Distribution and abundance of small plastic debris on beaches in the SE Pacific (Chile): A study supported by a citizen science project

The accumulation of large and small plastic debris is a problem throughout the world's oceans and coastlines. Abundances and types of small plastic debris have only been reported for some isolated beaches in the SE Pacific, but these data are insufficient to evaluate the situation in this region. The citizen science project "National Sampling of Small Plastic Debris” was supported by schoolchildren from all over Chile who documented the distribution and abundance of small plastic debris on Chilean beaches. Thirty-nine schools and nearly 1000 students from continental Chile and Easter Island participated in the activity. To validate the data obtained by the students, all samples were recounted in the laboratory. The results of the present study showed that the students were able to follow the instructions and generate reliable data. The average abundance obtained was 27 small plastic pieces per m2 for the continental coast of Chile, but the samples from Easter Island had extraordinarily higher abundances (>800 items per m2). The abundance of small plastic debris on the continental coast could be associated with coastal urban centers and their economic activities. The high abundance found on Easter Island can be explained mainly by the transport of plastic debris via the surface currents in the South Pacific Subtropical Gyre, resulting in the accumulation of small plastic debris on the beaches of the island. This first report of the widespread distribution and abundance of small plastic debris on Chilean beaches underscores the need to extend plastic debris research to ecological aspects of the problem and to improve waste management.

► The abundances of small plastic debris on beaches have been studied with the help of citizen scientists.
► Independent resampling was used to validate the data provided by citizen scientists.
► Average abundances on beaches from continental Chile were 27 small plastic pieces per m2.
►  Abundances on Easter Island beaches were more than 20-times higher than continental Chile.
► These data confirm that small plastic debris accumulates in the S Pacific subtropical gyre.