Ice algal bloom development on the surface of the Greenland Ice Sheet

• Published in: FEMS Microbiology Ecology
• Main Authors: Williamson, Christopher, Anesio, Alexandre, Cook, J, Tedstone, Andrew, Poniecka, E, Holland, Alexandra, Fagan, Dan, Tranter, Martyn, Yallop, Marian
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2018
• Subjects: cyanobacteria; cryosphere; polar; alpine; genomics; Greenland; Ice Sheet
• Online Access: https://pure.au.dk/portal/da/publications/ice-algal-bloom-development-on-the-surface-of-the-greenland-ice-sheet(ded74683-5275-49a6-8ac7-33964cbc5c06).html; https://doi.org/10.1093/femsec/fiy025; http://www.scopus.com/inward/record.url?scp=85054828959&partnerID=8YFLogxK

It is fundamental to understand the development of Zygnematophycean (Streptophyte) micro-algal blooms within Greenland Ice Sheet (GrIS) supraglacial environments, given their potential to significantly impact both physical (melt) and chemical (carbon and nutrient cycling) surface characteristics. Here we report on a space-for-time assessment of a GrIS ice-algal bloom, achieved by sampling an ∼ 85 km transect spanning the south-western GrIS bare ice zone during the 2016 ablation season. Cell abundances ranged from 0 to 1.6 × 104 cells ml−1, with algal biomass demonstrated to increase in surface ice with time since snow line retreat (R2 = 0.73, P < 0.05). A suite of light harvesting and photo-protective pigments were quantified across transects (chlorophylls, carotenoids and phenols) and shown to increase in concert with algal biomass. Ice-algal communities drove net autotrophy of surface ice, with maximal rates of net production averaging 0.52 ± 0.04 mg C l−1 d−1, and a total accumulation of 1.306 Gg C (15.82 ± 8.14 kg C km−2) predicted for the 2016 ablation season across an 8.24 × 104 km2 region of the GrIS. By advancing our understanding of ice-algal bloom development, this study marks an important step toward projecting bloom occurrence and impacts into the future.