Hanna Mazur-Marzec works at the Institute of Oceanography, University of Gdańsk, where she established the Division of Marine Biotechnology Throughout her whole career, Hanna’s research activities have been focused on bioactive metabolites produced by microalgae. Initially, she studied the plant growth regulating activity of microalgae, then she became interested in cyanobacteria and cyanotoxins. A significant part of her work was dedicated to the Baltic cyanobacterium Nodularia spumigena and cyanopeptides produced by this species. She studied structural diversity, biological activity, bioaccumulation and biodegradation of the compounds. In her recent studies, she has also explored the ecological role of cyanopeptides and demonstrated their application as molecular markers. Her current research interests extend to other cyanobacteria and their bioactive products. She has extensive experience in mass spectrometry. Since 2017, she has also been employed at the Institute of Oceanology, Polish Academy of Sciences.