Algal communities associated with aquatic macrophytes in some artificial ponds in Nyando District, Kenya

Abstract

This study describes the algal communities of six ponds colonised by aquatic macrophytes in Nyanza Province, Kenya. Plankton samples were collected from the water column and epiphytic samples from macrophytes such as Azolla, Pistia, Nymphaea, Ipomoea and Ludwigia. Pond pH, temperature, conductivity, concentration and dissolved oxygen saturation were also measured. The algal flora of the ponds comprised 139 species and varieties from 58 genera. Diatoms and green algae, mostly desmids, were the dominant groups. About 50 of the algal taxa were indicators of low mineral content of the water. Four distinct diatom communities were identified, using Canonical Correspondence Analysis. The constant dominant taxa were Achnanthes sp., Gomphonema gracile and Pinnularia gibba. The analysis showed that all samples from the same pond were grouped together, irrespective of the aquatic plants sampled.