PLANKTON SPECIES COMPOSITION, ABUNDANCE AND DIVERSITY INDICES IN THREE PONDS OF CHITTAGONG UNIVERSITY CAMPUS, BANGLADESH

Md. Saiful Islama, *, M. A. Azadib, Munira Nasiruddinc and Muhammad Mohiuddin Sarkerd
Page No. 1-14

Species composition, abundance and diversity indices of phytoplankton and zooplankton of three ponds in Chittagong University campus were evaluated for two years period from January 2017 to December 2018. A composition of 12 phytoplankton and 33 zooplankton species were recorded in the entire study area. Anacystis cyanea as phytoplankton and Nauplius larva, Brachionus forficula, Cyclops varicans rubellus as zooplankton were the most dominant species in all the ponds. Phytoplankton and zooplankton abundance during the two years study was almost same. Phytoplankton species belonged to four groups (blue-green algae, green algae, desmids and diatoms,) where blue-green algae occupied the highest position in all the ponds, whereas, the zooplankton species belonged to five groups (cladocera, copepoda, rotifera, protozoa, and nematoda), of which rotifera and copepoda occupied the first and second positions in all the ponds. Species richness (S) of phytoplankton was almost the same in both the years but for zooplankton, species richness was found to be much higher in 2017 (S = 30) than in 2018 (S = 19). The range of Simpson diversity index (D) of phytoplankton in the three ponds were found to be 1.362-2.879 and 1.362-2.265, whereas, the range of zooplankton in the three ponds were 6.495-10.05 and 5.372-8.826 during 2017 and 2018 respectively. The Shanon Wiener diversity index (H') of phytoplankton in the three ponds were varied from 0.636 to 1.317 and from 0.235 to 0.9981 and that for zooplankton ranged between 2.229-2.506 and 1.847-2.457 in 2017 and 2018 respectively. According to Simpson and Shanon Wiener’s diversity indices of phytoplankton and zooplankton, the highest diversity was found in pond 2 and the lowest in pond 1. The range of Species Evenness (E) of phytoplankton in the three ponds varied from 0.2269-0.6042 and 0.2755-0.3235, and that of zooplankton varied from 0.3608-0.5288 and 0.3816-0.5372 during 2017 and 2018 respectively. The species evenness of phytoplankton and zooplankton indicated pollution in pond 1, where the individuals of the community were not equally distributed than the other two ponds. Pond-1 was found to be polluted due to mass use by the local peoples and draining of surrounding run-off, which should be stopped to keep the water quality in good condition.
Key words: Phytoplankton, zooplankton, species composition, abundance, species diversity indices