- Education and Science»
- Life Sciences
Ocean and White Noise - The Sounds of Sonar and Whale Beaching
There is a huge quantity of white noise in our oceans caused mostly by humans. Many are concerned that ocean sounds may be the cause of mass whale beaching. Today many questions are raised by scientists, researchers, and biologists. The biggest question is whether the sonar and white noise induced by humans is harmful or even lethal to all marine life.
Marine animals depend on sound for communication, breeding, navigation, and feeding. Not only are the vocalizations of whales, dolphins and fish distinct from each other but most species have more than one way to communicate with each other by the use of sound.
Ocean Noise Volume Increases
For the past 60 years, ocean and white noise has drastically increased in volume. According to the World Wide Whale association (a company of researchers dedicated to whale survival), ocean noise rose 10 decibels between 1950 and 1975, a 900% increase in 25 years. (Ocean Noise) Today, ocean noise can be as high as 250 decibels which is equivalent to the takeoff of a commercial jet plane (Ocean Noise).
There are 2 basic problems associated with ocean sounds and white noise. One is the ambient noise level that is created by underwater explosive detonations, shipping traffic, echo sounding, and other industrial sounds. Ambient noise in the ocean is a real problem because sound waves propagate 12 times faster through water than they do in air. Any noise generated in water travels much further and carries a lot more energy. When ambient noise is generated, it is thought to interfere with a whale's ability to communicate, locate mates, find food, and possibly cause long term hearing loss. The second more deadly noise is the focused sound that is created by Sonar at high frequency low to mid-level which is used in war games by Navy submarines and surface ships.
On September 24, 2002, more than a dozen beaked whales for which eight died were beached on the Canary Islands west of Africa. The Los Angeles Times reported that the whale beaching was followed by a NATO exercise. It is believed that the US Navy's use of sonar of ocean sounds and noise is to blame for the mass beaching of whales.
In March 2000, there were mass whale beaching on the shores of the Bahamas. Necropsies of six dead whales showed that there was hemorrhaging around the ears and brain most likely caused by intense interior vibrations of mid-frequency sound waves or sonar (Researchers Probe).
By April 2001, the US Navy requested that they be exempt from federal law for harassment or the killing of whales by using sonar for the detection of super quiet submarines. As well, the Navy officials vowed to not use any sonar within a kilometer of any marine mammal including whales and sea turtles (U.S. Navy Asks to be Exempted).
Ocean Sound Channels
Some researchers believe that animals use the oceans sound channels to communicate over thousands of miles. Many experts say that by polluting the ocean with intense high and low frequencies we are interfering with natural ocean communication and harming marine animal life.
Today, even with new technology, it is hard to determine how much sound interferes with marine life. Ocean sounds and white noise cannot be monitored worldwide. Data that is collected from small sites are only measured in certain frequencies. Even more perplexing, underwater sound seems to affect marine animals in completely different ways.
According to Joel Reynolds, director of the Marine Mammal Program at the Natural Resource Defense Council, evidence shows that marine animals are changing their sound patterns and rates which could show that their normal communication has been disrupted (Oceans Getting Louder).
To reduce ocean and white noise, Kathy Metcalf, director of Marine Affairs at the Chamber of Shipping in America, states that installing quieter propellers in new ships would likely benefit the industry by increasing the efficiency of ships moving through water, but installing quieter propellers in current ships would be quite expensive and the benefits are not scientifically proven (Oceans Getting Louder).
Presently we are faced with numerous decisions and obstacles. The U.S. Navy depends on sonar for our national defense and our economy relies on an enormous amount of shipping. According to the Navel Medical Labor Research Laboratory (NSMRL), a healthy highly performing submarine force is essential to the nation's security (Fact Sheet). Yet many researchers feel that it is essential to preserve ocean life not only for humanities sake but for mankind's survival; we rely on the ocean for food, the weather, and to cure diseases; any disruption could be detrimental and irreversible.
How Sound and Hearing Works
Sound is created by the collision of molecules that expand and contract, thus changing air pressure. The changes in air pressure travels to the eardrum and slightly vibrates the middle ear. These vibrations are amplified 20 times, causing pressure waves within the fluid of the cochlea (where small hair cells in the middle ear are embedded). As a result of the movement, around 20,000 hair cells of the cochlea are bent, which creates impulses in the cochlear nerves to the brain. These impulses are sent to temporal lobe in the cerebrum (front part of the brain) and then interpreted as sound.
