Every year Ocean Conservancy coordinates the International Coastal Cleanup, the world's largest volunteer litter survey, in which participants record every item they pick up.
The 2025 cleanup involved 630,069 volunteers who logged 13,861,048 items. Plastic beverage bottles (1,338,712) and plastic bottle caps (885,854) were the most common items, displacing cigarette butts, which had topped the list for decades. Since 1986 about 20 million volunteers have removed more than 405 million pounds of rubbish and logged around 440 million items.
The dataset is valuable because it is consistent, global and item-level, which lets campaigners track how litter changes as policies such as bottle deposits take effect.
It counts items, not weight, and depends on where volunteers go, so it reflects visible shoreline litter rather than total pollution.