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Powerful Sonar Causes Deafness In Dolphins
Hugh Pickens writes "Mass strandings of dolphins and whales could be caused because the animals are rendered temporarily deaf by military sonar, experiments have shown. Tests on a captive dolphin have demonstrated that hearing can be lost for up to 40 minutes on exposure to sonar and may explain several strandings of dolphins and whales in the past decade. Most strandings are still thought to be natural events, but the tests strengthen fears that exercises by naval vessels equipped with sonar are responsible for at least some of them. For example, in the Bahamas in March, 2000, 16 Cuvier's beaked whales and Blainville's beaked whales and a spotted dolphin beached during a US navy exercise in which sonar was used intensively for 16 hours (PDF). 'The big question is what causes them to strand,' says Dr. Aran Mooney, of the University of Hawaii. 'What we are looking at are animals whose primary sense is hearing, like ours is seeing. Their ears are the most sensitive organ they have.' In the experiment, scientists fitted a harmless suction cup to the dolphin's head, with a sensor attached that monitored the animal's brainwaves, and when the pings reached 203 decibels and were repeated, the neurological data showed the mammal had become deaf, for its brain no longer responded to sound. 'We definitely showed that there are physiological and some behavioral effects [from repeated, loud sonar], but to extrapolate that into the wild, we don't really know,' said Mooney."
Wow. I think if you expose me to a 203 decibel sonar, it's not just my ears that would go poof.
Guess dolphins and whales can't go to concerts. Although, I hear The Pingers have quite the underwater following.
In other news, when exposed to brilliant flashes of light, humans are rendered temporarily blind.
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Experiments like these are like putting people next to a jet engine to see if their hearing gets damaged. I am no PETA freak, but putting 200+ decibels is bound to do permanent damage. I know they said it is temporary, but that might be like my "temporary" hearing loss from the Boston show a few months back. Yes, I could hear fine afterward* but I wonder what incremental loss I might have had from all that loudness.
*I have higher pitch loss that apparently came from shooting a lot many years ago without hearing protection.
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Seriously, everyone knows that human wants and needs are more important than some stupid fish being able to hear. Its not like they need sound for anything.
You don't need to actually make dolphins deaf to know if they will be deaf! Not only is that cruel, it's unnecessary.
It's common knowledge that exposure to 200+ decibels will make anything deaf. And this Dr. Mooney is an idiot.
If it makes them deaf in a lab, it fucking works outside the lab!
They're using their grammar skills there.
Loud noises tear the cilia in your cochlea out by the roots. In humans, and, as far as I know, other higher mammals, they don't grow back (Can someone who knows confirm that this is true in dolphins as well?).
So the word "temporary" might make this sound less bad than it is: Our sonar may only temporarily cause total deafness, but I suspect it permanently degrades hearing.
Sucks to be a dolphin. Reminds me of Douglas Adams' sympathy for whales, whose songs no longer can be heard across the ocean. (I think Douglas talked about this in Last Chance to See.)
"The deafness, though, was only temporary and the dolphin was not hurt in the experiment, said Mooney." So the experiment is still cruel but obviously no permanent damage. Deafness aside: Loud noise causes disorientation and nausea in humans, so why not in dolphins. BTW: A "singing" Whale produces a sound pressure level of up to 185 dB under water! (s. http://en.wikipedia.org/wiki/Sound_pressure_level#Examples_of_sound_pressure_and_sound_pressure_levels) So 200 sounds extreme but remember its not air we are talking about, but water. For comparison the hearing threshhold of a diver is 67dB at 1khz. The auditory threshhold through the air at 1khz is 0 dB.
The reality is that they don't particularly care. They have to, for purposes of public relations, act like there's no problem, like what they're doing is perfectly fine, but the reality is that they could care less if every cetacean in the ocean died tomorrow.
The world's burning. Moped Jesus spotted on I50. Details at 11.
No it isn't.
not a lot of high powered sonar use in the civilian world, i would guess.
