Primary Production in the Littoral Zone of Lake Onego and Its Contribution to the Productivity of the Reservoir

For the first time, two-year seasonal studies of phytoplankton production were carried out in the rocky–sandy littoral zone of the northern deep and cold-water Lake Onego. The research results showed that photosynthesis is characterized by two or three seasonal maxima, the values of which are within the limits of oligotrophic ecosystems. The main primary producers, the concentration of phosphorus in water, and the water temperature during the growing season are considered. Differences in the seasonal dynamics of photosynthesis and a similar level of seasonal average and maximum values were revealed in comparison with the deep-water region of the lake. The small contribution of littoral phytoplankton production to the primary productivity of the ecosystem is shown.