title: Effects of an atrazine, metolachlor and fipronil mixture on Hyalella azteca (Saussure) in a modified backwater wetland.
abstract: We examined the toxicity mitigation efficiency of a hydrologically modified backwater wetland amended with a pesticide mixture of atrazine, metolachlor, and fipronil, using 96 h survival bioassays with Hyalella azteca. Significant H. azteca 96 h mortality occurred within the first 2 h of amendment at the upstream amendment site but not at any time at the downstream site. H. azteca survival varied spatially and temporally in conjunction with measured pesticide mixture concentrations. Hyalella azteca 96 h survival pesticide mixture effects concentrations ranges were 10.214–11.997, 5.822–6.658, 0.650–0.817, and 0.030–0.048 μg L−1 for atrazine, metolachlor, fipronil, and fipronil-sulfone, respectively.
authors.affiliation: USDA-ARS National Sedimentation Laboratory, P.O. Box 1157, Oxford, MS 38655, USA. richard.lizotte@ars.usda.gov
authors.forename: Richard E
authors.initials: RE
authors.lastname: Lizotte
authors.forename: Scott S
authors.initials: SS
authors.lastname: Knight
authors.forename: F Douglas
authors.initials: FD
authors.lastname: Shields
authors.forename: Charles T
authors.initials: CT
authors.lastname: Bryant
mesh_terms: D000081:Acetamides / Q000032:analysis / Q000633:toxicity*; D033304:Amphipoda / Q000187:drug effects*; D000818:Animals; D001280:Atrazine / Q000032:analysis / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D006540:Herbicides / Q000032:analysis / Q000633:toxicity*; D007306:Insecticides / Q000032:analysis / Q000633:toxicity*; D011720:Pyrazoles / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity; D053833:Wetlands
chemical_list: D000081:Acetamides; D004338:Drug Combinations; D006540:Herbicides; D007306:Insecticides; D011720:Pyrazoles; D014874:Water Pollutants, Chemical; C082360:fipronil; D001280:Atrazine; C051786:metolachlor