Seawater samples were frozen at a temperature of -10°C for 12-24 hours, and then slowly thawed at room temperature during 1-2 days. Freezing/thawing was performed in 1.5 l and 2 l plastic bottles. In all bottles with initial salinity of 30 psu, a diluted layer with salinities between 3 and 15 psu (average 7 psu) was formed at the surface. Close to the ice/water interface, the salinity varied between 6 and 14 psu. At the bottom a thin layer with a salinity of 40-50 psu was created. These vertical salinity differences were preserved after a period of 24 h. Additional experiments showed that similar water stratification occurred for samples with initial salinities of 27, 24, 20, 15, 10, 6 and 1 psu. The observed phenomena resemble the formation of brine fingers in Antarctic waters.