.jpg)
Rocket science isn't just for the stars anymore. Researchers are using technology intended for a mechanical leviathan on biological behemoths: the giant X-ray machines used to scan space shuttle rockets have been turned to whales, unlocking secrets of how marine mammals hear.
The research, carried out by the US Navy, was conducted to learn how naval sonar may be affecting how the whales hear and hunt. Using the same CT scanners that seek out flaws in the fuel rockets of space shuttles, researchers created a detailed three-dimensional replica of the beaked whale's ear. They then employed a computer simulation known as the finite element model (FEM). Between the precise replica of the whale's head and FEM, scientists were able to observe the interaction between sounds and the whale's ear.
The results showed that the middle-frequency sounds of sonar are “largely filtered, or 'muffled,' before reaching the animal’s ears.” [ONR] However, the higher frequency noises that whale use to hunt are actually amplified in the ear. The findings serve as initial evidence that naval sonar does not greatly interfere with the environment of marine mammals—or at least not with that of the beaked whales.
"Even though these findings are promising, our next step is to reproduce the study with a similar species for which hearing tests are available, such as the bottlenose dolphin," said Dr. Ted Cranford, a San Diego State University marine biologist sponsored by the Office of Naval Research (ONR). "If we obtain like results, it will help to validate this new discovery." [ONR]
If their technique can be established, researchers hope to use the technology learn about a whole range of marine animals, from whales to fish. Auditory cues play a large role in watery environments. Not only do animals use sounds to hunt, but also to track the movements of their kind. Learning how marine life hears may help scientists looking to conserve and protect a species.
"Virtual experiments can also provide potential for evaluating and directing mitigation efforts," said ONR program manager Dr. Michael Weise. [ONR]
Comments