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dc.contributor.authorNielson, Mette R.
dc.date.accessioned2015-08-27T00:04:58Z
dc.date.available2015-08-27T00:04:58Z
dc.date.issued2006-12
dc.identifier.urihttp://hdl.handle.net/11122/5887
dc.descriptionThesis (M.S.) University of Alaska Fairbanks, 2006en_US
dc.description.abstractThe Arctic amphipod Onisimus litoralis migrates from the seafloor to the sea ice to graze on ice algae, a rich food source during the Arctic spring, resulting in complex trophic dynamics. I assessed the effect of temperature and season on the rate of change in stable isotopic composition of amphipods by simulating a diet switch in the laboratory using amphipods collected near Barrow, Alaska in spring and autumn 2004. Additionally, the proportional contributions of food sources to the amphipods' diet in the field were estimated. Isotopic change occurred faster in spring with half-lives of 13.9 (1°C) and 18.7 (4°C) days for carbon and 22.4 days for nitrogen compared to autumn rates of 77 (carbon) and 115 days (nitrogen). Temperature did not have a significant effect on turnover. Change occurred primarily through metabolic turnover (versus growth-related dilution) and was responsible for 84-89% of the change in carbon and 67-77% of the change in nitrogen in both seasons. A two-source mixing model estimated that ice-derived biota contributed 59 (±17)% to the amphipods' diet in May. These data show that the rate of isotopic change can vary temporally for a single species, highlighting the importance of experimental work for interpreting stable isotope field-data.en_US
dc.language.isoen_USen_US
dc.titleEstimating ¹³C and ¹⁵N turnover rates in the Arctic amphipod Onisimus litoralis: implications for analysing the transfer of sea ice production to under-ice faunaen_US
dc.typeThesisen_US
dc.type.degreemsen_US
dc.identifier.departmentProgram in Marine Science and Limnologyen_US
refterms.dateFOA2020-03-13T01:21:48Z


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