The 5th Joint Danube Survey (JDS5) project, implemented under the aegis of the International Commission for the Protection of the Danube River (ICPDR), is a six-yearly international program involving all member countries. This unique, large-scale international water quality assessment of the Danube River Basin aims to provide a comprehensive evaluation of the ecological and chemical status of the Danube and its tributaries using modern scientific methods.
The fifth phase of the scientific program series, which has a 24-year history, began in Vienna in July this year, with a focus on environmental DNA (eDNA) testing, assessing the presence of Danube sturgeons, studying biodiversity, and detecting micro-pollutants and microplastics, among other things. The results will provide a decisive basis for future measures aimed at improving water quality in the Danube basin.
The project is placing increasing emphasis on communities outside the scientific community, thereby promoting the initiative and conscious water use in the region.
During this year’s international survey, 49 surface water sampling sites (the Danube and its largest tributaries), 7 sub-surface water bodies and several wastewater treatment plants were extensively analysed by the participating countries’ own national experts during the same period. Coordination was provided by the National Coordinators and the so-called international “Core Team”.
Hungary again made a significant national contribution to the JDS5 survey this year by providing experts, laboratory analyses and logistical support.
Hungary was involved in a total of 7 Danube surface water, 1 sub-surface water and 1 wastewater testing sites. Sampling and laboratory analyses are carried out by domestic and international experts, with significant voluntary and institutional contributions.
- Surface water (Danube) sampling sites: Gönyű, Szob, Budapest (upper and lower sections), Dunaföldvár, Paks, and Baja.
- Sub-surface water sampling site: Surány with the support of Fővárosi Vízművek Zrt.
- Wastewater sampling site: Győr, at the premises of Pannon-Víz Zrt.
From Hungary, the international coordinator was György István Tóth (OVF), and his assistant, Dr. Zsófia Kovács (OVF).
Colleagues participating in the technical implementation process were the following: Zsuzsanna Pohner (wastewater), Dóra Kettinger (wastewater), Eszter Pulay (sub-surface water), Dr. Zsófia Kovács (floating solids sampling).
The General Directorate of Water Management (OVF) actively participated in organizing and conducting samplings, such as continuous sampling of suspended solids, wastewater, and sub-surface water from the Danube.
Modern science on the Danube (micropollutants, microplastic, eDNA and hundreds of analytical tests)
The platform suitable for taking samples from floating materials near Budapest
The sediment box, which was installed seasonally in the Danube’s drift line and operated continuously for a week, was particularly successful. Its installation was carried out under the supervision of Péter Beke (KDVVIZIG, Shipping Branch) and with the assistance of his colleagues, using a marker boat. This year, OVF staff set out for the third time to collect surface water and floating material samples, for which the sampling platform was again deployed for a week on the open waters of the Danube.
By boat to the middle of the Danube – moments of field work
A battery-powered submersible pump circulated water from the Danube at a rate of 2.6 litres/second through a sediment box attached to a marker buoy (KDVVIZIG-Shipping Branch) for one week. The volume of water circulated was recorded by a water meter. The floating samples collected by the sediment box were homogenized on site and then placed in 4-liter glass containers. A single point sampling was also performed from the marker boat by filtering 1000 litres of water through a 300, 100, and 50 micrometre membrane filter to examine the microplastic content of the Danube. The amount of water flowing through was recorded by a water meter.
The sampling site by the M0 Bridge in the lower section of Budapest is an iconic location because the submersible sediment box used in JDS4 was repeatedly used in JDS5. The sediment box collected significantly more floating material than before, which was then transferred to sample containers for microplastic determination.
Following the successful sampling, the marking boat returned to Újpest Port with hundreds of samples ready for laboratory analysis on board. With this action completed, JDS5 in Hungary has reached a new milestone.
The Danube is not only a natural treasure, but also our common responsibility.
Text: Dániel Szántó (International Department), dr. Zsófia Kovács (River Basin Management Department) – OVF
Translation: Daniel Szántó (International Department) - OVF
Photo: Dániel Szántó, István Szakács (International Department) - OVF