A new study reveals that endangered whale species such as Baleen and toothed whales alike could be suffering because of noisy ships, the Washington Post reports.
The study was published Tuesday in PeerJ.
Whales are troubled by noises at a frequency that disturbs the sounds that they use to communicate and navigate, rendering them unable to hunt and to lose their way.
Earlier studies by scientists have pointed out that low frequency sound of the ships is harmful to large baleen whales, like blue whales and humpbacks.
The present study indicates that the rumble of the ships also affects smaller whales, like orcas and dolphins.
For the study, the researchers listened to a wide range of frequencies as more than 1,600 ships sailed through their Washington state testing site a total of 3,000 times.
The researchers found that the ships emit low rumbles that disturbed massive baleen whales. They also increased noise at medium and high frequencies, which is the frequency where orcas hear best.
The Washington state area hosts the only population of orcas that are categorized as endangered.
The results of the study could also be applied to toothed whales and dolphins that live near coastal areas, where shallow water make ship noise appear louder.
However, Veirs and his colleagues did find that most of the noise came from container ships, while military vessels did a good job of keeping quiet.
"It should be easy to reduce noise pollution. Military ships are quite a bit quieter and there could be straightforward ways of transferring that technology to the commercial fleet." Said Veirs, according to the Guardian.
"Ships have been thought of as low-frequency sources of noise, like the rumbling of trucks or trains," he said. "Most noise is at that low frequency but the background noise of the ocean is raised even in the high frequencies. This could be causing a significant problem that we need to look into more."
"Decreasing speed by six knots could decrease noise intensity by half," Veirs added.