My wife is a wildlife conservation researcher, and specifically works with animals in the Delphinidae family (which include dolphins). There's a lot of stuff she, and others, have to - must - verify, even if it seems to be a "wellduh."
The alternative would be that science just thinks correlation = causation. Is that what we want? "Well, Navy ships used sonar, and these whales stranded themselves...must be related. Case closed." Instead, someone did actual science showing that sonar causes real deafness in these animals. And someone wants to harsh that?
I say instead that there should be a tag, "abouttimetheyverified"
you do realize that 99%+ of the time, these terrible nuclear submarines don't even use ANY form of sonar other than underwater microphones don't you?
To a similar (though not as high degree) neither do surface ships.
I didnt think so.
yet another example of a slashtard talking out of their ass with absolutely NO idea what they are talking about.
And yes, I did happen to serve on one of these terrible nuclear submarines.
and in the case of missle subs, it's probably closer to three nines or more.
ssbn subs are holes in the water that strive to make absolutely no noise.
you can hear the original sound wave a lot further off than you can hear the return echo which is always weaker.
and that's before you even throw in the effect of temperature gradients and convergence zones.
another thing to ponder is what was the frequency used?
and does this matter.
the reason i say this is that MOST sonar is low frequency or extremely low frequency, with the exception being high frequency sonar used to search for underwater mines and to penetrate ice fields.
of course, why mention these type things as they will just muddy the waters and potentially invalidate the test.........
(I said potentially, not that they do, i have no idea and based on the report, neither does anyone else)
Classic Greek authors tell us that in the ancient Greece, dolphins and whales were already found stranded on the shore. This was a windfall for the locals, who were not eating meat very often. They saw it as a divine gift and thanked Poseidon for it.
So considering that the Greek galleys didn't use sonar, we need to stop barking at the wrong tree and find the cause of this phenomenon. My money is on a parasitic disease that affects the brain.
Fantasy: http://ferrisfantasy.blogspot.com/
Now we have a new weapon for the inevitable dolphin uprising.
Saying your "phone ran out of batteries" is like saying your "car ran out of gas tanks".
what do you think?
the military probably uses less sonar in day to day operations than the rest of the scientific community does.
after all, how can you plot out that wreck without side scanning sonar?
how can you map those undersea ridges and trenches without using some sort of down firing sonar?
the truth of the matter is, sonar as used by the military is mostly a passive system.
it's kinda like sitting out in the woods while hunting. you don't go around making a lot of noise because it can be heard further away than you can hear the animals you're hunting.
which, depending on the animal, either allows them to flee undetected or allows them to hone in on your location and find you and kill you.
it's the same reason military jets don't just fly around with their search radar on, because it can be detected a long way off, and with some simple geometry and two reception points, they know where the jet now is.....
and then they can use a less detectable method to eliminate that jet.
like say an infra-red heat seeking missle instead of one that requires radar guidance.
WRT to all of the "203 decibels, OMG!" comments: water decibels aren't the same as SPL decibels.
A decibel is the logarithmic relationship between one quantity and a reference quantity. For sound pressure level, we use the RMS pressure of the sound wave compared to a reference pressure that represents the threshold of human hearing (20 microPa): 20*Log10(P/20e-6)
Other types of decibels use different reference quantities. For example, vibration velocity in the USA uses a reference quantify of 10^-6 in/sec. Sound intensity (sound power through a unit area) uses a reference quantity of 10^-12 W/m2. So comparing sad sound intensity decibels to vibration velocity decibels is meaningless without normalizing the units.
In the case of water decibels, we use pressure as we do for SPL in air, but the reference quantity is different: for water, the reference quantity is typically 1 microPa. Therefore the 203 dB in water is approximately equivalent to about 170 dB SPL in air. Of course you still can't directly compare water dB to SPL because the wavelengths of sound in water are so much longer than wavelengths of sound in air.
In any event, 203 dB in water is very loud (and obviously harmful to aquatic life as demonstrated in the articles), but not necessarily in the same way that 173 dB SPL is loud/harmful to us.
