Diel quenching of Southern Ocean phytoplankton fluorescence is related to iron limitation
Evaluation of photosynthetic competency in time and space is critical forbetter estimates and models of oceanic primary productivity. This isespecially true for areas where the lack of iron (Fe) limits phytoplanktonproductivity, such as the Southern Ocean. Assessment of photosyntheticcompetency on l...
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Online Access: | https://doi.org/10.5194/bg-17-793-2020 http://ecite.utas.edu.au/137508 |
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ftunivtasecite:oai:ecite.utas.edu.au:137508 2023-05-15T18:25:11+02:00 Diel quenching of Southern Ocean phytoplankton fluorescence is related to iron limitation Schallenberg, C Strzepek, RF Schuback, N Clementson, LA Boyd, PW Trull, TW 2020 application/pdf https://doi.org/10.5194/bg-17-793-2020 http://ecite.utas.edu.au/137508 en eng Copernicus GmbH http://ecite.utas.edu.au/137508/1/137508 - Diel quenching of Southern Ocean phytoplankton fluorescence.pdf http://dx.doi.org/10.5194/bg-17-793-2020 Schallenberg, C and Strzepek, RF and Schuback, N and Clementson, LA and Boyd, PW and Trull, TW, Diel quenching of Southern Ocean phytoplankton fluorescence is related to iron limitation, Biogeosciences, 17 pp. 783-812. ISSN 1726-4170 (2020) [Refereed Article] http://ecite.utas.edu.au/137508 Earth Sciences Oceanography Biological oceanography Refereed Article PeerReviewed 2020 ftunivtasecite https://doi.org/10.5194/bg-17-793-2020 2022-08-29T22:17:53Z Evaluation of photosynthetic competency in time and space is critical forbetter estimates and models of oceanic primary productivity. This isespecially true for areas where the lack of iron (Fe) limits phytoplanktonproductivity, such as the Southern Ocean. Assessment of photosyntheticcompetency on large scales remains challenging, but phytoplanktonchlorophyll a fluorescence (ChlF) is a signal that holds promise in thisrespect as it is affected by, and consequently provides information about,the photosynthetic efficiency of the organism. A second process affectingthe ChlF signal is heat dissipation of absorbed light energy, referred to asnon-photochemical quenching (NPQ). NPQ is triggered when excess energy isabsorbed, i.e. when more light is absorbed than can be used directly forphotosynthetic carbon fixation. The effect of NPQ on the ChlF signalcomplicates its interpretation in terms of photosynthetic efficiency, andtherefore most approaches relating ChlF parameters to photosyntheticefficiency seek to minimize the influence of NPQ by working under conditionsof sub-saturating irradiance. Here, we propose that NPQ itself holdspotential as an easily acquired optical signal indicative of phytoplanktonphysiological state with respect to Fe limitation. We present data from a research voyage to the Subantarctic Zone south ofAustralia. Incubation experiments confirmed that resident phytoplankton wereFe-limited, as the maximum quantum yield of primary photochemistry, F v ∕ F m ,measured with a fast repetition rate fluorometer (FRRf), increasedsignificantly with Fe addition. The NPQ capacity of the phytoplanktonalso showed sensitivity to Fe addition, decreasing with increased Feavailability, confirming previous work. The fortuitous presence of a remnantwarm-core eddy in the vicinity of the study area allowed comparison offluorescence behaviour between two distinct water masses, with the colderwater showing significantly lower F v ∕ F m than the warmer eddy waters,suggesting a difference in Fe limitation status between ... Article in Journal/Newspaper Southern Ocean eCite UTAS (University of Tasmania) Southern Ocean Biogeosciences 17 3 793 812 |
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Earth Sciences Oceanography Biological oceanography Schallenberg, C Strzepek, RF Schuback, N Clementson, LA Boyd, PW Trull, TW Diel quenching of Southern Ocean phytoplankton fluorescence is related to iron limitation |
topic_facet |
Earth Sciences Oceanography Biological oceanography |
description |
Evaluation of photosynthetic competency in time and space is critical forbetter estimates and models of oceanic primary productivity. This isespecially true for areas where the lack of iron (Fe) limits phytoplanktonproductivity, such as the Southern Ocean. Assessment of photosyntheticcompetency on large scales remains challenging, but phytoplanktonchlorophyll a fluorescence (ChlF) is a signal that holds promise in thisrespect as it is affected by, and consequently provides information about,the photosynthetic efficiency of the organism. A second process affectingthe ChlF signal is heat dissipation of absorbed light energy, referred to asnon-photochemical quenching (NPQ). NPQ is triggered when excess energy isabsorbed, i.e. when more light is absorbed than can be used directly forphotosynthetic carbon fixation. The effect of NPQ on the ChlF signalcomplicates its interpretation in terms of photosynthetic efficiency, andtherefore most approaches relating ChlF parameters to photosyntheticefficiency seek to minimize the influence of NPQ by working under conditionsof sub-saturating irradiance. Here, we propose that NPQ itself holdspotential as an easily acquired optical signal indicative of phytoplanktonphysiological state with respect to Fe limitation. We present data from a research voyage to the Subantarctic Zone south ofAustralia. Incubation experiments confirmed that resident phytoplankton wereFe-limited, as the maximum quantum yield of primary photochemistry, F v ∕ F m ,measured with a fast repetition rate fluorometer (FRRf), increasedsignificantly with Fe addition. The NPQ capacity of the phytoplanktonalso showed sensitivity to Fe addition, decreasing with increased Feavailability, confirming previous work. The fortuitous presence of a remnantwarm-core eddy in the vicinity of the study area allowed comparison offluorescence behaviour between two distinct water masses, with the colderwater showing significantly lower F v ∕ F m than the warmer eddy waters,suggesting a difference in Fe limitation status between ... |
format |
Article in Journal/Newspaper |
author |
Schallenberg, C Strzepek, RF Schuback, N Clementson, LA Boyd, PW Trull, TW |
author_facet |
Schallenberg, C Strzepek, RF Schuback, N Clementson, LA Boyd, PW Trull, TW |
author_sort |
Schallenberg, C |
title |
Diel quenching of Southern Ocean phytoplankton fluorescence is related to iron limitation |
title_short |
Diel quenching of Southern Ocean phytoplankton fluorescence is related to iron limitation |
title_full |
Diel quenching of Southern Ocean phytoplankton fluorescence is related to iron limitation |
title_fullStr |
Diel quenching of Southern Ocean phytoplankton fluorescence is related to iron limitation |
title_full_unstemmed |
Diel quenching of Southern Ocean phytoplankton fluorescence is related to iron limitation |
title_sort |
diel quenching of southern ocean phytoplankton fluorescence is related to iron limitation |
publisher |
Copernicus GmbH |
publishDate |
2020 |
url |
https://doi.org/10.5194/bg-17-793-2020 http://ecite.utas.edu.au/137508 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
http://ecite.utas.edu.au/137508/1/137508 - Diel quenching of Southern Ocean phytoplankton fluorescence.pdf http://dx.doi.org/10.5194/bg-17-793-2020 Schallenberg, C and Strzepek, RF and Schuback, N and Clementson, LA and Boyd, PW and Trull, TW, Diel quenching of Southern Ocean phytoplankton fluorescence is related to iron limitation, Biogeosciences, 17 pp. 783-812. ISSN 1726-4170 (2020) [Refereed Article] http://ecite.utas.edu.au/137508 |
op_doi |
https://doi.org/10.5194/bg-17-793-2020 |
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Biogeosciences |
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17 |
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