SELECTION OF HAUL-OUT SUBSTRATE BY HARBOR SEALS (PHOCA VITULINA) ASSOCIATED WITH TIDEWATER GLACIERS IN KENAI FJORDS NATIONAL PARK, ALASKA.
Abstract
In Alaska, 10-15% of harbor seals use glacial ice as a haulout substrate on which
to rest, molt, and care for young. Some glaciers in Kenai Fjords National Park are
receding at a staggering rate which could reduce the habitat available to seals in
the near future. Understanding the current usage of haulout substrate at both a local
and region scale will be vital to effective and proactive management of the species
in light of climate change predictions. The primary goal of the present study was
to evaluate the seasonal characteristics of ice availability and the associated patterns
of usage by harbor seals in Northwestern Fjord—which terminates in a rapidly receding
glacier. Patterns of seal attendance and ice conditions were evaluated across six
sub-regions and across two summers. Data from Northwestern Fjord was also contrasted
with observations conducted in a location, Aialik Bay, where the primary glacier is
relatively stable. Results of this analysis indicate seasonal patterns of ice availability
and linkages between seasonal ice conditions and the numbers of seals present. Overall
ice coverages did not have predictable seasonal trends but small and medium sized
ice platforms had significant trends in their availability throughout the summer.
In Northwestern Fjord attendance peaked in midsummer and was positively correlated
with ice availability and the availability of large sized bergs. Seal attendance also
exhibited seasonal trends in Aialik Bay but opposite those observed in Northwestern
Fjord. This study provided a baseline understanding of habitat availability and usage
for the study area. Further research examining the patterns of habitat use by sex,
age class and the movement between fjords is needed to fully understand the dynamics
of how harbor seals in Kenai Fjords National Park utilize habitat.
Type
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https://hdl.handle.net/10161/3628Citation
Bishop, Amanda (2011). SELECTION OF HAUL-OUT SUBSTRATE BY HARBOR SEALS (PHOCA VITULINA) ASSOCIATED WITH TIDEWATER
GLACIERS IN KENAI FJORDS NATIONAL PARK, ALASKA. Master's project, Duke University. Retrieved from https://hdl.handle.net/10161/3628.Collections
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