Scientists have for the first time shown that some wild corals are feeding on tiny shreds of plastic trash. Worse, the animals seem to prefer those ‘microplastics’ over their natural food—even when the plastic is carrying bacteria that can kill them.

The new study, published in Proceedings of the Royal Society B: Biological Sciences, focused on a temperate species of coral collected off Rhode Island, one that builds small clusters no larger than a human fist. But researchers say the findings suggest that more familiar tropical, reef-building corals may also be consuming—and being harmed by—microplastics, which are defined as bits of plastic waste smaller than a fifth of an inch across.

The new results add to the growing sense that microplastics