Originally posted by Sankari
How does acoustic trauma kill dolphins? Has anyone ever seen a dolphin killed by acoustic trauma?
This is a little equivocation on what was being claimed. No, you don't push a button labelled 'ping' and then all of a sudden, dolphin heads start
exploding all over the planet. That is not what is being claimed by the proponents, and even though I disagree, to be fair they bring up some good
points. The National Resources Defense Council, arguably biased of course, issued their report on the deleterious effects of marine noise on Cetacea
and other marine life here:
SOUNDING THE DEPTHS II: The Rising Toll of Sonar, Shipping and Industrial Ocean Noise on
Now, the Navy does not just simply run around pinging its sonar like they were in some WWII version of Up Periscope. Sonar is a gigantic beacon which
says to everything within 500 nm "Here I am, you know exactly where I am now!!!!!!" It is something a platform uses only really, in an emergency,
so to speak. Sonar is used to actively prosecute a submarine and is in no way employed enough to substantiate all the marine life deaths worldwide.
Most 'sonar' is passive - (ie. does not make an artificially added sound 'ping' in order to do its location ranging and direction, it simply
listens). Even sonobouys are mostly passive. They are much more effective that way. Even the high frequency topo mapping phased arrays employed by
submarines is of limited range and is very low intensity, and is used sparingly.
Navy exercises can get noisy, yes, because they simulate combat conditions. But 99.95% of the time - both ships and subs 'run silent" Making noise
is not an effective warfighting strategy on or in the ocean.
The simple fact is that this effect is being generated by conditions other than Navies. Dolphins will travel 100-200 miles to avoid whatever it
"Natural Causes" behind dolphin deaths in Peru
Coupled with this are the simultaneous group die-offs of crustaceans and birds en masse. Warm ocean temperatures and chasing food further are being
blamed for those deaths, but fail to explain why other creatures such as dolphins, whales, amphibiae and osteichthyes, who would not be affected by
this, are also dying in groups.
There is one thing however which affects them all, and that is infrasound. Infrasound causes distress in at least mammals (Science (NBC News:
"British scientists have shown in a controlled experiment that the extreme bass sound known as infrasound produces a range of bizarre effects in
people including anxiety, extreme sorrow and chills;" National Physical Laboratory, Sept 2003). Infrasound can be detected by a large percentage of
larger life forms, on both land and sea.
Still a great way to go with this, but most of the knee jerk assessments have not panned out in large scale marine deaths.