Scientific Report

JDS4 was a milestone in the series of Joint Danube Surveys. 

This document contains the key scientific findings of the Fourth Joint Danube Survey, conducted by many independent teams of different kinds of experts in 13 countries, utilising a new and coordinated data collection approach. It contains 47 chapters, covering a broad range of topics to create an overview of the Danube River Basin.

This report preparation was affected by the pandemic of coronavirus disease in Europe in 2020. The COVID-19 lockdowns adversely impacted the time plan of the analysis of JDS4 samples and consequently some of the results will have to be published later than planned.

Similarly to JDS3, the findings of JDS4 are supportive to the implementation of EU WFD providing an extensive homogeneous dataset acquired by the WFD compliant methods. Even though these data have no ambition to replace the national data used for the assessment of the ecological and chemical status they are an excellent reference database which can be used for WFD assessment methods harmonization throughout the Danube River Basin and for the new derivation and prioritization of the Danube River Basin Specific Pollutants.

JDS4 has provided a great deal of added value to the current monitoring practices in the Danube River Basin, including:

  • Independent basin-wide platform for improving national surface water monitoring practices;
  • Practical joint testing and comparison of national methodologies for biological and hydromorphological quality elements leading to their future harmonization;
  • Interactive platform for hands-on training in sampling and assessment of biological quality elements;
  • A unique source of data for a number of quality elements (especially for emerging substances) for the whole Danube;
  • Knowledge transfer between EU and non-EU member states.

JDS4 Scientific Report: A Shared Analysis of the Danube River Basin

List of Chapters

  1. Together for a cleaner and healthier Danube: Joint Danube Survey
  2. Survey logistics
  3. Data management
  4. Recording and assessment of hydromorphological changes 2013 - 2019
  5. Fish
  6. Aquatic macroinvertebrates
  7. Phytobenthos
  8. Phytoplankton
  9. Macrophytes
  10. Invasive alien species
  11. Zooplankton
  12. Introduction: (e)DNA-based activities
  13. Metabarcoding of macrozoobenthos samples
  14. Metabarcoding of fish eDNA samples
  15. Metabarcoding of phytobenthos samples
  16. Metabarcoding of sediment communities
  17. Summary: performance of (e)DNA-based activities
  18. Overview chapter on ecology and biology
  19. Microbial faecal pollution and source tracking
  20. Occurrence of non-wild type antibiotic resistant Escherichia coli in the River Danube
  21. Microbiome: Microbial community and environmental DNA analysis
  22. General physico-chemical determinands and nutrients
  23. Target analysis of organic substances in water
  24. Target analysis of organic substances and metals in biota
  25. Groundwater screening
  26. Wide-scope target and non-target screening of MAXX large-volume samples of the Danube River with LC-ESI-HRMS and GC-EI-HR-MS
  27. Wide-scope target and non-target screening of surface water samples by direct injection LC-HRMS techniques
  28. Screening of endocrine substances in combination with in vitro assays in the Danube River by MAXX large volume solid-phase extraction and LC-HRMS
  29. Wide-scope target screening of industrial chemicals and plant protection products in wastewater, groundwater, river water, sediments and biota by liquid and gas chromatography coupled with high-resolution mass spectrometry
  30. Wide-scope target screening of illicit drugs, pharmaceuticals, antibiotics and personal care products in wastewater, groundwater, river water, sediments and biota by liquid chromatography coupled with high resolution mass spectrometry
  31. Characterization of wastewaters in the Danube River Basin with chemical screening and a battery of in vitro bioassays
  32. Analysis of organic substances in the Danube River surface water by passive sampling
  33. Polarity-extended non-target screening using RPLC-HILIC-ESI-QToF-MS/MS and tailor-made data handling
  34. Comparability of data obtained by suspect and non-target screening and by NORMAN panel of in vitro and in vivo bioassays: results of an interlaboratory study
  35. Comparison of novel and current approaches for the target- and non-target screening, effect-based monitoring and prioritisation of river basin specific pollutants to improve future water quality monitoring
  36. Prioritisation of Danube River Basin specific pollutants using the NORMAN prioritisation framework
  37. Comparison of target screening and target analysis approaches for surface water samples
  38. Analysis of genotoxic activity of the JDS4 surface water samples collected by horizon large volume solid-phase extraction technique
  39. Overview chapter on chemical pollution
  40. Rare earth elements
  41. Synchronous fluorescence for characterization of dissolved organic matter
  42. Occurrence of microplastics in the Danube River – A first screening
  43. Nanoparticle inventory in a sediment core from the Iron Gate I reservoir
  44. Microplastics in biota – Asian clam case
  45. Radioactivity
  46. Stable isotopes of water and nitrate
  47. Conclusions