Silver nanoparticles (AgNP) are one type of contaminant that can enter treatment wetlands (Wiesner 2006) and impact the overall treatment efficacy. Grazing by filter feeding zooplankton, such as Daphnia magna, is critical to treatment wetland functioning (Ismail 2019), but the effects of AgNP on zooplankton are not fully understood, especially at environmentally relevant concentrations. In this study, the bioaccumulation kinetics of dissolved and nanoparticulate Ag in D. magna exposed to environmentally relevant Ag concentrations were characterized using isotopically labelled Ag as a tracer. References: Wiesner MR, Lowry GV, Alvarez P, Dionysiou D, Biswas P. 2006. Assessing the Risks of Manufactured Nanomaterials. Environmental Science & Technology 40:4336-4345. Ismail NS, Blokker BM, Feeney TR, Kohn RH, Liu J, Nelson VE, Ollive MC, Price SBL, Underdah EJ. 2019. Impact of Metazooplankton Filter Feeding on Escherichia coli under Variable Environmental Conditions. Applied and Environmental Microbiology 85: e02006-02019.