We know that the seas of the world suffer from plastic. Waste that is thrown into rivers and landfills contaminates endlessly. There is a particular species that plastic waste threatens. It is a particularly dangerous threat, and now it is known why. Sea turtles believe that plastic is food.
That smell that kills
It is explained by Joseph Pfaller of the University of Florida, Gainesville, who publish results in Current Biology. «We discovered something of silly turtles. They respond to the odors of plastics embedded in organic matter in the same way they respond to food odors. That suggests that the turtles They can be attracted to plastic waste not only because of its appearance. Also for its smell«,
That would explain why sea turtles ingest and get entangled in the plastic so often, ”he adds.
Bioincrustation refers to the accumulation of microbes, algae, plants and small animals on wet surfaces, which occurs with plastics in the ocean.
For a long time it was thought that sea turtles see plastics and visually confuse them with prey. It's what happens with jellyfish. But Pfaller and his colleagues realized that little was known about the sensory mechanisms that could attract sea turtles to plastic.
The co-author of the study is Matt Savoca, of the Hopkins Marine Station at Stanford University. He recruited 15 loggerhead turtles bred in captivity. A series of odorants in the air was added through a pipe in an experimental arena. Then they recorded their reactions on video. The smells they tested included deionized water and clean plastic as controls.
Sea turtles responded to plastic the same way they responded to their food. Future studies are still needed to better understand what chemicals were emitted by plastics to arouse the interest of turtles. But the new findings show that plastics will present problems for turtles.
«The problem of plastic in the ocean is complex. It is more than plastic bags that look like jellyfish. Or wandering straws stuck in a turtle's nose, ”warns Pfaller. These are important and problematic pieces for the puzzle. And all plastics represent a danger to turtles ».
Sea turtles believe that plastic is food. But we believe it is indispensable. But it is in our hands that it is not so. And stop the plastic from reaching the ocean.