Marine mammals communicate by emitting sounds that pass through the water and these sounds produced by the animals can be received at great distances. These sounds come in the form of sonar, as in the case of dolphins, or the songs performed as in the case of the humpback whale. Over the past twelve years, there have been a high number of observed bizarre behaviors exhibited by these marine mammals, including beachings which usually results in death to the animal. Although the exact cause to this change in behavior in unknown, a major candidate is active sonar. Navy sonar technology, or LFA, is capable of emitting man-made low-frequency sound pulses up to 240 decibels in the water over hundreds of miles. The noise is comparable to standing within one foot of a speaker at a loud rock concert. In many cases, the bizarre behaviors of the marine mammals have occurred in areas close to where sonar was being used, including Hawaii, Greece, the Bahamas, and the Canary Islands. These loud noises are capable of causing much distress in the animals. Although the direct connection between sonar and these types of behaviors is unclear, scientists are beginning to learn what exactly sonar can do to these animals.
The technology known as Low Frequency Sonar, or LFA, has become a major environmental concern over the past 10 years because of just how loud the noises produced are. LFA sonar uses both active and passive sonar in the sense that it sends out a loud sound and collects the reverberation of that noise. According to Byron Demmer, who has done much advocacy work on this matter, states that LFA emits sound pulses of 240 dB at a very low frequency, which can travel hundreds of miles (30). The Navy claims that the conversion between noise in air and water is 61.5 dB, making LFA safe to use. If this conversion factor is correct, the noise heard from the LFA is comparable to standing 20 ft away from a Saturn V rocket at takeoff (Calvez). According to the Navy's own research, and commented on by Calvez, the Navy states that LFA can approach 160 dB. Animals in close proximity to either sources of noise are certain to suffer some form of damage to their auditory systems, which occur at a range of 150-160 dB (58). The marine mammals' ears are constructed in a fluid to fluid coupler with a middle ear filled with air (Kastelein). According to the research done by Kastelein, the construction of their ears makes them very susceptible to compressive-rare-factive blast injury due to the nature of the ear to amplify noises. In a study done by a private company, it was found that LFA causes,
an instantaneous, high peak pressure, and broad spectrum blast. Therefore, the explosive front and acoustic signature of the proposed charges (1200 and 10000 lbs) are likely to cause equivalent damage to all species in the target area
(401).
Based on the technology of LFA sonar, the indication that sonar is capable of doing harm to any creature in close proximity is apparent. The dangerous nature of LFA sonar and it detrimental effects on marine life can be proved through the testing of the technology in the world's oceans.
LFA testing occurs all over the world in many different waters and in these tests, there has been many cases connecting sonar testing with whale or dolphin beachings. Such occurrences have occurred in the Bahamas where 17 whales from four species stranded themselves in March 2000. An autopsy report was completed on seven of the 17 whales which had stranded themselves and of the seven whales which died, all contained blood in their eyes and some type of tissue damage in their ears. These injuries all pointed to some explosive or high intensity sound blasts being the cause of death (Demmer). In recent years, only 4 species of whales have been tested to see the effects sonar has on them both physically and with their behavior. In the article “Time to Turn Off the LFA Sonar” written by Byron Demmer, Assistant Secretary of the Navy, Robert Price told CNN in July 2000 that the U.S. Navy did have an operational sonar exercise in the Bahamas in March 2000, “that was closely correlated with the strandings and that's the source of concern” (31). The US Navy has recognized that they were the ones at fault for the deaths of these animals. Leigh Calvez found a connection between the 12 Cuvier's beaked whales that were stranded along the Gulf Coast of Greece the 12th and 13th of May 1996. At the same time of those strandings, nearby NATO boats were testing new LFA technology (59). From these occurrences it is clear that there is a connection between the use of sonar and these beachings. Sonar emissions can not only cause damage to the auditory systems of whales but also alter specific behaviors of the animals.
Marine mammals communicate by emitting sounds through the water. Noise pollution from sources other than sonar, such as shipping, explosions, ect can have a great effect on the behavior of these animals. It has been observed that many marine animals have learned to avoid areas where such noise is produced. John Richardson has found that “due to ecological or physiological constraints cause by the human population, many marine mammals have no choice but to occupy these areas”, where these loud noises occur (383). During testing in Hawaii, it was found that “half of the humpback whales tested temporarily stopped singing -- the behavior which this species in famous” (Calvez). Although much testing of the affects of sonar on the animals physically has not occurred, there have been many observations in change of behavior seen all over the world. It was seen in migrating humpback whales that when subjected to 1-3.6 kHz of noise, they responded by increasing their swimming speeds (Richardson). Another example of how sonar affects the behaviors of marine mammals is that in juvenile whales. Whales are extremely social animals, with mother and child staying together thru maturity. In areas where sonar testing was occurring, many juvenile whales were found swimming on their own. This strange behavior was followed by numerous repetitions of pectoral fin slapping, a behavior exhibited by a whale in distress (Theriault). The alteration in behavior of these animals in close proximity to the sonar shows that there is some harm being done to the animals by sonar. Yet there has been great difficulty in testing the effects of sonar on marine mammals due to the vast locations which they occupy.
