title: Environmental effects and fate of the insecticide bifenthrin in a salt-marsh mesocosm.
abstract: Bifenthrin is a widely used synthetic pyrethroid insecticide that is often applied to crops, turf, and residential structures for the control of insects. Like other insecticides, bifenthrin has the potential to contaminate bodies of water that are adjacent to the application site via spray drift and runoff during storm events. The objective of this study was to examine the lethal and sublethal effects of bifenthrin on grass shrimp, Palaemonetes pugio, and sheepshead minnow, Cyprinodon variegatus in a 28 d mesocosm experiment under estuarine conditions. Endpoints included mortality and growth and the oxidative stress biomarkers of lipid peroxidation, glutathione, and catalase. In the mesocosm experiment, 24 h and 96 h caged shrimp LC50s were 0.061 and 0.051 μg L(-1), respectively. The uncaged grass shrimp 28 d LC50 was 0.062 μg L(-1). Fifty percent mortality was not reached in the uncaged sheepshead minnow. Bifenthrin did not have a significant effect on the growth of the shrimp, but there was an increasing impact on fish growth. However, it is uncertain as to whether this pattern is a direct effect of the chemical or if it is due to increased food availability resulting from mortality in prey species. The oxidative stress assays were largely inconclusive. Bifenthrin was eliminated rapidly from the water column and readily partitioned to sediments. The LC50s for adult and larval P. pugio were below published Estimated Environmental Concentration (EEC) values and were within the range of bifenthrin concentrations that have been measured in rivers, channels, and creeks.
authors.affiliation: NOAA's National Centers for Coastal Ocean Science, Center for Coastal Environmental Health and Biomolecular Research, Charleston, SC, United States. Electronic address: paul.pennington@noaa.gov.
authors.forename: Paul L
authors.initials: PL
authors.lastname: Pennington
authors.affiliation: College of Charleston, Graduate Program in Marine Biology, Grice Marine Laboratory, Charleston, SC, United States.
authors.forename: Heather
authors.initials: H
authors.lastname: Harper-Laux
authors.affiliation: JHT Incorporated, Contractor to NOAA, Charleston, SC, United States.
authors.forename: Yelena
authors.initials: Y
authors.lastname: Sapozhnikova
authors.affiliation: NOAA's National Centers for Coastal Ocean Science, Center for Coastal Environmental Health and Biomolecular Research, Charleston, SC, United States.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Fulton
mesh_terms: D000818:Animals; D054750:Ecotoxicology; D004780:Environment, Controlled; D004785:Environmental Pollutants / Q000032:analysis / Q000633:toxicity; D007306:Insecticides / Q000032:analysis / Q000633:toxicity*; D007695:Killifishes; D007814:Larva / Q000187:drug effects; D007928:Lethal Dose 50; D033541:Palaemonidae / Q000187:drug effects*; D011722:Pyrethrins / Q000032:analysis / Q000633:toxicity*; D012492:Salts; D053833:Wetlands
chemical_list: D004785:Environmental Pollutants; D007306:Insecticides; D011722:Pyrethrins; D012492:Salts; C099952:bifenthrin
keywords: Bifenthrin; Estuarine; Grass shrimp; Mesocosm; Sheepshead minnows