The volume of sound is determined by the number of hair cells stimulated and the pitch is determined by the distribution pattern of stimulated cells. Pitch is the highness or lowness of a sound. The pitch determines the speed of vibration of the sound wave. High pitches are fast vibrations, whereas low pitches are slower vibrations.
The amount of energy in the sound wave determines the loudness of the sound. A sound is louder the closer you are to the source and softer the further away you are. Eventually the sound wave travels far enough and it is absorbed by the air or an object such as a wall.
Under water, sound moves quite differently. The colliding molecules in water are spaced closer together and lose less energy before colliding with other molecules thereby creating a faster and more efficient sound. Under water sound goes five times farther and faster than in air. In conclusion, ocean sounds and white noise are far more intense than above water.
Recent State of Affairs
In Hawaii, July 2004, there were mass whale beaching. According to the National Oceanic and Atmosphere Administration (NOAA) report, there is a strong connection between the Navy's use of sonar transmitted July 2-3, 2004 and the beaching. Although biological factors and weather were ruled out, the NOAA stated that the strandings may never be unequivocally determined (Findings on Whales). However, many specialists feel that it is the increase of ocean sounds, white noise and sonar that may be the cause.
On January 15, 2005, off the coast of North Carolina, more than three dozen whale beaching. Immediately preceding the incident the Navy was testing sonar at a proposed 600 square mile Undersea Warfare Training Range. The NOAA's report again ruled out any biological factors and weather as the cause. Yet the NOAA concluded that "given the occurrence of the event simultaneously in time and space with a naval exercise using active sonar, the association between the naval sonar activity and the location and timing of the event could be causal rather than a coincidental relationship. However, evidence supporting a definitive association is lacking" (Findings on Whales).
With the NOAA report, many questioned why they ruled out sonar. Some feel that if may have been an unedited reflection of the understanding of the event, while others feel political pressures of establishing the Undersea Warfare Training Range influences the report (Findings on Whales).
Meanwhile, according to the documents released to the National Resources Defense Council, all references to the Navy's use of sonar and possible cause of the whale beaching were deleted from the report. A new NOAA report was released, stating that the cause of the whale beaching was "unclear" (Findings on Whales).
Current Whale Beaching
A Feb 15, 2010 research article from tree hugger.com reports that a death toll of 128 pilot whales beached on the shore of a New Zealand island over the past few months. The whale beaching has left scientists and conversationalists perplexed. The most current tragedy totaled 28 pilot whales that were beached on the shore of a small New Zealand island. According to reports there were 9 whales that were already dead before they beached and 19 of the pilot whales suffered immensely and were euthanized. Reports show that there have been a devastating total of 168 whales that have beached and died just over the last few months.
This is the fourth overwhelming report on whale beaching during the last couple of months. So far a total of 140 pilot whales were stranded and died. A total of 76 whales were saved by conservation work teams.
The same New Zealand islands had a similar occurrence of whale beaching in 2003. There were a total of 160 whales that died. Although the beaching remain a mystery, experts say the New Zealand islands are a direct path for whales that are on their way to the South Pacific to breed. Were the beaching caused by intense ocean and white noise?
Changing Migration Patterns
2009: Scientists have documented case studies of Blue whales changing their migration patterns from the California coast to British Columbia and the Gulf of Alaska. According to Marine Mammal Science research experts from Cascadia Research Collective in Washington state, Canada's Department of Fisheries and Oceans, and NOAA's Southwest Fisheries Science Center in California identified 15 different cases of blue whales changing their migration pattern. Many experts agree that intense ocean sounds and white noise may be the cause.
Some of the Many Tragedies
- June 2004: Ōpoutere, South Auckland New Zealand, 74 pilot whales beached, 2 saved
- March 2008, stranding in Senegal more than a 100 beached pilot whales 60 whales had released back into the ocean, 38 whales sadly died
- June 2008: Cornwall England, 26 dolphins are beached and die
- June 2008: Madagascar Africa, more than 100 melon headed whales beached and died
- February 2009: Manila Bay Philippines, Around 200 - 300 dolphins are beached, all were saved but 3
- March 2009: Hamelin Bay Australia, Around 80 whales and dolphins beached, 55 died
- March 2009: Tasmania's King Island, 194 pilot whales and 6-7 bottlenose dolphins beached
- April 2009: Hamelin Bay Australia, 90 long-finned pilot whales beached
- May 2009: Kommetjie beach in Cape Town, South Africa, 55 pilot whales beached and volunteers managed to move 20 back into the sea. The remaining died
- February 2010: New Zealand Islands, In a few month's time 168 pilot whales are beached and die
In August 2003 the Natural Resource Defense Council (NRDC) won a federal court suit that ruled illegal, the Navy's plan to use LFA (low frequency) sonar in 75% of the world's oceans. The Navy had agreed to limit the use of low frequency sonar in the area originally proposed by negotiated geographical limits and seasonal exclusions. For national security, none of the limits would apply during war or heightened threat conditions (Protecting Whales).
