Autor: |
Mushi D; Department of Biosciences, Solomon Mahlangu College of Science and Education, Sokoine University of Agriculture, P.O. Box 3038, Morogoro, Tanzania E-mail: douglas@sua.ac.tz; Douglas Mushi and Geda Kebede contributed equally to this article., Kebede G; Department of Biological Sciences, Ambo University, P.O. Box 95, Ambo, Ethiopia; Institute of Hydrobiology and Aquatic Ecosystem Management (IHG), BOKU, University of Natural Resources and Life Sciences, Gregor-Mendel-Straße 33, 1180 Vienna, Austria; Douglas Mushi and Geda Kebede contributed equally to this article., Linke RB; Research Group of Environmental Microbiology and Molecular Diagnostics 166/5/3, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorferstrasse 1A/166, 1060 Vienna, Austria., Lakew A; National Fishery and Aquatic Life Research Centre, Ethiopian Institute of Agricultural Research (EIAR), P.O. Box 64, Sebeta, Ethiopia., Hayes DS; Institute of Hydrobiology and Aquatic Ecosystem Management (IHG), BOKU, University of Natural Resources and Life Sciences, Gregor-Mendel-Straße 33, 1180 Vienna, Austria; Centro de Estudos Florestais (CEF), University of Lisbon, Instituto Superior de Agronomia, Tapada da Ajuda, 1349-017 Lisbon, Portugal., Graf W; Institute of Hydrobiology and Aquatic Ecosystem Management (IHG), BOKU, University of Natural Resources and Life Sciences, Gregor-Mendel-Straße 33, 1180 Vienna, Austria., Farnleitner AH; Research Group of Environmental Microbiology and Molecular Diagnostics 166/5/3, Institute of Chemical, Environmental and Bioscience Engineering, TU Wien, Gumpendorferstrasse 1A/166, 1060 Vienna, Austria; Research Division Water Quality and Health, Department of Pharmacology, Physiology and Microbiology, Karl Landsteiner University for Health Sciences, Dr.-Karl-Dorrek-Straße 30, 3500 Krems an der Donau, Austria. |
Abstrakt: |
Tropical communities in the developing world depend heavily on riverine systems for their socioeconomic development. However, these resources are poorly protected from diffuse pollution, and there is a lack of quantitative information regarding the microbial pollution characteristics of riverine water, despite frequently reported gastrointestinal diseases. The aim of our study was to apply faecal taxation (i.e., faecal pellet counting in representative test areas to estimate the potential availability of diffuse pollution sources) in combination with a detailed microbiological faecal pollution analysis in a riverine environment to elucidate the importance of diffuse pollution. To realize this approach, ambient faecal pellets, a multiparametric data set for standard faecal indicator bacteria (SFIB), including Escherichia coli, Clostridium perfringens spores and enterococci from catchment soil and river water, and a number of riverine water physicochemical variables were analysed during a one-year cycle. We demonstrated that the abundance of ambient faecal pellets, which were consistently counted at reference sites in the catchment, was associated with faecal pollution in the river water. Water SFIB, dissolved oxygen, nutrients, conductivity and total suspended solids were strongly linked with the abundance of ambient faecal pellets in the river catchment, as demonstrated by principal component analysis (PCA). Elevated concentrations of SFIB in the riverine water in the absence of rainfall also suggested the direct input of faecal bacteria into the riverine water by livestock (e.g., during watering) and humans (e.g., during bathing). Statistical analyses further revealed that the microbiological water quality of the investigated riverine water was not influenced by SFIB potentially occurring in the soil. This study demonstrates the importance of diffuse faecal pollution sources as major drivers of the microbiological quality of riverine water in the Ethiopian highlands. In addition, the new successfully applied integrated approach could be very useful for developing predictive models, which would aid in forecasting riverine microbiological quality in tropical developing countries. |