SEASONAL WATER SALINITY VARIABILITY OF THE MIDDLE PART OF THE SUKHOI LIMAN (BLACK SEA)

Abstract

Problem Statement and Purpose. The middle part of Sukhoi liman is connected to its lower part (including port area) by a narrow strait. Water exchange between the parts is limited by a pontoon ferry. The salinity of water masses determines by many economic and biological processes in the liman and their parts as well. The salinity of the Sukhoi liman water masses has been mostly studied in the lower part. The middle part was studied only in summer. Seasonal variability in the salinity of the middle part is unexplored. Annual salinity rates there changed depending on a water area from 12.8 ‰ to 15.6‰. As for mineralization the studied water masses are brackish (1–25‰). The main goal of the article is to determine current seasonal changes in the salinity of the Sukhoi liman middle part.Data & Methods. This study is based on results of the laboratory treatment of water samples collected during shore-based stationary exploration from May 2019 to Janu­ary 2020. Water samples were taken every last day of the month, close to noon when the temperature of water and its level stabilized. In June 2019, the salinity of the water was examined at sections in the northern, central and southern parts of the water body under investigation. Water samples were taken at 0.1H horizons from the surface and near the bottom. 10 samples were taken at the observation point and 12 at the sections. Water salinity was determined by the areometric method, not later than in two days after sampling. Data about meteorological conditions during the observation period (air temperature, wind speed and direction) are obtained from www.rp5ua.Results. Seasonal variability in the salinity of water masses has a number of distinc­tive features. The spatial distribution of the salinity of the middle part of the Sukhoi liman is homogeneous, with maximal values in the central part of the water body and decreasing towards the upper and lower parts. The salinity varies from 10.4‰ up to 15.3‰ per year: maximum values are observed in summer and autumn, the salinity is minimal in spring and the salinity is average moderate in winter. The salinity of water masses is influenced by meteorological conditions, mainly air temperature and wind. Further observations of the salinity and features of the hydrological regime of the mid-water area have practical and scientific significance for the development of the Sukhoi liman use, and for evaluating how the construction of a road bridge influ­ences to the natural resource. It is also scientifically valuable to study the patterns of transformation of water masses when they move from the sea to different parts of the liman.