WHALES MISTAKE PLASTIC WASTE FOR SQUID AND INVOLUNTARILY BECOME INTOXICATED

By hunting through acoustic signals to orient themselves in the depths of the sea, cetaceans mistake plastic waste for their food. Duke University Study Shows How Plastic Waste Tricks Whales

The plastic waste that crowds the seas can be dangerously similar to the feeding of whales, which are fooled by the response to their acoustic signals. This has been discovered by a new study from Duke University, according to which the use of sound waves by cetaceans to orient themselves in the dark ocean depths can prove to be a double-edged sword. Plastic waste in fact “bounces” these calls in a similar way to that of squid, confusing whales.

The University tested plastic waste collected on several beaches. It found that the acoustic signals emitted by such materials are comparable to those of whale prey animals. According to the study, published in the Marine Pollution Bulletin, all the plastic waste analyzed showed similar or even higher acoustic strength than whale prey. This could explain why whales swallow plastic, confusing it with food. The team conducted experiments aboard the R/V Shearwater vessel, using three different sonar frequencies to simulate the “clicks” that whales make to locate food.

Plastic and squid on the same wavelength?

The research tested various types of waste, including plastic bags and balloons, as well as squid remains recovered from dead whales. The results showed that plastic waste, especially plastic films, produces acoustic signals very similar to those of whale food. According to scientists, a possible solution could be to redesign some types of plastic to change their acoustic signature, but this option presents risks. If fishing nets become invisible, in fact, whales could get caught more easily. So, rather than making plastic “invisible” to whales, the most urgent solution is to reduce ocean pollution. Every year, at least 14 million tons of plastic enter the oceans, making up 80% of all marine waste material present, from surface waters to deep sediments.