A laboratory study on O 2 dynamics and photosynthesis in ice algal communities: Quantification by microsensors, O 2 exchange rates, 14 C incubations and a PAM fluorometer
The present study compared O2 exchange measurements, fluorometry and 14c incubations for measuring productivity of sea-ice algae. It is demonstrated that brine leaking out of ice during freezing conditions is supersaturated with respect to O2, while the melting water released during thawing is under...
Main Authors: | , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
2002
|
Subjects: | |
Online Access: | http://hdl.handle.net/10453/14801 |
id |
ftunivtsydney:oai:opus.lib.uts.edu.au:10453/14801 |
---|---|
record_format |
openpolar |
spelling |
ftunivtsydney:oai:opus.lib.uts.edu.au:10453/14801 2023-05-15T16:36:34+02:00 A laboratory study on O 2 dynamics and photosynthesis in ice algal communities: Quantification by microsensors, O 2 exchange rates, 14 C incubations and a PAM fluorometer Glud, RN Rysgaard, S Kühl, M 2002-04-16 application/pdf http://hdl.handle.net/10453/14801 unknown Aquatic Microbial Ecology 10.3354/ame027301 Aquatic Microbial Ecology, 2002, 27 (3), pp. 301 - 311 0948-3055 http://hdl.handle.net/10453/14801 Marine Biology & Hydrobiology Journal Article 2002 ftunivtsydney 2022-03-13T14:05:32Z The present study compared O2 exchange measurements, fluorometry and 14c incubations for measuring productivity of sea-ice algae. It is demonstrated that brine leaking out of ice during freezing conditions is supersaturated with respect to O2, while the melting water released during thawing is undersaturated with O2. This results in a highly variable O2 concentration at the ice-water interface during expanding or shrinking of sea ice. Consequently, great care should be taken when inferring biological activity from O2 exchange rates, whether they are obtained via microprofiles, bulk incubations or direct measurement of O2 concentrations in water below sea ice. Accounting for the O2 dynamics related to changes in sea-ice structure, the photosynthetic activity of a mixed ice algal culture, as measured by net O2 exchange rates and 14C incubation, co-varied as a function of biomass and irradiance. The ratio between the net O2 efflux and the gross C fixation rate (the photosynthetic quotient) was similar for frozen and non-frozen ice algal communities and averaged 1.43 ± 0.48. Quantification of the relative electron transport rate (ETR) from photosystem II (PSII) and the minimum fluorescence yield (F0) by a pulse-amplitude-modulated (PAM) fluorometer offers a fast, simple and non-invasive approach for estimating activity and biomass of ice algal communities. The relative ETR measurements correlated with the other 2 measures for primary production. However, the correlation was non-linear, leading to a poor resolution of the fluorometer approach at higher photosynthetic activities. A similar observation was made for the correlation between measurements and the concentration of chlorophyll a. Article in Journal/Newspaper ice algae Sea ice University of Technology Sydney: OPUS - Open Publications of UTS Scholars |
institution |
Open Polar |
collection |
University of Technology Sydney: OPUS - Open Publications of UTS Scholars |
op_collection_id |
ftunivtsydney |
language |
unknown |
topic |
Marine Biology & Hydrobiology |
spellingShingle |
Marine Biology & Hydrobiology Glud, RN Rysgaard, S Kühl, M A laboratory study on O 2 dynamics and photosynthesis in ice algal communities: Quantification by microsensors, O 2 exchange rates, 14 C incubations and a PAM fluorometer |
topic_facet |
Marine Biology & Hydrobiology |
description |
The present study compared O2 exchange measurements, fluorometry and 14c incubations for measuring productivity of sea-ice algae. It is demonstrated that brine leaking out of ice during freezing conditions is supersaturated with respect to O2, while the melting water released during thawing is undersaturated with O2. This results in a highly variable O2 concentration at the ice-water interface during expanding or shrinking of sea ice. Consequently, great care should be taken when inferring biological activity from O2 exchange rates, whether they are obtained via microprofiles, bulk incubations or direct measurement of O2 concentrations in water below sea ice. Accounting for the O2 dynamics related to changes in sea-ice structure, the photosynthetic activity of a mixed ice algal culture, as measured by net O2 exchange rates and 14C incubation, co-varied as a function of biomass and irradiance. The ratio between the net O2 efflux and the gross C fixation rate (the photosynthetic quotient) was similar for frozen and non-frozen ice algal communities and averaged 1.43 ± 0.48. Quantification of the relative electron transport rate (ETR) from photosystem II (PSII) and the minimum fluorescence yield (F0) by a pulse-amplitude-modulated (PAM) fluorometer offers a fast, simple and non-invasive approach for estimating activity and biomass of ice algal communities. The relative ETR measurements correlated with the other 2 measures for primary production. However, the correlation was non-linear, leading to a poor resolution of the fluorometer approach at higher photosynthetic activities. A similar observation was made for the correlation between measurements and the concentration of chlorophyll a. |
format |
Article in Journal/Newspaper |
author |
Glud, RN Rysgaard, S Kühl, M |
author_facet |
Glud, RN Rysgaard, S Kühl, M |
author_sort |
Glud, RN |
title |
A laboratory study on O 2 dynamics and photosynthesis in ice algal communities: Quantification by microsensors, O 2 exchange rates, 14 C incubations and a PAM fluorometer |
title_short |
A laboratory study on O 2 dynamics and photosynthesis in ice algal communities: Quantification by microsensors, O 2 exchange rates, 14 C incubations and a PAM fluorometer |
title_full |
A laboratory study on O 2 dynamics and photosynthesis in ice algal communities: Quantification by microsensors, O 2 exchange rates, 14 C incubations and a PAM fluorometer |
title_fullStr |
A laboratory study on O 2 dynamics and photosynthesis in ice algal communities: Quantification by microsensors, O 2 exchange rates, 14 C incubations and a PAM fluorometer |
title_full_unstemmed |
A laboratory study on O 2 dynamics and photosynthesis in ice algal communities: Quantification by microsensors, O 2 exchange rates, 14 C incubations and a PAM fluorometer |
title_sort |
laboratory study on o 2 dynamics and photosynthesis in ice algal communities: quantification by microsensors, o 2 exchange rates, 14 c incubations and a pam fluorometer |
publishDate |
2002 |
url |
http://hdl.handle.net/10453/14801 |
genre |
ice algae Sea ice |
genre_facet |
ice algae Sea ice |
op_relation |
Aquatic Microbial Ecology 10.3354/ame027301 Aquatic Microbial Ecology, 2002, 27 (3), pp. 301 - 311 0948-3055 http://hdl.handle.net/10453/14801 |
_version_ |
1766026908921757696 |