Underwater human noise is a great threat to whales. It disrupts their communication, mating, navigation, and more. Unfortunately, this threatens whale species that are already on the brink of extinction due to whaling.
The good news is that whales seem to have the ability to “plug their ears” and block out man-made noises. Well, this ability is still in a nascent stage, it seems, and it has just been discovered and is not known to be in use in the wild. But this is still big news, really big news.
What kind of noises are we talking about? What kind of man-made noises disrupt the lives of whales?
We’re talking motor boats, weapons testing, sonar, boy band music… oh wait, scratch that last one, I don’t think teenage whales have jumped on that bandwagon.
In all seriousness, just simply underwater listening devices may account for loss of hearing in over a quarter-of-a-million underwater mammals each year. That’s a pretty staggering figure.
So, whales’ ability to block out human noise to avoid such problems is huge. How they are doing so is still a bit unclear to scientists, though. Oh wait, it seems it’s completely unclear at this point… but at least they’ve learned that it’s possible.
Aside from trying to figure out how whales block out human noise, researchers are also trying to develop a warning signal that can help whales to know when a potentially harmful noise is coming.
While this seems like a valiant and worthwhile effort, others in the field are actually a bit concerned that could lead to relaxed efforts to cut the extra noise altogether. Let’s hope that’s not the case. Sending a warning signal before a drive-by gang shooting is not quite as useful as preventing drive-by shootings altogether.
If you’ve ever played around under the water, you know that sounds down there are a lot different, and can travel really far. Under the sea, sound can actually travels hundreds of miles. So, noise pollution can build up really fast.
And as we’ve discussed before, whale songs are very complicated and important to these highly intelligent animals.
If you’re wondering how scientists finally determined that whales could block out human noise, let’s finally get to that….
Scientists at a research facility off Oahu (where some of “Gilligan’s Island” was actually filmed) were studying how dolphins and toothed whales hear.
“In nature, the mammals emit sounds and listen for returning echoes in a sensory behavior known as echolocation,” The NYTimes writes. “In captivity, scientists taught the creatures to wear suction-cup electrodes, which revealed the patterns of brainwaves involved in hearing.”
“The discovery came in steps. First, Dr. Nachtigall and his team found the animals could adjust their hearing in response to their own sounds of echolocation, mainly sharp clicks. The scientists then wondered if the animals could also protect their ears from incoming blasts.
“The team focused on a false killer whale named Kina and sought to teach her a conditioned behavior similar to how Pavlov taught dogs to salivate upon hearing a bell.
“First, the scientists played a gentle tone repeatedly. Then they followed the gentle pulse with a loud sound. After a few trials, the warning signal alone caused Kina to decrease the sensitivity of her hearing.”
Sounds promising. And the researchers are excited. The hope is that they can quickly train various species in the wild to block out these harmful noises.
There is some belief that some whales already do this, but the hope is that a lot more can be trained to do so, saving their lives and perhaps even their species.