In the past decade or so, interest in glacier microbiology and “bioalbedo” has intensified, but it is important to remember that these ideas are not new. In fact, the early polar explorers wrote on these topics over 150 years ago and even identified species of algae in cryoconite and the role of ice algae for accelerating melt.
Cryoconite represents the best studied and most biodiverse microbial habitat on ice surfaces. Although cryoconite studies have increased in frequency over the past twenty years, the concepts which underpin our current understanding were largely established in the nineteenth century. The term ‘cryoconite’ itself was coined by Adolf E. Nordenskiold to describe dust filled depressions on the Greenland ice sheet in records from the 1870s. Papers such as Gribbon et al (1979) and Wharton et al (1985) are commonly credited with providing the first explanation of cryoconite hole formation, but actually Nordenskiold proposed a mechanism of enhanced melt beneath dark layers of sediment way back in the late 1870s and pre-empted modern glacial microbiology by appreciating cryoconite holes as microbial habitats. Furthermore, Nordenskiold examined individual cryoconite granules, recognising them to be aggregates of mineral grains and organic matter and even identifying cyanobacteria as the dominant species within them (Leslie, 1879). Further detailed analysis of cryoconite grain composition was provided by Bayley (1891) who identified further mineralogical and biological matter. Cryoconite hole morphology was further studied by Drygalski (1897) and Hobbs (1910). Interestingly, Nordenskiold identified fine dusts on ice surfaces which he suggested were of cosmic origin; being well into the industrial era it is possible that his observations were related to early anthropogenic contamination (now becoming a prolific topic of study), although he considered Greenland to be too remote to be affected by distant industry.
Although modern glacial microbiology is facilitated by advanced techniques and methodologies, the conclusions drawn by studies over the past century have predominantly confirmed the intuition and basic empirical observations of the pre-1900 glaciologists.
In the 1880’s, Nansen observed thin veils of photosynthetic algae with extremely high spatial coverage on the Greenland ice sheet which he suggested to impact glacier melt rates. This predates Yallop et al’s (2012) study, which uses modern techniques to draw the same conclusions, by over a century. Similarly, Cook et al (2010) proposed a mechanism of lateral equilibration in cryoconite holes, but this was not an entirely new concept – Gerdel and Drouet (1960) alluded to widening of cryoconite holes in their paper over fifty years previously. Recent studies of cryoconite biodiversity using molecular techniques build on Steinbock’s (1936) and Charlesworth’s (1957) early-mid twentieth century optical microscope studies. Even large scale spatial variability in cryoconite microbiota was touched upon by Nansen in1891 who suggested that concentrations of biogenic glacier impurities decreased with distance from the ice margin on the Greenland ice sheet (reported in Nansen 1924), which was mirrored by recent studies by Hodson et al (2008), Yallop et al (2012), Stibal et al (2012) and Cook et al (2012). What modern glacial microbiology has done is put numbers on the old ideas – to turn what was qualitative into something quantitative, and to add detail. We have delicately coloured-in between the lines sketched out by the early explorers.
What faces us now is to examine glacial microbiological responses to environmental changes and links with climate. This post simply emphasises the amazing diligence and foresight of the early polar explorers in pre-empting 150 years of future science.
Bayley, W.S. 1891. Mineralogy and Petrography. The American Naturalist, 25 (290): 138-146
Cook, J.M., Hodson, A.J., Anesio, A.M., Hanna, E., Yallop, M., Stibal, M., Telling, J., Huybrechts, P. 2012. An improved estimate of microbially mediated carbon fluxes from the Greenland Ice Sheet. Journal of Glaciology, 58 (212)
Cook, J.; Hodson, A.; Telling, J.; Anesio, A.; Irvine-Fynn, T.; Bellas, C. 2010. The mass-area relationship within cryoconite holes and its implications for primary production. Annals of Glaciology, 51 (56): 106-110.
Charlesworth, J.K. (1957): The Quaternary Era 1. Edward Arnold, London. 1700 pp.
Drygalski, E. von. 1897. Die Kryokonitlocher. Gronland-expedition der Gesellschaftfur Erdkunde zu Berlin 1891-1893, Bd 1: 93-103
Gerdel, R.W., Drouet,
Gribbon, P.W.F. 1979. Cryoconite holes on Sermikavsak, West Greenland. Journal of Glaciology, 22 (86): 177-181
Hobbs, H. 1910. Characteristics of inland-ice of the Arctic regions. Proceedings of the American Philosophical Society, 49 (194): 57-129
Hodson, A.J., Boggild, C., Hanna, E., Huybrechts, P., Langford, H., Cameron, K., Houldsworth, A. 2011. The cryoconite ecosystem on the Greenland ice sheet. Annals of Glaciology,51 (56):123 – 129
Leslie, A., (1879) The Arctic Voyages of Adolf Erik Nordenskiöld. MacMillan and Co., London, UK, 447 pp.
Nansen, F., 1924: Blant sel og Bjørn. Dybwads, Oslo, trans. B. Bigelow.
Nordenskjold, N.E. (1875): Cryoconite found 1870, July 19th-25th, on the inland ice, east of Auleitsivik Fjord, Disco Bay, Greenland; Geol. Mag., Decade 2, 2, 157-162.
Nordenskiöld, A. E., 1883: Nordenskiöld on the inland ice of Greenland. Science, 2, 732–739.
Steinbock, O. 1936. Uber ktyokonitlocher und ihre biologische Bedeutung, Zeitschrift fur Gletschergrund, 24: 1-21
Wharton, R. A., McKay, C. P., Simmons, G. M., and Parker, B. C., 1985: Cryoconite holes on glaciers. BioScience, 35: 449-503.
Yallop, M.L., Anesio, A.J., Perkins, R.G., Cook, J., Telling, J., Fagan, D., MacFarlane, J., Stibal, M., Barker, G., Bellas, C., Hodson, A., Tranter, M., Wadham, J., Roberts, N.W. 2012. Photophysiology and albedo-changing potential of the ice-algal community on the surface of the Greenland ice sheet. ISME Journal, 6: 2302 – 2313