10.18453/rosdok_id00005674 Santoro, Mariano Mariano Santoro http://d-nb.info/gnd/1412528674 https://orcid.org/0000-0003-2171-4785 Universität Rostock 2025 500 Natural sciences 570 Life science 2025 en https://purl.uni-rostock.de/rosdok/id00005674 urn:nbn:de:gbv:28-rosdok_id00005674-1 This dissertation explores ecological and physiological drivers of cyanobacterial blooms in the Baltic Sea, where nutrient imbalances and weather fluctuations influence them in summer. Using different approaches, it shows how cyanobacteria persist under phosphate limitation through uptake, metabolic flexibility, and buoyancy control. It highlights the role of cyanobacterial communities in retaining phosphorus, the importance of picophytoplankton in early phosphate uptake, and how environmental disturbances shape bloom succession. This work support improved ecosystem monitoring and management.