title: Storm-event-transport of urban-use pesticides to streams likely impairs invertebrate assemblages.
abstract: Insecticide use in urban areas results in the detection of these compounds in streams following stormwater runoff at concentrations likely to cause toxicity for stream invertebrates. In this 2013 study, stormwater runoff and streambed sediments were analyzed for 91 pesticides dissolved in water and 118 pesticides on sediment. Detections included 33 pesticides, including insecticides, fungicides, herbicides, degradates, and a synergist. Patterns in pesticide occurrence reveal transport of dissolved and sediment-bound pesticides, including pyrethroids, from upland areas through stormwater outfalls to receiving streams. Nearly all streams contained at least one insecticide at levels exceeding an aquatic-life benchmark, most often for bifenthrin and (or) fipronil. Multiple U.S. EPA benchmark or criterion exceedances occurred in 40 % of urban streams sampled. Bed sediment concentrations of bifenthrin were highly correlated (p < 0.001) with benthic invertebrate assemblages. Non-insects and tolerant invertebrates such as amphipods, flatworms, nematodes, and oligochaetes dominated streams with relatively high concentrations of bifenthrin in bed sediments, whereas insects, sensitive invertebrates, and mayflies were much more abundant at sites with no or low bifenthrin concentrations. The abundance of sensitive invertebrates, % EPT, and select mayfly taxa were strongly negatively correlated with organic-carbon normalized bifenthrin concentrations in streambed sediments. Our findings from western Clackamas County, Oregon (USA), expand upon previous research demonstrating the transport of pesticides from urban landscapes and linking impaired benthic invertebrate assemblages in urban streams with exposure to pyrethroid insecticides.
authors.affiliation: Oregon Water Science Center, 2130 SW 5th Avenue, Portland, OR, 97201, USA. kdcar@usgs.gov.
authors.forename: Kurt D
authors.identifier: http://orcid.org/0000-0002-6231-8335
authors.initials: KD
authors.lastname: Carpenter
authors.affiliation: Oregon Water Science Center, 2130 SW 5th Avenue, Portland, OR, 97201, USA.
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Kuivila
authors.affiliation: California Water Science Center, 6000 J Street, Placer Hall, Sacramento, CA, 95819, USA.
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Hladik
authors.affiliation: Oregon Water Science Center, 2130 SW 5th Avenue, Portland, OR, 97201, USA.
authors.forename: Tana
authors.initials: T
authors.lastname: Haluska
authors.affiliation: Cole Ecological, Inc., 15 Bank Row, Suite B, Greenfield, MA, 01301, USA.
authors.forename: Michael B
authors.initials: MB
authors.lastname: Cole
mesh_terms: D000818:Animals; D002947:Cities; D004784:Environmental Monitoring / Q000379:methods; D019015:Geologic Sediments / Q000032:analysis*; D007448:Invertebrates; D009922:Oregon; D010575:Pesticides / Q000032:analysis*; D011722:Pyrethrins / Q000032:analysis; D011891:Rain; D045483:Rivers; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D010575:Pesticides; D011722:Pyrethrins; D014874:Water Pollutants, Chemical
keywords: Benthic invertebrates; Bifenthrin; Fipronil; Pesticides; Source; Transport; Urban streams