Hydrocarbon-Oxidizing Bacteria in the Digestive System of Fish as an Indicator of Coastal Pollution

Assessment of pollution of marine environment and biota with hydrocarbons is of particular importance, since oil products are among the priority pollutants of many seas. Development of new environmental toxicological biomarkers is one of the promising methods of integrated assessment of pollution effects. Here, the first investigation on the abundance of hydrocarbon-oxidizing bacteria in the digestive system of coastal fish (stickleback, dace, white bream, common bleak, perch, gudgeon, and roach) from the eastern Gulf of Finland, Baltic Sea has been performed. The results reflect changes occurring in the environment and indicate contamination of water and sediments with oil and oil products. The relative abundance of hydrocarbon-oxidizing bacteria in the digestive tract of fish is an effective, sensitive, and low-cost indicator of environmental pollution that can be used in monitoring and environmental impact assessment of the aquatic ecosystems.