Phytoplankton Biodiversity in the Black Sea: A Comprehensive Study of Community Structure based on High-Performance Liquid Chromatography (HPLC) Pigment Analysis

The Black Sea's marine ecosystem houses a diverse phytoplankton community crucial for the region's biogeochemical processes. Recent attention has focused on comprehending the taxonomy and community dynamics of Black Sea phytoplankton. High-performance liquid chromatography (HPLC) serves as a potent analytical tool for pigment separation and identification in phytoplankton samples. This study examines HPLC pigment data collected between 2006 and 2019 during 12 oceanographic bio-optic campaigns in the Black Sea. The research investigates taxonomic composition and community structure of the phytoplankton community. Analysis of the dataset involved employing various machine learning and bioinformatics tools. Additionally, the dataset was used for chemotaxonomycal classification and for the development of phytoplankton functional type (PFT) regionalized model. All these methods aimed to identify distinct phytoplankton groups and their relative abundance throughout the campaigns. Results indicate that the Black Sea phytoplankton community is predominantly composed of diatoms and dinoflagellates, with varying contributions from other groups such as prasinophytes, haptophytes (coccolitophores), and chlorophytes. Additionally, the study discerned diverse patterns of community composition and pigment ratios across the campaigns, revealing spatial variations in phytoplankton community structure influenced by factors like nutrient availability and water column stratification. This research significantly contributes to understanding the taxonomy and community structure of Black Sea phytoplankton through the application of advanced multivariate analysis techniques.