scholarly journals Microbiological and Physico-Chemical Parameters of the Danube River (Romanian–Bulgarian Sector) with Ichthyofaunal Diversity

2021 ◽  
Author(s):  
Mădălina-Andreea Ivan ◽  
Carmen Curuțiu ◽  
Nicolai Craciun ◽  
Valentin Jujea ◽  
Cristian-Emilian Pop
Keyword(s):  
Point Sources ◽  
Danube River ◽  
Current Status ◽  
Water Stream ◽  
The Danube River ◽  
Pollution Levels ◽  
Physico Chemical ◽  
The Status ◽  
Point And Diffuse Sources ◽  
Agricultural Areas

Water and water habitats are essential to life and to the wellness of the communities that rely on them, as the Danube river is subject to human impact and vice versa, periodic surveys are required to determine the status of its pollution levels. In this work we used known microbiological indicators as well as physico-chemical ones to assess the ecotoxicological status of the Danube river from eleven locations partially forming the “Romanian–Bulgarian Danube Sector”. Most of the microbial communities found, and their densities, could be explained by point and diffuse sources scattered along the sector such as discharged household and farm wastewater, as well as nearby agricultural areas where fertilizers have been used and then leaked in the water stream during rainfalls. However, microbial data on non-point sources that lead to diffuse pollution of surface waters could be linked to such parameters and furthermore shown a slight correlation with the current status of fish communities.

scholarly journals Expansion of the marbled crayfish in Slovakia: beginning of an invasion in the Danube catchment?

2016 ◽  
Author(s):  
Boris Lipták ◽  
Agata Mrugała ◽  
Ladislav Pekárik ◽  
Anton Mutkovič ◽  
Daniel Gruľa ◽  
...  
Keyword(s):  
Horizontal Transmission ◽  
Local Population ◽  
Danube River ◽  
Exotic Fish ◽  
The Danube River ◽  
Procambarus Fallax ◽  
Danube Catchment ◽  
The Status ◽  
Marbled Crayfish ◽  
Two Populations

The marbled crayfish, <em>Procambarus fallax</em> f. <em>virginalis</em>, is a taxon widely available in the aquarium pet trade, which has been introduced to open waters in several European countries and in Madagascar. Recent studies confirmed this parthenogenetically reproducing crayfish as a high-risk invasive species, and vector of the crayfish plague pathogen, <em>Aphanomyces</em> <em>astaci</em>. It has been first discovered in Slovakia in 2010, but the status of the local population was not studied since then. Due to enlarged sampling area around the first report and one locality, where we presupposed the crayfish occurrence, we identified new marbled crayfish populations. Here, we report presence of three newly established marbled crayfish populations in Slovakia. Two populations are located critically close to the Váh River, a major tributary of the Danube River; one of them being directly connected to the Váh River <em>via</em> a side channel during occasional floods. The third established marbled crayfish population was found at the mouth of a thermal stream flowing into the Nitra River, a tributary of the Váh River. In this stream, crayfish coexist with other exotic fish and gastropod species of aquarium origin. We presume that the reported localities may serve as a source for further expansion of the marbled crayfish in the mid-part of the Danube catchment. Floods, active dispersal (including overland), passive dispersal by zoochory or anthropogenic translocations are among the major drivers facilitating the marbled crayfish colonization. We have not detected the crayfish plague pathogen in any of the studied populations. However, if spreading further, the marbled crayfish will encounter established populations of crayfish plague carriers in the Danube River, in which case they may acquire the pathogen by horizontal transmission and contribute to spread of this disease to indigenous European crayfish species.

Human Impacts on Fish Fauna in the Danube River in Serbia: Current Status and Ecological Implications

2020 ◽  
pp. 257-279
Author(s):  
Mirjana Lenhardt ◽  
Marija Smederevac-Lalić ◽  
Aleksandar Hegediš ◽  
Stefan Skorić ◽  
Gorčin Cvijanović ◽  
...  
Keyword(s):  
Human Impacts ◽  
Fish Fauna ◽  
Danube River ◽  
Current Status ◽  
The Danube River ◽  
Ecological Implications

Changes in the Quality of the Danube River Water in the Section Smederevo-Kladovo in the Conditions of Backwater Effects

1990 ◽  
Vol 22 (5) ◽  
pp. 181-188 ◽  
Author(s):  
M. Peršić ◽  
M. Miloradov ◽  
V. Tutundžić ◽  
Z. Čukić
Keyword(s):  
River Water ◽  
Danube River ◽  
Hydropower Plant ◽  
Biochemical Processes ◽  
The Danube River ◽  
Global View ◽  
Physico Chemical ◽  
Composition And Structure

