INVESTIGATION OF COLIFORMS IN LAGOS LAGOON ECOSYSTEM WITH A FOCUS ON SALINITY AND POLLUTION LEVELS

Abstract

Pollution of the Lagos Lagoon is one of the major ecological concerns in Lagos metropolis. The ecological survey of coliform was performed to determine the level of pollution in Lagos Lagoon. Water samples were collected from Iddo, Makoko, Unilag, Oyingbo, and Marina sample stations. The physicochemical and bacteriological analyses were performed under standard procedures. The values of the water samples ranged from; 4.2±0.019 to 7.7±0.016 for pH; 26.7±0.012 to 28.9±0.125 for temperature (°C); 0.38±0.016 to 0.56±0.044 for turbidity (nephelometric turbidity unit (NTU)) and 541.8±13.207 to 40672.02±1252.930 for salinity(mg/L). The selected physicochemical parameter results were analyzed using the one-way ANOVA test. The test revealed that the mean values of the parameters were not significantly different for the five sample stations. The pairwise test revealed no significant difference between the sample stations in the Lagos Lagoon. The predominant bacteria isolated belonged to the following genera: Klebsiella, Escherichia, Providencia, Salmonellae, Enterobacter, Aeromonas, Pseudomonas, and Citrobacter. The total viable counts ranged from 1.0 x 10⁷ cfu/mL to 2.5 x 10⁹ cfu/mL, and the total coliform counts ranged from 1.0 x 10⁵ cfu/mL to 2.5 x 10⁶ cfu/mL. The study revealed high coliform count in Lagos Lagoon. Therefore, the study stresses the need for authorities to implement laws and regulations to prohibit the discharge of untreated wastes into waterbodies to control faecal pollution.