The Short Version
Misleading. Scientists have made significant progress identifying several fates for previously unaccounted-for ocean plastic — including fragmentation into nanoplastics, deep-sea accumulation, and coastal sediment trapping — but no single definitive "destination" has been established. The claim's framing implies a resolved mystery, when in reality multiple partial explanations coexist and the scientific community continues to debate whether the "missing plastic" problem itself may be partly an artifact of measurement limitations.