In a noisy ocean, whales go quiet but dolphins start shouting, new studies show
- Bottlenose dolphins near loud ship traffic tended to ‘speak’ like humans in a noisy bar
- But humpback whales seem to stop singing entirely when a ship goes by
The oceans are loud and getting louder all the time, but marine mammals that must live in the din take different approaches to the noise: dolphins perform the equivalent of shouting, while humpback whales go silent, two new studies have found.
“A lot of people imagine that underwater is this really quiet place, but it isn’t,” said biologist Helen Bailey, who studies marine mammals and sea turtles at the University of Maryland.
Sharp noises, like sonar used in oil exploration or explosive Navy war games, can damage whale ears.
Busy cargo lanes thrum with ship traffic. And as the Arctic warms, allowing more ships and industrial developments in previously ice-locked regions, northern marine mammal populations are exposed to more noise.
Increasing ocean noise was identified as a potential problem more than 20 years ago. Near California, the loudness of ship traffic has roughly doubled each decade since the 1960s. But the specific effects of this human-made cacophony are still being pieced together.