Impact of some hydrological factors on phytoplankton community structures in Agaie-Lapai dam reservoir of Niger State

Abstract

The impact of sons hydrological factors (rainfall inflow and depth of water) on phytoplankton biodiversity in Agaie-Lapai dam reservoir were studied by monthly sampling and measurements taken from May.213 to October. 2014.This reservoir ba19°30'N latitudes and 6° 33'E of longitudes. The reservoir is near Bakaje village at the confluence of the River Jatau and two other rivers Jimada and Chemi. Samples of phytoplankton were collected with plankton net of 50um mesh size in designated stations within the reservoir. Seven (7) phytoplankton taxa are identified during the study belonging to Chrysophyta (with 196 spp). Bacillariophyta (104 spp. Chlorophyta(with 196 spp). Cyanophyta (with 21 spp) Euglenophyta (with93 spp), phytophyta( with 35 spp) and Cryptophyta (with 35spp). The highest level of impact of rainfall was corrected by the phytoplankton from the month of November to December. Cytophyta recorded the highest respond while other phytoplankton taxa showed increase or decrease in the first and second season respectively. The Bacillariophyta and Euglenophyta taxa did not respond to the fall and rise of rainfall level while other phytoplankton taxa were significantly correlated by the rainfall.