The TRANSDRIFT II expedition was part of the joint Russian-German cooperation and the Laptev Sea System project. The Arctic and Antarctic Research Institute (AARI) in St. Petersburg and the GEOMAR Research Center for Marine Geosciences were jointly responsible for the organization and coordination of the TRANSDRIFT II expedition, which was funded by the Russian Ministry for Research and Technology and the German Ministry for Research and Technology.The TRANSDRIFT II expedition was carried out aboard the Russian RV PROFESSOR MULTANOVSIY. The main target areas of the expedition were located in the eastern Laptev Sea, north of the Lena Delta, and along the Anabar-Khatangar Valley. A multi-disciplinary meteorological, oceanographical, chemical, biological and geological working program was carried out in bilateral cooperation. The specific tasks of the expedition were to identify the present pathways of river discharge and to differentiate the sediments and variability of the rivers feeding the Laptev Sea during the Holocene. CTD data were retrieved at a total number of 102 positions in the Laptev Sea. Hydrochemical sampling with oxygen, silicate and phosphate analysis was carried out at 93 of these stations. During the transit through the Kara Sea and Vilkitskiy Strait an additional number of 16 stations were sampled with CTD oxygen, silicate and phosphate analysis.