Big cleanup plans may be in the works, but there is currently a lot of plastic waste swirling about in the ocean. This often shows up in the bellies of deceased animals, but why exactly the creatures are drawn to the debris hasn't been so well understood. Now a new study has revealed that the stench emitted from the plastic waste is the same one that some species have relied on for thousands of years to find food, shining new light on why sometimes these last suppers come all too fast.

The key to the discovery is a sulfur compound called dimethyl sulfide (DMS). DMS is released when animals such as krill consume algae, and previous research has revealed that it serves as a type of dinner bell for tubenosed seabirds like albatross and petrels by alerting them to the krill's presence, which just happens to be one of their favorite meals.

Scientists at the University of California, Davis, built on this earlier work by placing three of the most common types of plastic debris into the ocean (in contained environments). They retrieved them three weeks later and had them analyzed at the university's Department of Viticulture and Enology, facilities typically reserved for analyzing wine flavor chemistry.

A Tristram’s storm-petrel that mistakenly consumed plastic debris(Credit: Sarah Youngren)

The team found that the samples were coated by and stank of DMS, in effect tricking the birds into mistaking them for food. The researchers note that seabirds that rely on the scent of DMS to find food are almost six times more likely to eat plastic than other species.

"This study shows that species that don't receive lot of attention, like petrels and some species of shearwaters, are likely to be impacted by plastic ingestion," says UC Davis professor Gabrielle Nevitt. "These species nest in underground burrows, which are hard to study, so they are often overlooked. Yet, based on their foraging strategy, this study shows they're actually consuming a lot of plastic and are particularly vulnerable to marine debris."

The research was published in the journal Science Advances.

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