Pollution of the Volga River basin with petroleum products in the Astrakhan region, Russia

Water bodies of the delta part of the Lower Volga are extremely important for preservation of biodiversity as feeding and breeding grounds for valuable fish species, including sturgeon species. Meanwhile, the anthropogenic load on these water ecosystems is increasing alongside the growth of oil and gas industry. Thus, the aim of this study is to dynamically assess the pollution of water bodies of the prime grade of fishery importance with petroleum products throughout 2014-2018.  The objects of this study are the water bodies exposed to anthropogenic impact of both operating enterprises and formerly active industrial facilities. The content of petroleum products in the samples of water and benthos deposits was defined in accredited laboratories as prescribed by Federal Environment Protection Regulatory Documents (PND F) 14.1:2:4.128-98 and 16.1:2.2.22-98. According to the results of the study, it was found that the content of petroleum products in water exceeds the maximum permitted concentrations (MPC) in all monitored sites, its highest value is 4.2 times the MPC in Kizan River in the vicinity of Sokolovskie Neftyanye Yamy (Sokolovsky Oil Pits), a formerly active industrial facility. Here, the maximum level of pollution of benthos deposits with petroleum products (18719.3 mg kg-1) was recorded, and, as a consequence, the degradation of zoobenthos diversity with oligochaeta remaining its only representative was observed.