Seasonal Dynamics of Algal Flora in the Stratified Kislo-Sladkoe Lake Partially Separated from the White Sea.

The article presents data on the composition and abundance of algal flora in the coastal stratified Kislo-Sladkoe Lake (the Karelian coast of the White Sea) after its flushing with seawater in autumn. The seasonal dynamics and vertical structure of the phytoplankton were monitored from March 17 to October 3, 2019. We also studied ice flora on March 17 and April 1. The largest carbon biomass of ice algae (0.79 g C/m3) dominated by Nitzschia frigida was recorded in April. The integrated biomass of phytoplankton in the water column varied from 0.01 g C/m2 in March to 5.83 g C/m2 during spring bloom in late May (when it was dominated by Chaetoceros invisibilis) and remained at the level of 0.07 to 0.29 g C/m2 until October; heterotrophic forms replaced autotrophic algae during this period. A regression analysis has shown that the structure of the phytoplankton was influenced by length of daylight, water temperature, dissolved oxygen level, depth, pH, salinity, and illuminance. [ABSTRACT FROM AUTHOR]