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Effect of copper on the photochemical efficiency, growth, and chlorophyll A biomass of natural phytoplankton assemblages
Author(s) -
Pérez Patricia,
EstévezBlanco Patricia,
Beiras Ricardo,
Fernández Emilio
Publication year - 2006
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1897/04-392r1.1
Subject(s) - phytoplankton , photosynthesis , environmental chemistry , chlorophyll a , fluorometer , biomass (ecology) , diatom , copper , eutrophication , algae , chemistry , botany , ecology , biology , fluorescence , nutrient , physics , organic chemistry , quantum mechanics
In this investigation, we have tested the potential usefulness of variable fluorescence, i.e., the potential photochemical efficiency of photosystem II ( F v / F m ), determined with a fast repetition rate fluorometer (FRRF), as an indicator of the effect of metal pollution on natural phytoplankton assemblages. Phytoplankton populations were collected from an eutrophic embayment and exposed to different copper concentrations within the ppb range for 4 d. Enhanced photosynthesis was found for Cu concentrations of 10 and 20 μg/L, at very short exposure times (1 and 5 h). However, after 72 h even at 10 μg/L of Cu, F v / F m ‐values were significantly lower than those measured in the control. The highest Cu concentration tested (80 μg/L) caused a statistically significant decrease of F v / F m after 5 h. This response was contrasted with parallel determinations of chlorophyll a concentration, measurements of photosynthetic O 2 production rates, and changes in the taxonomic composition and size structure of the microplankton communities. A reduction in overall particle size was found at Cu concentrations of 80 and 40 μg/L. Enhanced abundance of flagellates and the diatom Pseudonitzschia pungens was observed at 20 μg/L of copper. This study demonstrates the utility of this methodological approach as a rapid, nondestructive way for detecting trace‐metal toxicity on natural phytoplankton.