Fungi in marine environments, including yeasts, are far less studied than fungi in terrestrial environments, not only in Black Sea but also all over the world. The data about the biochemical activity of marine yeasts are presented. Yeast strains were able to be isolated from bottom sediments of three Sevastopol bays (Karantinnaya bay, Kruglaya Bay, and Yuzhnaya bay) during a sanitary-ecological survey of department of marine sanitary hydrobiology IBSS. We have showed hydrochemical characteristic of the studied area based on the literature review. The isolates grew well in a medium composed of sugars (glucose, lactose), in vitro ability to degrade starch and peptone. In addition, they used oil and petroleum hydrocarbons as the only source of carbon and energy actively. The indigenous microflora in heavily polluted environments faces a regular threat from pollutants and has therefore evolved the necessary enzymatic setup for their detoxification.