POSSIBLE SCENARIOS FOR THE FORMATION OF THE CONTINENTAL RUNOFF AND THE SALINITY OF THE AZOV SEA, TAKING INTO ACCOUNT THE CURRENT AND FUTURE TRENDS IN CLIMATE CHANGE
Authors:   Russian Federal Research Institute of Fisheries and Oceanography (FSBSI “VNIRO”), Azov-Black Sea Branch of the FSBSI “VNIRO” (“AzNIIRKH”), Zhukova S.V. , Mirzoyan A.V. ,   Russian Federal Research Institute of Fisheries and Oceanography (FSBSI “VNIRO”), Shishkin V.M. ,   Russian Federal Research Institute of Fisheries and Oceanography (FSBSI “VNIRO”), Azov-Black Sea Branch of the FSBSI “VNIRO” (“AzNIIRKH”), Podmareva T.I. ,   Russian Federal Research Institute of Fisheries and Oceanography (FSBSI “VNIRO”), Azov-Black Sea Branch of the FSBSI “VNIRO” (“AzNIIRKH”), Lutynskaya L.A. ,   Russian Federal Research Institute of Fisheries and Oceanography (FSBSI “VNIRO”), Azov-Black Sea Branch of the FSBSI “VNIRO” (“AzNIIRKH”), Taradina E. A. ,   Russian Federal Research Institute of Fisheries and Oceanography (FSBSI “VNIRO”), Azov-Black Sea Branch of the FSBSI “VNIRO” (“AzNIIRKH”), Burlachko D.S. ,   Russian Federal Research Institute of Fisheries and Oceanography (FSBSI “VNIRO”), Azov-Black Sea Branch of the FSBSI “VNIRO” (“AzNIIRKH”), Karmanov V.G. ,   Russian Federal Research Institute of Fisheries and Oceanography (FSBSI “VNIRO”), Azov-Black Sea Branch of the FSBSI “VNIRO” (“AzNIIRKH”)
Published: April 2024

Introduction. The ongoing climate changes have a significant impact on the formation of the habitat conditions for the aquatic biological resources of the Azov Sea. Salinity of the Azov Sea waters and continental runoff, which role in maintaining the ecological well-being of the habitat of aquatic biological resources is paramount, has underwent particularly noticeable transformations. Relevance. Assessment of the degree of influence of ongoing and expected climate changes on the formation of abiotic parameters of the marine ecosystem is a prerequisite for planning the successful development of the fisheries industry of the Azov Sea Basin. The aim of this work is to assess the current and expected changes in the hydrometeorological parameters of the Azov Sea ecosystem, as well as to identify the most probable scenarios of changes in the Azov Sea salinity depending on the annual volume of continental runoff. Methods. The study is based on the data from AzNIIRKH database for the time range 1960–2020 collected over the course of the expedition surveys examining the Azov Sea hydrological regime and the data of the reference observation network of the Russian Federal Service for Hydrometeorology and Environmental Monitoring (Roshydromet). Methods of mathematical statistics, graphoanalytical construction, mapping and analogy have been used for the data analysis. Results. This paper assesses the changes in the hydrological regime of the Azov Sea based on the annual monitoring of the habitat of aquatic biological resources. Preliminary calculations have been performed, and new data on the changes in the parameters of the sea water balance equation not covered by monitoring over the past forty-five years have been presented. The most probable formation scenarios for the continental runoff and the Azov Sea water salinity for the future up to 2030 are considered, with the observed trend of climate warming taken into account. Conclusions. Both the climatic and anthropogenic factors have contributed to considerable changes in the current hydrometeorological regime of the Azov Sea. These changes have mainly been manifested in an increase in air and water temperatures, a decrease in wind activity, and in a reduced continental runoff, in the formation of which, since 2006, a prolonged low water content cycle has been observed. The shortage of river runoff and increased water evaporation rate, along with other factors, have induced an unprecedented increase in the Azov Sea salinity, the average annual value of which in 2021 reached a record high (14.97 %). In the most probable scenario (60 %) with the continuation of the low water content period and the continental runoff into the Azov Sea of about 22 km3 in volume, the average annual salinity of the Azov Sea, including Taganrog Bay, can reach 15±0.40 ‰ with a variation range from 14.5 to 16.5 ‰ in the sea itself (excluding Taganrog Bay). 2021 can serve as an analogous year in terms of salinity formation and its spatial distribution.