Relationship between macroinvertebrate diversity and physico-chemical parameters in the « Blondai » river at Anyama (South; Côte d'Ivoire)

The aim of the present study was to determine the relationships between macroinvertebrate distribution and the physico-chemical parameters that influence their distribution in the "Bondai" river in southern Côte d'Ivoire. Macroinvertebrate sampling was carried out in this river using a Van Veen bucket and a drag net over an area of 1 m² (2 m *0.5 m). Next, benthic community structure was studied using Shannon-Weather diversity and Piélou equitability indices. Finally, a Canonical Correspondence Analysis (CCA) was performed to highlight relationships between macroinvertebrate community distribution and physicochemical parameters. The results showed that a total of 50 macroinvertebrate individuals, divided into 03 Classes, 09 Orders and 11 Families, were identified in the “Blondai” river. The structure of this macrofauna indicates that it is composed of 50% Arthropods, 42% Mollusks, and 8% worms. The class of insects was the best represented with several orders including Diptera, Odonata, Coleoptera, Hemiptera. The orders of Basommatophora, Coleoptera, and Diptera are the most dominant, each representing 17% of the taxonomic richness. The analysis of diversity revealed that the macroinvertebrate communities of the "Blondai" river are poorly diversified and poorly balanced. The distribution of macroinvertebrates was strongly influenced by dissolved oxygen, conductivity, temperature, turbidity, pH, chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total phosphorus, total nitrogen, and dissolved solids. These results lay the foundation for any biosurveillance action regarding the ecological quality of the water in this river.