TY - JOUR
T1 - Bacterial Dynamics in Supraglacial Habitats of the Greenland Ice Sheet
AU - Nicholes, Miranda Jane
AU - Williamson, Christopher James
AU - Tranter, Martyn
AU - Holland, Alexandra
AU - Poniecka, Ewa
AU - Yallop, Marian Louise
AU - Black and Bloom Team
AU - Irvine-Fynn, Tristram
AU - Anesio, Alexandre
N1 - Funding Information:
This work was funded as part of the UK Natural Environment Research Council Consortium Grant “Black and Bloom” (NE/M021025/1).
Funding Information:
The authors thank and acknowledge the entire Black & Bloom team, especially those involved in the 2016 and 2017 field seasons. Paul Newcomb and Dagmara Szmigiel (Bristol Medical School, Department of Translational Health Sciences) are thanked for their assistance with leucine analysis. The authors also acknowledge support from the MicroArctic Innovative Training Network (European Commission’s Marie Sklowdowska Curie Actions program, project 675546).
Publisher Copyright:
Copyright © 2019 Nicholes, Williamson, Tranter, Holland, Poniecka, Yallop, The Black & Bloom Group and Anesio. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
PY - 2019/7/3
Y1 - 2019/7/3
N2 - Current research into bacterial dynamics on the Greenland Ice Sheet (GrIS) is biased toward cryoconite holes, despite this habitat covering less than 8% of the ablation (melt) zone surface. In contrast, the expansive surface ice, which supports wide-spread Streptophyte micro-algal blooms thought to enhance surface melt, has been relatively neglected. This study aims to understand variability in bacterial abundance and production across an ablation season on the GrIS, in relation to micro-algal bloom dynamics. Bacterial abundance reached 3.3 ± 0.3 × 10
5 cells ml
-1 in surface ice and was significantly linearly related to algal abundances during the middle and late ablation periods (
R
2 = 0.62,
p < 0.05;
R
2 = 0.78,
p < 0.001). Bacterial production (BP) of 0.03-0.6 μg C L
-1 h
-1 was observed in surface ice and increased in concert with glacier algal abundances, indicating that heterotrophic bacteria consume algal-derived dissolved organic carbon. However, BP remained at least 28 times lower than net primary production, indicating inefficient carbon cycling by heterotrophic bacteria and net accumulation of carbon in surface ice throughout the ablation season. Across the supraglacial environment, cryoconite sediment BP was at least four times greater than surface ice, confirming that cryoconite holes are the true "hot spots" of heterotrophic bacterial activity.
AB - Current research into bacterial dynamics on the Greenland Ice Sheet (GrIS) is biased toward cryoconite holes, despite this habitat covering less than 8% of the ablation (melt) zone surface. In contrast, the expansive surface ice, which supports wide-spread Streptophyte micro-algal blooms thought to enhance surface melt, has been relatively neglected. This study aims to understand variability in bacterial abundance and production across an ablation season on the GrIS, in relation to micro-algal bloom dynamics. Bacterial abundance reached 3.3 ± 0.3 × 10
5 cells ml
-1 in surface ice and was significantly linearly related to algal abundances during the middle and late ablation periods (
R
2 = 0.62,
p < 0.05;
R
2 = 0.78,
p < 0.001). Bacterial production (BP) of 0.03-0.6 μg C L
-1 h
-1 was observed in surface ice and increased in concert with glacier algal abundances, indicating that heterotrophic bacteria consume algal-derived dissolved organic carbon. However, BP remained at least 28 times lower than net primary production, indicating inefficient carbon cycling by heterotrophic bacteria and net accumulation of carbon in surface ice throughout the ablation season. Across the supraglacial environment, cryoconite sediment BP was at least four times greater than surface ice, confirming that cryoconite holes are the true "hot spots" of heterotrophic bacterial activity.
KW - Bacterial abundance
KW - Bacterial production
KW - Glacier algae
KW - Greenland
KW - Ice sheet
UR - http://www.scopus.com/inward/record.url?scp=85068960179&partnerID=8YFLogxK
U2 - 10.3389/fmicb.2019.01366
DO - 10.3389/fmicb.2019.01366
M3 - Article
C2 - 31333595
SN - 1664-302X
VL - 10
JO - Frontiers in Microbiology
JF - Frontiers in Microbiology
IS - JUL
M1 - 1366
ER -