The hydrological regime of Baltic Sea bottom water is strongly influenced by irregular inflows of high-saline, oxygen-rich North Sea water through the narrow Danish Straits. The aim of this work was to study the interrelation between the distribution of benthic foraminifera in the SouthEastern Baltic Sea and hydrology of the bottom water. Benthic foraminiferal distribution was analyzed in the 26 surface sediment samples, collected in the Baltic Sea during spring and winter 2016. Micropaleontological data were compared to the changes in dissolved oxygen content and the salinity of the bottom water. The species diversity of the benthic foraminifera in the studied region was very low. Agglutinated species, mostly single-chambered, were the most abundant in the assemblages. The distribution of the foraminiferal concentrations in the sediments had similar spatial patterns in both seasons. High shell concentrations as well as increase in faunal diversity were identified at the deeper parts of the study region where saline oxygen-enriched North Sea water is accumulated. Maximum foraminiferal concentration was found in the sediments of the Gdansk-Gotland Sill where halocline reaches the bottom which favors nutrient accumulation. However, the sharp dominance of very small individuals of Pseudothurammina shows that only some species can survive in the variable conditions associated with the halocline.

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Strong acceleration of abyssal flows in narrow deep‐water channels and fracture zones is a key feature of bottom circulation in the Atlantic Ocean. In the Equatorial Atlantic, these bottom currents transport Antarctic Bottom Water (AABW) over the Mid‐Atlantic Ridge from west to east. The main pathway for Antarctic waters in this region is the Romanche Fracture Zone. The deepest point of this fracture zone is the Vema Deep; its maximum depth based on the published data is 7,856 m. This deep basin is filled by waters of Antarctic origin overflowing a sill in a narrow channel. During the expedition on the R/V Akademik Ioffe (August 2022), we revealed a strong flow in the middle part of the Romanche Fracture Zone and collected new data on thermohaline and kinematic structures of this gravity current. Our survey is the first observational evidence of the intense flow into the Vema Deep. At the sill, the flow splits into branches flowing through three distinct channels of intricate configuration located in the southern transform valley of the fracture zone. The northern channel is proved to be the main pathway of the coldest and densest bottom waters to the Vema Deep. We also found that vertical structure of the flow is presented by two individual jets, namely the deep and bottom jets. The total transport of AABW through the Romanche Fracture Zone at this location was estimated at 1.40 Sv; the velocities exceeding 10 cm/s were found at depths greater than 5,000 m.

The sediment drift north of the Kane Gap has been investigated by means of the seismoacoustic profiling. The surface area of the drift is about 500 km 2 and maximal thickness is 70 m. The contourite drift was formed under the control of the Antarctic Bottom Water (AABW) flow in the Kane Gap. It is suggested naming this contourite fan as the "Kane Drift". Variations in the activity of the AABW current were registered in the sediment core ANS-33056, retrieved near the summit of the drift. For this purpose, the mean size of sortable silt (, mineral fraction 10-63 m) was used. It was shown that during the Mid-Pleistocene to Holocene, the speed of the AABW flow north of the Kane Gap was not strictly determined by the alternation of the climatic cycles. A strong relationship between the AABW flow and the short-time climatic fluctuations was found only during the marine isotope stages (MIS) 4 and 5: intensification of the near-bottom current coincides with the cold intervals. Moreover, during the Terminations II and I (MIS 2/1 and MIS 6/5, respectively), the intensity of the current also increased. Maximal near-bottom current activity was registered at the end of the MIS 2.

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