The paper assesses the quality of the marine environment of Laspi Bay near the Batiliman Stow according to main chemical and microbiological parameters under various recreational impacts on the water area. The material for the study was water and fouling samples taken in May, July and October 2023. The qualitative and quantitative composition of hydrocarbons was determined by gas chromatography on a Crystal 5000.2 chromatograph with a flame ionization detector in the Scientific and Educational Center for Collective Use «Spectrometry and Chromatography» of A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS. Diagnostic markers of the origin of hydrocarbons were used to identify possible sources of organic substances. The abundance of bacteria groups (saprophytic heterotrophic, hydrocarbon-oxidizing, lipolytic and phenol-oxidizing) was determined by the method of tenfold dilutions using elective nutrient media. From May to October 2023, the concentration of hydrocarbons in the coastal waters of the Batiliman Stow was 0.013-0.304 mg·L⁻¹. The composition of n-alkanes indicated the absence of oil pollution in the studied water area. The exceedance of the maximum permissible concentration for hydrocarbons, noted in July at one of the stations, is of natural origin and is associated with an active intake of allochthonous compounds. The quantitative assessment of the mentioned bacteria groups in the water and microperiphyton of macrofouling indicates an increase in the abundance of indicator groups of bacteria in all samples taken in July. Nevertheless, the results of the hydrocarbon content study and the quantitative assessment of the main microbiological indicators in the water and microperiphyton of macrofouling suggest that there are active bacterial self-purification processes in the water area of the Batiliman Stow. According to microbiological indicators, the studied area can be classified as conditionally clean.
Article text not included.