Aquatic Insects as Biomonitoring Tools in Assessing Water Quality in a Tropical Freshwater Ecosystem

Michael Olufemi Ashamo, Babasola Williams Adu, Joseph Adewumi Adeyemi, Richard Olajide Owaseye* and Kemi Josephine Fehintola

Background: Freshwater ecosystems, particularly in tropical regions, are increasingly threatened by anthropogenic activities that compromise water quality. Aquatic insects are widely used as tools for monitoring water quality in freshwater ecosystems. The ecological status of the Owena River, a tropical freshwater system in southwestern Nigeria, was assessed using aquatic insect communities, biotic indices, and physicochemical parameters. 

Methods: Sampling was conducted across six stations along the river. Physicochemical parameters (including pH, temperature, dissolved oxygen, electrical conductivity, total dissolved solids, water depth, and flow rate) were measured in situ. Aquatic insects were collected using standardized sweep nets and identified to the family level. The Biological Monitoring Working Party (BMWP), Average Score Per Taxon (ASPT), Family Biotic Index (FBI), and Pollution Tolerance Index (PTI) were used to evaluate ecological health. 

Results: A total of 2,920 aquatic insects belonging to six orders and 17 families were recorded. Odonata (32%) and Hemiptera (29%) dominated the assemblage. BMWP and ASPT values indicated moderate water quality, with slightly better conditions at the downstream stations. FBI values suggested fair water quality with some degree of organic pollution. The PTI results indicated that most insect families collected were moderately sensitive to pollution (73%). 

Conclusion: The study demonstrates that aquatic insects and associated biotic indices are reliable, cost-effective tools for monitoring the ecological health of tropical freshwater ecosystems. These findings support their continued use in environmental assessment and water resource management strategies in developing regions.

Keywords:

Published on: Sep 30, 2025 Pages: 23-30

Full Text PDF Full Text HTML DOI: 10.17352/gje.000112
CrossMark Publons Harvard Library HOLLIS Search IT Semantic Scholar Get Citation Base Search Scilit OAI-PMH ResearchGate Academic Microsoft GrowKudos Universite de Paris UW Libraries SJSU King Library SJSU King Library NUS Library McGill DET KGL BIBLiOTEK JCU Discovery Universidad De Lima WorldCat VU on WorldCat