Observations of late-winter marine microbial activity in an ice-covered fjord, west Greenland

• Published in: Earth System Science Data
• Main Authors: D. Chandler, S. Mackie
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2020
• Subjects: Environmental sciences; GE1-350; Geology; QE1-996.5; Arctic; Greenland; polar night; Sea ice
• Online Access: https://doi.org/10.5194/essd-12-897-2020; https://doaj.org/article/e106eeeffda74a559bb394f943416f96

Direct observations of marine microbial metabolism are sparse in the Arctic, particularly under sea ice during winter. This paper presents the first observations of Arctic winter microbial activity under sea ice in a west Greenland fjord (Lillefjord, ∼ 70 ∘ N). Here, measured changes in dissolved oxygen (DO) content in light and dark in situ incubations were used to calculate net community productivity, respiration and photosynthesis rates. Data were collected at two fully ice covered sites during February 2013, shortly after the end of the polar night. Averaged over the full study period, dark incubations showed statistically significant decreases in DO of <math xmlns="http://www.w3.org/1998/Math/MathML" id="M3" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">0.36</mn><mo>±</mo><mn mathvariant="normal">0.24</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="64pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="5fff6923f9e55cfcaf93eb4211138c29"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="essd-12-897-2020-ie00001.svg" width="64pt" height="10pt" src="essd-12-897-2020-ie00001.png"/></svg:svg> (near shore) and <math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>-</mo><mn mathvariant="normal">0.09</mn><mo>±</mo><mn mathvariant="normal">0.07</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="64pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="fe73e5e154e0ac55a702a96f7c8f6364"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="essd-12-897-2020-ie00002.svg" width="64pt" height="10pt" src="essd-12-897-2020-ie00002.png"/></svg:svg> g O 2 m −3 d −1 (fjord centre), indicating respiration rates that were 2–20 times greater than ...