The major threats to the biodiversity of mountain lakes are growth in tourism, rapid urbanization, pollution, land use intensification, water uptake, progressive eutrophication, introduction of alien species and climate change, with variable weight in different Protected Areas. Typical phenological responses to changing conditions include shifts in timing, magnitude and duration of phytoplankton blooms, as well as altered community composition, nutrient load and pollutants. Waters samples for physical and chemical parameters (major and minor ions, organic carbon, nitrogen, phosphorous, pH, conductivity) and population dynamics (phytoplankton, zooplankton) have been collected since 2008 from alpine lakes, following a depth-integrated sampling. Measurements are carried out two times for year.