Abstract—Not much has been done to investigate the uptake
and synergic effect of multiple classes of cyanotoxins on aquatic
plants. Two aquatic plants Ludwigia adscendens and
Amaranthus hybridus (biomass ranging 3.27 to 9.4 gL-1) were
exposed to contaminated water for 14 days to test the synergic
effects of cyanotoxins in solution on the plants. The plants were
exposed to concentrations of 5.385-7.641 μg mL-1 for MC-LR;
8.905 μg mL-1 for MC-RR). L.adscendens accumulated
microcystins up to a concentration of 0.04595 ± 0.0004 ng mg-1
wet weight and A.hybridus accumulated microcystins up to a
concentration of 0.0166 ± 0.0016 ng mg-1 wet weight of plant
material over the 14 days. Except in beaker experiments where
the plants were exposed to artificial water dosed with crude
extracts, the treatments and their respective controls did not
show any significant difference in toxin removals (one-way
ANOVA at p=0.05), showing that the plants were unable to
significantly remove the toxins from solution. When exposed to
raw dam water, both plants were negatively affected as
demonstrated by the loss in fresh wet weight. It was thus
concluded that the cyanotoxins had adverse effects on aquatic
plants at the concentrations used.
Index Terms—Cyanotoxins, aquatic plants, Ludwigia
adscendens, Amaranthus hybridus, microcystins.
The authors are with the Environmental Remediation and Water Pollution
Chemistry Research Group, Department of Ecology and Resources
Management, University of Venda, Private bag X5050, Thohoyandou, 0950,
Limpopo, South Africa (e-mail: gpindihama@gmail.com,
Mugera.Gitari@univen.ac.za).
Cite: Glynn K. Pindihama and Mugera W. Gitari, "Uptake and Growth Effects of Cyanotoxins on Aquatic Plants Ludwigia Adscendens and Amaranthus Hybridus in Raw Surface Waters," International Journal of Environmental Science and Development vol. 8, no. 2, pp. 93-101, 2017.