Shortly after the August 2003 federal settlement, the Bush administration legislated through congress that exempted the U.S. Military from core provisions of the Marine Mammal Protection Act, allowing the use of high-intensity sonar and underwater explosives (Protecting Whales).
In October 2005, the NRDC brought suit in the U.S. federal court asking the Navy to take common sense precautions during peacetime training with mid-frequency sonar. The measure included rich marine habitat off limits, the avoidance of migration routes and feeding or breeding areas when marine mammals were present, and listening with passive sonar to ensure marine mammals are not in the testing area before using sonar (Protecting Whales).
On June 29, 2006, the NRDC, the International Fund for Animal Welfare, the Cetacean Society International, the Ocean Futures Society, and Jean-Michel Cousteau filed a federal lawsuit to stop the U.S. Navy from using high-intensity sonar in a 210,000 square mile area around Hawaii called the RIMPAC 2006 (U.S. Navy Sued).
This lawsuit will challenge the National Marine Fisheries Service that authorized the Navy to "take" (harass, hunt, or kill) as many as 25,000 marine mammals by blasting high-intensity and mid-frequency sonar during exercises and reduce ocean sounds. The suit is requesting a temporary order to restrain the use of high-intensity and mid-frequency sonar during the Navy's exercises unless effective measures are taken to prevent harm to marine life (U.S. Navy Sued).
Wendy Williams (a researcher from the Audubon Society) feels that little is understood about how marine animals and other marine life experiences ocean sound and white noise. In March 2000, beached whales were stranded on the beaches of the Bahamas. In William's report, the National Marine Fisheries Service (NMFS) sent their own scientists to do necropsies. Two of the whales were sent to Darlene Ketten (an auditory specialist) of Harvard University and the Woods Hole Oceanographic Institution. The studies showed that the whales probably beached themselves due to some intense underwater noise from a distant explosion or underwater landslide (Noise Pollution).
Williams stated that the Navy is spending 3 million a year studying the effects of sound on marine animals, which is more than half the money spent worldwide on such research (Noise Pollution).
In a report from David Kohn, the Navy had already spent 300 million in 2002 on a sonar system designed to detect super quiet submarines by using low frequency, the same frequencies that whales use to communicate (Sonic Blast).
Williams stated that Paula Storum (a Navy spokeswoman) says that with careful precautions by using a warning system to detect nearby whales and dolphins, the technology will not hurt animals (Noise Pollution).
Fact Sheet. Navel Submarine Medical Research Laboratory, May 10, 2002
Findings on Whales and Sonar Remain Murky. OMB Watch, 2004
Noise Pollution, Not-So-Silent Seas. Audubon Field Notes, Wendy Williams, 2000
Ocean Noise. WorldWideWhale.com 2006.
Oceans Getting Louder; Effects Unclear. Associated Press, Jay Lindsay, April 18, 2005
Protecting Whales from Dangerous Sonar Following a historic victory, NRDC steps up the campaign at home and abroad to regulate active sonar systems that harm marine mammals. NRDC The Earth's Best Defense, Natural Resource Council, 09 Nov, 2005
Researchers Probe Whether Sonar Caused Deaths of Whales. Los Angeles Times, Kenneth Weiss, September 26, 2002
Sonic Blast. Mother Jones, Smart, fearless Journalism, David Kohn, Sept/Oct, 2002 http://www.commondreams.org/headlines01/april2001.htm
U.S. Navy Asks to be Exempted from Federal Law Forbidding Harassment or Killing of Whales. Los Angeles Times, Kenneth Weiss, April 26, 2001
U.S. Navy Sued to Stop Sonar During RIMPAC War Games. Environmental News Service, AmeriScan 29 June, 2006
CommonDreams.org, April 26, 2001: http://www.commondreams.org/headlines01/april2001.htm
Environment News Service, June 2006: http://www.ens-newswire.com/ens/