Sampling of riverine litter with citizen scientists — findings and recommendations

Abstract

The quantity and composition of litter at riversides and in the surface waters, as well as the occurrence of illegal dumping sites, were studied along four rivers in Chile. Data generated by volunteers were compared to the results from a professional survey, using an identical protocol. Litter was found in considerable quantities at the riversides and in the surface waters at all the sites investigated. A generalized linear mixed model analysis showed that the recorded litter densities did not differ between volunteers and professionals, even after controlling for river, site, or distance between sampling locations, demonstrating that the volunteers successfully applied the sampling protocol. Differences occurred with respect to litter composition, which is most likely due to difficulties in the classification of litter items and particles and to the underestimation of litter present in surface water samples. Even though this study was only conducted at a small number of rivers and sites, a comparatively consistent pattern of direct and intentional litter deposition at riversides was recorded, highlighting that river basins require more protection. The results also show that the citizen science approach can be a suitable means for more extensive litter surveys at riversides and in other natural environments.

Plastic debris in rivers

“…For rivers, several citizen science studies were done on Chilean and German rivers. In both studies, schoolchildren were motivated to participate in sampling and quantifying plastics along riverbanks (Rech et al, 2015;Kiessling et al, 2019). Barrows et al (2018) organized collection of water samples by 120 volunteers for microplastic analysis, and showed that such an approach allows for (micro)plastic characterization at watershed scale.…”

Short-term exposure with high concentrations of pristine microplastic particles leads to immobilisation of Daphnia magna

“…Only recently, microplastics have also been reported in lakes and rivers in Europe (Imhof et al, 2013;Faure et al, 2015;Klein et al, 2015;Lechner et al, 2014), North America (Castañeda et al, 2014;Eriksen et al, 2013;Zbyszewski and Corcoran, 2011;Zbyszewski et al, 2014), South America (Rech et al, 2015), Africa (Biginagwa et al, 2016) and Asia (Free et al, 2014;Zhang et al, 2015). The observed abundances can reach up to several hundreds of thousands of microplastic items per km 2 in the surface water in size classes <5 mm.…”

Citizen‐based scientific data collection: Fact or fiction?

“…This can be achieved by an appropriate program design that allows a small number of professional scientists to train and orchestrate a large number of citizen scientists. For example, Rech et al () mobilized citizen scientists to quantify and qualify litter along a series of Chilean river systems. This study assessed the quality of categorical data (i.e., litter type) collected by citizen scientists and found that citizen scientists could provide reliable data comparable to professional scientists with appropriate training.…”