Tidal effect on the dispersion of fecal pollution indicator bacteria and associated health risks along the Kribi beaches (Southern Atlantic coast, Cameroon)

Assessment of fecal contamination indicator bacteria concentrations on beaches are important for health risk prevention and management. This study assessed temporal changes in bacterial abundances as a function of tidal cycles and seasons along the Kribi beaches, Cameroon. Overall, samples taken during low and high tides during the different seasons of the year showed that the waters of Kribi beaches are exposed to fecal contamination due to the presence of different concentrations of fecal coliforms (5–35 CFU/100 ml), total coliforms (100–600 CFU/100 ml), Escherichia coli (0–15 CFU/100 ml), Streptococcus feacalis (50–700 CFU/100 ml), Pseudomonas aeruginosa (300–7200 CFU/100 ml), Vibrio cholerea (5–250 CFU/100 ml), Vibrio parahemoliticus (0–115 CFU/100 ml), and Aerobic Mesophilic Heterotrophic Bacteria (99–875 CFU/100 ml). Regardless of bacterial strain and sampling site, cell abundances were significant at low tides and during rainy seasons. At each sampling station (Mpalla, Ngoyè and Mboamanga), depending on the seasons and tidal cycles, significant correlations were recorded between the abundances of some bacterial strains and some environmental variables (P< 0.05). The presence and high abundance of these potentially pathogenic bacterial strains in the waters of Kribi beaches constitute a real public health threat for swimmers. The limitation of this microbiological pollution requires the implementation of an efficient collection and treatment plan for solid and liquid waste (sanitary wastewater) in the city of Kribi.