EN
The aim of the study was to investigate Holocene history as recorded in a single sediment core taken from the Slupsk Furrow, southern Baltic Sea, with the use of diatom analysis. Diatom stratigraphy and abundance of cysts of Chrysophyceae Pascher enabled the changes in salinity and depth of the Baltic during the last 7500 years or so to be followed. Four developmental stages of the Baltic Sea were distinguished on this basis: the decline of the Ancylus Lake (or the Ancylus/Mastogloia transition), the Mastogloia Sea, the Litorina Sea and the Postlitorina Sea.