Tropical and Sub-tropical Cost-effective Tools for an Integrated Risk Assessment of Wetlands
The main objective of this project was to evaluate the environmental impact of pesticide use on organisms.
The project goals were:
A) to describe land use and agricultural patterns in the study area: The main land use in the Palizada river area is the rice crop followed by livestock farming, however the mangrove, forest and popal are well distributed in the area. The main pesticides used in the rice crop are carbofuran, glyphosate and malathion with a rate of 0.5 to 1.0 liter/hectare of each.
B) To investigate the environmental and human impacts of agriculture practices on ecosystems, carrying experimental research through laboratory and in situ ecotoxicological test and the use of biomarkers in aquatic (fish) and terrestrial (birds and human beings) ecosystems.
These goals were met by:
1) Estimating the natural variability in enzymatic activity of AChE, LDH and GST in head, muscle and gills of Gambusia yucatana and analyzing the environmental factors that contribute to this;
2) Assessing whether the measured levels of enzymatic activity in fish among streams were affected by wastes generated by human activities and by land use surrounding the stream;
3) Developing and validating an in situ test-chamber for ecotoxicity tests with mosquitofish (G. yucatana).
4) Determining the natural values of AChE enzymatic activity in black-bellied whistling ducks (Dendrocigna autumnalis) for use as a bioindicator of pesticide contamination;
5) Determining the depression of AChE activity in workers exposed to pesticide.