The Danube so colourful: A potpourri of plastic litter outnumbers fish larvae in Europe's second largest river

Previous studies on plastic pollution of aquatic ecosystems focused on the world's oceans. Large rivers as major pathways for land-based plastic litter, has received less attention so far. Here we report on plastic quantities in the Austrian Danube. A two year survey (2010, 2012) using stationary driftnets detected mean plastic abundance (n = 17,349; mean ± S.D: 316.8 ± 4664.6 items per 1000 m−3) and mass (4.8 ± 24.2 g per 1000 m−3) in the river to be higher than those of drifting larval fish (n = 24,049; 275.3 ± 745.0 individuals. 1000 m−3 and 3.2 ± 8.6 g 1000 m−3). Industrial raw material (pellets, flakes and spherules) accounted for substantial parts (79.4%) of the plastic debris. The plastic input via the Danube into the Black Sea was estimated to 4.2 t per day. [Display omitted] •Here we first report on abundance and composition of plastic litter in a large river.•The mass and abundance of drifting plastic items in the Austrian Danube are higher than those of larval fish.•The plastic input of the River Danube into the Black Sea is estimated to 4.2 t per day. 1) More plastic items than larval fish are drifting in the Austrian Danube. 2) The Danube is a major pathway of land-based plastics waste into the Black Sea.