Seasonal, inter-annual, and spatial variation in ringed seal feeding ecology in Hudson Bay assessed through stable isotope and fatty acid biomarkers
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Date
2013-02-18
Authors
Young, Brent G.
Journal Title
Journal ISSN
Volume Title
Publisher
CSIRO Publishing
Abstract
Current trends toward warmer air temperatures and longer ice free seasons in Hudson Bay are expected to cause changes in Arctic marine ecosystem dynamics. Ringed seals (Phoca hispida) will likely experience changes in levels of predation, competition, and prey availability. The purpose of this thesis was to investigate seasonal, inter-annual, and spatial variation in Hudson Bay ringed seal feeding ecology. Fatty acid composition, δ15N, and δ13C varied significantly by season, suggesting seasonal changes in foraging habitat and diet. Spatial differences in ringed seal stable isotope ratios occurred between western and eastern Hudson Bay, and there was a strong relationship between spring air temperature and δ15N. Peak δ15N occurred within a range in spring air temperatures between approximately -5°C and -2°C. I propose that the high δ15N observed in ringed seals within this temperature range is indicative of relatively greater importance of capelin (Mallotus villosus) in the ringed seal diet.
Description
Keywords
ringed seal, feeding ecology, Hudson Bay, stable isotopes, fatty acids
Citation
Young BG and Ferguson SH. 2013. Seasons of the ringed seal: pelagic open-water hyperphagy, benthic feeding over winter and spring fasting during molt. Wildlife Research, doi: 10.1071/WR12168