The complex expedition will be carried out in several areas of research, one of which will assess the distribution, qualitative structure and reserves of three species of Caspian sprat (anchovy, common and big-eyed), the conditions and efficiency of their reproduction, including the use of hydroacoustic research methods. It is necessary to study the areas of commercial concentrations of Caspian sprat in the summer, the density and area of aggregations. The sprat survey is based on a scheme of standard sections and stations distributed across the waters of the Middle Caspian. The stations are located at nine sections with depths from 50 to 120 m, crossing the coastal zone and the circular current zone. The sections are located perpendicular to the coast. The section length, depending on the shelf width, ranges from 20 to 70 miles, the distance between stations is from 2 to 10 miles. The purpose of this study is to assess the qualitative structure and stocks of sprats in the Caspian Sea for further calculation of the forecast of the recommended catch, which indicates the important role of the annual sprat survey.
Another direction - oceanographic survey - will allow to study the hydrological-hydrochemical and ecological-toxicological conditions for the formation of biological productivity of the Caspian Sea, to analyze how favorable these conditions are for the growth and development of aquatic bioresource populations, their provision with food. The next direction of research planned for this expedition is monitoring of aquatic biological resources and their habitat in licensed areas for the development of fields in the Caspian Sea.
Leading specialist of the Central Institute of VNIRO Ruslana Anokhin is taking part in the expedition with the aim of studying the hydrochemical structure of the waters of the Middle Caspian in conditions of extremely low sea level and determining the degree of hydrogen sulfide contamination of its deep-sea basins. The vertical distributions of organic carbon and silicon will also be determined as an indicator of the development of diatoms.
Such complex expeditions, conducted in the Caspian Sea for many years, are traditional, they allow tracking the state and dynamics of changes in the populations of commercial bioresources and other aquatic organisms, changes in the environmental situation.
Press service of VNIRO