Evidence on plastic pollution has already been gathered in both the freshwater systems and the marine environment (including the Danube and the Black Sea) over the last decades. Scientific investigations identified strong linkages between marine pollution, terrestrial areas and land-based activities. Poor waste management, everyday littering, plastic industry facilities, consuming of products of textile and cosmetic industries in households and tire abrasion pollute rivers that further discharge plastic litter into the receiving seas.
Plastic pollution is the accumulation and transport of (macro)plastic litter along and in surface waters and the contamination of waters with plastic microparticles.
Plastic pollution has massive impacts on the freshwater ecosystems. Plastic particles may cause a lot of interference with inhabitants of the freshwater environment. Aquatic plastics (micro- and macro plastic particles alike) cause entanglement, optical and acoustic pollution, ingestion and even suffocation and starvation for all kinds of species. Accumulated riverine litter can alter shoreline conditions and habitats and can lead to the colonization of floodplains by invasive species. Moreover, harmful chemicals could be adsorbed to the surface of plastic particles, leading to the incorporation of these contaminants into animal tissues. This contamination can reach human populations via the aquatic food chain, thus raising concerns about not just animal but also human health.
In addition, plastics are subject to degradation. Photodegradation by UV light and oxidation affects mostly plastic litter accumulations that become susceptible to micronization by a very light pressure. Submerged aquatic plastics are either subjected to degradation via abrasion or bacterial decay. Plastic pollution also affects water-dependent economic sectors such as recreation, fishing and tourism. Since 80% of the marine plastic litter can be attributed to land-based activities and are transported from land to sea by rivers, plastic pollution is a basin-wide issue.