Hot Mix By The Humpbacks: Why Ancient Whale Songs Have Scientists Hooked
If humans could hear with the naked ear all of the racket and singing going on under the surface of the sea, they would be amazed. Whales, dolphins and seals are some of the ocean creatures that use other-worldly vocalizations, calls, moans and clicks to communicate and find food.
Ocean researchers and marine biologists have recently taken a strong interest in the science of whale sounds. All along Earth’s coastlines, whale calls and songs are being studied for several important reasons:
Elusive whales can be counted
Whale populations are always on the move finding places to eat and mate, and whales are constantly being monitored around the world using tags, visual census-taking and sonar tools. These monitoring efforts make it easier for countries and agencies to set harvesting limits and make ocean-friendly policies. Experts use the data to pinpoint where whales migrate, feed and raise their calves in order to better protect sensitive areas.
Over the years, researchers have learned to distinguish the various cries and songs of specific whale species. By setting hydrophones (microphones that pick up underwater sounds) in busy undersea areas, scientists can now hear the cries of certain types of whales that are very difficult to see.
Recently in Monterey Bay, California, a hydrophone picked up the call of the shy and rarely seen beaked whale. The beaked whale’s song is as timid as its creator, since the notes can’t be picked up by the human ear even with the hydrophone’s help. However, all sounds recorded by the submerged microphone are turned into graphs called spectograms, and with these visual records, biologists are able to discover the presence of whales they might otherwise miss.
Noise pollution can be tamed
Scientists also want to understand how human activity impacts whales’ ability to communicate. Researchers don’t really understand all of the meanings behind whale songs, but they do suspect that interference from outboard motors, boat propellers and industrial noise pollution can disorient whales and cause them more stress.
Some biologists speculate that over time, whales may raise the pitch of their songs in order to compensate for increased auditory stimuli in our oceans. Since some whales live hundreds of years, researchers can study the songs of individual whales over many years to determine if this is true.
By comparing whale sound patterns in areas where there is little human noise to sounds from areas with a lot of human activity, researchers may be able to discover how to best help whales deal with excess racket in the underwater environment. This will hopefully lead to happier and healthier whale populations.
If you want to hear a live performance of whale music and chatter, join a whale watching tour that has an on-board hydrophone. Many whale sightseeing boats have such devices and will place them in the water when the watercraft is close to a pod of whales, so you can hear the whales “talk” to one another.
There are also personal hydrophone devices you can purchase that include earphones, a rubber-sealed hydrophone “disc,” and a long cable. You simply drop the hydrophone off the side of the boat or pier and adjust the controls to listen to undersea sounds. Contact a company like Orca Enterprises LLC for more information.