Premium
Chlorophyll content and fluorescence responses cannot be used to gauge reliably phytoplankton biomass, nutrient status or growth rate
Author(s) -
Kruskopf Mikaela,
Flynn Kevin J.
Publication year - 2006
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2005.01601.x
Subject(s) - nutrient , phytoplankton , chlorophyll a , biomass (ecology) , biology , photosystem ii , photosynthesis , chlorophyll , botany , ecology
Summary• To consider the relationship between chlorophyll a (Chl a ) content and phytoplankton growth and nutrient status, four phytoplankton species were grown in nitrogen (N)‐limited [and, for one species, phosphorus (P)‐limited] culture and measurements were made of CNP biomass, in vivo and in vitro Chl a content, the ratio of variable to maximum fluorescence ( F V / F M ) and the performance index for photosynthesis, PI ABS (a derivative of the O‐J‐I‐P analysis of photosystem II functionality). • Interspecies differences plus the development of intraspecies differences during nutrient stress produced c . 10‐fold variations in Chl : C. Estimates of C from in vivo Chl content were better than those from extracted Chl content, as the decline in Chl : C during nutrient stress was offset in part by increased Chl fluorescence. • FV / F M was not a robust indicator of nutrient status or relative growth rate. Responses of F V / F M in cells re‐fed the limiting nutrient showed no consistent pattern with which to gauge nutrient status. PI ABS showed some promise as an indicator of nutrient status and relative growth rate. • Chl a content and fluorescence parameters do not deserve the unquestioned status they usually enjoy as indicators of biomass and physiological status.