In Cameroon, the environmental profile is increasingly marked by anarchic urbanisation, which is strongly illustrated by the discharge of waste into the aquatic environment, leading to pollution. Indeed, the tributaries of the Mfoundi and Mefou river basins have nowadays become dumping grounds and receptacles for all kinds of waste, leading to the degradation of water quality and a reduction in biodiversity. This study aims to evaluate the effect of anthropogenic pressure on the biodiversity of benthic macroinvertebrates in three rivers of the Mfoundi basin (Ebogo, Abiergue, and Ako’o). For this purpose, some physicochemical parameters were measured according to standard methods, and benthic macroinvertebrates were collected according to the multihabitat approach. To this end, the physicochemical analyses revealed that the waters of these different streams are slightly basic and poorly oxygenated, with a saturation rate of 9.725 ± 11.74% and significant organic pollution. Biologically, a total of 5793 benthic macroinvertebrates divided into three phyla, eight orders, and more than thirty families were collected, with a population dominated by the order of insects and a low level of diversity dominated by pollutant organisms such as the Chironomidae, Lumbriculidae, and Physidae, which are saprobionts and saprophilous organisms. A redundancy analysis indicated that the main groups of benthic macroinvertebrates obtained were related to the gradients of the physicochemical parameters measured. The Shannon–Weaver diversity and Piélou equitability indexes showed the low diversity of the organisms within the different courses and their low equipartition, mainly due to the saprobiont and saprophilous groups that dominate the population. The exogenous inputs due to the increase in the population of the city of Yaoundé, which dumps its waste into the waterways, have major repercussions on the quality of the water and the population that abounds in this environment, particularly the benthic macroinvertebrates, which are an important link in the monitoring of water quality.

Urban growth can induce changes in the use and transformation of urban land. In the context of rapid urbanization, monitoring key indicators of sustainable development is essential. The aim of this study was to monitor and assess the level of sustainable development in the city of Ouagadougou between 2002 and 2022, based on global indicators such as Sustainable Development Goal 11.3.1 indicator and the Singapore City Biodiversity Index. A remote sensing and Geographic Information System approach was used to acquire and analyze open-source geospatial data. The results show an increasing inefficiency in land use, with excessive consumption to population growth until 2013. Between 2013 and 2022, this trend declined, but urban biodiversity nevertheless decreased significantly, with a 40% loss of natural areas between 2002 and 2022. Fragmentation of natural areas, due to infrastructure development, has amplified this degradation, posing ecological risks to the city. This study underlines the importance of strengthening the ecological connectivity of urban spaces to improve their sustainability and resilience. It also recommends reorienting urban strategies by integrating nature-based solutions and placing biodiversity preservation at the heart of sustainable urban development policies.

Urban sprawl leads to the degradation of aquatic environments and, consequently, to the destruction of biodiversity. With the aim of highlighting the distribution profile of benthic macroinvertebrates in the city of Yaoundé and its surroundings according to the level of degradation, this study was carried out in seven rivers. A total of 144 taxa of benthic macroinvertebrates, belonging to 74 families, 15 orders, five classes, and three phyla, were collected from seven rivers in urban, peri-urban, and forest environments on Yaoundé and its surroundings. The self-organizing map (SOM) analysis tool was used to group the collected taxa from all stations into three clusters or affinity cores. The indicator value analysis (IndVal) method was employed to determine, based on their ecological preferences, which organisms were most likely to belong to each group. Out of the 144 collected taxa, only 44 were indicated to represent the three different groups. Thus, three communities were defined: the Hydropsyche community, with Hydropsyche sp. as the predominant taxon in Group III, characterizing well-oxygenated and low-mineralized stations; the Hydrocyrius community, where the species Hydrocyrius sp. predominates in Group I, describing stations with low oxygenation and moderate mineralization; and the Lumbriculidae community, where Lumbriculidae is the taxon associated with environments with high mineralization and critical oxygenation. These two methods contribute to the biomonitoring of tropical aquatic environments, firstly by grouping organisms by affinity and then identifying those that reflect the environment conditions. This facilitates the detection of changes in the quality of hydrosystems and guides management and conservation efforts.