Water quality and transpiration responses of Eichornia crassipes at Lake Tana, Ethiopia

Abstract

Lake Tana is the largest freshwater body in Ethiopia, and it is a multi-use water body. However, currently the lake size reduced by different pressures, of these the occurrence of aquatic invasive weeds specifically, water hyacinth (Eichornia crassipes). The study was focused to evaluate the physiology of water hyacinth and its effect on water transpiration and quality in Lake Tana. In addition to water hyacinth, two wetland grasses (Cyperus papyrus and Typha latifolia) were selected based on predominance along the lake shore line. Plant physiology parameters (e.g., leaf width, height, and number of leaves) and transpiration data were collected in every week and day, respectively. In situ field measurements were also taken to observe vegetation treatments response for water quality. The result showed that transpiration of water hyacinth was two times higher than papyrus and T. latifolia. The number of leaves and leaf widths are significantly (p < 0.1) increased in water hyacinth weed compared to the corresponding wetland vegetations. Dissolved oxygen and temperature were statistically significant (p < 0.05) due to water hyacinth compared to the corresponding treatments, and the values were also beyond the desirable standard. Therefore, Lake Tana water alterations due to water hyacinths will be continued where effective controlling mechanisms have not been taken there.