The Joint Danube Survey 3: Usage of freshwater mussels as bioindicators for detection of the genotoxic pollution

Abstract

The Joint Danube Survey 3 (JDS3) was the world‟s biggest river research expedition of its kind in 2013. JDS3 catalyzes international cooperation from all 14 of the main Danube Basin countries and the European Commission. The JDS is carried out every six years – JDS1 was in 2001 and JDS2 in 2007. During the JDS3 we assessed the level of genotoxic pollution along the Danube River by measuring the level of DNA damage in the haemocytes of freshwater mussels of Unio sp. and Sinanodonta woodiana with comet assay. The research was performed on 34 out of 68 sites analysed within the JDS3. During research, 2,285 river kilometres were covered with an average distance of 68 km between the sites. The complex data set on concentrations of various substances present in water, suspended particulate matter and sediment on investigated sites gave the opportunity to identify the groups of xenobiotics which mostly affect the studied biomarker – DNA damage. The highest levels of DNA damage were recorded in the section VI (Panonnian Plain), which is under the impact of untreated wastewater discharges. Both positive and negative influence of the large tributaries on the level of genotoxicity in the Danube River was evident. Significant correlation in response was detected between the studied freshwater mussels. The level of DNA damage in mussels correlated with concentrations of compounds from the group of hazardous priority substances (polycyclic aromatic hydrocarbons), persistent organic pollutants (dioxins) and emerging pollutants (Oxazepam, Chloridazon-desphenyl).