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Scientific article
English

Biological- and physical-induced oxygen dynamics in melting sea ice of the Fram Strait

Contributors

Glud, Ronnie N.; Rysgaard, Søren; Turner, Gavin; McGinnis, Daniel Frank; Leakey, Raymond J. G.

Published in

Limnology and oceanography, vol. 59, no. 4, p. 1097-1111

Publication date

2014

Abstract

We investigated the production, consumption, and exchange of O 2 in melting sea ice to assess the biological-and physical-induced O 2 turnover. The underside of the ice was covered with 5–20 cm 3 large, buoyant algal aggregates. Their gross primary production amounted to 0.49 mmol C m 22 d 21 , which was 4.5 times higher than the primary production of sea ice–encrusted microalgae (0.11 mmol C m 22 d 21). The phototrophic biomass of the aggregates (2.94 mg chlorophyll a m 22) was six times higher than that encountered in the sea ice itself. Taxono-specific investigations strongly suggest that the aggregates were formed from agglutinated algae released from the melting ice. At the prevailing light conditions, the sea ice–encrusted communities were almost at metabolic balance, while the aggregates were net heterotrophic. Together, the two communities were responsible for an overall O 2 consumption of 0.32 mmol m 22 d 21 . The sea ice–associated communities thereby represent a southward-drifting carbon source that is being exhausted by sea ice–affiliated food webs. The sea ice volume decreased rapidly, releasing meltwater at a rate 25 L m 22 d 21 , but no surface melt ponds were formed. Aquatic eddy correlation (EC) measurements on the underside of the ice revealed a light-dependent O 2 exchange rate. However, the integrated signal resolved a net O 2 uptake of 7.70 mmol m 22 d 21 . The net O 2 exchange was therefore dominated by the production of O 2 -depleted meltwater rather than biological activity. The EC technique represents a new non-invasive tool for O 2 studies in sea ice communities.

Keywords

  • Eddy correlation
  • Arctic
  • Sea-ice
  • Dissolved oxygen

UNIGE affiliation entities

Not a UNIGE publication

Citation (ISO format)

GLUD, Ronnie N. et al. Biological- and physical-induced oxygen dynamics in melting sea ice of the Fram Strait. In: Limnology and oceanography, 2014, vol. 59, n° 4, p. 1097–1111. doi: 10.4319/lo.2014.59.4.1097

Main files (1)

Article (Published version)

Identifiers

Additional URL for this publication

http://www.aslo.org/lo/toc/vol_59/issue_4/1097.html

Journal ISSN

0024-3590
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Technical informations

Creation

02/10/2014 15:30:00

First validation

02/10/2014 15:30:00

Update

14/03/2023 21:49:21

Status update

14/03/2023 21:49:21

Last indexation

30/10/2024 20:14:21
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