Urban light pollution alters the diel vertical migration of Daphnia

et al.1990), and these areas often border freshwater lakes,coastal ecosystems, or both. Urban water qualitymay be influenced indirectly by light pollution,because zooplankton grazing influences water qualityand the depth distribution of many zooplankters isaffected by light.We tested the hypothesis that light pollution asso-ciated with urban areas reduces the amplitude andmagnitude of zooplankton vertical migration. A fieldexperiment manipulating underwater light intensityat night was performed in a suburban lake borderinga large metropolitan area.