The monitoring has been carried out in the Caspian Sea aquatoria, especially on the West shelf of the sea belonging to Azerbaijan during the last 50 years. Microbiological and hidrobiological investigations revealed that allochthonous organic matter from different sources accelerated the generation of phytoplankton and bacterioplankton. It was established that in aqueous layers and sediments enriched with allochthonous and autochthonous organic compounds, labile energy sources increased oxygen consumption. As a result of antropogenic effects, depending on the geographical position and climatic conditions phytoplankton growth continued all year round. In the course of time this process became more intensive. The effect of allochthonous organic compounds on the oxygen regime of water was investigated in the context of the general biological productivity of the territory in the whole Caspian Sea aquatoria, from the valley of the Kura River, which is one of the most productive areas of the sea, to Astara.