A retrospective assessment of primary productivity on the Bering and Chukchi Sea shelves using stable isotope ratios in seabirds
dc.contributor.author | Abromaitis, Grace Elizabeth | |
dc.date.accessioned | 2015-02-12T01:37:07Z | |
dc.date.available | 2015-02-12T01:37:07Z | |
dc.date.issued | 2000-12 | |
dc.identifier.uri | http://hdl.handle.net/11122/4944 | |
dc.description | Thesis (M.S.) University of Alaska Fairbanks, 2000 | en_US |
dc.description.abstract | Recent declines of marine mammal seabird populations in the Bering Sea have raised the question of whether the changes are caused by fishing pressure or a decrease in ecosystem carrying capacity. Stable carbon (¹³C⁾ and nitrogen (¹⁵N⁾ isotope ratios in Thick⁻billed Murre muscle and feathers were used as indicators of changing seasonal primary production. ¹³C values in phytoplankton vary directly with growth rates and are passed up the food web to consumers. Muscle and feather ¹³C values decreased over the period 1976-1998 suggesting a decline in Bering/Chukchi continental shelf primary production. Carbon isotope ratios in murres were correlated with bowhead whale baleen isotope ratios and to some climate indices. In contrast, ¹⁵N values in the birds showed no significant change indicating no concurrent shifts in trophic status. | en_US |
dc.language.iso | en_US | en_US |
dc.title | A retrospective assessment of primary productivity on the Bering and Chukchi Sea shelves using stable isotope ratios in seabirds | en_US |
dc.type | Thesis | en_US |
dc.type.degree | ms | en_US |
dc.identifier.department | Marine Science and Limnology | |
dc.contributor.chair | Schell, Donald | |
dc.contributor.committee | Castellini, Michael | |
dc.contributor.committee | Springer, Alan | |
refterms.dateFOA | 2020-03-05T09:18:51Z |
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Marine Sciences
Includes Marine Biology and Marine Science and Limnology