Marine Biology

Whales Sonar



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"Whales Sonar"
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Imagine trying to do any of your everyday activities, only this time, someone is standing by you, constantly irritating you, disrupting your senses. It would be an impossible feat. Unfortunately, most marine mammals must deal with this issue, which stops being a mere annoyance, and turns into something more deadly.

A majority of marine mammals use echolocation, a technique that is extremely similar to sonar. Animals will create a noise, often a high pitched clicking noise. If the sound wave hits something it will bounce back to the animal's receptor, slightly changed, and the animal can tell how far away from the object it is and which direction the object may be heading. Humans attempted to emulate nature and created sonar to help detect underwater obstacles and enemies.

Sonar is a useful naval technology that works very much like echolocation. Modern day sonar, the Surtass LFA, is often housed on a ship, which carries 18 loudspeakers that generate sound above 200 decibels. This noise is akin to standing next to an Apollo rocket on land, and this noise travels even better in the water. The noise is lower in frequency, and much louder than sonar in the past. While this frequency means the signal is harder for spies to perceive, this lower frequency is what causes the whales trouble. While humans cannot perceive the noise, whales can feel this spectrum of sound just as easily as they can hear human speech. The released sound waves interfere with the whale's ability to perceive where it is going, and may cause some terrible results.



Scientists who study the animals have found that there is a high correlation between beaching of whales and dolphins and nearby Navy sonar testing. Scared, confused, and possibly deafened by the noise, the whales attempt to flee, and in their floundering, they often end up going into areas of shallow water, crashing onto sand bars and beaches. Without help, they cannot get back into the water. Once beached for even a short amount of time, the weight of the animals crushes their organs, leading to their death. Upon autopsy of these whales, scientist often find that the whales' eardrums have ruptured and their brains may suffer internal bleeding and hemorrhaging. These results often show that the whales came into contact with a low frequency sonar test that may have taken place nearby.

Another possible outcome between a clash of whales and sonar occurs in the deep sea. Whales can use their echolocation to perceive their world in three dimensions, and use this to figure out the depth of their swim. However, sonar interferes with that perception, causing them to perceive the wrong depth. This causes them to rapidly rise or dive, resulting in bends, an affliction often occurring in divers. The bends is a painful affliction that causes the gasses in the body to either swell or shrink according the surrounding pressure. Blood vessels, tissues, and the lungs are soon horribly damaged, and the whales are soon killed by the bends.

Many animal activists are on the look out to try and stop military testing of sonar near areas frequented by marine mammals. The NRDC, Natural Resources Defense Council, recently won a lawsuit that prohibited a White House waiver to allow the US Navy to bypass an environmental law to start sonar training exercises in an area that is home to several endangered species of whales. There are also efforts by the same group to create laws to enforce more safety precautions when conducting these exercises. There are many other groups that share similar goals and causes. Hopefully, we will soon find a way to use our technology to protect not only ourselves, but many of the creatures that share our planet.

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