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[52] [53] On 29 February 2008, a three-judge federal appeals court panel upheld the lower court order requiring the Navy to take precautions during sonar training to minimize harm to marine life. [30] In Winter v. Natural Resources Defense Council. the U.S. Supreme Court overturned the circuit court ruling in a 5:4 decision on 12 November 2008.
Some marine animals, such as whales and dolphins, use echolocation systems, sometimes called biosonar to locate predators and prey. Research on the effects of sonar on blue whales in the Southern California Bight shows that mid-frequency sonar use disrupts the whales' feeding
The Navy has spent over $16 million on scientific research on the effects on marine mammals and mitigation systems as well as the development of an Environmental Impact Statement. [3] The SURTASS Low Frequency Active Sonar system, on board Impeccable, commenced sea trials in late February 2004.
It concluded that the effects of mid-frequency active sonar are strongest on Cuvier's beaked whales but vary among individuals or populations. The review suggested the strength of response of individual animals may depend on whether they had prior exposure to sonar, and that symptoms of decompression sickness have been found in stranded whales ...
Biomass estimation is a method of detecting and quantifying fish and other marine organisms using sonar technology. [1] An acoustic transducer emits a brief, focused pulse of sound into the water. If the sound encounters objects that are of different density than the surrounding medium, such as fish, they reflect some sound back toward the source.
Sonar is the name given to the acoustic equivalent of radar. Pulses of sound are used to probe the sea, and the echoes are then processed to extract information about the sea, its boundaries and submerged objects. An alternative use, known as passive sonar, attempts to do the same by listening to the sounds radiated by underwater objects.
Biomass estimation is a method of detecting and quantifying fish and other marine organisms using sonar technology. [3] As the sound pulse travels through water it encounters objects that are of different density than the surrounding medium, such as fish, that reflect sound back toward the sound source.
Some species of hawkmoths (Sphingidae) produce ultrasound capable of sonar jamming. [25] Sonar jamming capability has evolved independently in at least six subfamilies. [26] Because sonar jamming seems to require high duty cycle ultrasound, it is believed to be a derived form of the simpler ultrasound used for aposematism and mimicry. [27]