Weddell
Seal Population Dynamics
in
Erebus Bay, Antarctica Interactions of Environmental Variability, Life History Traits,
and Demography in an Apex Antarctic Predator
Project Overview
A breeding population of Weddell seals, a prominent Antarctic apex
predator associated with fast ice, has been intensively
studied in Erebus Bay at the southern extent of the Ross Sea
since 1968. The current project uses synthesis and
modeling of long-term data for Weddell seals with
multi-decadal data on temporal variation in climate, marine, and
sea-ice conditions in the Ross Sea to evaluate a
variety of hypotheses regarding effects of environmental variation on
life-history evolution and population dynamics. Additional details
regarding how
physical drivers influence ecosystem dynamics from the bottom-up are
being obtained by conducting field studies of how seal body mass, a
surrogate for annual variation in marine food resources, varies among
years and individuals. The study’s broad
objective is to evaluate how temporal variation in the marine
environment affects a long-lived mammal’s population
dynamics. The study uses a combination of mark-recapture
analysis of vital rates and matrix
population modeling to evaluate hypotheses regarding how fitness is
affected by temporal environmental
variation and collects longitudinal and cross-sectional data on
body
mass dynamics for mother-pup pairs to evaluate hypotheses
relating environmental variation to changes in body mass and variation
in body mass to effects on population dynamics. Bob
Garrott, Jay Rotella, and Don Siniff are co-PI's on
the study, which is funded by the National Science Foundation through the U.S. Antarctic Program.
