08 Where are the microplastics on Kosh?

Microplastics were found in samples from all environmental media. The highest concentrations were found in sediment and beach samples, and the lowest in surface water. However, these concentrations cannot be directly compared because they represent different parts of the lake system. Sediment represents a long-term pool of microplastics, where particles accumulate over time, while surface water is a snapshot of the current movement of microplastics in the lake.

Higher concentrations in the sediments do not mean that most of the microplastics in the lake are found in the sediments. Because the volume of water in the lake is so large, the microplastics within it are still likely very large, even though the estimated concentration is low. Our estimate is more than 57 billion microplastics in the lake, and 10 billion in the upper 10 cm of sediment.