The paper describes specific changes in the quality of the Danube river water under the conditions of backwater effects in the Hydropower Plant Djerdap I storage. The results of longterm tests in five profiles of the investigated section, at various discharges give a global view of the intensity of changes in the composition of water mass. The analysis included changes in the contents of: organic matter, oxygen regime, reduction of turbidity and changes in the composition and abundance of plankton. The specific changes in the domain of physico-chemical and biochemical processes and changes in the biological status of the watercourse (composition and structure of plankton) at varying retention times complete the picture of short-term changes in the investigated system. Presentation of some settling effects and processes in the sediment of the storage provides an idea of some long-term changes in the conditions of backwater effects of the Danube in the investigated section.

scholarly journals Modification of the MONERIS Nutrient Emission Model for a Lowland Country (Hungary) to Support River Basin Management Planning in the Danube River Basin

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 859 ◽  
Author(s):  
Zsolt Jolánkai ◽  
Máté Krisztián Kardos ◽  
Adrienne Clement
Keyword(s):  
River Basin ◽  
Shallow Groundwater ◽  
Point Sources ◽  
Water Bodies ◽  
Danube River ◽  
Subsurface Water ◽  
The Danube River ◽  
Subsurface Runoff ◽  
Retention Parameters ◽  
Danube River Basin

The contamination of waters with nutrients, especially nitrogen and phosphorus originating from various diffuse and point sources, has become a worldwide issue in recent decades. Due to the complexity of the processes involved, watershed models are gaining an increasing role in their analysis. The goal set by the EU Water Framework Directive (to reach “good status” of all water bodies) requires spatially detailed information on the fate of contaminants. In this study, the watershed nutrient model MONERIS was applied to the Hungarian part of the Danube River Basin. The spatial resolution was 1078 water bodies (mean area of 86 km2); two subsequent 4 year periods (2009–2012 and 2013–2016) were modeled. Various elements/parameters of the model were adjusted and tested against surface and subsurface water quality measurements conducted all over the country, namely (i) the water balance equations (surface and subsurface runoff), (ii) the nitrogen retention parameters of the subsurface pathways (excluding tile drainage), (iii) the shallow groundwater phosphorus concentrations, and (iv) the surface water retention parameters. The study revealed that (i) digital-filter-based separation of surface and subsurface runoff yielded different values of these components, but this change did not influence nutrient loads significantly; (ii) shallow groundwater phosphorus concentrations in the sandy soils of Hungary differ from those of the MONERIS default values; (iii) a significant change of the phosphorus in-stream retention parameters was needed to approach measured in-stream phosphorus load values. Local emissions and pathways were analyzed and compared with previous model results.

Current status and restoration options for floodplains along the Danube River

2016 ◽  
Vol 543 ◽  
pp. 778-790 ◽  
Author(s):  
Thomas Hein ◽  
Ulrich Schwarz ◽  
Helmut Habersack ◽  
Iulian Nichersu ◽  
Stefan Preiner ◽  
...  
Keyword(s):  
Danube River ◽  
Current Status ◽  
The Danube River

Nutrient emissions from diffuse and point sources into the River Danube and its main tributaries for the period of 1998–2000 – results and problems

2005 ◽  
Vol 51 (3-4) ◽  
pp. 283-290 ◽  
Author(s):  
H. Schreiber ◽  
H. Behrendt ◽  
L.T. Constantinescu ◽  
I. Cvitanic ◽  
D. Drumea ◽  
...  
Keyword(s):  
River Basin ◽  
Urban Areas ◽  
Inorganic Nitrogen ◽  
Point Sources ◽  
Danube River ◽  
Mean Deviation ◽  
Diffuse Sources ◽  
The Danube River ◽  
Nutrient Emissions ◽  
Danube River Basin

Nutrient emissions by point and diffuse sources were estimated for 388 sub-catchments of the Danube river basin for the period 1998–2000 by means of the Model MONERIS. For nitrogen total emissions of 684 kt/a N were estimated for the Danube basin. 80% of these emissions were caused by diffuse sources (mainly groundwater, urban areas and tile drainage). For phosphorus the emission was 57 kt/a P, with a contribution of diffuse sources to this sum of 58%. The comparison of calculated and observed loads shows that the mean deviation for the investigated sub-catchments of the Danube river basin is 20% for dissolved inorganic nitrogen and 34% for phosphorus. The spatial resolution of the emission calculations allows the identification of regional hot spots and the derivation of specific regional measures to reduce the emissions into the Danube and consequently into the Western Black Sea.

Sign in / Sign up

Export Citation Format

Share Document