Carbon And Nitrogen Isotope Ratios In Bowhead Whales (Balaena Mysticetus) And Their Zooplankton Prey As Indicators Of Feeding Strategy And Environmental Change.

• Main Author: Vinette, Kimberly Ann
• Other Authors: Schell, Don
• Format: Thesis
• Language: unknown
• Published: 1993
• Subjects: Biological oceanography; Bering Sea; Fairbanks; Balaena mysticetus; Beaufort Sea; bowhead whale; Chukchi; Alaska
• Online Access: http://hdl.handle.net/11122/8507

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.