Carbon And Nitrogen Isotope Ratios In Bowhead Whales (Balaena Mysticetus) And Their Zooplankton Prey As Indicators Of Feeding Strategy And Environmental Change.
Thesis (M.S.) University of Alaska Fairbanks, 1993 This study details regional, seasonal and inter-annual differences in $\delta\sp{13}$C and $\delta\sp{15}$N of zooplankton in the Bering and Chukchi Seas. These isotopic variations were correlated with inter-annual and long-term variations in $\delt...
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| Format: | Thesis |
| Language: | unknown |
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1993
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| Online Access: | http://hdl.handle.net/11122/8507 |
| Summary: | Thesis (M.S.) University of Alaska Fairbanks, 1993 This study details regional, seasonal and inter-annual differences in $\delta\sp{13}$C and $\delta\sp{15}$N of zooplankton in the Bering and Chukchi Seas. These isotopic variations were correlated with inter-annual and long-term variations in $\delta\sp{13}$C and $\delta\sp{15}$N of bowhead whale baleen. Statistical analyses indicate significant $\sp{13}$C-enrichment in Bering/Chukchi seas zooplankton relative to Beaufort Sea zooplankton, supporting the observed trends of $\sp{13}$C-depletion at higher latitudes and enrichment at lower latitudes. Bering/Chukchi seas zooplankton show a weak trend in $\sp{13}$C-depletion between 1987-1990, possibly due to inter-annual environmental changes affecting phytoplankton $\delta\sp{13}$C. The $\delta\sp{13}$C of baleen produced in fall/winter months is inversely correlated to sea surface temperature trends in the Bering Sea. Long-term changes in baleen $\delta\sp{13}$C may be helpful in assessing past climatic change. The observed $\delta\sp{15}$N oscillations in baleen may be due to changes in trophic level of prey between seasonal feeding grounds or from physiological cycles in the bowhead whale. |
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