Effect of water quality on adult and larvae of odonate in freshwater ecosystem of southwestern Ethiopia: comparison of river, wetland and dam

Odonates, in both their larval and adult stages, are widely used worldwide as bioindicators to assess water quality, habitat integrity, and overall ecosystem health in freshwater ecosystems. However, limited information is available on how adult and larval odonates vary across different freshwater ecosystems and how water quality influences their assemblages. This study aimed to evaluate differences between adult and larval odonates across various freshwater ecosystems and to examine the effects of water quality on their assemblages. Water quality parameters, along with data on adult and larval odonates, were collected from 30 sampling sites. Principal Component Analysis (PCA) was used to examine relationships between habitat characteristics and water quality. Generalized Linear Model (GLM) was applied to identify the most important variables influencing odonates assemblage. The results showed that river ecosystems supported a higher abundance of adult odonates, whereas wetland ecosystems supported a greater abundance of larvae. Water quality had a stronger influence on larval odonates than on adults. In addition, the abundance of both adult and larval odonates was strongly affected by water quality. Water quality parameters influenced adult and larval odonates differently, particularly in terms of larval abundance and richness. Overall, the findings highlight the importance of freshwater ecosystems in sustaining both adult and larval odonate populations, as well as the influence of water quality on their assemblages. Therefore, conserving these ecosystems and preventing factors that degrade water quality are essential for maintaining the diversity and abundance of odonates.