The haunting tunes of mating humpback whales are in jeopardy, one study found.
In research that will add to fears about noise pollution altering the behavior of wildlife, scientists in Japan monitored the effects of the noise of a cargo ship on the songs of male humpbacks around the Ogasawara Islands, just over 600 miles south of Tokyo. What they found is that the sound of noisy ships make the whales stop singing their songs temporarily.
This could have a huge impact on whale numbers as male humpbacks rely on these songs to find a partner during mating season.
The study, led by Ogasawara Whale Watching Association and Hokkaido University, used two underwater recorders to capture the whales’ songs and locations between February and May last year. As the ship passed, whales within about 3,900 feet tended to reduce, or stop their singing, instead of adapting their tune. Additionally, most of the creatures didn't resume their songs for at least half an hour after the ship passed.
"In the Ogasawara water, humpback whales seemed to stop singing temporarily rather than modifying sound characteristics of their song such as through frequency shifting or source level elevation," the study states.
"Remarkably," wrote the authors, whales swimming under a ship "continued to sing as usual." And most of the whales that stopped singing did not restart for at least 30 minutes after the ship passed, they added.