At Long Marine Lab there is a group that takes care of and researches 3 pinnipeds (1 harbor seal, 1 california sea lion, and 1 elephant seal). Their goal is to investigate pinniped acoustics and to find out their range of hearing. The reason behind this work is due to the increasing levels of noise in the oceans, such as: sonar from ships, noises in ocean exploration, and military operations. This group established auditory profiles for each of the three residents, and also with a stellar sea lion Astro (picture above). They began testing their hearing in air and under water at different ranges of hearing, to determine if they could detect certain frequencies. The animals are trained to respond if they hear any noise and therefore they can determine pinnipeds range of hearing. The result of this research are used to generate models which predict how noise of a given intensity, duration, or character will effect the hearing of pinnipeds in the wild. The data is useful for regulatory agencies who establish policies to protect pinnipeds and other marine mammals from the damaging effects of noise in the open ocean.
Since there is no research previously done to prove that noise pollution in the oceans effect marine mammals, this research has been important in discovering the effects that noise has on the behavior, and physiology of these diving mammals.
Random:
If you want to hear what Bernyce the elelphant seal sounds like this time of year click the link below...
1 comment:
I found this article very interesting, quite informative, and directly realted to the effects of off coast noises on sea life on the West Coast.
This article highlights our quaint comparison with whales singing and the complex science the takes place behind the travel of noises under water.
After reading this article I found this passage to be extremely interesting...
"When it comes to evaluation of the impact of underwater sound sources on marine animals, a common misconception is to compare underwater sound pressures with sound pressures in air. First of all, the reference values in air and water are different in that the reference value in air is 20 times higher than in water. Secondly, because there is a huge difference in the density and the sound speed of air and water, it takes much more energy to produce a given sound pressure in air than in water. One should therefore generally not compare sound pressure in air and water. "
I found this article to be a good introduction to the effects of sound pollution on sea animals along the coasts. Hopefully this can contribute to some of the work that is being done to make the effects of detrimental noise pollution on sea life known.
http://www.pbs.org/odyssey/voice/20041103_vfts_transcript.html
check it out!
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