Scientific Report

The first Joint Danube Survey was carried out in 2001. For the first time, comparable data about the entire course of the river was provided covering over 140 different biological, chemical and bacteriological parameters. This data was used as an essential information source for the first analysis of the Danube River Basin District according to Art. 5 of the EU WFD. Six years later, the second Joint Danube Survey (JDS2) created a comprehensive and homogeneous database on the status of the aquatic ecosystem of the Danube and its major tributaries. For the first time, the fish survey was carried out along the entire Danube River, bringing a unique dataset and also contributing to methodological harmonization between EU and non-EU countries. The findings of JDS2 contributed to the first Danube River Basin Management Plan and were used in the EU intercalibration process of large rivers.

The third Joint Danube Survey (JDS3), which took place in 2013, provided the largest ever amount of knowledge about the Danube water pollution collected within a single scientific exercise. It reconfirmed that the Danube flora and fauna show a high degree of biodiversity. During JDS3, the depth of information on hydromorphological conditions was significantly improved, as in-situ measurements of hydrological, morphological and hydraulic characteristics were performed for the first time along the entire Danube and its tributaries. The first complex testing of antibiotic resistance was carried out along the entire stretch of the Danube River. Several new analytical techniques and strategies were applied targeting hundreds of organic substances, resulting in the most comprehensive information ever acquired on this topic for the Danube River. The analysis of such a large amount of organic substances enabled the first suggestions for the update and prioritization of Danube River Basin Specific Pollutants.

As a result, the signatories of the Danube Declaration (adopted at the 2016 ICPDR Ministerial Meeting) appreciated the very valuable scientific results of the third Joint Danube Survey in 2013 as well as its considerable effect on awareness raising for the ICPDR, requested the ICPDR to prepare, based on an evaluation of the previous surveys, a fourth Joint Danube Survey to be held in 2019, and committed to secure the necessary funding.