Spatial evolution of the diversity of macroinvertebrate-Odonate larva population dynamics in relation to the environmental variables of the Niete hydrosystem (South Cameroon)

A study was carried out in the Niété, a tributary of Lobé, to evaluate quality it’s water through follow-up longitudinal evolution various abiotic (physico-chemical) and biotic (Odonate larva) parameters this aquatic ecosystem. The results physico-chemical analysis according grid evaluation system (SEQ-Eau), show that, with exception aquaculture production, rate oxygen saturation (79.39±0.54%) electrical conductivity (42.59±, 16.52 µS/cm), sulphate (2.78±0.71 mg/L), suspended solids (10.88±0.54 nitrate ions (1.10±0.21mg/L) are very good range, whatever intended use. This is not case for orthophosphate (12.32±0.35 which rather range poor requiring complex treatment drinking production likely cause lethal effects on most sensitive species, leading decrease abundance. Out 92 individuals collected, 09 genera were identified: 4 Coenagrionidae (44.44%), Libellulidae (44.44%) 1 genus Corduliidae (11.12%). Orthetrum (family Libellulidae), Coenagrion Nehalennia Coenagrionidae) have relative abundance 65.22%. Sörensen's similarity coefficient reveals high dissimilarities between populations stations N1 N2 (36.36%), N3 (28.57%) (25%). diversity indices Shannon Weaver, Simpson Piélou that station diversified favours installation polluotolerant Odonata, whereas more balanced better development Odonata larvae. confirmed by Hilsenhoff index, shows has low quality, compared N3, reflecting self-purifying action Niété river.