The Cryoconite of the Thule Area, Greenland

Gerdel, R. W.; Drouet, Francis

doi:10.2307/3223732

Cited by 80 publications

(69 citation statements)

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“…Gerdel and Drouet (1960) reported on the dominance of cyanobacterial filaments in cryoconite samples in the Thule area in Greenland, where yellow or brown sheathed filaments of Calothrix parietina were very common. Their species bore similarities to the orange-sheathed filaments occasionally found in the surface ice during the present study, (Figure 2a), though no heterocysts were recorded in our samples.…”

Section: Resultsmentioning

confidence: 99%

“…The algae are all members of the saccoderm desmid family Mesotaeniaceae, (Zygnematophyceae), a relatively specialised group capable of growth on bare glacial ice (Uetake et al, 2010;Remias et al, 2012). Ancylonema and Cylindrocystis were first recorded in 'vast quantities' on the GrIS in the 1870s (Berggren, 1871; Nordenskiö ld, 1872) and more recently by Gerdel and Drouet (1960). Both genera have been recorded on glaciers from nearby Ellesmere Island (Mueller et al, 2001) and all are geographically widespread in polar regions (Kol, 1968;Ling and Seppelt, 1990;Takeuchi, 2001).…”

Section: Resultsmentioning

confidence: 99%

“…Gerdel and Drouet (1960) surveyed cryoconite from Northwest Greenland suggesting that biological processes directly on the ice surface, involving algal metabolism, might partly explain surface melt and formation of cryoconite holes. Filamentous cyanobacteria have been shown to facilitate the formation of cryoconite granules and to promote darkening on the surface of glaciers Langford et al, 2010), thus affecting surface albedo .…”

Section: Introductionmentioning

confidence: 99%

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Photophysiology and albedo-changing potential of the ice algal community on the surface of the Greenland ice sheet

et al. 2012

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Darkening of parts of the Greenland ice sheet surface during the summer months leads to reduced albedo and increased melting. Here we show that heavily pigmented, actively photosynthesising microalgae and cyanobacteria are present on the bare ice. We demonstrate the widespread abundance of green algae in the Zygnematophyceae on the ice sheet surface in Southwest Greenland. Photophysiological measurements (variable chlorophyll fluorescence) indicate that the ice algae likely use screening mechanisms to downregulate photosynthesis when exposed to high intensities of visible and ultraviolet radiation, rather than non-photochemical quenching or cell movement. Using imaging microspectrophotometry, we demonstrate that intact cells and filaments absorb light with characteristic spectral profiles across ultraviolet and visible wavelengths, whereas inorganic dust particles typical for these areas display little absorption. Our results indicate that the phototrophic community growing directly on the bare ice, through their photophysiology, most likely have an important role in changing albedo, and subsequently may impact melt rates on the ice sheet.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Photophysiology and albedo-changing potential of the ice algal community on the surface of the Greenland ice sheet

et al. 2012

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“…In contrast, Antarctic cryoconite holes, most extensively studied on glaciers in the McMurdo dry valleys, commonly become lidded over by ice, insulating the contents from the influence of atmosphere and meltwater for as long as 10 years Hodson et al, 2008). In both cases, these cylindrical melt holes comprise pelagic (meltwater) and benthic (granular organic/mineral sediment) zones (Gerdel and Drouet, 1960).…”

Section: Introductionmentioning

confidence: 99%

“…High Arctic glaciers often contain significant amounts, up to 36 g m À2 of cryoconite sediment , with cryoconite holes covering up to 6% of the glacier surface . These cylindrical holes are formed on the ice surface by localized melting that is caused by the reduced albedo associated with the progressive accumulation of dark-coloured supraglacial material (Gerdel and Drouet, 1960;Takeuchi et al, 2001;Takeuchi, 2002).…”

Section: Introductionmentioning

confidence: 99%

Possible interactions between bacterial diversity, microbial activity and supraglacial hydrology of cryoconite holes in Svalbard

et al. 2010

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The diversity of highly active bacterial communities in cryoconite holes on three Arctic glaciers in Svalbard was investigated using terminal restriction fragment length polymorphism (T-RFLP) of the 16S rRNA locus. Construction and sequencing of clone libraries allowed several members of these communities to be identified, with Proteobacteria being the dominant one, followed by Cyanobacteria and Bacteroidetes. T-RFLP data revealed significantly different communities in holes on the (cold) valley glacier Austre Brøggerbreen relative to two adjacent (polythermal) valley glaciers, Midtre Lové nbreen and Vestre Brøggerbreen. These population compositions correlate with differences in organic matter content, temperature and the metabolic activity of microbial communities concerned. No within-glacier spatial patterns were observed in the communities identified over the 2-year period and with the 1 km-spaced sampling. We infer that surface hydrology is an important factor in the development of cryoconite bacterial communities.

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Disappearing Kilimanjaro snow—Are we the last generation to explore equatorial glacier biodiversity?

Zawierucha

Shain

2019

Ecology and Evolution

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Glaciation accompanied our human ancestors in Africa throughout the Pleistocene. Regrettably, equatorial glaciers and snow are disappearing rapidly, and we are likely the last generation who will get to know these peculiar places. Despite the permanently harsh conditions of glacier/snow habitats, they support a remarkable diversity of life ranging from bacteria to animals. Numerous papers have been devoted to microbial communities and unique animals on polar glaciers and high mountains, but only two reports relate to glacial biodiversity in equatorial regions, which are destined to melt completely within the next few decades. Equatorial glaciers constitute “cold islands” in tropics, and discovering their diversity might shed light on the biogeography, dispersal, and history of psychrophiles. Thus, an opportunity to protect biota of equatorial glaciers hinges on ex situ conservation. It is timely and crucial that we should investigate the glacial biodiversity of the few remaining equatorial glaciers.

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The Cryoconite of the Thule Area, Greenland

Cited by 80 publications

References 0 publications

Photophysiology and albedo-changing potential of the ice algal community on the surface of the Greenland ice sheet

Photophysiology and albedo-changing potential of the ice algal community on the surface of the Greenland ice sheet

Possible interactions between bacterial diversity, microbial activity and supraglacial hydrology of cryoconite holes in Svalbard

Disappearing Kilimanjaro snow—Are we the last generation to explore equatorial glacier biodiversity?

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