TITLE:   Growth of larval Antarctic krill in the pack ice habitat: interannual
         and seasonal variability
AUTHORS: L.B. Quetin*, R.M. Ross*, T.K. Frazer#, M.O. Amsler~, C. Wyatt_Evens+, 
	 and S.A. Oakes*
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/

	  POSTER - PC05
	  Zooplankton Production, Physiology, and Ecology

         *University of California at Santa Barbara, Santa Barbara, CA, USA
         #University of Florida, Gainesville, FL, USA
         ~University of Alabama at Birmingham, AL, USA
         +CUBE Corporation, New Orleans, LA, USA 

ABSTRACT:
 Physiological and behavioral evidence suggests that larval Antarctic
krill survive prolonged periods of low phytoplankton abundance in the
winter water column by feeding on pack ice-associated biota. If growth
during this period is primarily a function of the presence of sea ice
and its biota, then growth rates of larval krill in fall and winter
should vary with the presence of sea ice. To test this hypothesis,
instantaneous growth rate experiments were conducted during eight
cruises over six years (1987 - 1999). Cruises occurred west of the
Antarctic Peninsula from fall through early spring. In 1993, there were
three cruises: (1) during fall prior to ice formation, (2) during
mid-winter ice-formation, and (3) during early spring ice-melt. Growth
increments decreased from fall (Apr-May, ~6%) to early winter (Jun, ~
0%), then increased markedly by early spring (Sept, ~ 11%). Data from
other years were consistent with the 1993 findings, i.e. interannual
was less than seasonal variability. These results explained the limited
increases in length generally observed in larval populations over
winter.