Spatio-temporal distribution of zooplankton and physico-chemical conditions of Wasai Reservior, Kano State, Nigeria

Abstract

A study of spatio-temporal distribution of zooplanktonic community in relation to physico-chemical water condition of Wasai Reservoir was carried out between March and October, 2018. Three sampling sites selected for the purpose of this study were based on different human activities taking place in the areas like fishing, sand collection, washing etc. Nine physico-chemical and biological parameters were determined on fortnight basis 8:00 to 10:00am using standard methods. The result revealed that temperature, pH, Electrical conductivity, Total dissolved solids, Dissolved oxygen, Biochemical oxygen demand, transparency, nitrate and phosphate ranged from 24.4 to 29.1°C, 6.4 to 8.4, 353.3 to 846.6µS/cm, 264.3 to 602.8mg/L, 6.7 to 10.9mg/L, 2.8 to6.8mg/L, 5.6 to 12.3cm, 0.12 to 0.55mg/L and 0.08 to 0.22mg/L respectively. A total of thirteen (13) species of zooplankton were identified from the reservoir out of which three (3) belong to the class copepoda with a highest mean value of 37.67 recorded in May and lowest, 8.88 in October. Five species belong to the class Rotifera with a highest mean of 2.93 recorded in March and lowest in June (0.80). Similarly five species belong to the class Cladocera, with highest mean of 3.40 in April and lowest (0.27) in June and October respectively. The result showed seasonal variation in zooplankton species, as thier distribution increased in the dry season than in wet season, primarily due to the increase in photic depth of the water. Pearson correlation coefficient was used to determine the relationship between zooplankton and physico-chemical parameters. The correlation coefficient of physico-chemical parameters and zooplankton of the reservoir revealed strong positive correlation between zooplankton, EC, TDS, pH, Temperature and transparency at (P<0.05)while negative correlation exist between zooplankton, BOD₅, DO, Nitrate and Phosphate at (P<0.05).

Keywords: Distribution, Diversity, Reservoir, Wasai, Zooplankton.