Plankton Diversity and Water Quality of River Ose, Ondo State, Southwest Nigeria

Abstract

This study was conducted to investigate the plankton diversity and physico-chemical characteristics of River Ose in providing information that can be used for proper management and conservation of the water body. Plankton samples and water quality parameter were observed for 12 months (February, 2022 to January, 2023). Plankton abundance was estimated using Shannon-wiener diversity index (H). Physico-chemical parameters which include: pH, Temperature, Conductivity, Dissolved Oxygen, Salinity and Total Dissolved Solid were determined insitu using a multi-parameter probe meter. The species composition of phytoplankton was dominated by five phyla, Bacillariophyta, Chlorophyta, Cyanobacteria, Ochrophyta, and, Myzozoa while that of zooplankton were the Arthropod, Ciliophora and Rotifera groups. Spirogyra sp. which belongs to the phylum Chlorophyta had the highest relative abundance (8.31%) while Thalassionema sp. which belong to phylum Ochrophyta had the lowest relative abundance (0.83%). Higher abundance of plankton was recorded during the dry season (61.13%) when compared with the raining season (38.38%). Shannon-Wiener diversity index (H) and Evenness (E) were 3.25 and 0.93 respectively. The results of the physicochemical parameters were within the acceptable range across the 12 months of study.