Explorative analysis of the mechanisms of Phaeocystis globosa blooms in the Beibu Gulf using amplicon sequencing data

Phaeocystis is an ecologically important cosmopolitan genus with several species that form harmful algal blooms. Previous studies of the mechanisms of Phaeocystis blooms have been hindered by the small size of Phaeocystis cells and the complex Phaeocystis life cycle, which includes multiple free-living stages and a colonial stage that dominates during blooms. In this thesis, I apply 16S amplicon sequencing to explore the mechanisms underlying a P. globosa bloom in the Beibu Gulf. Using the spatial-temporal dynamics of P. globosa, bacteria, archaea, phytoplankton and environmental variables, I develop a model for the development and progression of the P. globosa bloom. After, I identify bacteria that interact with P. globosa during the bloom by studying the P. globosa colony microbiome. While P. globosa colonies had different bacterial compositions compared to seawater samples collected from the same locations, I did not find evidence for a core P. globosa colony microbiome.