Assessment of the Bacteriological Quality of an Aquatic Ecosystem in South of Benin: Case of Ahémé Lake

Abstract

The study aims to assess the bacteriological quality of water of the Ahémé lake, the second most productive lake of Benin, after Nokoué lake. For this, 21 points were sampled on the lake during two campaign periods during the year 2016: the low water period (March) and the flood period (September). A total of 42 water samples were taken and their charges in total flora, thermotolerant and total coliforms, Staphylococcus and Salmonella were determined. Despite the absence of salmonella in all those withdrawn waters, average charges recorded in both periods (low water period as flood period) for these counted germs were not consistent with standards. Mean charges expressed in CFU/mL of the total flora, total and thermotolerant coliforms and staphylococci recorded at low water were respectively of 19.69.108, 17.49.105, 12.07.105 and 12.40.103. These values increased and reached respectively 29.56.108, 22.41.105, 15.84.105 and 27.53.103 during the flood. Waters of Ahémé lake are considerably loaded with germs of fecal contamination. This lake pollution affects the quality of fishery products in it and perhaps also a potential source of disease.