Spatial and temporal variations of microinvertebrates across temporary floodplains of the lower Okavango Delta, Botswana

Abstract The connectivity of the Okavango Delta to its temporary floodplains may reduce due to threats of increasing human water demands and climate change. Microinvertebrates in aquatic systems have a regulatory effect on juvenile fish production. Microinvertebrates in this study refer to both non- and planktonic microscopic invertebrates such as rotifers, cladocerans, copepods and ostracods. To understand the response of microinvertebrates to flooding of different types of temporary floodplains of the Delta, selected floodplains from primary, secondary and rarely inundated floodplains were sampled for microinvertebrates between May 2009 and February 2010. Field sampling coincided with different hydrological phases of flooding; flood rising, peak flooding and flood recession phase. Vegetation cover, woody debris, and a suite of physicochemical water parameters were assessed at each study floodplain. Woody debris, oxygen saturation (%), turbidity and conductivity were all significantly highest in rarely flooded floodplains (ANOVA, p  p  p