Health status of the Abiergué river in Yaounde (Cameroon): Diversity and abundance dynamics of protozoans

In Cameroon, particularly in urban areas, watercourses are often transformed into receptacles for all kinds of waste, resulting in significant deterioration quality. This is the case of the Abiergué watercourse, which flows through several densely populated neighbourhoods of Yaounde, such as Tsinga and Briqueterie. In order to determine the state of health (ecological health status) of the Abierguć watercourse, a study based on the diversity and abundance dynamics of ciliates (Protozoans) was conducted from October 2019 to October 2020. Physico-chemical parameters were measured using standard methods. Ciliated protozoans were collected and identified at monthly intervals using appropriate techniques and identification keys. Physicochemical analyses showed that the water of the Abierguć stream was moderately oxygenated (50.93 13.98%), slightly alkaline (7.14 ± 0.47 CU), high in organic matter (3.43 ±1.64mg L) and highly colored (353.52 ± 245.28 Pt-Co). Biological results revealed a total of 1511 organisms collected, divided into 2 subphyla, 10 classes, 21 orders, 29 families and about 50 species. The classes Oligohymenophora and Peniculida order were predominant. Parameciidae family predominated, represented by the species Parameciun caudatum. Calculation of the saprobic index indicated that the water of Abiergué was revolved from β- to α-mesosaprobes state. These results sufficiently demonstrate that the water of the Abiergué stream is subject to organic pollution of anthropogenic origin.