beached whales got bent avoiding sonar

[JonAustin]

Guess not:

Noun 1. pilot whale

pilot whale - small dark-colored whale of the Atlantic coast of the United States; the largest male acts as pilot or leader for the school

http://www.thefreedictionary.com/dict.asp?Word=pilot+whale

 

[Rickg]

1. I went on line to see if I could find a NOAA final report on the Bahamas Marine Mammal Stranding but couldn't find one. What I did find is this US Navy site where they discuss:

http://www.whalesandsonar.navy.mil/stranding_events.htm

"The Navy and NOAA Fisheries learned from the Bahamas stranding that certain marine mammals, particularly beaked whales, may be sensitive to mid-frequency sonar."

The site also discusses Navy-funded research and protective measures the Navy is taking to prevent a similar occurrence in the future.

2. If you read the interim report that I posted previously you will see that they believe a mid-frequency sonar (not LFA) being operated for an extended period of time (ASW exercise) in a confined space (channels between islands) also occupied by the marine mammals contributed to this stranding.

Rickg

 

[cerich]

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.

Then ask the Navy why it is SOP to use sonar as an anti Diver defensive mode? Because it is powerfull enough to kill them! Waters reaches a boil at the transducer on some sonars.

I can't imagine the whales enjoy it.

I'm generally not a die hard enviornmental issue type guy and having served in Submarines in the navy see that the sonar is needed, but to think it has no impact on the sea life is just garbage.

 

[E_mcSCOW]

.

 

[archman]

Then ask the Navy why it is SOP to use sonar as an anti Diver defensive mode? Because it is powerfull enough to kill them! Waters reaches a boil at the transducer on some sonars.

I can't imagine the whales enjoy it.

I'm generally not a die hard enviornmental issue type guy and having served in Submarines in the navy see that the sonar is needed, but to think it has no impact on the sea life is just garbage.

You didn't read any of those articles, apparently. There are extensive discussions of sonar types, frequencies, ranges, and what levels are believed to cause direct tissue damage. The Navy likes to use 180 decibels as a common benchmark.

 

[DivePartner1]

Well, I’ve done some hunting. Everything I’ve found keep leading back to the multi-species Bahamian stranding event in March 2000. No pilot whales, however. This is the most exhaustively studied stranding event ever undertaken, and it’s also the report most often misquoted and misinterpreted by the media and various NGO’s. That’s due to the report’s findings lending credence to a tactical sonar exercise as the most logical culprit. The fruitcake media clung to that bit like a golden talisman, and have been weaving tall tales about it ever since.

. . . .
http://www.nmfs.noaa.gov/prot_res/readingrm/MMSURTASS/lfasonar_fr02.pdf

Good detective work Arch.

The Navy's dilemma is that by honestly acknowledging harm under the unique circumstances of the Bahamas Report (noisy ASW fleet exercise catching deep diving whales in the shallows) they opened the Pandora's Box of inviting blame anytime a whale beaches in different, unrelated circumstances.

I believe the Bahamas incident involved beaked whales, not pilot whales. Pilot whales and others beached themselves before sonar existed, they still do and probably always will for reasons that we may some day better understand.

Blaming all groundings on the Navy without rigorous, objective, unbaised study of the cause of individual incidents does nothing to enhance this understanding of why whales do this.

 

[archman]

I have noticed that over the last decade, whenever a marine mammal beaching occurs, media reports tend to implicate any nearby military naval activity through association. Spanish navy, Canadian navy, US Navy... these are just ones off the top of my head that I've seen reported. Except for the Bahamian incident, I do not believe a single one of these accusations has ever been substantiated.

Merely by stating that naval vessels were in the area, news media places the assumption of causality into the minds of the public. If done repetitively without check (which it has for several years for this case), such behaviour can confuse peoples' ability to differentiate fact from theory.

 

[Diver0001]

Well,

I just typed in a lengthy response to this but lost it when my browser took a nap....

here's the summary of my conclusions:

1) the technology itself wouldn't appear to be inherently damaging to marine life

2) however, they play it too loud. The Navy determined a maximum safe operating volume of 190db, but they're typically playing it at 215 (300-odd times louder) and it has an operational capability of at least 240db, which is 100,000 times louder than they determined is "safe".

It would also appear that bottom topology and depth can have an affect. I guess that means that if it's echoing off the bottom that it can have an amplifying effect. That's not a surprise but it's worrying in the sense that they don't really have a good idea of what the total generated volume will be if it's used in shallow water. This could have been one of the issues a play in the Bahama's. In the Bahama's incident, there were several ships and the sonar was played at a maximum of 235 decibels in relatively shallow water. Worst of all worlds.

And here's what they said about the incident in the Bahama's

Based on the way in which the strandings coincided with ongoing naval activity involving tactical mid-range frequency sonar use in terms of both time and geography, the nature of the physiological effects experienced by the dead animals, and the absence of any other acoustic sources, the investigation team concludes that tactical mid-range frequency sonars aboard U.S. Navy ships that were in use during the sonar exercise in question were the most plausible source of this acoustic or impulse trauma.

That's an honest assessment and it wasn't written by the media.

It's easy to give the media the blame for it and I'm sure that perceptions of it being a bigger problem than it is might be realated to media exposure, but I would submit that without media exposure, the government's response to this issue may have been slower--or non existent. Bad media coverage or not, the conclusions are out there. Even by the Navy's own research, they're playing the system at unsafe volumes and as a result it *can* harm whales *if* they are close enough to the source of the sound.

It doesn't seem to me like it's an earth-shaking problem, though. The Navy appears to understand the issues and they appear to be acting responsibly in response. What I would still like to know, however is why they don't just play the system at 190db if they know that this is the safe limit..... I couldn't find any information about why they choose not to do this.

One more point; I was prepared to be very skeptical of the research but it would appear to be a lot more balanced than I was expecting.

R..

 

[archman]

Two major reasons why navies aren't too sorry, range and use.

It's mostly due to range. The noisy mid and high-frequency sonars don't travel very far underwater, unless there's unusual acoustic conditions.

The reason that active sonars operate at such high powers is linked to maximum effective range, just like radar. If you want a good max range, you're going to have to crank out more power. Ever wonder why aircraft and fixed radars have "stand clear!" warnings around them? A strong radar set can fry near-flying birds out of the sky. But the radiation intensity rapidly attenuates with distance, excepting steered beam types.

But unlike radar, active sonar is rarely used by naval vessels, even during wartime. It gives your position away. Most navies place far more emphasis on using passive sonar systems, which don't project sound. They only listen. And that doesn't harm marine life one bit.

The general public has the impression that navy sonars are primarily active types that ping away 24/7, and greatly exaggerate the effective ranges of active sonar. This is a gross mistake.

 

[Santa]

LOL, sure.

(In the slightly annoyed and slightly contemptful voice of Homer Simpson):
Tsch! "Pilot" whale.