Phytoplankton Diversity in the Caspian Sea: A comprehensive Checklist

The Caspian Sea, the world’s largest inland body of water, supports a highly diverse community of phytoplankton species that play a crucial role in its ecosystem and overall food web dynamics. This unique, enclosed environment, which spans several countries, is subject to various ecological pressures, including climate change and anthropogenic activities, making it a critical area for biodiversity research. In this study, a comprehensive checklist of these species has been compiled based on an extensive literature review, revealing a total of 970 species and subspecies from 242 genera across 7 phyla. Bacillariophyceae was identified as the dominant class, comprising 347 species (36.37%), followed by Chlorophyta with 289 species (30.29%) and Cyanobacteria with 190 species (19.92%). Other notable groups include Myzozoa with 72 species (7.55%), Ochrophyta with 56 species (5.87%), Cryptophyta with 13 species (1.36%), and Haptophyta with 3 species (0.31%). This detailed inventory provides essential data on the phytoplankton biodiversity in the Caspian Sea, contributing to a deeper understanding of its ecological complexity. The checklist not only highlights the diversity within each phylum but also emphasizes the dominance of diatoms and chlorophytes, which are key to the sea’s primary productivity. These findings serve as a critical resource for future ecological and environmental assessments, offering a baseline for monitoring biodiversity changes, potential threats to the ecosystem, and the impacts of climate change and human activities. The rich phytoplankton diversity outlined in this study underscores the ecological significance of the Caspian Sea and its importance for regional and global biodiversity conservation efforts.