5 days ago
Researchers make alarming discovery inside whales' stomachs: 'May therefore be misinterpreting acoustic cues'
It's one of the known problems with plastic pollution: Marine animals like seals and whales keep turning up dead with their stomachs full of plastic bags and deflated Mylar balloons, having eaten these nonfood items until it kills them.
That makes some sense near the surface, where the soft shape of a drifting bag might be mistaken for a jellyfish or squid, but what about deep underwater, where hunting whales can't even see the plastic? A new study has shed light on the factor at play here, specifically, sound, PBS North Carolina reported.
Marine scientists from Duke University, NC State, UNC-Chapel Hill, and the National Oceanic and Atmospheric Administration came together for a study that tested the way plastic bags and debris appear when detected with echolocation.
Echolocation is a sense that some animals, including whales, dolphins, and bats, use to get around in conditions when ordinary visibility is poor. The animal emits a specific sound, then listens for the way that the sound bounces off surrounding objects and returns to them. The time it takes for the sound to return tells them the distance to the object, and the way that the sound changes — such as becoming distorted or muffled — tells them about the characteristics of the object, like its hardness. Echolocation helps these animals build a very precise view of the world, but as these researchers discovered, it doesn't give them all the information.
According to PBSNC, all of the plastic items tested reflected sound in a way similar to the bodies or beaks of squids, the prey that toothed whales hunt in the dark depths of the ocean. That explains why so many whales are turning up with plastic in their stomachs — it really does sound like food.
"Assuming these animals are ingesting plastic at depth and not at/near the surface, they are consuming plastic without visually identifying it," said a passage in the study, per PBSNC. "Deep-diving toothed whales may therefore be misinterpreting acoustic cues when echolocating; presumably plastic's acoustic signature resembles that of primary prey items, driving plastic consumption."
Whale species are already under severe threat. After many years of being hunted — some of which continues to this day — and in an ocean which is getting warmer and more difficult to survive in every year, populations have severely diminished over time, and conservationists are scrambling to keep these intelligent and charismatic species afloat.
Plastic waste in the ocean presents another threat to species already under pressure. There are 170 trillion pieces of plastic in our ocean now, from tiny microplastics to full-sized pieces of trash and fishing equipment, all of which are killing sea life.
If these hazards succeed in destroying whale species, we will not only have lost an irreplaceable part of our planet's diversity and some of the smartest creatures in existence. We will also have lost a key part of our ocean ecosystem, and humans rely on the ocean for a huge amount of food and a major portion of our economy. The estimated worth of the oceans is $24 trillion.
Companies and individuals around the globe are looking for ways to keep plastic out of the ocean and to clean up what's already there. Even middle schoolers are making strides with a robot to clean up microplastics, and researchers are putting AI on the job as well.
Do you think America has a plastic waste problem?
Definitely
Only in some areas
Not really
I'm not sure
Click your choice to see results and speak your mind.
Join our free newsletter for good news and useful tips, and don't miss this cool list of easy ways to help yourself while helping the planet.