Maybe not Terrorists, but our Naval Superiority, , does play a lot into our relationship with China.
Our Military superiority, (or inferiority,) dictates how much economic pressure we can apply.
people use sonar trying to FIND subs, moron. If the subs aren't there, no sonar.
God, no wonder you went into the military. no other options.
You are the moron. Subs dont use active sonar unless there is no other choice because it reveals their location. Subs use passive sonar 98% of the time. Calling him a moron and having no choice is an assumption based on that you are the moron. Any member on a submarine is not your normal enlisted seaman, they actually have to screen candidates so they can get the job done. Its not some infantry man throwing on some headphones and listening. Also if submarines used active sonar, we would never have news about two subs colliding as they could easily see each other.
Submarines are sneaky little bitches. 200+ dB sonar is painting a glowing "Shoot me!" sign on your hull for enemy torpedoes to follow. The "Shoot me!" effect goes (much) further than the effective range of your sonar, meaning that turning on active sonar is giving away a large advantage, and essentially a panic button. It is a thing to be avoided, so unless in times of war, active sonar is rarely used.
To the best of my knowledge, SONAR is short bursts of loud noise broken by longer periods of quiet to receive and process the return echos. Two minutes of continuous sound is not going to happen. Even if the effect is cumulative, a cetacean would have to travel with the source for over five minutes which it is unlikely to do if the SONAR is injurious. Would you hang out in an excruciatingly loud environment?
Now, some will point to this:Sound can become trapped if a layer of warm water lies over cold water. When sound created in the warm zone reaches the cold water it can bounce back instead of travelling though it. This, Dr Mooney said, would have the effect of trapping the sound in the warm layer, where it would bounce around "like a ping-pong ball", giving whales and dolphins little chance of escaping it.
But, the thing is, dolphins and whales are mammals. The would leave the noisy layer when they surfaced. Therefore, they would quickly learn how to escape the sound: surface or dive.
The conclusions seem specious to me.
There is no "-1 offended" or "-1 you don't agree with me" mod options for a reason.
Well if you're really so pressed for time...
According to the very first result, a sonar source of 240dB will result in a perceived intensity of 180dB at a distance of 1km, and 150-160dB at a distance of 160km. However, this does not mean that the experiment was "dumb", and your attempt to dismiss what was in fact an entirely rigorous scientific experiment solely on the basis of your own failure to read the damned summary (let alone TFA) is more than a little grating.
In actual fact, prior research (albeit conducted "in the wild" rather than in the strict laboratory conditions that this recent article was) has shown that whales and dolphins will actively avoid, and even show obvious physical distress at sonar at intensities as "low" (relatively speaking - in fact it's actually not very low at all) as 120dB. Yes, that does mean that marine life over 100 miles away from the actual source of the sonar will be suffering negative effects.
Going back to this recent experiment, however, and your oh so obligatory /. car analogy, allow me to correct the analogy to something more suitable. This experiment was like testing whether someone would be hurt by having a car run into you at 50 mph, and discovering that, yep, that's gonna hurt. Then they gradually ramped up the speed, and brought in bigger cars, until they discovered that when you get hit by an SUV going at 90 mph, you're going to be dead before you hit the ground. That's what the 203dB figure represents. They increased the intensity of the sonar pings until they discovered the point at which the dolphin became totally deaf. The experiment was totally methodical and rigorous, and about as far from "dumb" as you can possibly get.
Santa's suicide mission go!
I'd personally kill every Dolphin myself if it would save a human life.
Ah, if you kill every dolphin, you'll also be killing humans. Though rare, dolphins have saved humans, especially from sharks.
Falcon
Should there be a Law?
http://www.underwatertimes.com/news.php?article_id=48723961015
That study used fish. Fish are not mammals but dolphins, porpoises, and whales are.
Not that I personally believe it don't effect them, though we may not know how to tell.
Marine mammals are shown to hemorrhage from sonar.
Falcon
Should there be a Law?
It's not panicky if you want 1 ping only ;)