beached whales got bent avoiding sonar

[JonAustin]

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.

Right, but these are whales. In contrast to human divers, whales exhale almost all of the air out of their lungs, prior to diving. Among other adaptations, they use the oxygen reserves in their blood (they proportionately have a lot more hemoglobin than humans), rather than what's in their lungs.

With little or no air in their lungs, there's nothing to compress. Therefore, there is no increased partial pressure. Therefore there is no nitrogen dissolution. Therefore there can be no nitrogen coming out of solution. Therefore there is no DCS or arterial gas embolism.

I'm certainly no marine biologist, but color me skeptical about this article.

 

[archman]

Actually, there is a highly interesting article that supports naturally occurring decompression illness in whales. Hmm... let me see if I find a link.

http://www.whoi.edu/oceanus/viewArticle.do?id=4720

You gotta love those photos.

 

[Diver0001]

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.

I need to take some time to read this before I respond further. I clearly recall reading a statement from the Navy after the pilot whale incident in the Caribbean that basically said that they thought the sonar was the cause. IIRC the statement also said that it needed to be researched. I guess that's happened now and they're back to denying it..... It's going to be hard to not be skeptical about the results given the sponsor but I'll do my best.

R..

 

[archman]

I clearly recall reading a statement from the Navy after the pilot whale incident in the Caribbean that basically said that they thought the sonar was the cause. IIRC the statement also said that it needed to be researched.

If you can give me the year of the beaching, and the exact location (Bahamas?), I can track it down for you. NOAA's got everything posted online, it's just tricky finding some stuff.

 

[Diver0001]

If you can give me the year of the beaching, and the exact location (Bahamas?), I can track it down for you. NOAA's got everything posted online, it's just tricky finding some stuff.

My memory isn't that accurate. Can you use a date-range?

R..

 

[archman]

The problem is its pilot whales. These things strand for a nothing, all the time. There are TONS of incident reports worldwide to pore over.

 

[Humuhumunukunukuapua'a]

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 think you're confusing lung over-expansion and getting bent. You are safe from lung overexpansion if you breathe air at the surface, descend, then ascend. You risk lung overexpansion if you breathe a volume of air at depth, hold your breath, and ascend.

The bends don't have anything to do with compressed air per se. The air in your lungs is under pressure greater than surface level, so your body absorbs more Nitrogen from the air in your lungs. So if you can stay down long enough or go deep enough, you can absorb a lot of extra Nitrogen. Then, if you ascend too quickly, bubbles form and you get bent.

Also, the way I understand the whale issue, it's not the sonar making bubbles in the whales (or maybe that's part of it too.) But an article I read (in the DAN magazine I think?) said that whales definitely do get DCS symptoms naturally. The bones of old Sperm Whales show pitting at the joints that scientists attribute to Nitrogen bubbles.

The concern with sonar as presented in this article was that the sonar makes the whales ascend much faster than usual to avoid the sonar. Thus they get badly bent. Maybe the "sonar making bubbles" phenomenon is real too, but I don't know anything about that. The explanation I had was much simpler. The whales are basically being "startled" into ascending much too quickly and they get bent because of the enormous depths and long times that they dive.

 

[archman]

Dang pilot whales... is it this one?

http://www.cbsnews.com/stories/2003/11/25/tech/main585590.shtml

 

[Diver0001]

The problem is its pilot whales. These things strand for a nothing, all the time. There are TONS of incident reports worldwide to pore over.

What I recall is that the incident occured immediately after a test of that big-asss low frequency sonar. The test involved several ships and I don't remember the location but it might have been the Bahama's. If memory serves *no* whales were spotted in the entire region for a period of weeks or possibly months after the incident, leading to speculation that they had fled and the Navy admitted it might have had something to do with the sonar because a number (maybe all) of the whales were bleeding from their eyes and had serious internal trauma, possibly to the ears (or whatever it is that whales have). I think it was in 1999 but it might have been earlier. Try 1998-2001.

Is that enough to go on?

R..

 

[Diver0001]

Dang pilot whales... is it this one?

http://www.cbsnews.com/stories/2003/11/25/tech/main585590.shtml

We crossed posts. No it doesn't sound like the same incident.

R..