beached whales got bent avoiding sonar

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veek

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This is the first time I've heard of this, but it appears that there is now evidence from beached whales that sonar may cause some whales to dive and surface to avoid the noise...

From Nature, vol. 440, 30 March 2006, p. 593:

"More whale strandings are linked to sonar

Examinations of four whales found stranded along the Spanish coast in January seem to confirm a 2003 Nature report linking sonar to the deaths of several beaked whales.

In recent years, naval sonar devices have been the suspected cause of an increasing number of whale strandings worldwide. The whales are thought to take evasive action to avoid the noise, sometimes diving and surfacing until they suffer decompression sickness and die.

In 2003, British and Spanish researchers reported that Cuvier's beaked whales (Ziphius cavirostris), stranded off the Canary Islands the previous year, had deadly gas-bubble lesions called emboli in their livers. They suggested these were caused by decompression (P. D. Jepson et al. Nature 425, 575-576; 2003).

After a group of beaked whales went ashore in January, along Spain's Costa del Sol, the Spanish Cetacean Society in Madred called veterinarian Antonio Fernandez to perform necropsies on four of the animals. He and his colleagues from the University of Las Palmas de Gran Canaria found the same embolic syndrome as that found in the 2003 study.

"This is the first confirmation of the 2003 report," says veterinarian Paul Jepson of the Zoological Society of London, lead author of that article. The new findings are expected to be published in the coming months.

Officials at the Cetacean Society suspect that mid-frequency naval sonar caused the strandings. But Fernandez notes that the ships that might have been responsibile have not been identified.

Earlier this month, about 45 pilot whales died after stranding on the western side of the island of Sulawesi in Indonesia, following joint US and Indonesian naval exercises in the nearby Macassar Strait. The cause of the stranding is under investigation.

Some US Navy officials, and oceanographers who use devices to generate air bursts underwater for seismic studies, have been accused of blocking efforts to uncover the links between noise and whale strandings (see Nature 439, 376-377; 2006).

Rex Dalton"
 
Most reports coming out of Nature or Science are highly preliminary, which the media does not seem to understand.

So wait for the full-blown article to come out.
 
archman:
Most reports coming out of Nature or Science are highly preliminary, which the media does not seem to understand.

So wait for the full-blown article to come out.


Come on Archman....even the bloody navy admits that the high-volume low-frequency sonar is the death ray of the sea....they don't plan on actually *doing* anything about it but by now we can accept this as common knowledge...

Sheesh.

R..
 
beaked or beach.. not quite sure what was meant there becuase beached would fit in its spot but beaked whales exist :S any insight?
 
How do these whales get bent by breathing air at sea level only?? Do they breath compressed gas at lower levels?? I have no dout they stranded due to sonar but getting bent is a little far fetched. Where is Dr. Decompression when you need him?
These whale are able to dive thousands of feet deep with no problem with great repitition.
Unless Im missing something about free divers getting bent but have never heard of that.
 
MALTA_DIVER:
How do these whales get bent by breathing air at sea level only?? Do they breath compressed gas at lower levels?? I have no dout they stranded due to sonar but getting bent is a little far fetched. Where is Dr. Decompression when you need him?
These whale are able to dive thousands of feet deep with no problem with great repitition.
Unless Im missing something about free divers getting bent but have never heard of that.

Think of whales as extreme free-divers. The physiology is very different but when you're freediving at 100m for 20 min there is compressed gas .... in the lungs.

A human free-diver would have a similar problem if they could stay underwater long enough.

R..
 
Diver0001:
Come on Archman....even the bloody navy admits that the high-volume low-frequency sonar is the death ray of the sea....they don't plan on actually *doing* anything about it but by now we can accept this as common knowledge...
Quite the contrary, in fact. The U.S. Navy has performed the most comprehensive study of this by far. It’s endorsed by NOAA and their NMFS subsidiary. Their results put a stopper over a lot of the media rhetoric. Oddly, I have found that hardly anyone (including marine mammalogists) is even aware of these NMFS-approved studies, much less have read them. They have a lovely website too, but nobody ever visits it.
http://www.surtass-lfa-eis.com/

Despite all the hooplah, there is very little quantifiable data to support most of the claims from environmentalists. It's primarily ancedotal reporting and coincidental conjecture. I've been keeping close tabs on this for a few years, now. On three occasions I've actually had to forward these studies to colleagues who actually WORK in this field. They were blissfully ignorant, which is... highly unprofessional.

The NOAA 2002 final ruling report can be accessed from this link
The comments and response sections starting on p. 46719 are a great read.
http://www.nmfs.noaa.gov/prot_res/readingrm/MMSURTASS/lfasonar_fr02.pdf


Here’s a graphic summary of the original study. Also ignored by most anti-sonar websites.
http://www.surtass-lfa-eis.com/Research/index.htm

This Q&A dispenses most of the commonly regurgitated sonar myths seen online and in magazines.
http://www.surtass-lfa-eis.com/FAQ/index.htm

Here’s a listing of most of the public outreach work performed by the Navy, from which many of the 2002 final ruling questions originated.

http://www.surtass-lfa-eis.com/EIA/index.htm

People can always argue the merits of a study sponsored by the Navy, but I ask such critics to read the reports and back up their claims first.
 
MALTA_DIVER:
How do these whales get bent by breathing air at sea level only?? Do they breath compressed gas at lower levels?? I have no dout they stranded due to sonar but getting bent is a little far fetched. Where is Dr. Decompression when you need him?
These whale are able to dive thousands of feet deep with no problem with great repitition.
Unless Im missing something about free divers getting bent but have never heard of that.
Human freedivers can get dcs symptoms, ama divers, who are proffesional asiatic free divers have reported dcs symptoms to studies on it, the conclusion was they are getting dcs but do not report it.
 
MALTA_DIVER:
How do these whales get bent by breathing air at sea level only?? Do they breath compressed gas at lower levels?? I have no dout they stranded due to sonar but getting bent is a little far fetched. Where is Dr. Decompression when you need him?
These whale are able to dive thousands of feet deep with no problem with great repitition.
Unless Im missing something about free divers getting bent but have never heard of that.

I don't think that the whales get DCS "naturally". However, exposure to high intensity ultrasound such as sonar can create bubbles (from the dissolved gas in tissues), induce cavitation etc. Not only in whales- at certain ultrasound levels it can also occur in humans who never dived, at sea level :05:

It is something like this: Tissues have a certain amount of dissolved gasses, the cause of breathing air, whether at sea level or depth there is always dissolved gas.
A sonar/ultrasound wave can be considered as a pressure wave propagating at the speed of sound. When it passes through tissue, there is a compression of the particles, immediately followed by a decompression as the wave passes. In some sonars or ultrasound systems this cicle is repeated hundred of thousands of times each second. These sudden changes in pressure can be strong enough to cause bubbles and cavitation within tissues, and at certain levels they can cause violent damage.

Of course, it depends on many factors such as ultrasound intensity to begin with, distance from source, beam shape etc. etc. etc. But the bottom line is that in *some* circumstances, sonar can be harmful to whales, as well as humans or anything in the water which has dissolved gasses. I guess that this rarely happens, though.
 

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