The effect of elevated levels of phaeophytin in natural water on variable fluorescence measured from phytoplankton

Variable fluorescence methods are becoming popular in studies related to aquatic photosynthesis. In natural ocean water, phytoplankton co-exist with their zooplankton and flagellate predators, viral parasites and the waste products of digested phytoplankton cells that contain phaeophytin (a chromo-p...

Full description

Saved in:
Bibliographic Details
Published in:Journal of plankton research 2002-11, Vol.24 (11), p.1221-1229
Main Authors: Fuchs, Eran, Zimmerman, Richard C., Jaffe, Jules S.
Format: Article
Language:English
Subjects:
Algae
Animal, plant and microbial ecology
Biological and medical sciences
Brackish
Chlorophyll
Chlorophylls
Coastal waters
Fluorescence
Fluorometry
Fundamental and applied biological sciences. Psychology
General aspects. Techniques
Levels
Marine
Methods and techniques (sampling, tagging, trapping, modelling...)
Parasites
Phaeophytin
Photochemistry
Photosynthesis
Photosystem
Phytoplankton
Predators
Presenilin 2
Sea water
Zooplankton
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Variable fluorescence methods are becoming popular in studies related to aquatic photosynthesis. In natural ocean water, phytoplankton co-exist with their zooplankton and flagellate predators, viral parasites and the waste products of digested phytoplankton cells that contain phaeophytin (a chromo-phore produced by digestion of chlorophyll a). Fast repetition rate fluorometry, a technique mainly applied in phytoplankton studies, was used to evaluate and quantify the effect of phaeophytin abundance in sea water on variable fluorescence parameters: the photochemical quantum yield, ΦF (also known as Fv/Fm), and the functional cross-section of photosystem 2 (PS2), σPS2. If the value of ΦF determined is lower than what it actually is, phytoplankton may be labeled as less healthy (or productive) than their true condition. Results were compared with data collected using another widely used variable fluorescence technique: pulse amplitude modulation (PAM). Our study concludes that for significantly elevated levels of phaeophytin in the water, the measured values of ΦF should be corrected to avoid misinterpretation. This conclusion is independent of the measuring instrument. In waters with phaeophytin levels that constitute less than ∼30% of the total measured pigment, no correction is required (
ISSN:0142-7873
1464-3774
1464-3774
DOI:10.1093/plankt/24.11.1221