Dynamics of aerobic and anaerobic microperiphyton formation in a pilot installation of a hydrobiological purification system

Background. The fuel oil spill, which occurred after a tanker accident in the Kerch Strait in December 2024, caused considerable damage to the Black Sea ecosystem. Relevance. Due to the recent events, the installation of hydrobiological purification systems (artificial reefs) in the coastal waters of the Black Sea has become an urgent issue. These systems are based on the natural processes of self-purification of the marine environment, including the removal of oil hydrocarbons. The aim of this work was to study the features of the formation of some physiological groups of the aerobic and anaerobic bacterial community of macroperiphyton in a hydrobiological purification system (HPS). Methods. Sampling and subsequent processing of the material were carried out in accordance with standard methods used in hydrobiology and general microbiology. Results. It was found that, in the annual cycle of observations, the abundance of heterotrophic and hydrocarbon-oxidizing bacteria in the macroperiphyton formed on the installed netting components of the HPS is several times higher than in seawater, both near the HPS and at some distance from it. The degradation of organic matter in the HPS involving the oxygen was generally accompanied by its anaerobic transformation. No seasonal differences in the quantitative content of anaerobic bacterial groups were observed. Conclusion. Bacterial activity (ability to process and remove organic compounds) is moderately higher in the vicinity of the experimental system installation than at a distance from it and significantly increases within the periphyton of the netting components of the system, which confirms the high sorption capacity of the periphyton of the hydrobiological purification system and its crucial role in the self-purification processes in this water area.