The structure, biological activity and biogeochemistry of cryoconite aggregates upon an Arctic valley glacier: Longyearbreen, Svalbard

Hodson, Andy, Cameron, Karen, Bøggild, Carl, Irvine-Fynn, Tristram, Langford, Harry, Pearce, David and Banwart, Steven (2010) The structure, biological activity and biogeochemistry of cryoconite aggregates upon an Arctic valley glacier: Longyearbreen, Svalbard. Journal of Glaciology, 56 (196). pp. 349-362. ISSN 0022-1430

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Abstract

Glacier surfaces support unique microbial food webs dominated by organic and inorganic debris called 'cryoconite'. Observations from Longyearbreen, Spitsbergen, show how these aggregate particles can develop an internal structure following the cementation of mineral grains (mostly quartz and dolomite) by filamentous microorganisms. Measurements of carbon and dissolved O2 show that these microorganisms, mostly cyanobacteria, promote significant rates of photosynthesis (average 17 gC g−1 d−1) which assist aggregate growth by increasing the biomass and producing glue-like extracellular polymeric substances. The primary production takes place not only upon the surface of the aggregates but also just beneath, due to the translucence of the quartz particles. However, since total photosynthesis is matched by respiration (average 19 gC g−1 d−1), primary production does not contribute directly to cryoconite accumulation upon the glacier surface. The microorganisms therefore influence the surface albedo most by cementing dark particles and organic debris together, rather than simply growing over it. Time-lapse photographs show that cryoconite is likely to reside upon the glacier for years as a result of this aggregation. These observations therefore show that a better understanding of the relationship between supraglacial debris and ablation upon glaciers requires an appreciation of the biological processes that take place during summer.

Item Type:	Article
Subjects:	C500 Microbiology
Department:	Faculties > Health and Life Sciences > Applied Sciences
Depositing User:	Becky Skoyles
Date Deposited:	21 Dec 2015 16:12
Last Modified:	12 Oct 2019 18:26
URI:	http://nrl.northumbria.ac.uk/id/eprint/25163

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