Short-term photoacclimation effects on photoinhibition of phytoplankton in the Drake Passage (Southern Ocean)

We assessed whether short-term photoacclimation responses of natural phytoplankton populations in the Drake Passage (Southern Ocean) were affecting protection from photodamage as cells are mixed up to the surface from depth. To this end, we measured phytoplankton fluorescence characteristics and the...

Full description

Bibliographic Details
Published in:Deep Sea Research Part I: Oceanographic Research Papers
Main Authors: Alderkamp, Anne-Carlijn, Garcon, Veronique, de Baar, Hein J. W., Arrigo, Kevin R.
Format: Article in Journal/Newspaper
Language:English
Published: 2011
Subjects:
Phytoplankton
Photoacclimation
Antarctic
Xanthophyll
Pigments
Upper mixed layer
NATURAL ULTRAVIOLET-RADIATION
PHOTOSYSTEM-II EFFICIENCY
ANTARCTIC MARINE DIATOM
UV-B RADIATION
CHLOROPHYLL FLUORESCENCE
PHAEOCYSTIS-ANTARCTICA
ENERGY-DISSIPATION
IRON LIMITATION
FRAGILARIOPSIS-CYLINDRUS
DIADINOXANTHIN CYCLE
Southern Ocean
Drake Passage
Antarc*
Antarctica
Online Access:https://hdl.handle.net/11370/bd821ef5-cb41-41d1-a8b2-c14a98ce5f4e
https://research.rug.nl/en/publications/bd821ef5-cb41-41d1-a8b2-c14a98ce5f4e
https://doi.org/10.1016/j.dsr.2011.07.001
Description
Summary:We assessed whether short-term photoacclimation responses of natural phytoplankton populations in the Drake Passage (Southern Ocean) were affecting protection from photodamage as cells are mixed up to the surface from depth. To this end, we measured phytoplankton fluorescence characteristics and their ratio of xanthophyll cycle pigment to photosynthetic pigments within the upper mixed layer (UML) and in short-term deck incubation experiments. Phytoplankton within the UML photoacclimated by increasing their ratio of xanthophyll cycle (diadinoxanthin [dd] and diatoxanthin [dt]) pigments to chlorophyll a. The photoacclimation processes observed within the UML did, however, not influence the protection of phytoplankton from photodamage during short-term near-surface irradiance experiments. Exposure to near-surface irradiance resulted in photodamage in all experiments, regardless of the phytoplankton community composition and irradiance levels. Incubating phytoplankton for six hours at either 2% or 50% of surface irradiance prior to exposure to near-surface irradiance did not alter the photodamage characteristics. This suggests that short-term photoacclimation processes within the UML are not adequate to protect phytoplankton from photodamage when cells are mixed up to the surface from depth, and that repair of damaged photosystems is crucial for maintaining photosynthesis under fluctuating irradiance conditions, even at very low mean irradiance levels. Likely, continuously operating photoacclimation processes offset to some extent the negative effects of photodamage on photosynthetic performance, albeit with increased metabolic costs. (C) 2011 Elsevier Ltd. All rights reserved.

Similar Items