A Pan-European study of the bacterial plastisphere diversity along river-to-sea continuums.

Microplastics provide a persistent substrate that can facilitate microbial transport across ecosystems. Since most marine plastic debris originates from land and reaches the ocean through rivers, the potential dispersal of freshwater bacteria into the sea represents a significant concern. To address this question, we explored the plastisphere on microplastic debris (MPs) and on pristine microplastics (pMPs) as well as the bacteria living in surrounding waters, along the river-sea continuum in nine major European rivers sampled during the 7 months of the Tara Microplastics mission.

Comparison of macrolitter and meso- and microplastic pollution on French riverbanks and coastal beaches using citizen science with schoolchildren.

Rivers are the major source of anthropogenic litter entering the ocean, especially plastic debris that accumulates in all ecosystems around the world and poses a risk to the biota. Reliable data on distribution, abundance, and types of stranded plastics are needed, especially on riverbanks that have received less attention than coastal beaches. Here, we present the citizen science initiative Plastique à la loupe (Plastic under the magnifier), which compares for the first time the distribution of different litter sizes (macrolitter and meso- and microplastics) over 81 riverbanks and 66 coastal beaches sampled in France between 2019 and 2021.

Plastic debris exposure and effects in rivers: Boundaries for efficient ecological risk assessment.

Until recently, plastic pollution research was focused on the marine environments, and attention was given to terrestrial and freshwater environments latter. This discussion paper aims to put forward crucial questions on issues that limit our ability to conduct reliable plastic ecological risk assessments in rivers. Previous studies highlighted the widespread presence of plastics in rivers, but the sources and levels of exposure remained matters of debate.