An alternative method for correcting fluorescence quenching
Under high light intensity, phytoplankton protect their photosystems from bleaching through non-photochemical quenching processes. The consequence of this is suppression of fluorescence emission, which must be corrected when measuring in situ yield with fluorometers. We present data from the Souther...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2015-01-01
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| Series: | Ocean Science |
| Online Access: | http://www.ocean-sci.net/11/83/2015/os-11-83-2015.pdf |
| _version_ | 1798046218744496128 |
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| author | L. Biermann C. Guinet M. Bester A. Brierley L. Boehme |
| author_facet | L. Biermann C. Guinet M. Bester A. Brierley L. Boehme |
| author_sort | L. Biermann |
| collection | DOAJ |
| description | Under high light intensity, phytoplankton protect their photosystems from
bleaching through non-photochemical quenching processes. The consequence of
this is suppression of fluorescence emission, which must be corrected when
measuring in situ yield with fluorometers. We present data from the Southern Ocean,
collected over five austral summers by 19 southern elephant seals
tagged with fluorometers. Conventionally, fluorescence data collected during
the day (quenched) were corrected using the limit of the mixed layer, assuming
that phytoplankton are uniformly mixed from the surface to this depth.
However, distinct deep fluorescence maxima were measured in approximately
30% of the night (unquenched) data. To account for the evidence that
chlorophyll is not uniformly mixed in the upper layer, we propose correcting
from the limit of the euphotic zone, defined as the depth at which
photosynthetically available radiation is ~ 1% of the
surface value. Mixed layer depth exceeded euphotic depth over 80% of the
time. Under these conditions, quenching was corrected from the depth of the
remotely derived euphotic zone <i>Z</i><sub>eu</sub>, and compared with fluorescence
corrected from the depth of the density-derived mixed layer. Deep
fluorescence maxima were evident in only 10% of the day data when
correcting from mixed layer depth. This was doubled to 21% when
correcting from <i>Z</i><sub>eu</sub>, more closely matching the unquenched (night) data.
Furthermore, correcting from <i>Z</i><sub>eu</sub> served to conserve non-uniform
chlorophyll
features found between the 1% light level and mixed layer depth. |
| first_indexed | 2024-04-11T23:33:57Z |
| format | Article |
| id | doaj.art-de73be1d08094651abc76b4573a52dfc |
| institution | Directory Open Access Journal |
| issn | 1812-0784 1812-0792 |
| language | English |
| last_indexed | 2024-04-11T23:33:57Z |
| publishDate | 2015-01-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Ocean Science |
| spelling | doaj.art-de73be1d08094651abc76b4573a52dfc2022-12-22T03:57:00ZengCopernicus PublicationsOcean Science1812-07841812-07922015-01-01111839110.5194/os-11-83-2015An alternative method for correcting fluorescence quenchingL. Biermann0C. Guinet1M. Bester2A. Brierley3L. Boehme4Sea Mammal Research Unit, Scottish Oceans Institute, St. Andrews, UKCentre National de la Recherche Scientifique, Centre d'Etudes Biologiques de Chizé, Villiers en Bois, FranceMammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South AfricaPelagic Ecology Research Group, Scottish Oceans Institute, St. Andrews, UKSea Mammal Research Unit, Scottish Oceans Institute, St. Andrews, UKUnder high light intensity, phytoplankton protect their photosystems from bleaching through non-photochemical quenching processes. The consequence of this is suppression of fluorescence emission, which must be corrected when measuring in situ yield with fluorometers. We present data from the Southern Ocean, collected over five austral summers by 19 southern elephant seals tagged with fluorometers. Conventionally, fluorescence data collected during the day (quenched) were corrected using the limit of the mixed layer, assuming that phytoplankton are uniformly mixed from the surface to this depth. However, distinct deep fluorescence maxima were measured in approximately 30% of the night (unquenched) data. To account for the evidence that chlorophyll is not uniformly mixed in the upper layer, we propose correcting from the limit of the euphotic zone, defined as the depth at which photosynthetically available radiation is ~ 1% of the surface value. Mixed layer depth exceeded euphotic depth over 80% of the time. Under these conditions, quenching was corrected from the depth of the remotely derived euphotic zone <i>Z</i><sub>eu</sub>, and compared with fluorescence corrected from the depth of the density-derived mixed layer. Deep fluorescence maxima were evident in only 10% of the day data when correcting from mixed layer depth. This was doubled to 21% when correcting from <i>Z</i><sub>eu</sub>, more closely matching the unquenched (night) data. Furthermore, correcting from <i>Z</i><sub>eu</sub> served to conserve non-uniform chlorophyll features found between the 1% light level and mixed layer depth.http://www.ocean-sci.net/11/83/2015/os-11-83-2015.pdf |
| spellingShingle | L. Biermann C. Guinet M. Bester A. Brierley L. Boehme An alternative method for correcting fluorescence quenching Ocean Science |
| title | An alternative method for correcting fluorescence quenching |
| title_full | An alternative method for correcting fluorescence quenching |
| title_fullStr | An alternative method for correcting fluorescence quenching |
| title_full_unstemmed | An alternative method for correcting fluorescence quenching |
| title_short | An alternative method for correcting fluorescence quenching |
| title_sort | alternative method for correcting fluorescence quenching |
| url | http://www.ocean-sci.net/11/83/2015/os-11-83-2015.pdf |
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