The Variability in the Fluxes and Viability of Microbes Liberated in Supraglacial Stream Runoff

  • Jennifer McGowan

Student thesis: Master's ThesisMaster of Philosophy


Supraglacial ecosystems harbour diverse microbial communities. However, the reaction of such microbes to evident climatic global warming and longer summer ablation is still unconstrained. Assessments of microbial fluxes through supraglacial streams, with such microbes ultimately liberated from the ice surface by melt, are sparce. Here, the microbial abundance found on the surface of Storglaciären, Sweden, and within supraglacial streams on Fountain Glacier, Canadian Arctic and the high-Arctic glaciers of Midtre Lovénbreen and Foxfonna, Svalbard, were quantified. Using flow cytometric protocols, mean microbe abundances were found between 1.47 to 10.78 × 104 cells mL⁻¹ for different ice types on Storglaciären, with superimposed ice harbouring the highest mean microbial abundance. Supraglacial streams on Fountain and Foxfonna Glacier revealed estimated mean microbial fluxes of 5.46 × 1011 cells h-1 and 4.81 × 1012 cells h-1, respectively. The mechanism for superimposed ice formation and melt presents a likely process for cell liberation at the glacier surface, but with the environmental variables of short-wave incident solar radiation, melt, discharge and EC, found to significantly associate with microbial abundances found within supraglacial streams. Here, the first viability determination of cells within supraglacial stream samples has been carried out using the dualstaining combination of PI and TO. An estimated 54.65 % of the cells exported through the Foxfonna supraglacial stream per hour were revealed as ‘live’, holding the potential to interact with the ecohydrology of glacier-fed environments. However, unexpected shifts in TO fluorescence in the presence of glutaraldehyde necessitate further exploration into viability staining of supraglacial samples
Date of Award2022
Original languageEnglish
Awarding Institution
  • Aberystwyth University
SupervisorTristram Irvine-Fynn (Supervisor) & Arwyn Edwards (Supervisor)

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