LFA sonar is used not only by the United States but also all over the world. Most government agencies would argue that until the affects of sonar on marine mammals are completely clear, they are unable to set forth any type of regulation. NATO is another strong advocate for the use of active sonar. With today's technology, nuclear submarines have becomes too quiet for passive sonar to be useful. Passive sonar is a system where the ship listens to the water in hopes of locating the enemy vessels (Richardson). Many government agencies have now begin to require the use of passive sonar to listen for the presence of marine mammals before the use of LFA can commence. Other agencies wish for the use of active sonar to be stopped during times of peace. The U.S. government's reply to this was that LFA sonar is needed to protect the shipping vessels and our country's commerce (Calvez). Richardson expands the need for such sonar technology not only in our country's defense, but also in the field of research. He states that, “some underwater acoustics and oceanographic research involves projection of strong, low-frequency sounds into the sea” (245). The Navy has produced an Environmental Impact Statement, as required by law, to asses the effects of LFA sonar technology on the marine environment. The US Navy claims that according to their studies, there is no evidence that sonar can do as much harm to the animals as people claim (Calvez). Even scientists agree that, at this moment in time, there is not enough evidence to support such claims. According to Kastelein, “The animals are sufficiently mobile and without more explicit data, definitive guidelines for safe limits on underwater signals are not possible” (404). Until more testing is done to see the exact harm caused to the marine mammals by sonar is done, it is difficult for governments to put forth any type of regulation. Today, the government argues that LFA is a much needed technology to keep the world's oceans safe.
The evidence that the use of sonar technology can have detrimental effects on marine life is overwhelming. The loud noise produced by the LFA has been shown to be comparable to standing near a Saturn V rocket at take off. The auditory systems of all mammals, including marine mammals, were not constructed to handle such loud noise. The day to day lives of marine mammals has been impacted by sonar, altering migratory routes and basic behaviors such as communication. All over the world, governments are testing LFA technology in preparation for times of war, including the United States. The United States government believes that this technology is of great importance to our nation and claims that the technology they currently employ does no harm to the environment. Yet in these same locations, many marine mammals, mainly whales and dolphins, have exhibited strange behaviors, at some instances resulting in death. After beachings have occurred, autopsies have proved that damage has occurred to the auditory systems of the deceased animals and most likely were the cause of death. In order to prevent future occurrences, more testing needs to be done to find solutions to help protect these animals. Until such actions are complete, the people need to fight for the rights of these animals to live their lives safely and freely in the environment which they have called home for thousands of years.
1 comment:
Marine mammals communicate by emitting sounds that pass through the water and these sounds produced by the animals can be received at great distances. These sounds come in the form of sonar, as in the case of dolphins, or the songs performed as in the case of the humpback whale. Over the past twelve years, there have been a high number of observed bizarre behaviors exhibited by these marine mammals, including beachings which usually results in death to the animal. Although the exact cause to this change in behavior in unknown, a major candidate is active sonar. Navy sonar technology, or LFA, is capable of emitting man-made low-frequency sound pulses up to 240 decibels in the water over hundreds of miles. The noise is comparable to standing within one foot of a speaker at a loud rock concert. In many cases, the bizarre behaviors of the marine mammals have occurred in areas close to where sonar was being used, including Hawaii, Greece, the Bahamas, and the Canary Islands. These loud noises are capable of causing much distress in the animals. Although the direct connection between sonar and these types of behaviors is unclear, scientists are beginning to learn what exactly sonar can do to these animals.
The technology known as Low Frequency Sonar, or LFA, has become a major environmental concern over the past 10 years because of just how loud the noises produced are. LFA sonar uses both active and passive sonar in the sense that it sends out a loud sound and collects the reverberation of that noise. According to Byron Demmer, who has done much advocacy work on this matter, states that LFA emits sound pulses of 240 dB at a very low frequency, which can travel hundreds of miles (30). The Navy claims that the conversion between noise in air and water is 61.5 dB, making LFA safe to use. If this conversion factor is correct, the noise heard from the LFA is comparable to standing 20 ft away from a Saturn V rocket at takeoff (Calvez). According to the Navy's own research, and commented on by Calvez, the Navy states that LFA can approach 160 dB. Animals in close proximity to either sources of noise are certain to suffer some form of damage to their auditory systems, which occur at a range of 150-160 dB (58). The marine mammals' ears are constructed in a fluid to fluid coupler with a middle ear filled with air (Kastelein). According to the research done by Kastelein, the construction of their ears makes them very susceptible to compressive-rare-factive blast injury due to the nature of the ear to amplify noises. In a study done by a private company, it was found that LFA causes,
an instantaneous, high peak pressure, and broad spectrum blast. Therefore, the explosive front and acoustic signature of the proposed charges (1200 and 10000 lbs) are likely to cause equivalent damage to all species in the target area
(401).
Based on the technology of LFA sonar, the indication that sonar is capable of doing harm to any creature in close proximity is apparent. The dangerous nature of LFA sonar and it detrimental effects on marine life can be proved through the testing of the technology in the world's oceans.
