The assessment of the quality of the waters of the Cotonou Channel was made to see the degree of contamination of this ecosystem subjected today to various forms of pollution.
The methodology used in this study consisted of taking water samples, the necessary treatments of which were made at the Water Quality Laboratory of the Directorate-General for Water (DG-Eau). For this purpose, certain physical and chemical parameters (turbidity, color, pH, temperature, conductivity, chlorides, ammonium, sulphates, nitrates, nitrites and phosphates) were measured in situ and others have been assayed by atomic absorption spectrophotometry.
The results obtained for the analyzes of the physicochemical parameters reveal that the temperatures recorded are within the range tolerated by the hot water species (25 to 30 0 C.). The pH values varying between (7.58-7.95) express a slight basicity of the medium; the dissolved oxygen varies between (3.75-4.49), which explains a strong presence of organic matter in this medium. The conductivity is between (270-476 ?S / cm), the salinity is zero, suspended solids vary between (20-40mg / l), sulfate (05-11mg / l), chloride (77- 152 mg / l), nitrite (? 0.001 mg / l), nitrate (0.1-0.3), ammonium (0.23-0.42 mg / l) and phosphorus (0.50- 3.59 mg / l).