Ecology and diversity of cyanobacteria in changing ecosystems in the Eastern Adriatic area

Cyanobacteria are ubiquitous bacteria that evolved photosynthesis and therefore made life on Earth possible by creating aerobic atmosphere more than 2 billion years ago. As primary colonizers, they have adapted to diverse types of environments, and primordial as well as actual extreme conditions. In that respect, they are considered indicators of the ecological properties of the environment in which they are found. This thesis aims at exploring the vast diversity and ecology of the Cyanobacteria, from ecosystems under different selective pressures: extreme drought and flood conditions as well anthropogenic pressures such as aquaculture, agriculture and urbanization Modern molecular-based methods, with emphasis on the highthroughput sequencing, were the main methods used in this study, thus providing an accurate picture of their diversity and community composition in different ecological niches. In both freshwater and marine ecosystems, habitats such as microbial mats, sediment and water column were explored to give an overview of diversity and adaptation of Cyanobacteria to different environmental conditions. These conditions are ever shifting under the climate change, whose impact is actually observed in the semi-enclosed Adriatic Sea. As a matter of fact, the relevance of the Cyanobacteria is especially highlighted in the vulnerable geographical and geological area of the karstic Adriatic, where the effects of climate change and land-based pollution are acting much faster than in other areas.