LOFROBLTBA!!!
Scientists say whales were bent!!
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There may NOT be something unnatural happening. As we know, whale strandings and whale deaths occur from natural causes on a somewhat regular basis. The point here is that we don't have enough information to know with any certainty what the cause is.
ROFLMAO
All I could think of was the Stone Age scene in Mel Brooks' History of the World Part 1.
This would have fit nicely in that scene, along with the appropriate narration.
Rickg
Contributor
Diver0001,
What you forgot to say was that the only USN Low Frequency Active (LFA) equipped vessel was not only NOT TURNED UP ALL THE WAY - IT WASN'T EVEN IN THE ATLANTIC OCEAN. This stranding can not be attributed to the USN's LFA.
That said, there was a naval exercise going on when this stranding occurred and there were multiple surface vessels (destroyers, frigates, etc) transmitting medium/high frequency sonars in a constricted area which may well have contributed to the stranding.
Rickg
I stand corrected. I don't suppose it matters much to the whales which frequency it was that killed them. I suppose that only gives us evidence that the frequency isn't as much the problem as the volume.
I can understand a navy wanting this kind of technology but I can't help thinking that all the best minds in the world should be able to think of a way for listening for subs at long distance that doesn't hurt marine wildlife......
R..
Rickg
Contributor
Diver0001,
One often heard possible reason for what happenned in the Bahamas was that it was the location of the exercise that contributed to the beaching. Unfortunately ASW has moved from a deepwater problem to a littoral/coastal problem. The major Navy's of the world have been transmitting these MF/HF frequencies at these levels in mid-ocean/deep-water for years with no apparent problem.
Now the the major Navy's are trying to tackle the small, quiet diesel submarine operating in shallow water near to shore. Unfortunately, passive sonar (which for years was the sonar of choice for deep water ASW) is not very effective in shallow water for a multitude of reasons which is why there is a renewed interest in active sonar of all types. Hence the move to conducting ASW exercises in littoral/coastal waters. In this case during part of the exercise there were multiple surface vessels (destroyer, frigates, etc) conducting a transit in a confined/restricted area/channel between 2 islands. One thought is that multiple active sonar pulses were being transmitted simultaneously and also being reflected in many directions because of the shallow water and this may have caused the whales to be disorientated.
I know the US Navy has adopted some new procedures in an attempt to minimize the possibility of future occurences and is also continuing to research this issue.
Rickg
One often heard possible reason for what happenned in the Bahamas was that it was the location of the exercise that contributed to the beaching. Unfortunately ASW has moved from a deepwater problem to a littoral/coastal problem. The major Navy's of the world have been transmitting these MF/HF frequencies at these levels in mid-ocean/deep-water for years with no apparent problem.
Now the the major Navy's are trying to tackle the small, quiet diesel submarine operating in shallow water near to shore. Unfortunately, passive sonar (which for years was the sonar of choice for deep water ASW) is not very effective in shallow water for a multitude of reasons which is why there is a renewed interest in active sonar of all types. Hence the move to conducting ASW exercises in littoral/coastal waters. In this case during part of the exercise there were multiple surface vessels (destroyer, frigates, etc) conducting a transit in a confined/restricted area/channel between 2 islands. One thought is that multiple active sonar pulses were being transmitted simultaneously and also being reflected in many directions because of the shallow water and this may have caused the whales to be disorientated.
I know the US Navy has adopted some new procedures in an attempt to minimize the possibility of future occurences and is also continuing to research this issue.
Rickg
FreeFloat
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Freedivers are taught to never breathe compressed air during a freedive.
If a freediver starts breathing compressed air while at depth (however deep that meay be) they are suddenly no longer a freediver but are subject to the same NDLs and ascent rate as a scuba diver.
Moreover - I don't know for sure if this would be a factor or not - scuba divers are taught "Never ever hold your breath" which means that even in an OOA situation the scuba diver is exhaling (the "steady stream of tiny bubbles"). OTOH, the freediver has probably spent years training on holding his breath, especially during ascent.
Breathe compressed gas at depth and hold your breath on ascent is a guarantee of DCS.
As I recall, many cetaceans EXHALE before doing deep descents. This takes care of a lot of the buoyancy, nitrogen loading and compression/recompression problems. Virtually all deep diving marine mammals go into a "oblique glide" as they descend, that expends no energy.
Comparing human freedivers to marine mamals in physiological terms is often not as clear cut as it may seem.
Comparing human freedivers to marine mamals in physiological terms is often not as clear cut as it may seem.
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