The Federal Appeals Court for the Ninth Circuit reversed a lower court ruling allowing the Navy to use low frequency sonar during its training exercises. The appeals judges said in their opinion the permission granted in a 2012 court case was erroneous and sent the it back for further proceedings. Low frequency sonar interferes with marine mammals normal behavior and
can even cause death. The Navy admitted in a 2012 study acoustic sources and sonar use more than 2.5 million times
annually exposed marine animals to sounds considered “disturbing”, while
around 500 times a year marine animals were exposed to sound levels
that were considered to result in injury.
Conservation groups led by the National Resource Defense Council brought the appeal of a National Marine Fisheries Service permit that allowed the Navy to impact about thirty whales and two dozen pinnipeds each year. The appeals court ruled 3-0 that the permit violated the Marine Mammal Protection Act which requires the least practicable impact on marine mammals. The Navy's current permit expires this year.
