We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Substantial burial of terrestrial microplastics in the Three Gorges Reservoir, China
Summary
Researchers found substantial burial of terrestrial microplastics in Three Gorges Reservoir sediments, suggesting that large hydropower dams act as significant traps that intercept microplastic transport from rivers to the ocean, with implications for the Yangtze River's plastic output.
Abstract Hydropower dams impact the transport of microplastics from rivers to the ocean. The Yangtze River is a large source of plastics to the ocean. Here, we report microplastic concentrations and compositions across a range of size fractions for sediment samples collected in the upper and lower reaches of the Three Gorges Dam in 2008, 2015, 2019 and 2020. We find a gradual increase in microplastic abundance over time, with preferential retention of small-sized (<300 μm) microplastics in the dam reservoir sediments. Small microplastics accounted for between approximately 44 and 90% of identified microplastics, and 82% of all polyethylene particles, which were the dominant polymer type. Our estimate of the total plastic mass load in reservoir sediments suggests that the Three Gorges Dam retains as much as 8048 ± 7494 tons yr ‒1 microplastics in sediments, which is equivalent to 47 ± 44% of the Yangtze River microplastic flux to the ocean.