Composition, Diversity of Phytoplankton Community Structure and Its Environmental Correlates: A Baseline Study of Igbidin Stream, Edo State, Nigeria

Abstract

The objective of this paper is to investigate and provide baseline information on the composition, diversity of phytoplankton community structure and its environmental correlates in Igbidin Stream, Edo State, Nigeria analyzed according to standard methods. A total of four phytoplankton divisions were identified—Euglenophyta (46.67%), Bacillariophyta (30.0%), Chlorophyta (13.33%), and Cyanophyta (10.0%) with Euglenophyta contributing the highest proportion. Ecological indices (taxa richness, Shannon diversity, dominance) revealed spatial and seasonal variability in phytoplankton distribution, with generally higher diversity during the dry season. Study reveals that the stream is relatively pristine with low phytoplankton abundance. Palmer’s Pollution Index indicated low to very low organic pollution, with Station 3 showing relatively higher scores. Principal Component Analysis (PCA) identified nitrate, conductivity, and alkalinity as major environmental drivers of phytoplankton dynamics. The study provides vital baseline data for assessing ecological health and serves as a reference for monitoring anthropogenic impacts on freshwater ecosystems.