Phytoplankton Abundance, Distribution and Diversity in Upper River Benue, Adamawa State, Nigeria

Phytoplankton Abundance, Distribution and Diversity of Upper River Benue were examined between January and June. Biological conditions of Upper River Benue were assessed at five selected sites on monthly basis between 6:00 – 10:00a.m. Water Samples were taken using standard procedure for the analysis of phytoplankton. A total of 1,803 organisms were recorded for phytoplankton abundance. Chlorophyceae was observed to have a total abundance of 34.28%, followed by Cyanophyceae contributed a total of 31.54%, while the least was Rhodophyceae that gave 4.93%. The number of taxa (19) was recorded across the sites. The abundance of individuals was highest at site V. Nineteen (19) species of phytoplankton were identified during the study period ranging from seven Chlorophyceae, five Cyanophyceae, four Bacillariophyceae, two Euglenophyceae and one Rhodophyceae. The order of dominance of the phytoplankton in Upper River Benue was Chlorophyceae > Cyanophyceae>Bacillariophyceae>Euglenophyceae>Rhodophyceae respectively with Oscillatoria splendid being the most dominant (8.54%) of the total phytoplankton in Upper River Benue. The study showed that the river was eutrophic with high ecological with diverse assemblages of phytoplankton. It was recommended that there should be continuous monitoring of the biological of the river to ascertain the long-term impact of anthropogenic inputs to take remedial measures so as to ensure the health of aquatic life.