Meeting Abstract
Herbicides are introduced to aquatic systems through variable modes of entry: overland runoff, ground water contamination, and spray drift following application (Davies et al., 2003). Previous work on chemical dispersion has established that exposure pattern of contaminants can differ depending on the method that toxicants are introduced to an aquatic system (Edwards and Moore, 2015; Lahman and Moore, 2015; Wolf et al., 2014). The purpose of this study is to understand how differing routes of exposure to an herbicide, atrazine, alter social behaviors and physiological responses of aquatic organisms. Many studies have indicated that crayfish behaviors and physiology are sensitive to herbicide pollutants, thus these species serve as bioindicators for overall ecosystem health (Weis, 2015; Burba, 1999; Cook and Moore, 2008; Browne and Moore, 2014). This study used agonistic encounters in the crayfish Orconectes virilis as a behavioral assay to investigate impact of sublethal concentrations of atrazine (0, 40, 80, and 160 µg/L). Atrazine was delivered by methods mimicking groundwater and surface runoff influx into a flow through exposure arena for a total of 23 hours. Each experimental animal then participated in a dyadic fight trial with unexposed opponents. Fight duration and intensity was calculated and analyzed using a pre-established crayfish ethogram. Experimental crayfish hepatopancreas and abdominal muscle tissue samples were extracted and analyzed for cytochrome P450, glutathione, and acetylcholinesterase levels to discern mechanism of detoxification and mode of action of atrazine. This study demonstrates that method of entry of a toxicant has differential effects on an aquatic organism’s health.
