Distribution, abundance and spatial variability of microplastic pollution on the surface of Lake Superior

In 2014, 94 paired neuston net samples (0.5 mm mesh) were collected from the surface waters of Lake Superior. These comprise most comprehensive water survey for microplastics any Great Lakes to date, and first employ double trawls. Microplastic abundance estimates showed wide variability, ranging between 4000 more than 100,000 particles/km2 with locations having abundances 20,000 50,000 particles/km2. The average in Superior was ~30,000 which similar previous within this Laurentian suggests a total count 2.4 billion (1.7 3.3 billion, 95% confidence interval) particles across lake’s surface. Distributions plastic particles, characterized by size fraction type, differed nearshore offshore samples, eastern versus western portion lake. Most found fibers (67%), (62%) contained smallest classified (0.50–1 mm). common type polymer polyethylene (51%), followed polypropylene (19%). This is consistent global plastics production results obtained other studies. No statistically significant difference detected indicating that single sampling should produce representative estimate microplastic particle distribution body water.