Impact of the brine discharge on the bottom ecosystem of the Sambia Peninsula coast (South-Eastern Baltic Sea)

The first underground gas storage facility in Russia, built in rock salt deposits, was developed in the coastal zone of the Kaliningrad Region. Since 2018, seawater for erosion of rock salt is taken from the Baltic Sea, and after appropriate treatment, brine is discharged back to the sea. The aim of the work was to assess the impact of the brine discharge on the bottom ecosystem of the coastal shallow area. A comprehensive study was carried out on the possible path of salt brine propagation, including a bathymetric survey, CTD sounding of the water, sampling of bottom sediments and zoobenthos, determination of heavy metals in sediments. The main pathways for the spread of brine along the bottom were determined, and the additional supply of salt to the coastal zone naturally led to local changes in the existing bottom ecosystem of the coastal shallow water, including changed in the structure of zoobenthos.