NatureModernPacific Oceanhigh confidence

About 94 percent of the plastics in the Great Pacific Garbage Patch are microplastics—pieces smaller than a grain of rice that are often invisible to the naked eye.

Notes on verification

Confirmed by peer-reviewed Lebreton et al. 2018 Scientific Reports study and corroborated by The Ocean Cleanup organization and independent media (PBS NewsHour, CBC, Discover Wildlife). Figure specifically refers to piece-count (94%), not mass (8%), which is consistent across sources. Minor variation (92% in one source) noted but 94% is the dominant figure. [tier=gold indep_score=0.95 clusters=3 claim_tier=notable]

Sources