"You could be diving and you think someone's tapping your shoulder but it's just a bottle knocking against you, or a plastic trash bag stuck on your tank," lead author Joleah Lamb of Cornell University told Reuters. "It's really sad," she said. "Corals are animals like us and have really thin tissues that can be cut and wounded, especially if they are cut by an item covered in all sorts of micro-organisms," she said. The scientists, from the United States, Australia, Thailand, Myanmar, Canada and Indonesia, surveyed 159 reefs from 2011-14 in the Asia-Pacific region. They found most plastic in Indonesia, with about 26 bits per 100 square meters (1076 square feet) of reef, and least off Australia, which has the strictest waste controls.