PESTICIDE DISSIPATION IN EXPERIMENTAL AQUARIA AND ARTIFICIAL PONDS

Authors: Bialek Kalinski, Krystyna; Rice, Clifford; MAZANTI, L - NRCS

Submitted to: NRCS Design Guide
Publication Type: Other
Publication Acceptance Date: 7/12/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary: Wetlands have long been suspected of helping retain pesticides and encouraging their degradative loss. In 1998 our lab initiated a program to treat and address the retention of three commonly used pesticide, atrazine, metolachlor and chlorpyrifos in a laboratory and outdoor pond setting. Organisms were also added to the laboratory tanks and natural populations were allowed to remain in the outdoor ponds. The study was a cooperative effort managed by our laboratory and the Wetlands Institute of the Natural Resources Conservation Service. A major goal of the study was to assess the possible impacts of retained pesticides on living resources within these ecosystems; however, this particular report and study deals only with the pesticide chemicals, their concentrations and concentrations of measurable degradates. In the aquarium studies, the loss of pesticides was quite different for the herbicides versus chlorpyrifos. The loss of herbicides was practically nonexistent while chlorpyrifos was reduced by between 80 to 84% during the first 10 days after treatment. The unusually low measured chlorpyrifos levels may have resulted from enhanced volatility due to the use of aspirators in the aquaria. In the pond treatments, the losses of especially the herbicides were much more obvious than with the aquaria studies. The losses of chlorpyrifos was also more rapid in the pond studies.

Technical Abstract: In 1998 our lab initiated a program to treat and address the retention of three commonly used pesticide, atrazine, metolachlor and chlorpyrifos in a laboratory and outdoor pond setting. Organisms were also added to the laboratory tanks and natural populations were allowed to remain in the outdoor ponds. The study was a cooperative effort managed by our laboratory and the Wetlands Institute of the Natural Resources Conservatio Service. A major goal of the study was to assess the possible impacts of retained pesticides on living resources within these ecosystems; however, this particular report and study deals only with the pesticide chemicals, their concentrations and concentrations of measurable degradates. In the aquarium studies, the loss of pesticides was quite different for the herbicides versus chlorpyrifos. The loss of herbicides was practically nonexistent while chlorpyrifos was reduced by between 80 to 84 % during the efirst 10 days after treatment. There also was a differences in the loss o chlorpyrifos depending on amount of accompanying herbicide. The unusually low measured chlorpyrifos levels may have resulted from enhanced volatility due to the use of aspirators in the aquaria. In the pond treatments, the losses of especially the herbicides were much more obvious than with the aquaria studies. The losses of chlorpyrifos was also more rapid in the pond studies.