Water motion as a transformation mechanism of algal communities structure in Lake Baikal

The diversity of algal communities of phytoplankton and meio-and macrophytes was investigated in Lake Baikal. Fragments of Spirogyra thallomes were recorded in the phytoplankton community of Southern Baikal, which had never been recorded before in its composition. It was also established that the structure of benthic algal communities changed in comparison with that in 2000 due to intense development of filamentous algae, particularly Spirogyra. Its lowest biomass was recorded in the surf zone and wave breaking, whereas the highest biomass was registered in the area of weakened effect of waves on the bottom. The cover percent of the bottom with filamentous algae in different areas of the coastal zone varied from 0 to 100%. Hydraulic characteristics of Spirogyra were the same as those of planktonic diatoms. The circulation currents and wave effect on the bottom favoured transfer and distribution of Spirogyra from the location of its intense development into the coastal area of Lake Baikal.