tankoslojna kromatografija, tekućinska kromatografija, masena spektrometrija, Environmental changes inevitably lead to acclimation or adaptation of phytoplankton in order to survive. Life in estuaries, especially in surface waters, is a challenge, particularly because of the fluctuating salinity. Here we present the acclimation/adaptation of phytoplankton thylakoid membranes to salinity stress, which includes remodeling of monogalactosyldiacylglycerol (MGDG) fatty acids. The conclusions were drawn on the basis of work on two completely different estuaries, the Krka River estuary, in Croatia and the subtropical Wenchang River estuary, in China. The estuaries differ in phytoplankton community compositions, nutrient status and temperature. We used thin-layer chromatography and liquid chromatography/tandem mass spectrometry.