Branched glycerol dialkyl glycerol tetraethers (GDGTs) are bacterial membrane lipids, ubiquitously present in soils and peat bogs, as well as in rivers, lakes and lake sediments. Their distribution in these environments can provide valuable information on the environmental conditions and the microbial communities present. The analysis of GDGTs in aquatic environments has been used to reconstruct past temperatures, salinity, and other environmental parameters. This research activity aims to investigate the distribution and fate of GDGTs in different aquatic environments, including rivers, lakes, and estuaries, and to develop new methods for their analysis and interpretation.