Diatoms as indicators of eutrophication in the SW part of the Gulf of Gdańsk, the Baltic Sea

Abstract

The aim of this study was to reconstruct paleoenvironmental changes of the SW part of the Gulf of Gdańsk. Three subbottom sedimentary cores were analyzed with respect to diatom flora. Post-Littorina Sea assemblages were noticed in the lower parts of the cores, whilst the present-day eutrophication of the gulf was evidenced in their superficial sediments, with high abundance of so-called 'anthropogenic assemblage' taxa. Shifts in the species composition might have been caused by intensified nutrient load, increasing organic matter concentrations and possible silica limitation.

Late Holocene Vistula River Floods Recorded in Grain Size Distributions and Diatom Assemblages of Marine Sediments of the Gulf of Gdańsk (Baltic Sea)

“…Damrat et al (2013) estimated that more than two-thirds of the sediment mass deposited on the Vistula River prodelta may be redeposited to the deeper part of the Gulf of Gdańsk. The waters are eutrophic (Niemkiewicz and Wrzołek, 1998;Szymczak-Żyła and Kowalewska, 2009;Leśniewska and Witak, 2011;Voss et al, 2011;Szymczak-Żyła et al, 2019) and with low visibility, which limits the photic zone up to a few meters (Łysiak-Pastuszak et al, 2004;Witak and Pędziński, 2018). Moreover, during summer periods cyanobacteria blooms were frequently observed in recent decades (Pawelec et al, 2018;Pliński et al, 2007).…”