Abundance and Distribution of MacroInvertebrates in Relation to Physicochemical Properties of Pindiga Lake, Akko Local Government Area, Gombe State

Abstract

The distribution and abundance of aquatic macroinvertebrates and physicochemical parameters was studied in Pindiga Lake. The focuses were to identify the families of aquatic macroinvertebrates, to compare their abundance in the selected sampling areas and to investigate the effect of physico-chemical parameters (Air and water temperature, pH, Electrical Conductivity, Dissolved Oxygen, Biochemical Oxygen Demand, Turbidity, Nitrate and phosphate) on their abundance and distribution. The lake was divided in to four sampling stations (A, B, C and D). Samples were collected by using aquatic nets from each sampling station fortnightly for six months. Physical and chemical parameters were measured in situ and recorded. The sum total of individual macroinvertebrates was classified into different orders and families. Analysis of Variance (ANOVA) was employed to test any significant variation among the four sampling stations within the lake. All the physico-chemical parameters measured were observed to be within the tolerable limit that can support aquatic productivity. Aquatic macroinvertebrates collected were identified using taxonomic keys, and for the estimation of their distribution and abundance, Simpson and Margalef richness indices were employed. The result showed a total of 200 individual species of aquatic macroinvertebrates belonging to 9 genera among the five taxa of Odonata, Decapoda, Diptera, Plecoptera and Trichoptera. The Order Diptera comprised 74%, Decapoda 3.5%, Trichoptera 0.5%, while Plecoptera and Odonata comprised 11% each of the total macroinvertebrates identified. The Simpson’s species diversity index of the five taxa are; Odonata (0.01), Decapoda (0.001), Plecoptera (0.01), Diptera (0.5), Trichoptera (0). And the Margalef index of genera richness are; Odonata (0.434), Decapoda (0), Plecoptera (0), Diptera (1.3), Trichoptera (0). The outcome of this study indicated that Pindiga lake is a very productive ecosystem that can support broader ecological studies, hence the need to maintain its integrity is paramount.