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.

Automated summary

This study collected scientific reports on cyanobacterial blooms in terrestrial water bodies and coastal seas of Russia from the 20th and early 21st centuries, and compared them with data on fertilizer use in agriculture, volume of polluted wastewaters, and average air temperature. The results suggest that the cyanobacterial bloom problem was most severe during the period of 1930-1991, driven by large reservoir construction, untreated wastewater discharge, and widespread fertilizer use in agriculture. After the collapse of the Soviet Union, there was a reduction in polluted wastewater and fertilizer use, leading to a decrease in bloom intensity. However, the resumption of fertilizer use and a sharp increase in average annual temperatures may be causing an intensification of cyanobacterial blooms in water bodies observed in the early 21st century.