Effect of effluents from anthropogenic activities on the diversity and abundance of aquatic macroinvertebrates in Lubigi wetland, Kampala district

Abstract

Aquatic macroinvertebrates are good indicators of pollution and therefore can be used to determine the health of aquatic environments. The effect of effluents from anthropogenic activities on the diversity and abundance of aquatic macroinvertebrates was determined in Lubigi wetland with the aim of contributing to the available information. Sampling was carriedout five times in three sites (upper, mid and lower sections: 1, 2, and 3 respectively each 500m from the next) in January 2020. Twenty-one (21) families of aquatic macroinvertebrates were found including: Enchytraeidae, Lumbricidae, Chironomidae, Physidae, Hydrophilidae, Acanthodrilidae, Sialidae, Tipulidae, Syrphidae, planorbidae, Lymnaeidae, Elmidae, Pschodidae, Anthericidae, Hirudinea, Thiaridae, Veliidae, Unionidae, Aeshnidae, Stratiomyidae, and Muscidae. The diversity indices indicated that site 3 had the highest diversity with a diversity index H’=4.02, followed by site 2 with an index H’=3.24 and site 1 had the lowest diversity with an index H’=3.10. The abundance of aquatic macroinvertebrates was highest in site 1 with family Enchytraeidae constituting the highest number than sites 2 and 3 with low relative mean abundances for Enchytraeidae. The low diversity in sites 1 and 2 could be attributed to the various anthropogenic activities including settlement Markets, urbanisation and industrialisation and less vegetation cover. The presence of highly tolerantaquatic macroinvertebrates and absence of sensitive macroinvertebrates to pollution in all the sites indicates that Lubigi wetland is undergoing pollution as a result of effluents from anthropogenic activities. Therefore, the effluents from anthropogenic activities should be treated before they are release into the wetland.