TITLE:
Dynamics of Benthic Macroinvertebrates in Relation to Water Quality in Two Small Reservoirs in Burkina Faso, West Africa
AUTHORS:
Idrissa Ouedraogo, Victor Bance, Noellie W. Kpoda, Adama Oueda
KEYWORDS:
Macroinvertebrate Diversity, Small Reservoirs, Seasonal Dynamics, Ecological Assessment, West Africa
JOURNAL NAME:
Open Journal of Ecology,
Vol.15 No.10,
October
29,
2025
ABSTRACT: In Burkina Faso, small reservoirs play a key ecological and socio-economic role for populations. Unfortunately, their biodiversity, ecological functioning, and response to diverse environmental changes remain less understood. This study aimed to determine the taxonomic composition and the temporal dynamics of macroinvertebrates and their environmental determinants in two small reservoirs in a semi-arid zone. Macroinvertebrates were collected from both sites monthly from May 2018 to March 2019, and physico-chemical parameters were monitored. The results revealed pronounced seasonal and spatial variability in water quality. In turn, this influenced macroinvertebrate diversity and assemblages. In total, 30 families of macroinvertebrates, composed of three phyla (Arthropoda, Mollusca, and Annelida) and five classes, were recorded. The diversity indices showed that species richness was high during the rainy or post-rainy seasons. This may reflect habitat complexity and resource availability. The lower values correspond to the dry season and are dominated by tolerant taxa. Notable community turnover occurred during periods of hydrological transition, where temporal beta diversity was high. The key environmental drivers structuring macroinvertebrate community composition were conductivity, TDS, water level, and pH. Sensitive taxa such as Baetidae, Caenidae, and Hydropsychidae appeared during stable, high water quality periods, while tolerant taxa such as Chironomidae and Oligochaetae dominated during stress periods. The more persistent presence of sensitive taxa in Ladwenda reservoir reveals better quality than in Bidiga. Findings of this study highlight narrow relationships between hydrology, water quality, and macroinvertebrate community structure. This information shows that protecting catchment integrity and adapting management to seasonal cycles are very important for conserving aquatic biodiversity and ecosystem services.