Marine fish don’t just gobble up plastic in the ocean accidentally. They’re actually drawn to eat it, because the algae that attaches itself to the surface of our plastic waste gives it an irresistible (for fish, anyway) rotten seaweed smell, says a study in the journal Proceedings of the Royal Society B.
“I’ve heard both scientists and nonscientists say that there’s so much plastic out there that these animals sort of bump into it and consume it without thinking,” Matthew Savoca, a California Sea Grant State Fellow at the National Oceanic and Atmospheric Administration’s Southwest Fisheries Science Center, told Popular Science. “But people who know about foraging behavior and study this sort of thing know that couldn’t be further from the truth.”
Instead, even fish with a reputation for being picky eaters are compelled to the eat the plastic thanks to an enticing chemical — dimethyl sulfide — produced by algae cell walls when the plants start to die.
“Algae like to attach to hard, smooth surfaces, and they float up near the air to collect sunlight — so they often hitch a ride on our garbage,” says Popular Science. Unfortunately, that means fish end up eating our garbage. Which means we end up eating our garbage, too, as tiny plastic particles move up the food chain and back onto our plates.