TITLE:
Pesticide Influence on the Desmid Flora of a Reservoir in an Agricultural Region at Campo Verde, Mato Grosso, Brazil
AUTHORS:
Juliana Kawanishi Braga, Edna Lopes Hardoim, Eliana Freire Gaspar de Carvalho Dores, Charles William Heckman
KEYWORDS:
Algal Abundance, Atrazine, Seasonality, Springs
JOURNAL NAME:
Journal of Environmental Protection,
Vol.5 No.12,
September
24,
2014
ABSTRACT: The objective
of the research was to investigate the influence of pesticides on the desmid
flora. Five series of samples were taken between July 5, 2005, and April 6,
2006, for analysis of pesticide content and algal community structure in the
Sao Lourenco River springs on the Pirassununga Ranch, Campo Verde, Mato Grosso.
The greatest amounts of pesticides were detected in July, when the abundance of
algae was also greatest. Positive correlations were determined between the
concentrations of endosulfan (r = 0.94; p = 0.051), cyhalothrin (r = 0.96; p = 0.037) and endrin (r =
0.96; p = 0.037) and the biomass of
desmids. Insecticides, such as endosulfan, inhibit the activity of ATPase,
contributing considerably to the mortality of the biota, since ATP is of
fundamental importance in the energy metabolism of all organisms. This suggests
that the pesticides promote algal growth both by removing the small herbivores
that feed on the algae and increasing the release of inorganic nutrients from
decomposing animals in the water. Algae were least abundance in January,
possibly due to the presence of the herbicide atrazine (r = -0.63; p > 0.05).