The sounds produced by marine animals are many and varied. Marine mammals, such as blue whale and harbor porpoise, produce sounds over a wide frequency range, from less than 10 Hz to over 100,000 Hz, depending on the species of marine mammal. Many fish, such as the oyster toadfish and plainfin midshipman, and some marine invertebrates, such as snapping shrimp, also produce sounds. Examples of these marine animal sounds can be heard in the Audio Gallery.
In some locations, at certain times of year, and in specific frequency bands, sounds produced by marine life can be the dominant source of underwater sound. Marine mammal calls, for example, can increase ambient noise levels by 20–25 dB in some locations at certain times of year.
Recordings made in a wide frequency band (up to 700 Hz) off Lahaina, Maui, in Hawaii, during the 1998 humpback whale winter season show a peak between mid-February and mid-March, when the population of humpback whales in Hawaii tends to peak. Ambient sound levels are nearly 15 dB higher during this time than in early January or late May because of humpback whale vocalizations. Aerial surveys showed a peak in whales sighted in this area on March 7, 1998, which is correlated with the highest sound levels recorded between January and May (Au et al. 2000).
The humpback whale choruses were loudest at frequencies of 315 Hz and 630 Hz. The data also showed that night sound levels were louder than day sound levels.
The sounds produced by snapping shrimp are the main contributors to the ambient sound fields in shallow bays, harbors, and inlets worldwide at latitudes less than about 40° north or south of the equator. During World War II, extensive measurements of the sounds produced by snapping shrimp were made along the southeast coast of the United States and in the central and south Pacific Ocean. Snapping shrimp sounds in Kaneohe Bay, Oahu, Hawaii, has been reported to be among the loudest anywhere, although recent measurements in Gladstone, Australia, indicate that snapping shrimp sounds may even exceed that in Kaneohe Bay.
- Audio Gallery
- Blue Whale
- Fin Whale
- Harbor Porpoise
- Humpback Whale
- Introduction to Decibels
- Oyster Toadfish
- Plainfin Midshipman
- Snapping Shrimp
- Andrew, R. K., Howe, B. M., and Mercer, J. A. 2011, "Long-time trends in ship traffic noise for four sites off the North American West Coast." J. Acoust. Soc. Am. 129, 642–651.
- Au, W. W. L., and Banks, K. 1998, "The acoustics of the snapping shrimp Synalpheus parneomeris in Kaneohe Bay." J. Acoust. Soc. Am. 103, 41–47.
- Au, W. W. L., Mobley, J., Burgess, W. C., Lammers, M. O., and Nachtigall, P. E. 2000, "Seasonal and diurnal trends of chorusing humpback whales wintering in waters off western Maui." Marine Mammal Science 16, 530–544.
- Burtenshaw, J. C., Oleson, E. M., Hildebrand, J. A., McDonald, M. A., Andrew, R. K., Howe, B. M., and Mercer, J. A. 2004, "Acoustic and satellite remote sensing of blue whale seasonality and habitat in the northeast Pacific." Deep-Sea Res. II 51, 967–986.
- Hildebrand, J. A. 2009, "Anthropogenic and natural sources of ambient noise in the ocean." Marine Ecology Progress Series 395, 5–20.
- Knowlton, R. E., and Moulton, J. M. 1963, "Sound production in the snapping shrimp Alpheus (Crangon) and Synalpheus." Biol. Bulletin 125, 311–331.
- National Research Council. 2003, "Ocean Noise and Marine Mammals." The National Academies Press, Washington, D.C.
- Ross, D. G. 1976, "Mechanics of Underwater Noise." Pergamon Press Inc., New York.
- Ross. D. G. 1993, "On ocean underwater ambient noise." Acoust. Bull. 18, 5–8.