TITLE:    Long Term Observations of Meltwater and Biomass in Antarctic 
          Coastal Waters
AUTHORS:  Heidi M. Dierssen, R.C. Smith, M. Vernet
DATE:     12-16 February 2001
PLACE:    The American Society of Limnology and Oceanography (ASLO),
	  Aquatic Sciences 2001, Albuquerque, New Mexico
THEME:    Making Connections in the 21st Century
URL:      http://www.aslo.org/albuquerque2001/

	   Special Session
	   SS40 - Long-Term Research Programs in the Twenty-first
	          Century (Spatial and Temporal Connections)

            University of California, Santa Barbara, Santa Barbara, USA


ABSTRACT

In the Antarctic region, melting of land-based glaciers and snowpack releases
freshwater into the coastal surface waters each year.  The effects of meltwater
on the marine ecosystem, particularly the phytoplankton at the base of food 
chain, are not well characterized.  However, meltwater conditions may become
more prevalent in Antarctic coastal waters given the statistically significant
warming trend in air temperature that has been documented along the Antarctic
Peninsula.  To address the relationship between meltwater and phytoplankton
biomass in this climatically sensitive region, we utilize a unique long-term
(1991-1999) dataset of physical and biological parameters collected in 
nearshore waters of the Antarctic Peninsula.  As part of the Palmer Station 
Long Term Ecological Research Project, data has been collected approximately
weekly to bi-weekly during the Antarctic growing season (November-March) for
nearly a decade.  Both the amount of meltwater in the surface waters and
concentrations of phytoplankton biomass (denoted as chlorophyll a) in the
water column vary dramatically from year to year.   Within this large
interannual variability, however, we will address the patterns of meltwater
and biomass.  Generally, biomass appears to increase with the presence of
meltwater.  Meltwater provides a stable layer for phytoplankton to remain
within the euphotic zone and may provide key nutrients, particularly at the
end of summer when nutrients can become limiting.   The feedbacks between
meltwater, biomass, and climate change are explored.