Trends and Driving Forces of Cyanobacterial Blooms in Russia in the 20th and Early 21st Centuries

In order to study long-term trends and factors affecting the development of cyanobacteria in the terrestrial water bodies and coastal seas of Russia, we collected scientific reports on the cyanobacterial blooms throughout the 20th and early 21st centuries and compared this information with available data on the amount of fertilizers used in agriculture, volume of polluted wastewaters and average air temperature. We suppose that the problem of cyanobacterial blooms was most acute during the period 1930–1991. The main driving factors at that time were the large reservoir construction, untreated wastewater discharge and the widespread use of fertilizers in agriculture. In post-Soviet Russia, there was a noticeable reduction of polluted wastewater runoff along with a decrease in the use of fertilizers in agriculture, which caused a drop in the intensity of blooming. Nevertheless, the resumption of the use of fertilizers and a sharp increase in average annual temperatures in Russia may be responsible for intensification of cyanobacterial blooms in water bodies observed in the early 21st century.