Hydrochemical Structure of the Waters in the Eastern Part of the Laptev Sea in Autumn 2015

The study of the Laptev Sea was a part of a comprehensive program for investigating Arctic seas during the cruise 63 of the R/V Akademik Mstislav Keldysh. On a transect along 130 degrees E (September 8-14, 2015) from the estuary area of the Lena River on the traverse of the city of Tiksi to the continental slope (over 700 km), water samples were taken to study the hydrochemical structure of waters and the influence of the Lena River flow. From the obtained data, it was found that the effect of fresh water on the sea surface layer was very high and can be traced to a great distance from the river delta. An unconservative distribution of some hydrochemical parameters in the mixing zone was recorded. The concentration of nutrients in the surface layer, and a high turbidity can serve as limiting factors in the development of the phytoplankton community.