Floristic Study on Aquatic and Terrestrial Algal Community in the Natural Ponds of the Shibkouh District (Hormozgan, Iran); Occurrence of a Green Bloom of Dunaliella salina

Natural ponds are renowned for harboring a unique microalgal community, encompassing a wide diversity of common and rare species, including diatoms, cyanobacteria, and green microalgae. Yet, no comprehensive floristic study has ever been conducted on the natural ponds within the Shibkouh District. In this study, water and soil samples were collected from three distinct sites within the Shibkouh District (water bodies, wetland, and soil) to investigate the algal diversity present in these habitats. To cultivate the collected samples for further analysis, two different culture media were employed - BG11 and BG11: 1.5 M NaCl. Notably, an intriguing occurrence observed during this study was the bloom of Dunaliella salina in its green phase specifically in the semipermanent pond. Our findings revealed a total of 26 taxa comprising 12 genera of cyanobacteria, four genera of diatoms, and two genera of Chlorophyta. Remarkable variations were observed in both species richness and taxonomic composition between aquatic and terrestrial ecosystems. Furthermore, notable differences were observed when comparing samples cultured in different types of culture media. Diatoms were also identified as the dominant microorganisms adapted to extreme conditions typically found within wetland habitats (Site 2). This Site exhibited higher taxa richness compared to other sampling locations. As a result, these natural ponds have a vital role in preserving algal biodiversity. They serve as habitats not only for typical freshwater microalgae but also for halotolerant taxa such as diatoms that can thrive under difficult environmental conditions.