Assessment of the Pollution by Organic Substances of Water and Sea Bottom Sediments of the Kerch Strait and the Adjacent Azov-Black Sea Water Area

Abstract

The concentration of total petroleum hydrocarbons in the surface layer of seawater in the Azov part of the pre-strait area did not exceed the sanitary norm (0.05 mg l−1). In the waters of the Black Sea pre-strait zone, isolated cases of exceeding the MPC were noted. In the surface water layer of the Azov Sea the number of heterotrophic bacteria ranged from 104 to 105 cells ml−1, hydrocarbon degrading bacteria were isolated in single quantities. In the water area of the Black Sea region of the Kerch Strait, the number of heterotrophic bacteria was 106 cells ml−1, the number of hydrocarbon degrading bacteria did not exceed 10 cells ml−1. The number of heterotrophic bacteria in the bottom sediments of the Azov pre-strait zone varied within 2.5 × 104–4.5 × 104 cells g−1, the quantitative indicators of hydrocarbon degrading bacteria did not exceed 102 cells g−1. In the Black Sea region of the strait, the number of heterotrophic bacteriobenthos was 2.5 × 104 cells g−1, hydrocarbon degrading bacteria: 95 cells g−1. Compared with previous data, an increase in the quantitative indicators of the content of chloroform-extractable substances and total petroleum hydrocarbons in sea bottom sediments was noted. At the same time, the overall level of pollution did not exceed the average values determined for this region.