Biohydrochemical causes of the changes of Black Sea ecosystem and its present condition

The principal regularities of the biogenic elements distribution in Black Sea are discussed, particulary such labile compounds as ammonium, organic nitrogen, urea, aminoacids, organic phosphorous, other organic substances and also albumens, lipids and carbohydrates. The permanent growth of the contrations of phospates, nitrogen and silicon results from the construction of numerous hydroelectric power-stations on all the great rivers flowing to the Black Sea. Most of silicon is accumulated in the reservoirs where phytoplankton is rapidly developed, and instead of phospates and nitrates, organic compounds of these elements flow out to the sea. This has caused the essential transformation of the whole Black Sea ecosystem.