Environmental State of a Small Northern River after an Emergency Discharge of Oil Products

Abstract

The chemistry of surface water, bottom sediments, and zoobenthos communities is studied in a small forest watercourse after an accident on a petroleum pipeline. Nine months after the oil spill, the surface water downstream of the site of emergency discharge of oil-containing liquid still shows higher petroleum hydrocarbon content (2.8 MAC). The determined high concentrations of ions of iron (1.1−4.6 MAC) and copper (1.2−2.6 MAC), as well as difficult to decompose organic compounds (1.2−3.3 MAC), are also typical of the background area, thus suggesting their predominantly natural origin. The concentration of petroleum hydrocarbons in bottom sediments in water downstream of the emergency petroleum discharge site is 7–214 times its background value. The zoobenthos in the streams in the study area is represented by 18 groups of aquatic organisms, of which 14 are detected in the polluted zone. In the direction from the oil spill zone toward the mouth of the Vozei-shor Creek, the structure of zoobenthos changes and its quantitative characteristics decrease. Crustaceans and oligochaetes were found to dominate in the benthic communities of oil-polluted areas.