Submitted to: Bulletin of Environmental Contamination and Toxicology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/24/2009
Publication Date: 5/8/2009
Citation: Kroger, R., Lizotte Jr, R.E., Moore, M.T. 2009. Survival, growth, and body residues of Hyalella azteca (Saussure) exposed to fipronil contaminated sediments from non-vegetated and vegetated microcosms. Bulletin of Environmental Contamination and Toxicology 83(3):369-373. DOI 10.1007/s00128-009-9759-8. Interpretive Summary: Pesticide runoff from agricultural fields can damage aquatic resources in downstream receiving systems. One suggestion to remediate this problem is the use of vegetated drainage ditches as a best management practice. Little research has been conducted, however, on the toxicity of pesticides in sediment of these ditches. Survival and growth assessments were conducted on a macroinvertebrate (insect) that normally lives in ditch sediment, using sediment collected from an experimental ditch system dosed with the insecticide fipronil. No significant differences were noted in either survival or growth of macroinvertebrates exposed to sediment with plants or sediment without plants. Results indicated that even in vegetated systems, fipronil may be bioavailable to certain macroinvertebrates.
Technical Abstract: We assessed chronic effects of fipronil and metabolite contaminated sediments from non-vegetated and Thallia dealbata vegetated wetland microcosms on Hyalella azteca during wet and dry exposures. Mean sediment concentrations (ng g-1) ranged from 0.72-1.26, 0.01-0.69, 0.07-0.23, and 0.49-7.87 for fipronil, fipronil-sulfide, fipronil-sulfone, and fipronil-desulfinyl, respectively. No significant differences in animal survival or growth were observed between non-vegetated and vegetated microcosms during wet or dry exposures. Mean animal body residue concentrations (ng g-1) ranged from 28.4-77.6, 0-30.7, and 8.3-43.8 for fipronil, fipronil-sulfide, and fipronil-sulfone. Fipronil-desulfinyl was not detected in any animal samples.