This website stores cookies on your computer. These cookies are used to collect information about how you interact with our website and allow us to remember your browser. We use this information to improve and customize your browsing experience, for analytics and metrics about our visitors both on this website and other media, and for marketing purposes. By using this website, you accept and agree to be bound by UVic’s Terms of Use for web and social media privacy.  If you do not agree to the above, you can configure your browser’s setting to “do not track.”

Skip to main content
People Departments Maps Buildings Rooms A-Z
University
of Victoria
Apply Library
Sign in Online tools Sign out
Faculty of Graduate Studies

Sofie Ohrling

  • B.Sc. (University of Victoria, 2024)
Notice of the Final Oral Examination for the Degree of Master of Science

Topic

Decoupled Dissolved and Particulate Trace Metal Distributions in a High-Arctic Fjord, Archer Fjord (Nunavut)

School of Earth and Ocean Sciences

Date & location

  • Thursday, October 22, 2026
  • 12:00 P.M.
  • Bob Wright Centre, Room A202

Examining Committee

Supervisory Committee

  • Dr. Jay Cullen, School of Earth and Ocean Sciences, University of Victoria (Supervisor)
  • Dr. Colin Goldblatt, School of Earth and Ocean Sciences, UVic (Member)
  • Dr. Roberta Hamme, School of Earth and Ocean Sciences, UVic (Member)

External Examiner

  • Dr. Jon Hawkings, Department of Earth and Environmental Science, University of Pennsylvania

Chair of Oral Examination

  • Dr. Levi Smith, Department of Electrical and Computer Engineering, UVic

Abstract

This study aims to provide the first record of trace metal micronutrients in Archer Fjord, a land terminating glacial fjord system and known biological hotspot located within the Tuvaijuittuq Marine Protected Area in the Canadian Arctic. During leg 3 of the 2024 Amundsen Expedition, 4 oceanographic profiles were collected along with a variety of seawater surface samples and freshwater samples (nearby glaciers, rivers and lakes) to create a comprehensive picture of trace metal cycling within the Archer Fjord system.

Trace metals such Mn, Fe, Co, Ni, Cu, Zn, and Cd are are required by marine microbes to support the base of the arctic food web. Additionally, elements such as Cd and Pb are examined as potential tracers for anthropogenic contamination. As the Arctic warms, biogeochemical cycles are changing due to increased permafrost thaw and higher freshwater discharge from glaciers, rivers, lakes and sea ice melt. Findings on the distributions of trace metals provides insights into nutrient cycling dynamics and offers key indicators of High Arctic marine ecosystem health during ongoing climate change.

Trace metal analysis results in Archer Fjord show riverine and glacial discharge to input high concentrations of total Fe, Pb, Mn and Co. Fe and Pb exhibit concentrations 100-1000x higher in total unfiltered samples than dissolved samples. Low dissolved Fe is attributed to a lack of available organic ligands supplied in Archer Fjord due to lake-buffering of glacial meltwater. Mn and Co concentrations are elevated by freshwater in both total and dissolved samples within the fjord. In addition, an 180m sill separating the end of Conybeare Fjord creates a basin in which Fe and Mn accumulate at depth which is proposed to occur through benthic cycling, remineralization, and resuspension of trace metals. Opposingly, freshwater discharge into the fjord carries lower concentrations of Ni, Cu, Zn, and Cd showing dilution of surface metals at the end of the fjord arms. The results of this work from this thesis suggests that even with increased glacial-fed riverine discharge due to climate warming, lake buffered systems such as Archer Fjord may deliver less bioavailable dissolved Fe than neighbouring marine-terminating glacial fjords.

Back to oral exams