A year-long field study of buried plastics reveals underestimation of plastic pollution on Hawaiian beaches.

Global models estimate that two-thirds of floating ocean plastic has accumulated in coastal areas since the 1950s, with Hawai'i's windward shores particularly vulnerable due to their proximity to the North Pacific Garbage Patch. Our quarterly surveys revealed that 91 % of recovered plastic particles were buried below the surface (deeper than 2 cm), with most particles being small fragments (93 %) with an average mean max length of 6.7 ± 4.