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Mapping
Anthropogenic Noise in the Sea – An Aid to Policy Development
Sources of Sound in the Sea
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| As shown in this
table, anthropogenic ocean noise is generated by many activities
that occur on or near the ocean. The sea is not naturally
silent—noise in the ocean also is generated by wind,
waves, rain, earthquakes, and marine life itself.
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Sources of Sound in
the Ocean |
Naturally Occurring |
Manmade |
- Wind
- Waves
- Rain
- Ice
- Volcanic and Tectonic Activity
- Biological Activity (shrimp, marine mammals)
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- Shipping
- Oil & Mineral Exploration/Extraction
- Recreational Boating
- Fishing & Aquaculture
- Military Activities
- Oceanographic Research
- Other Sources - Aircraft, Icebreaking
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| The graph at the right illustrates the overlap
of frequencies generated by anthropogenic activities and produced
by marine mammals. It depicts the broad spectrum of ocean noise,
the natural and anthropogenic activities that generate it, and
its distribution by frequency range and source level. It also
illustrates current understanding about the range of frequencies
that some marine mammals use for echolocation and communication.
There is a significant amount of overlap between frequencies
generated by marine mammals and many anthropogenic activities.
(Note: the bars identifying the frequency ranges are not positioned
to represent corresponding spectrum levels.) |
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Source:Adapted from Wenz, GM. 1962 “Acoustic
Ambient Noise in the Ocean: Spectra and Sources.”
Journal of the Acoustic Society of America 34:1936-1956.
Overlay of marine mammal “activity” ranges
added by David Bradley, Applied Research Laboratory, Penn
State University. |
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