ABSTRACT

Water quality, composition, abundance and distribution of plankton community in Obodu stream were assessed. The stream were divided into three stations for samplings, samples were collected from August 2019-July 2020 to reflect spatial and temporal dynamic water and plankton sample were collected rapidly in all the stations. One-way analysis of variance (ANOVA) was used to test significant difference among physico-chemical parameters within and between the stations at 0.05 level of significance while spearman correlation method was used to described the relationship between plankton abundance and phsico-chemical parameter. A total of (16) sixteen physic-chemical parameters were examined and had the following results: water temperature value ranged from 26.80^oc to 27.30^oc conductivity from 63µS/cm to 94µs/cm Ph from 4.9 to 6.9. total Dissolved solids and Dissolved Oxygen ranged from 37.0mg/1 to 94.1mg/m and 3.1/mg/1 to 6.7 mg/1. Total suspended solid ranged from 1.1 mg/1 to 4.2 mg/1, phosphate and Nitrate ranged from 0.3mg/1 to 3.1mg/1 and 0.1mg/1 to 2.2mg/1. The parameters showed clear seasoned variation among all the stations. There was no significant difference in all the parameters except zinc and Iron which showed similar trend. During the study, a total of (16) species of phytoplankton belonging to four (4) taxanomic group were recorded. The group chrysophyta was represented one species. Consisting of 6.25% composition by species, followed by xanthophyta represented by two species consisting of 12.5% species composition. Chlorophyta represented by five species (31.3%), and eight spices of cyanophyta (50%). While zooplankton fauna of Obohu stream comprised (4) phyla with a relative abundance of 3.74% across the stations were sampled. Copepods dominated with ten (10) species while protozoa were represented by one five families, copepods, dominated each station followed by cladocerans, rotifers, protozoa in this order. The taxa richness, diversity, evenness and dominance index showed that station 1 and 3 recorded high taxa richness (Margalef index) and diversity index values were low in station 2. Similarly, station 1 and 3 recorded high values of evenness (Simpson’s dominance index) values was high in station 2 compared to other two stations examined. It was recommended that human activities such as bathing and washing of clothes should not be carried out in the stream.