“…The mean concentration of NO 3 À recorded in the study was higher than the concentrations obtained in Daihai Lake (Hou et al, 2013), Ziqualla Lake (Degefu et al, 2014) and Tinishu Abaya (Enawgaw & Lemma, 2018). However, it was lower than that reported in Lake Tana (Tibebe et al, 2019).…”