NSF Org OPP
Latest Amendment Date September 11, 1995
Award Number 9525803
Award Instr. Standard Grant
Prgm Manager Polly A. Penhale
OPP OFFICE OF POLAR PROGRAMS
O/D OFFICE OF THE DIRECTOR
Start Date October 1, 1995
Expires September 30, 1998 (Estimated)
Expected Total Amt. $172,199 (Estimated)
Investigator Peter J. Franks pfranks@ucsd.edu
Sponsor U of Cal SD Scripps Inst
La Jolla, CA 92093
NSF Program 5111 POLAR BIO & MEDIC ((US ANTARC)
Fld Science 43 Biological Oceanography
Fld Applictn 0204000 Oceanography
0311000 Polar Programs-Related
Abstract
9525803 Franks This project will investigate how spatial and temporal
variability in physical-biological features affects the development,
condition and survival of Antarctic krill larvae (Euphausia superba). It is
believed that adult spawning behavior and regional differences in primary
productivity and temperature are significant forces controlling krill
mortality, population demography and recruitment. Using a modified
stage-structured larval population model, the effects of spawning behavior and
variations in stage durations and mortalities on demography and recruitment
will be examined. The model results will be compared with observed larval
distributions to determine which processes best account for the observed
population structures. Using a detailed metabolic model with stage structure
and realistic external forcing, we will determine how much of the
variability in stage durations and mortalities can be explained by the
effects of food availability and temperature. Larval lipid metabolism will be
incorporated into the model for elucidating the influences of physical and
biological variability on larval krill condition. Models will integrate the
effects of multiple parameters and will intimately coupled to field
observations and laboratory experiments. This study will provided a valuable
contribution to the understanding of interactions between marine populations
and physical processes in the Southern Ocean ecosystem. The results from
this study will be applicable to concurrent research investigating the
physical-biological interactions affecting Euphausia superba in the Southern
Ocean, and Euphausia pacifica in the California current. The ultimate
intent is to quantify the impact of physical-biological patchiness
associated with physical features and phenomena on larval condition,
demography and recruitment in euphausiid populations. Understanding species'
responses to physical perturbations will elucidate how environments have
evolutionarily constrained life-history patterns to maximize survival in
inherently patchy and variable systems. Through this understanding, this
study will provide insights into the potential effects of climatic change on
euphausiid populations and their ecosystems.