ПРОГНОЗ ДИНАМИКИ ПЕРВИЧНОЙ ПРОДУКЦИИ ОРГАНИЧЕСКОГО ВЕЩЕСТВА И ЗАГРЯЗНЕНИЯ ПРИОРИТЕТНЫМИ ТОКСИКАНТАМИ АЗОВСКОГО МОРЯ НА КРАТКОСРОЧНУЮ ПЕРСПЕКТИВУ

Abstract

Background. Modern climate changes and increasing anthropogenic water withdrawal in the Azov Sea river basins have led to a reduction in freshwater runoff and a record increase in the sea salinity. Relevance. Salinization of the Azov Sea leads to a transformation of the structure of biological communities and a decrease in primary productivity, which inevitably has a negative impact on fish productivity. Another important factor in the stock formation of aquatic biological resources is the quality of their habitat. Aim of this work is to make a short-term forecast of the hydrochemical foundation of biological productivity and toxicological status of the Azov Sea up to 2030. Methods. This study was based on the long-term data on the level of primary production, hydrochemical regime and accumulation of priority toxicants in the Azov Sea ecosystem. Results. In the present period, adaptation of the Azov Sea ecosystem to increasing water salinity is manifested in a decrease in the level of primary production. In recent years, during the summer season, an unfavorable physiological state of phytoplankton has been observed due to the high content of pheophytin in the cells. In the Azov Sea, from 1986 (the peak of industrial development and anthropogenic load) up to the present, in the water, bottom sediments and muscles of commercial fish species, has been observed a decrease in the average annual concentration of the majority of monitored toxicants. Conclusions. Under the most likely forecasted scenario for the river flow and water salinity (14.5–16.5 ‰), a further decrease in the level of primary production is expected. It is possible that the ecosystem will adapt to the increase in water salinity; phytoplankton will be characterized by a more favorable physiological state in the summer. No deficiency of biogenic elements is predicted. If the existing anthropogenic load remains unchanged (the most likely scenario), the level of sea pollution by anthropogenic toxicants is predicted to be low, and in certain areas—Taganrog Bay, the waters of the Yeysk and Temryuk Sea Ports—it is expected to be moderate. The quality and safety of aquatic biological resources as a food product will meet regulatory requirements.