Multiparametric monitoring of microbial faecal pollution reveals the dominance of human contamination along the whole Danube River

Abstract

The microbial faecal pollution of rivers has wide-ranging impacts on a variety of human activities that rely on appropriate river water quality. Thus, detailed knowledge of the extent and origin of microbial faecal pollution is crucial for watershed management activities to maintain safe water use. In this study, the microbial faecal pollution levels were monitored by standard faecal indicator bacteria (SFIB) along a 2580 km stretch of the Danube, the world's most international river, as well as the Danube's most important tributaries. To track the origin of faecal pollution, host-associated Bacteroidetes genetic faecal marker qPCR assays for different host groups were applied in concert with SFIB. The spatial resolution analysis was followed by a time resolution analysis of faecal pollution patterns over 1 year at three selected sites. In this way, a comprehensive faecal pollution map of the total length of the Danube was created, combining substantiated information on both the extent and origin of microbial faecal pollution. Within the environmental data matrix for the river, microbial faecal pollution constituted an independent component and did not cluster with any other measured environmental parameters. Generally, midstream samples representatively depicted the microbial pollution levels at the respective river sites. However, at a few, somewhat unexpected sites, high pollution levels occurred in the lateral zones of the river while the midstream zone had good water quality. Human faecal pollution was demonstrated as the primary pollution source along the whole river, while animal faecal pollution was of minor importance. This study demonstrates that the application of host-associated genetic microbial source tracking markers in concert with the traditional concept of microbial faecal pollution monitoring based on SFIB significantly enhances the knowledge of the extent and origin of microbial faecal pollution patterns in large rivers. It constitutes a powerful tool to guide target-oriented water quality management in large river basins.

Hotspots and main drivers of fecal pollution in Neusiedler See, a large shallow lake in Central Europe

“…1 Boxplots of EC and ENT concentrations at the 26 monitoring sites of Neusiedler See (1992–2013) on a logarithmic scale. Classes of fecal pollution are shown as blue (little), green (moderate), yellow (critical), and orange backgrounds (strong pollution), after Kirschner et al ( 2009 , 2017 ). Data falling outside a value of 1.5 times the interquartile range are indicated with a circle (outliers and extreme values); the black lines in the boxes represent the median …”

Water Quality Changes during Riverbank Filtration in Budapest, Hungary

“…The removal rate of microorganisms was between 1.5 log and 3.5 log efficiency and is in the same order as for other RBF sites worldwide.Local redox conditions, however, can only be indirectly controlled in the aquifer by the operator (i.e., pumping rates). In spite of the improvements in traditional water quality parameters, concerns arise regarding the microbial parameters of the Danube both upstream [8] and downstream of Budapest [9] related to the increasing incidence and severity of extremities.The aim of this study is to give an overview regarding the efficiency of RBF processes. The basic concept is to analyze physical, chemical, microbiological and biological parameters and highlight existing connections.…”

“…Local redox conditions, however, can only be indirectly controlled in the aquifer by the operator (i.e., pumping rates). In spite of the improvements in traditional water quality parameters, concerns arise regarding the microbial parameters of the Danube both upstream [8] and downstream of Budapest [9] related to the increasing incidence and severity of extremities.…”

Efficiency of technical constructions with the use of the fiber carrier "Vija" for the purification of surface water of protected and anthropogenically loaded sections of the river network of the Pokutsko-Bukovynian Carpathians

“…Проведені раніше дослідження санітарноекологічного стану басейну Дунаю [3][4][5] свідчать про значне погіршення якості поверхневих вод в результаті антропогенного впливу.…”

“…З іншої сторони, ідентифікація водних патогенів ускладнена через методологічні обмеження, зокрема низьку концентрацію бактерій у поверхневих водах та тривалі технології виявлення [4]. Ряд дослідників [5,9 ] для подолання даних методологічних обмежень пропонують використовувати сучасні ДНКтехнології. Даний підхід виявився досить ефективним для виявлення низького рівня патогенних мікроорганізмів у порівнянні з традиційними методами, які потребують досить багато часу (2-4 дні).…”