“…Phytoplankton as one component of an aquatic ecosystem play keys ecological roles in the ecosystem: (1) maintaining the balance of the ecosystem and its complex food webs (Vallina et al, 2017) as their species diversity, biomass and production determine the strength of the energy transfer (Degerman et al, 2018;Ghedini et al, 2021) and they are autotrophic organisms and usually found in aquatic ecosystems serving as the base food sources for most aquatic organisms like zooplankton, fishes and crustaceans (Manickam et al, 2020;Tharik et al, 2021), (2) they play a very vital role in controlling the carbon level in the atmosphere and generate about half the atmospheric oxygen through the process of photosynthesis (Basu & Mackey, 2018;Käse & Geuer, 2018) and (3) are very good biological indicator to understand the water quality and they also respond to other physiological indicators like pH, oxygen, salinity, temperature, light and toxic chemicals (Manickam et al, 2020). Therefore, their distribution is mostly explained as a response to a complex of environmental factors operating at various scales of different biotic and abiotic factors (Wagaw et al, 2021). The effects of seasonality and nutrient availabilities (Tessema et al, 2020), underwater light conditions and phytoplankton buoyancy characteristics (Degefu et al, 2014) wind and temperature regime (Degefu & Schagerl, 2015), food availability and trophic conditions (Fetahi et al, 2014) have all been revealed as key driving factors for heterogeneity of phytoplankton composition and biomass in Ethiopian highland lakes.…”