Examining impacts of current‐use pesticides in Southern Ontario using in situ exposures of the amphipod Hyalella azteca

Abstract

In situ exposures with Hyalella azteca were used to assess impacts of current-use pesticides in Southern Ontario, Canada. Exposures were conducted over 2 growing seasons within areas of high pesticide use: 1 site on Prudhomme Creek and 3 sites on Twenty Mile Creek. Three sites on Spencer Creek, an area of low pesticide use, were added in the second season. Surface water samples were collected every 2 wk to 3 wk and analyzed for a suite of pesticides. Hyalella were exposed in situ for 1 wk every 4 wk to 6 wk, and survival and acetylcholinesterase (AChE) activity were measured. Pesticides in surface waters reflected seasonal use patterns: lower concentrations in spring and fall and higher concentrations during summer months. Organophosphate insecticides (chlorpyrifos, azinphos methyl, diazinon) and acid herbicides (2,4-dichlorophenoxyacetic acid [2,4-D], mecoprop) were routinely detected in Prudhomme Creek, whereas neutral herbicides (atrazine, metolachlor) dominated the pesticide signature of Twenty Mile Creek. Spencer Creek contained fewer pesticides, which were measured at lower concentrations. In situ effects also followed seasonal patterns: higher survival and AChE activity in spring and fall, and lower survival and AChE activity during summer months. The highest toxicity was observed at Prudhomme Creek and was primarily associated with organophosphates. The present study demonstrated that current-use pesticides in Southern Ontario were linked to in situ effects and identified sites of concern requiring further investigation.

Sensitivity of multiple life stages of 2 freshwater mussel species (Unionidae) to various pesticides detected in Ontario (Canada) surface waters

“…When compared to the maximum Ontario surface water concentration, the EC50 value for azoxystrobin was approximately 1668 times greater (National Pesticides Monitoring and Surveillance Network 2017; Figure 2). The ECx values for all pesticides were greater than the highest concentration measured in the surface waters of Ontario and the United States (no surface water data for flupyradifurone; Struger and Fletcher 2007;Bartlett et al 2016;Struger et al 2016Struger et al , 2017; National Pesticides Monitoring and Surveillance Network 2017; US Geological Survey 2017). Two of the 11 pesticides reported NOEC values lower than the greatest concentration tested, azoxystrobin (NOEC ¼ 186 mg/L) and carbaryl (NOEC ¼ 2380 mg/L); but they were still greater than any reported concentration in Ontario surface waters (Tables 1 and 2).…”

“… a The associated Canadian Council for the Ministers of the Environment (2007), World Health Organization (), and US Environmental Protection Agency () water quality guidelines or benchmarks are included (all concentrations are reported in micrograms per liter). Concentrations in Ontario water from the National Pesticides Monitoring and Surveillance Network (Struger and Fletcher ; Bartlett et al ; Struger et al , 2017; National Pesticides Monitoring and Surveillance Network ), and those in US water from the US Geological Survey ().…”

“…The exposure distributions were constructed to relate the effect endpoints estimated in the present study to concentrations of pesticides in surface waters of North America. A hazard assessment of the pesticides to the different life stages of freshwater mussels was also conducted by calculating hazard quotients that compared viability and survival (EC10, 25, or 50 for V. iris glochidia at 24 or 48 h; LC50 for juvenile and adult L. siliquoidea at 28 d) to the maximum reported concentrations of pesticides measured in Ontario (Struger and Fletcher ; Bartlett et al ; Struger et al , ; National Pesticides Monitoring and Surveillance Network ) and United States (US Geological Survey ) surface waters. Ontario and United States surface water concentrations and associated water quality guidelines/criteria for available pesticides are reported in Table .…”

Critical and systematic evaluation of data for estimating human exposures to 2,4-dichlorophenoxyacetic acid (2,4-D) – quality and generalizability

“…These studies included a wide range of study locations, settings and approaches. In terms of steps taken to avoid and/or quantify the extent of sample contamination, 18 studies are considered Tier 2 as the investigators documented use of either field blanks (Bartlett et al 2016;Loos et al 2009Loos et al , 2010aLoos, Locoro, and Contini 2010b;Phillips and Bode 2004) or lab blanks (Birch et al 2015;Buser and Muller 1998;DeLorenzo et al 2012DeLorenzo et al , 2007Donald et al 2001;Frank et al 1990;Frank, Logan, and Clegg 1991;King and Balogh 2010;McManus et al 2014;Park et al 2011;Rawn et al 1999b;Woudneh et al 2006Woudneh et al , 2007. Nine studies included both and are considered as Tier 1 (Cohen et al 1990;Ensminger et al 2013; Felix-Canedo, Duran-Alvarez, and Jimenez-Cisneros 2013; Glozier et al 2012;Messing et al 2011;Palma et al 2004;Struger and Fletcher 2007;Waite et al 2002a;Wijnja, Doherty, and Safie 2014).…”

In Situ Reproductive Bioassay with Caged Gammarus fossarum (Crustacea): Part 1—Gauging the Confounding Influence of Temperature and Water Hardness

“…Active biomonitoring that is based on in situ bioassays with transplanted caged organisms is recognized as a relevant approach with which to diagnose the toxicity of aquatic environments by displaying realistic exposure scenarios, and because this approach makes it possible to limit the confounding effect of biotic factors influencing endpoint measurements (e.g., source population, body size, sex, and reproductive and energetic status; Liber et al 2007). As has already been implemented for different aquatic invertebrates species (e.g., Kater et al 2001; Maltby et al 2002; Soares et al 2005; Barata et al 2007; Krell et al 2011; Bartlett et al 2016; Martinez‐Haro et al 2016), we developed in situ caging protocols for the amphipod Gommarus fossarum to determine toxicity in freshwater ecosystems (Coulaud et al 2011; Xuereb et al 2011). However, the limitation of in situ bioassays is the lack of control assays to be used as relevant references (Calow 1989).…”