Dataset for: Agrochemical mixtures and amphibians: The combined effects of pesticides and fertilizer on stress, acetylcholinesterase activity and bioaccumulation in a terrestrial environment

Tank mixtures are popular within the agricultural community because they are time- and cost-effective, but field applications leave non-target organisms at risk of exposure. Here we explore the effects of a common herbicide (atrazine and alachlor) and fertilizer (urea) tank mixture on juvenile frog corticosterone stress levels (CORT), acetylcholinesterase activity (AChE), and pesticide bioaccumulation. Single agrochemical or tank mixtures were applied to terrestrial microcosms, then individual Southern leopard frog (Lithobates sphenocephala) juveniles were added to microcosms for an 8-hour exposure. Afterward, frogs were transferred to aquatic microcosms for 1 hr to monitor CORT prior to euthanasia, brain tissues were excised to evaluate AChE, and tissue homogenates were analysed for pesticide bioconcentation with GC/MS. Atrazine significantly increased CORT in frogs, particularly when combined with alachlor and urea. Atrazine increased AChE while urea decreased AChE, although no interactive effects of chemical combinations were discernible. Relative to their individual treatments, the complete tank mixture with all three agrochemicals resulted in 64% greater bioconcentration of atrazine and 54% greater bioconcentration of alachlor in frog tissues. Results suggest that agrochemical mixtures as well as their active ingredients can lead to altered stress levels and impaired physiological responses in amphibians. Although challenging, an improved understanding of the effects of co-exposure to environmental contaminants in amphibians is important in assessing the ecological risks these compounds pose.