The 52-hertz whale is an individual of unidentified whale species, which has been regularly detected in many locations since the 1980s, calling at the very unusual frequency of 52 Hz. This pitch is much higher frequency than that of the Blue Whale (15-20Hz) or Fin Whale (20Hz), whose migration patterns it is most similar to. It appears to be the only individual with this call, and has hence been described as the world’s loneliest whale.
The whale was discovered by a team from the Woods Hole Oceanographic Institution. Its call was first detected in 1989, then again in 1990 and 1991. In 1992, following the end of the Cold War, the U.S. Navy partially declassified the recordings and technical specifications of its SOSUS anti-submarine hydrophone arrays, and made SOSUS available for oceanographic research. As of 2004, the whale had been detected every year since. Research by scientists at Woods Hole has been supported by the U.S. Army Corps of Engineers, the Department of Defense, and the National Marine Fisheries Service, in addition to the Navy.