere Programme (IGBP), however it could potentially contribute 
significantly to the kinds of scientific goals of that program as well as GLOBEC 
and the UV/Ozone program.
POLICY RELEVANCE:  Field monitoring and process studies will provide 
data for the early detection of global change.  Changes in sea-ice cover will 
have direct influence on food webs in the Antarctic, as well as direct feedback 
effects on climate.  This program is important to the Antarctic Treaty and the 
implementation of the new Protocol on the Environment.  It is also a 
provider of useful data to the Commission for the Conservation of Antarctic 
Marine Living Resources (CCAMLR) which monitors populations and 
recommends action/limitations to the commercial fishing nations.  Thus, the 
program will enable more informed stewardship of one of the Earth's major 
PROGRAM CONTACTS:  Polly Penhale and Dennis Peacock, Office of Polar