Composition and Diversity of Algal Flora in Jahanara Imam-Pritilota Hall Sorobar (JP) Lake of Jahangirnagar University Campus, Savar, Dhaka, Bangladesh

The study aimed to evaluate the composition and diversity of algae in the JP Lake of Jahangirnagar University campus. The research was carried out between the period of December 2021 to November 2022. A total of 72 water samples were used to carry out the investigation. Shannon and Simpson diversity indexes were used to determine the level of diversity. 234 phytoplankton species under 98 genera were found belonging to 8 classes (Cyanophyceae, Chlorophyceae, Bacillariophyceae, Synurophyceae, Euglenophyceae, Cryptophyceae, Dinophyceae, and Xanthophyceae). According to the generic percentage composition, Chlorophyceae comprised 46%, followed by Bacillariophyceae (20%) and Cyanophyceae (18%). At the species level, Euglenophyceae were found to dominate (34%) the studied sites that were followed by Chlorophyceae (31%) and Cyanophyceae (18%). The total density of phytoplankton was 387.34×105 ind/l. The highest phytoplankton density was found in April, and the lowest one was in November. Cell dispersion was below average in May for Cyanophyceae, Bacillariophyceae, Cryptophyceae, and Synurophyceae. Oscillatoria, Monoraphidium, Actinastrum, Cosmarium, Trachelomonas, and Euglena dominated the surveyed region. The Shannon Diversity Index showed a value of 1.51, while Simpson's Diversity Index showed a value of 0.28. The overall variation (80.73%) among the classes was represented by PCA cells. According to the Shannon and Simpson Diversity Indexes, the diversity was low.