Ecological Survey of Aquatic Macrophytes in Tatabu Reservoir, Niger State, Nigeria

Tatabu reservoir water body was divided into three distinct sampling sites (Upper, Middle and Lower course). Three different sampling locations were established between each sampling site. The entire areas of each of the sampling plots were inventoried into details and the biological forms and spatial distributions of the aquatic macrophytes were noted, water and sediment samples were also collected for analysis and nutrient load. A total of 21 plant species belonging to 13 families were recorded during the low water regime while 24 plant species belonging to 14 families were recorded during the high water regime. The floristic biological life form of these plants consists of 17 emergent plant species, 5 floating and 2 submerged plant species during the low water regime while during the high water regime, there were14 emergent, 5 floating and 2 submerged macrophyte species. comparative studies of low and high water regime showed that the maccrophytic species composition during both water regimes were a bit similar. Nitrogen concentration (mg/l) in water samples ranges between 3.5 to 13.5 during the low water regime and 5.5-17.5 during high water regime, Phosphorous (mg/l) ranged between 2.8-15.7 and 2.7-17.5 during low and high water regime respectively. Potassium (mg/l) ranged between 3.5-14.0 and 3.0-16.5 during low and high water regime respectively. Nitrogen concentration (mg/l)in soil (sediments) samples ranges between 3.0 to 12.5 during low water regime and 3.0-6.0 during low and high water regime respectively, potassium (mg/kg) ranged between 3.0-12.5 and 3.0-13.5 during lowand high water regime respectively. Higher proliferation of aquatic macrophytes and more species were observed during the higher water regime than what was observed during the low water regime. This present study shows a dangerous trend in the rate at which invasive plants are colonizing the reservoir, it is therefore essential to monitor and manage the influx of these invasive plants in the reservoir, most especially typha spp, water lilly and other aquatic plants that can bore heavy financial loses.