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Comparison of Cd, Cu, and Zn toxic effects on four marine phytoplankton by pulse‐amplitude‐modulated fluorometry
Author(s) -
Miao AiJun,
Wang WenXiong,
Juneau Philippe
Publication year - 2005
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 - 10.1897/05-009r.1
Subject(s) - bioaccumulation , phytoplankton , environmental chemistry , thalassiosira weissflogii , metal , algae , cyanobacteria , metal toxicity , chemistry , photosystem ii , botany , biology , photosynthesis , ecology , heavy metals , genetics , organic chemistry , nutrient , bacteria
The toxic effects of Cd, Cu, and Zn on four different marine phytoplankton, Dunaliella tertiolecta, Prorocentrum minimum, Synechococcus sp., and Thalassiosira weissflogii , were examined by comparing the cell‐specific growth rate, pulse‐amplitude‐modulated (PAM) parameters (maximum photosystem II quantum yield ϕ M and operational quantum yield ϕ' M ), chlorophyll a content, and cellular metal concentration, over a 96‐h period. The calculated no‐observed‐effect concentration (NOEC) based on both cell‐specific growth rate and two PAM parameters (ϕ M and ϕ' M ) were mostly identical. Thus, these PAM parameters and cell‐specific growth rate were comparable in their sensitivities as the biomarkers for trace metal toxicity to marine phytoplankton. The cyanobacteria Synechococcus sp. was the most sensitive species among the four algal species tested because of its higher cell surface to volume ratio. The toxicity of the three tested metals followed the order of Cd > Cu > Zn based on the cellular metal concentration of the four algae at the NOEC. The cellular metal bioaccumulation followed the same Freundlich isotherm for each metal regardless of the algal species, indicating that the metal accumulation was a nonmetabolic process under high ambient metal concentrations and that the cell surface metal binding was comparable among the different species. For all the algae examined in our study, the bioaccumulation potentials of Cu and Zn were similar to each other, while the Cd bioaccumulation was much lower under environmentally realistic metal concentration.