Particulate trace metals & iron availability to phytoplankton in a changing Arctic Ocean
department or school: Science, Faculty of
department or school: Earth, Ocean and Atmospheric Sciences, Department of
data provider: DSpace
degree campus: UBCV
creator: Li, Jingxuan
issued: 2017-06-28T22:57:14Z
issued: 2017
related degree: Master of Science - MSc
degree grantor: University of British Columbia
description: This thesis, focusing on the Canadian Arctic Ocean, investigates the cycling of particulate trace metals, and the bioavailability of iron to phytoplankton in this rapidly changing ocean. Full depth profiles of particulate Al, Cd, Pb, P, V, Mn, Fe, Co, Cu, Zn and Ba were determined. Trace elements displayed various vertical distributions. Firstly, some elements had a strong lithogenic component (Al, Fe and V), and were characterized by a maximum at the surface. Indeed, their concentrations strongly correlated with each other across basins. Secondly, elements with a significant biogenic component (Cd and Cu) were characterized by a decrease in concentration with depth. Furthermore, preferential remineralization of P over Cd at shallow depths in numerous stations is reported. In some stations across basins, the molar ratio of particulate Cu and P approached a plateau at the meso- or bathy-pelagic zone, suggesting the presence of ammonium oxidizing archaea, which require Cu-dependent enzymes. Thirdly, Mn, a trace metal with a predominant redox cycle, showed a spike in concentration between 100-200 m, as well as a bottom enrichment. In the Canada Basin, we suggest interactions between the production of manganese oxide, cobalt oxide and barite by manganese oxidizing bacteria. The Arctic Ocean is experiencing the greatest decrease in seawater pH, as well as rapid ice melting which elevates light intensity in surface waters. To examine changes in Fe bioavailability to Arctic phytoplankton under a varying environment, two incubation experiments were conducted. After natural phytoplankton assemblages were acclimated to different light/CO2 treatments for one week, short-term Fe uptake assays were performed to assess the capability of phytoplankton to access Fe. Generally, Fe uptake capability was positively influenced by CO₂ level, and negatively impacted by light level in the incubations. These observations imply that high CO₂ has a significant negative effect on Fe bioavaila…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/62119
note: i Particulate Trace Metals & Iron Availability to Phytoplankton in a Changing Arctic Ocean by Jingxuan Li B.Sc., Xiamen University, 2010 A DISSERTATION SUBMITTED IN PARTIAL FULFILLMENT OF The REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Oceanography) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) June 2017 © Jingxuan Li, 2017 ii Abstract This thesis, focusing on the Canadian Arctic Ocean, investigates the cycling of particulate trace metals, and the bioavailability of iron to phytoplankton in this rapidly changing ocean. Full depth profiles of particulate Al, Cd, Pb, P, V, Mn, Fe, Co, Cu, Zn and Ba were determined. Trace elements displayed various vertical distributions. Firstly, some elements had a strong lithogenic component (Al, Fe and V), and were characterized by a maximum at the surface. Indeed, their concentrations strongly correlated with each other across basins. Secondly, elements with a significant biogenic component (Cd and Cu) were characterized by a decrease in concentration with depth. Furthermore, preferential remineralization of P over Cd at shallow depths in numerous stations is reported. In some stations across basins, the molar ratio of particulate Cu and P approached a plateau at the meso- or bathy-pelagic zone, suggesting the presence of ammonium oxidizing archaea, which require Cu-dependent enzymes. Thirdly, Mn, a trace metal with a predominant redox cycle, showed a spike in concentration between 100-200 m, as well as a bottom enrichment. In the Canada Basin, we suggest interactions between the production of manganese oxide, cobalt oxide and barite by manganese oxidizing bacteria. The Arctic Ocean is experiencing the greatest decrease in seawater pH, as well as rapid ice melting which elevates light intensity in surface waters. To examine changes in Fe bioavailability to Arctic phytoplankton under a varying environment, two incubation experiments were conducted. After natural phytoplankt…
has type: Thesis/Dissertation
date issued: 2017-09
is shown at: 10.14288/1.0348666
language: eng
degree discipline: Oceanography
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/62119