Inventory of the entomofauna associated with waste water drainage canals in the city of Ouagadougou in Burkina Faso

Abstract

Aquatic insects are a main source of food for fish and amphibians. They contribute to the degradation of
organic matter on which the ecological functioning of ecosystems depends. They are widely used today as
bioindicators for their ability to reflect the different disturbances of aquatic ecosystems. Aquatic insects
have been little studied in urban water plans in Burkina Faso. Our study aims to inventory living insects in the polluted waters of Ouagadougou and to assess their level of pollution. From August to November
2018, aquatic insects were collected in (04) canals (Kadiogo Bridge, University Hospital Center -
Yalgado OUEDRAOGO, Kossodo and University Joseph KI ZERBO) of the city of Ouagadougou.
Quantitative samples of aquatic insects are made using a troubled net opening 30 cm by 30 cm long. The
faunistic inventory has identified 5753 individuals and reveals a taxonomic diversity of twenty (20)
families distributed under five (05) orders. The greatest taxonomic wealth is found in the Kossodo Canal
and the University Joseph KI ZERBO with 17 families. As for families, Chironomidae dominate all
channels and represent (47.26%) relative abundance, followed by Culicidae (24.21%). This study made it
possible to know the diversity of the aquatic insects and to appreciate the level of pollution of (04)
channels of the city of Ouagadougou.