Lake Nokoué is the most productive Lake in West Africa, but unfortunately its resources are declining due to several factors including organic and chemical pollution. The present study aims to investigate the impact of this advanced pollution onestuarine tilapia Sarotherodon melanotheron. Thus, 60 sexually mature individuals (30 males and 30 females) of this specie were captured from the Lakes Nokoué and Toho with the Lake Toho considered as a reference. Blood samples were taken from fish of both sites to compare the hematological parameters (hemoglobin level (Hb), total leukocyte count (TLC), differential leukocyte count) and biochemical parameters (glycemia level, creatinine and transaminases). In addition, the physicochemical parameters of water from three sites (S1, S2 and S3) of Lake Nokoué and two sites (S4 and S5) of Lake Toho were recorded and the organic pollution indices (OPI) calculated. The findings of this investigation revealed an OPI = 1.33 ± 0.14 for Lake Nokoué, confirming its very high organic pollution compared to Lake Toho which has compatible OPI for living fish (OPI=3.875 ± 0.18).Regarding the hematological parameters, the study revealed in S. melanotheron from Lake Nokoué a low Hb and a high TLC emphasizing leukocytosis due to the compensation and defensive response versus the toxic effect of pollutants on fish. As for the biochemical parameters, high levels of plasma glucose, creatinine and transaminases reveal an environmental stress and hepato-nephrotoxic effects of the cocktail of pollutants on S. melanotheron in Lake Nokoué. All together, on one hand the study demonstrated the poor state and threat to the survival of S. melanotheron in Lake Nokoué and on the other hand, raises a public health problem related to the consumption of such fish.

Hematological parameters; Biochemical parameters; Lake Nokoué; Cocktail of pollutants; Sarotherodon melanotheron.