Effects of Pollution on Vibrios in Woji River

Abstract

The effect of pollution on Vibrio spp. in five sampling stations along Woji River in Port Harcourt was studied in the months of April and November 2010. Vibrio vulnificus, V. parahaemolyticus and V. alginolyticus were isolated. The Plate count technique on Thiosulphate Citrate Bile Salt agar revealed a high population density of vibrios in the sampling stations than the Most Probable Number (MPN) technique. The average population density of vibrios ranged from 21MPN/100ml at Oginigba (station 1) to 1100MPN/100ml at Trans Amadi by slaughter (station 3) in April and 43MPN/100ml to 1100MPN/100ml in November respectively compared to plate counts that ranged from 2.2 x 10⁵cfu/100ml to 1.6 x 10⁸cfu/100ml in April and 3.2 x 10⁵cfu/100ml to 2.6 x 10⁸cfu/100ml in November respectively. The percentage proportion of Vibrio spp. to other heterotrophic bacteria ranged from 0.01 to 5.44% in April and 0.03 to 9.96% in November. The concentration of Total Dissolved Solids (TDS), Calcium, Magnesium, Hardness and chloride were much higher than the DPR/WHO limits and were not related to increase in presence of vibrios or their relative densities except for total dissolved solids. However, heterotrophic counts were high irrespective of the sampling station. There is therefore an urgent need to curtail the continued negative anthropogenic activities along the river course.