You are here:
Effects of indirect agricultural spray drift on amphibians and their habitats in southern Georgia
Citation:
Glinski, D., R. Van Meter, Tom Purucker, AND Matt Henderson. Effects of indirect agricultural spray drift on amphibians and their habitats in southern Georgia. 2021 SETAC North America Annual Meeting, Virtual, November 14 - 18, 2021.
Impact/Purpose:
In order to study spray drift contribution to non-targeted habitats, pesticide concentrations were measured in stemflow (water flowing down the trunk of a tree during a rain event), rainfall, and amphibians in an agriculturally impacted wetland area near Tifton, Georgia, USA.
Description:
Pesticides are used to control insects and diseases; however, non-target exposure to amphibians and other species frequently occurs. We determined pesticide concentrations in amphibians and stemflow from two agriculturally impacted wetlands near Tifton, Georgia and Joseph Jones Ecological Research Center (JJERC), Albany, Georgia to assess the risk from spray drift contributions to non-targeted habitats. Amphibians were collected from three wetland types: reference (semi-forested interior sites not likely to be impacted by spray drift), agricultural fields, and edge (sites that border agricultural fields, and likely impacted by spray drift). All samples were analyzed for > 200 pesticides, with more than 30 pesticides detected across all matrices. The herbicide metolachlor was the most frequently detected pesticide with highest concentrations in stemflow samples. Additionally, a few legacy pesticides such as mirex and DDE were detected in amphibian tissues collected at Tifton study sites in addition to reference, edge, and agricultural sites at JJERC. Trace levels of parent pesticides were found in amphibians, likely due to hepatic metabolism. Stemflow concentrations were compared against environmental water screening values and aquatic life benchmarks as a proxy to determine hazard to amphibians. Several pesticides were present at concentrations that exceeded the aquatic life benchmark value. Exposure to pesticides through spray drift on tree trunks and resultant stemflow could be problematic for many amphibians, especially treefrogs, due to their arboreal residence times. Additionally, pesticide mixtures were present in all environmental matrices, making it difficult to determine the adverse effects these chemicals may have due to potential additive, antagonist, or synergist effects. Amphibian populations are in decline and pesticide exposure has been identified as one of the primary causative factors. These data can aid in the assessment of risk of indirect spray drift and subsequent exposures for amphibian species and their wetland habitats.
