(CNN) Although sea turtles have been chomping down on plastic bags for years, scientists didn't know why -- until now. Plastic bags may smell like a tasty treat because of the bacteria and algae that accumulate on them.

In a new study published on Monday in the journal Current Biology, scientists presented captive sea turtles with multiple different smells.

The turtles responded almost identically to the smell of their food as they did to the smell of a plastic bag that had been soaked in water, according to Matthew Savoca, a postdoctoral research fellow at Stanford University's Hopkins Marine Station and one of the study's authors.

In fact, the turtles kept their noses out of the water three times as long to smell the plastic bags compared to control smells.

Nick Mallos, senior director of Ocean Conservancy's Trash Free Seas program, says this study provides alarming new information about why turtles eat plastic.

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