2024/08/07 by Mieraf Addisalem, Addisalem, Mieraf, Zerihun Girma
Agricultural and Biological Sciences · Environmental Science · #Aquatic Ecosystems and Biodiversity #Biological Control of Invasive Species #Constructed Wetlands for Wastewater Treatment #Ethiopia #dissolved oxygen #hydrogen potential (pH) #invasive species #nitrate #phosphate
paper · doi:10.20372/3hjkvn93
openalex publication_date 2024/08/07 · openalex created_date 2025/12/23 · openalex updated_date 2026/07/01
Water hyacinth (Eichhornia crassipses) is one of the most invasive weeds in aquatic ecosystems. It has been a serious threat to aquatic biodiversity. This study was conducted to investigate the impact of water hyacinth on the water physicochemical quality of Lake Ziway. Water physicochemical quality samples were taken at four sites in two triplicate and vertically stratified as surface, medium, or deeper, using an FL-2010N Digital multimeter and plastic water sampler. For PO3 and NO3 analyses, water samples were collected from the surface, stored in polyethylene bottles, and transported to the laboratory in an icebox. Two samples were taken from areas with dense water hyacinth cover (site 1), less dense (site 2), sparsely infested (site 3), and without water hyacinth (site 4). Furthermore, to investigate the distribution of water hyacinth, key informant interviews were conducted. The results showed that the amount of PO3) between sites 2 and 3 was significantly different at p 0.05. The amount of NO3 at sites 1 and 2 was significantly different from that at site 3, at p 0.05. There was a significant difference in the pH values among the sites. The pH value at site 1 was significantly different from those at sites 3 and 4 (p 0.05. The results of the study showed that there was a significant difference in dissolved oxygen (DO) among all sites at, p 0.05. Pearson's correlation coefficient (r) analysis showed that water hyacinth coverage was positively correlated with PO3 (r = 0.77, N = 4, P 0.05), NO3 (r = 0.69, N = 4, P 0.05), pH (r = 0.16, N = 4, P 0.05), and (T) temperature (r = 0.78, N = 4, P 0.050). On the other hand, a negative correlation was observed between DO and water hyacinth percent cover (r = -0.94, N = 4, P = 0.05). This implies that water hyacinth infestation in Lake Ziway adversely affects the water physicochemical quality of the lake. In addition, agrochemical nutrient inputs from the lake shore, intensive irrigation, and floricultural activities have been attributed by key informants to be the main sources of eutrophication in the lake, with consequent expiation of water hyacinth infestation. Therefore, an integrated management approach is urgently needed to control the infestation of water hyacinth and its further expansion into the lake.