Ecological integrity of upper Warri River,Niger Delta using aquatic insects as bioindicators

Aquatic insects are bioindicators of water quality. Their structure and species composition is used in assessing the ecological integrity of streams and rivers. Their composition and density of the upper Warri River, Niger Delta, Nigeria were assessed and the influence of different physical and chemical variables on their distribution was explored at three designated stations. A total of 57 taxa were recorded with station 2 accounting for the greatest Ephemeroptera–Plecoptera–Trichoptera (EPT) richness. Abundance of the aquatic insects was affected by the nature of the substrate, macrophytes and canopy cover at the various stations examined. Generally, the upper Warri River is a fairly clean water body rich in EPT organisms. Pollution tolerant insect taxa such as chironomids and culicids larvae were only sporadically present.