Ocean plastic emits chemical that tricks seabirds into eating trash

blue petrel

Some seabirds, including blue petrels (Halobaena caerulea), use the smell of dimethyl sulfide to find food. Plastic debris in the ocean gives off the same smell, sometimes tricking the birds into eating garbage.

J.J. Harrison

Plastic smells like supper for some seabirds. When the ubiquitous material ends up in the ocean, it gives off a chemical that Antarctic prions, petrels and shearwaters often use to locate food, researchers report online November 9 in Science Advances. That might lead the birds to ingest harmful junk instead of a real meal.

Researchers let small beads of three common plastics linger off the coast of California. After a couple of weeks, the once-clean plastic accumulated grit, grime and bacteria that gave off an odiferous gas called dimethyl sulfide. Phytoplankton give off the same gas, and certain seabirds use its odor as a cue that dinner is nearby. Birds that rely more heavily on dimethyl sulfide as a beacon for a nearby meal are more likely to ingest plastic than birds that don’t, the team found. And other plankton-feeding marine animals could also be fooled.

Editor’s note: This story was updated Nov. 22, 2016, to correct which birds are among those that respond to the smell of dimethyl sulfide. Antarctic prions, not albatrosses as previously stated, use the chemical as a food cue. 

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