LFA testing occurs all over the world in many different waters and in these tests, there has been many cases connecting sonar testing with whale or dolphin beachings. Such occurrences have occurred in the Bahamas where 17 whales from four species stranded themselves in March 2000. An autopsy report was completed on seven of the 17 whales which had stranded themselves and of the seven whales which died, all contained blood in their eyes and some type of tissue damage in their ears. These injuries all pointed to some explosive or high intensity sound blasts being the cause of death (Demmer). In recent years, only 4 species of whales have been tested to see the effects sonar has on them both physically and with their behavior. In the article “Time to Turn Off the LFA Sonar” written by Byron Demmer, Assistant Secretary of the Navy, Robert Price told CNN in July 2000 that the U.S. Navy did have an operational sonar exercise in the Bahamas in March 2000, “that was closely correlated with the strandings and that's the source of concern” (31). The US Navy has recognized that they were the ones at fault for the deaths of these animals. Leigh Calvez found a connection between the 12 Cuvier's beaked whales that were stranded along the Gulf Coast of Greece the 12th and 13th of May 1996. At the same time of those strandings, nearby NATO boats were testing new LFA technology (59). From these occurrences it is clear that there is a connection between the use of sonar and these beachings. Sonar emissions can not only cause damage to the auditory systems of whales but also alter specific behaviors of the animals.
Marine mammals communicate by emitting sounds through the water. Noise pollution from sources other than sonar, such as shipping, explosions, ect can have a great effect on the behavior of these animals. It has been observed that many marine animals have learned to avoid areas where such noise is produced. John Richardson has found that “due to ecological or physiological constraints cause by the human population, many marine mammals have no choice but to occupy these areas”, where these loud noises occur (383). During testing in Hawaii, it was found that “half of the humpback whales tested temporarily stopped singing -- the behavior which this species in famous” (Calvez). Although much testing of the affects of sonar on the animals physically has not occurred, there have been many observations in change of behavior seen all over the world. It was seen in migrating humpback whales that when subjected to 1-3.6 kHz of noise, they responded by increasing their swimming speeds (Richardson). Another example of how sonar affects the behaviors of marine mammals is that in juvenile whales. Whales are extremely social animals, with mother and child staying together thru maturity. In areas where sonar testing was occurring, many juvenile whales were found swimming on their own. This strange behavior was followed by numerous repetitions of pectoral fin slapping, a behavior exhibited by a whale in distress (Theriault). The alteration in behavior of these animals in close proximity to the sonar shows that there is some harm being done to the animals by sonar. Yet there has been great difficulty in testing the effects of sonar on marine mammals due to the vast locations which they occupy.
LFA sonar is used not only by the United States but also all over the world. Most government agencies would argue that until the affects of sonar on marine mammals are completely clear, they are unable to set forth any type of regulation. NATO is another strong advocate for the use of active sonar. With today's technology, nuclear submarines have becomes too quiet for passive sonar to be useful. Passive sonar is a system where the ship listens to the water in hopes of locating the enemy vessels (Richardson). Many government agencies have now begin to require the use of passive sonar to listen for the presence of marine mammals before the use of LFA can commence. Other agencies wish for the use of active sonar to be stopped during times of peace. The U.S. government's reply to this was that LFA sonar is needed to protect the shipping vessels and our country's commerce (Calvez). Richardson expands the need for such sonar technology not only in our country's defense, but also in the field of research. He states that, “some underwater acoustics and oceanographic research involves projection of strong, low-frequency sounds into the sea” (245). The Navy has produced an Environmental Impact Statement, as required by law, to asses the effects of LFA sonar technology on the marine environment. The US Navy claims that according to their studies, there is no evidence that sonar can do as much harm to the animals as people claim (Calvez). Even scientists agree that, at this moment in time, there is not enough evidence to support such claims. According to Kastelein, “The animals are sufficiently mobile and without more explicit data, definitive guidelines for safe limits on underwater signals are not possible” (404). Until more testing is done to see the exact harm caused to the marine mammals by sonar is done, it is difficult for governments to put forth any type of regulation. Today, the government argues that LFA is a much needed technology to keep the world's oceans safe.
The evidence that the use of sonar technology can have detrimental effects on marine life is overwhelming. The loud noise produced by the LFA has been shown to be comparable to standing near a Saturn V rocket at take off. The auditory systems of all mammals, including marine mammals, were not constructed to handle such loud noise. The day to day lives of marine mammals has been impacted by sonar, altering migratory routes and basic behaviors such as communication. All over the world, governments are testing LFA technology in preparation for times of war, including the United States. The United States government believes that this technology is of great importance to our nation and claims that the technology they currently employ does no harm to the environment. Yet in these same locations, many marine mammals, mainly whales and dolphins, have exhibited strange behaviors, at some instances resulting in death. After beachings have occurred, autopsies have proved that damage has occurred to the auditory systems of the deceased animals and most likely were the cause of death. In order to prevent future occurrences, more testing needs to be done to find solutions to help protect these animals. Until such actions are complete, the people need to fight for the rights of these animals to live their lives safely and freely in the environment which they have called home for thousands of years.
Post a Comment