Naked Science Forum
Life Sciences => Plant Sciences, Zoology & Evolution => Topic started by: thedoc on 14/12/2009 11:34:17
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Why do whales beach themselves?
Asked by Etienne De Villiers
Read the naked scientists answer here (http://www.thenakedscientists.com/HTML/content/questions/question/2491/)
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This is a real puzzle.
It may be due to distortions in the Earths magnetic field, although it is questionable whether whales use this field for navigation.
It may be due to shipping. In 2002, 14 beaked whales came ashore in the Canary Islands. Navy ships in the area were using active sonar.
Some may come ashore due to illness making them too weak to swim. Or it could be that they come into shallow water for support during this time to avoid drowning and get washed further inshore than they intended by waves or left in too shallow water by receding tides.
Only a couple of days ago 55 False Killer Whales beached near Cape Town. Volunteers helped them back into the water, but they turned back and beached themselves again.
It has also been suggested that it could be due to pollution, but this strange phenomenon is known to have been going on for hundreds of years, so man cannot be blamed for this.
The fact is, we just don't know the answer to this question. Read this interview with DARLENE KETTEN http://www.myhero.com/myhero/hero.asp?hero=Darlene_Ketten_06 (http://www.myhero.com/myhero/hero.asp?hero=Darlene_Ketten_06)
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Listen to the answer to this question on our podcast. (http://www.thenakedscientists.com/HTML/podcasts/show/2009.11.29/)
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I have studied seismic activity and Earthquakes around the world for over 26 years. I have found to prove that with most whales or Dolphins beaching is caused by underwater sounds from seismic activity is very excruciating on these animals and they beach to get out of the water. Even trying to put them back into the ocean they will simply turn around and beach again. I have noticed in my finding that a few days after the beaching earthquakes above 6.0 usually occur in the surrounding regions. An example late last month whales beaches in New Zealand near Wellington, a few days after Christchurch was hit be a 7.1 earthquake. I have much more evidence and information available on this. Sonar from naval submarines etc also upsets them. Its like a dog whistles, we can not hear it, but it drives dogs crazy.
Regards
Gary Matthews
Adelaide Australia
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Diving pods of offshore toothed whales and dolphins (odontoceti) feed on squid above mid-oceanic ridges where they are often exposed to oscillations in ambient water pressure when shallow-focused earthquakes suddenly erupt in the seafloor below them. On rare occasion these changes in pressure are too excessive and/or too rapid to be counterbalanced by the whales' pressure regulating anatomy resulting in barotrauma in the sinuses and air sacs of each animal's head. Since echo-navigation and echo-location are not possible without intact and functional sinuses and air sacs, a pressure related injury in this system renders the victims unable to use their acoustic navigation system to determine their position and find food. Nor are they able to dive without suffering intense pain. The injured pod huddles together for protection against sharks and swims slowly away from the epicenter, but not in a random direction. Rather, increased resistance (drag) to swimming against or perpendicular to the surface flow will turn the whales headfirst and point them in the path of the least drag, which is always downstream with the flow of the surface currents.
Many barotraumatized pods recover after an unknown period of rest on the surface. Those that do not recover are eventually: (a) guided to a stranding beach by the surface current, (b) harvested by sharks and killer whales, or (c) die and sink to the bottom. Decomposing gases will form in the carcasses that sink in water less than 100 meters deep. After about a week underwater, the gases formed will re-float these carcasses and they will be carried by the surface currents to a beach.
Non-navigating whales, carcasses, and flotsam are deposited on beaches because the current that carried each grain of sand to build the beach in the first place, is the same energy determining the path of everything floating on the surface. Where currents wash shoreward, there are beaches, flotsam, and beached whales; where current does not wash toward the shore, there are no beaches, no flotsam, and no beached whales.
http://deafwhale.com/seaquake_solution/