A study by Duke University shows how plastic waste deceives whales
Plastic waste crowding the seas can dangerously resemble whale food, tricking them through the response to their acoustic signals. This was discovered by a new study from Duke University, which found that the use of sound waves by cetaceans to navigate the dark ocean depths can be a double-edged sword. Plastic waste “bounces back” these signals in a way similar to squid, confusing the whales.
The university tested plastic waste collected from various beaches and found that the acoustic signals emitted by these materials are comparable to those of the whales’ prey. According to the study, published in Marine Pollution Bulletin, all the analyzed plastic waste showed an acoustic strength similar to or even greater than whale prey. This may explain why whales ingest plastic, mistaking it for food. The team conducted experiments aboard the R/V Shearwater, using three different sonar frequencies to simulate the “clicks” whales emit to locate food.
Plastic and squid on the same wavelength?
The research tested various types of waste, including plastic bags, balloons, and 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 the scientists, a possible solution could be redesigning some types of plastic to alter their acoustic signature, but this option presents risks. If fishing nets became invisible, whales might get entangled more easily. Therefore, rather than making plastic “invisible” to whales, the most urgent solution is to reduce ocean pollution. Each year, at least 14 million tons of plastic enter the oceans, making up 80% of all marine debris, from surface waters to deep-sea sediments.