In the 1940s the scientist Otto Jaag was a pioneer who characterized TC communities in different areas of Switzerland using morphological analysis. Cyanobacteria also can produce toxic metabolites that are well studied in surface waters. However, we currently have no information about cyanotoxins from Tintenstrich in the Swiss. With our work, we return to Jaag field sites and investigate the genetic and metabolite biodiversity of cyanobacteria with state-of-the art analytical tools including Illumina sequencing and high-resolution tandem mass spectrometry. Beyong the biodiversity, we further investigate possible transport of bacteria or toxins from the TCs with the runoff water and study herbivore interaction with cyano-lichen.