In situ seagrass photosynthesis measured using a submersible, pulse-amplitude modulated fluorometer
Assessments of photosynthetic activity in marine plants can now be made in situ using a newly developed, submersible, pulse-amplitude modulated (PAM) fluorometer: Diving-PAM. PAM fluorometry provides a measure of chlorophyll a fluorescence using rapid-light curves in which the electron-transport rat...
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Language: | English |
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Springer Science and Business Media LLC
1998
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Online Access: | https://espace.library.uq.edu.au/view/UQ:2dcc88c |
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ftunivqespace:oai:espace.library.uq.edu.au:UQ:2dcc88c 2023-05-15T13:39:41+02:00 In situ seagrass photosynthesis measured using a submersible, pulse-amplitude modulated fluorometer Ralph, P. J. Gademann, R. Dennison, W. C. 1998-10-01 https://espace.library.uq.edu.au/view/UQ:2dcc88c eng eng Springer Science and Business Media LLC doi:10.1007/s002270050403 issn:0025-3162 Ecology Aquatic Science Evolution Behavior and Systematics 1104 Aquatic Science 1105 Ecology 2303 Ecology Journal Article 1998 ftunivqespace https://doi.org/10.1007/s002270050403 2020-10-13T00:58:28Z Assessments of photosynthetic activity in marine plants can now be made in situ using a newly developed, submersible, pulse-amplitude modulated (PAM) fluorometer: Diving-PAM. PAM fluorometry provides a measure of chlorophyll a fluorescence using rapid-light curves in which the electron-transport rate can be determined for plants exposed to ambient light conditions. This technique was used to compare the photosynthetic responses of seagrasses near Rottnest Island, Western Australia. Several fluorescence parameters were measured as a function of time of day and water depth; electron-transport rate (ETR), quantum yield, photochemical quenching and non-photochemical quenching and Photosystem II (PSII) photochemical efficiency (F(v):F(m) ratio) were measured. Results indicate that recent light-history plays a crucial role in seagrass photosynthetic responses. Maximum ETR of Posidonia australis, Amphibolis antarctica and Halophila ovalis is influenced by the irradiance during the diurnal cycle, with low rates at dawn and dusk (< 10 μmol electron m s), highest rates in late morning (40 to 60 μmol electron m s) and a mid-day depression. Maximum ETR and PSII photochemical efficiency varied widely between seagrass species and were not correlated. A comparison of photochemical to non-photochemical quenching indicated that seagrasses in shallow water receiving high light have a high capacity for non-photochemical quenching (e.g. light protection) compared to seagrasses in deep water. These results indicate that in situ measurements of photosynthesis will provide new insights into the mechanisms and adaptive responses of marine plants. Article in Journal/Newspaper Antarc* Antarctica The University of Queensland: UQ eSpace Marine Biology 132 3 367 373 |
institution |
Open Polar |
collection |
The University of Queensland: UQ eSpace |
op_collection_id |
ftunivqespace |
language |
English |
topic |
Ecology Aquatic Science Evolution Behavior and Systematics 1104 Aquatic Science 1105 Ecology 2303 Ecology |
spellingShingle |
Ecology Aquatic Science Evolution Behavior and Systematics 1104 Aquatic Science 1105 Ecology 2303 Ecology Ralph, P. J. Gademann, R. Dennison, W. C. In situ seagrass photosynthesis measured using a submersible, pulse-amplitude modulated fluorometer |
topic_facet |
Ecology Aquatic Science Evolution Behavior and Systematics 1104 Aquatic Science 1105 Ecology 2303 Ecology |
description |
Assessments of photosynthetic activity in marine plants can now be made in situ using a newly developed, submersible, pulse-amplitude modulated (PAM) fluorometer: Diving-PAM. PAM fluorometry provides a measure of chlorophyll a fluorescence using rapid-light curves in which the electron-transport rate can be determined for plants exposed to ambient light conditions. This technique was used to compare the photosynthetic responses of seagrasses near Rottnest Island, Western Australia. Several fluorescence parameters were measured as a function of time of day and water depth; electron-transport rate (ETR), quantum yield, photochemical quenching and non-photochemical quenching and Photosystem II (PSII) photochemical efficiency (F(v):F(m) ratio) were measured. Results indicate that recent light-history plays a crucial role in seagrass photosynthetic responses. Maximum ETR of Posidonia australis, Amphibolis antarctica and Halophila ovalis is influenced by the irradiance during the diurnal cycle, with low rates at dawn and dusk (< 10 μmol electron m s), highest rates in late morning (40 to 60 μmol electron m s) and a mid-day depression. Maximum ETR and PSII photochemical efficiency varied widely between seagrass species and were not correlated. A comparison of photochemical to non-photochemical quenching indicated that seagrasses in shallow water receiving high light have a high capacity for non-photochemical quenching (e.g. light protection) compared to seagrasses in deep water. These results indicate that in situ measurements of photosynthesis will provide new insights into the mechanisms and adaptive responses of marine plants. |
format |
Article in Journal/Newspaper |
author |
Ralph, P. J. Gademann, R. Dennison, W. C. |
author_facet |
Ralph, P. J. Gademann, R. Dennison, W. C. |
author_sort |
Ralph, P. J. |
title |
In situ seagrass photosynthesis measured using a submersible, pulse-amplitude modulated fluorometer |
title_short |
In situ seagrass photosynthesis measured using a submersible, pulse-amplitude modulated fluorometer |
title_full |
In situ seagrass photosynthesis measured using a submersible, pulse-amplitude modulated fluorometer |
title_fullStr |
In situ seagrass photosynthesis measured using a submersible, pulse-amplitude modulated fluorometer |
title_full_unstemmed |
In situ seagrass photosynthesis measured using a submersible, pulse-amplitude modulated fluorometer |
title_sort |
in situ seagrass photosynthesis measured using a submersible, pulse-amplitude modulated fluorometer |
publisher |
Springer Science and Business Media LLC |
publishDate |
1998 |
url |
https://espace.library.uq.edu.au/view/UQ:2dcc88c |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_relation |
doi:10.1007/s002270050403 issn:0025-3162 |
op_doi |
https://doi.org/10.1007/s002270050403 |
container_title |
Marine Biology |
container_volume |
132 |
container_issue |
3 |
container_start_page |
367 |
op_container_end_page |
373 |
_version_ |
1766122195734495232 |