Date of Award

5-2020

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Biomedical and Chemical Engineering and Sciences

First Advisor

Kurt Winkelmann

Second Advisor

Alan B. Brown

Third Advisor

Pavithra Pathirathna

Fourth Advisor

Maria Pozo de Fernandez

Abstract

The Arctic Ocean and its marginal seas are key areas for understanding the global climate system. Climate change causes increased terrigenous materials to be carried into the ocean as well as higher production of marine organic matter in the ocean. This study determined the concentrations, distribution, and sources of fatty acids in core sediments from four locations: Stations H32, H30, BarC5 and H24 in the Chukchi Sea, which are in the Arctic Ocean. Fatty acids are valuable tracers of marine or terrigenous inputs and may give evidence to the extent of climate change. Fatty acids were analyzed, characterized using GC-MS in all four core sediments in the Chukchi Sea. The core sediment concentrations varied from 5.93 µg/g at depth 18-20 cmin station H24 to 173 µg/g at depth 22-24 cm in station BarC5. Principal component analysis was used to determine the sources of fatty acids. In general, results from this study clearly show marine input is the main source of fatty acids in the Chukchi Sea sediments with a minor terrestrial input due to the low concentrations of long-chain saturated fatty acids at all four stations. The relationship between fatty acid concentrations and alkane, total organic carbon and arsenic concentrations were studied but there was no apparent correlation. Historical temperature data was used to interpret the trends in fatty acid concentrations with depth during its sedimentation periods, but the distribution of fatty acid concentrations did not exhibit any systematic trends with the temperature data except in core H30.

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