title: Spatial and Temporal Variability in Pesticide Exposure Downstream of a Heavily Irrigated Cropping Area: Application of Different Monitoring Techniques.
abstract: Pesticide exposure threatens many freshwater and estuarine ecosystems around the world. This study examined the temporal and spatial trends of pesticide concentrations in a waterway within an agriculturally developed dry-tropics catchment using a combination of grab and passive sampling methods over a continuous two-year monitoring program. A total of 43 pesticide residues were detected with 7 pesticides exceeding ecologically relevant water quality guidelines/trigger values during the study period and 4 (ametryn, atrazine, diuron, and metolachlor) of these exceeding guidelines for several months. The presence and concentration of the pesticides in the stream coincided with seasonal variability in rainfall, harvest timing/cropping cycle, and management changes. The sampling approach used demonstrates that the application of these complementary sampling techniques (both grab and passive sampling methods) was effective in establishing pesticide usage patterns in upstream locations where application data are unavailable.
authors.affiliation: Catchment to Reef Research Group, TropWATER, ATSIP, DB145, James Cook University , Townsville, Queensland 4811, Australia.
authors.forename: Dominique
authors.initials: D
authors.lastname: O'Brien
authors.affiliation: Catchment to Reef Research Group, TropWATER, ATSIP, DB145, James Cook University , Townsville, Queensland 4811, Australia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Lewis
authors.affiliation: Catchment to Reef Research Group, TropWATER, ATSIP, DB145, James Cook University , Townsville, Queensland 4811, Australia.
authors.forename: Aaron
authors.initials: A
authors.lastname: Davis
authors.affiliation: The University of Queensland, Entox , 39 Kessels Road, Coopers Plains, Queensland 4108, Australia.
authors.forename: Christie
authors.initials: C
authors.lastname: Gallen
authors.affiliation: Water Quality and Investigations, Environmental Monitoring and Assessment Science, Science Delivery, Queensland Department of ScienceInformation Technology and Innovation (DSITI) , Dutton Park, Queensland 4102, Australia.
authors.forename: Rachael
authors.initials: R
authors.lastname: Smith
authors.affiliation: Water Quality and Investigations, Environmental Monitoring and Assessment Science, Science Delivery, Queensland Department of ScienceInformation Technology and Innovation (DSITI) , Dutton Park, Queensland 4102, Australia.
authors.forename: Ryan
authors.initials: R
authors.lastname: Turner
authors.affiliation: Water Quality and Investigations, Environmental Monitoring and Assessment Science, Science Delivery, Queensland Department of ScienceInformation Technology and Innovation (DSITI) , Dutton Park, Queensland 4102, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Warne
authors.affiliation: Organic Chemistry, Forensic and Scientific Services, Health Support, Queensland Department of Health, Queensland Government , 39 Kessels Road, Coopers Plains, Queensland 4108, Australia.
authors.forename: Scott
authors.initials: S
authors.lastname: Turner
authors.affiliation: Organic Chemistry, Forensic and Scientific Services, Health Support, Queensland Department of Health, Queensland Government , 39 Kessels Road, Coopers Plains, Queensland 4108, Australia.
authors.forename: Stewart
authors.initials: S
authors.lastname: Caswell
authors.affiliation: The University of Queensland, Entox , 39 Kessels Road, Coopers Plains, Queensland 4108, Australia.
authors.forename: Jochen F
authors.initials: JF
authors.lastname: Mueller
authors.affiliation: Catchment to Reef Research Group, TropWATER, ATSIP, DB145, James Cook University , Townsville, Queensland 4811, Australia.
authors.forename: Jon
authors.initials: J
authors.lastname: Brodie
mesh_terms: D057914:Agricultural Irrigation; D004784:Environmental Monitoring; D005618:Fresh Water / Q000032:analysis*; D010573:Pesticide Residues / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014877:Water Pollution, Chemical / Q000032:analysis; D060753:Water Quality
chemical_list: D010573:Pesticide Residues; D014874:Water Pollutants, Chemical
keywords: Great Barrier Reef; herbicides; irrigation; passive sampling; pesticides; sugar cane