The 52-Hertz Whale is a unique whale that calls at a characteristic frequency of 52 Hz, a much higher frequency than the vocalizations of most whales. It appears to be the only individual with this call, and has been described as the world's loneliest whale.
The sonic signature is that of a whale, albeit at a unique frequency. At 52 Hertz, it is just higher than the lowest note on a tuba. The call patterns resemble neither blue nor fin whales – they are shorter and more frequent, besides being at a much higher frequency. Blue whales usually vocalize at 15–20 Hz, fin whales at 20. The 52-Hertz signals are highly variable in their pattern of repetition, duration, and sequence, although they are easily identifiable due to their frequency and characteristic clustering.
The track of the 52-Hertz whale is unrelated to the presence or movement of other whale species. Its movements have been somewhat similar to that of blue whales, but its timing has been more like that of fin whales. It is detected in the Pacific Ocean every year beginning in August–December, and moves out of range of the hydrophones in January–February. It travels as far north as the Aleutian and Kodiak Islands, and as far south as the California coast, swimming between 30 and 70 km each day. Its (recorded) distance traveled per season has ranged from a low of 708 km to a high of 11,062 km in 2002–2003.
Scientists at the Woods Hole Oceanographic Institution have been unable to identify the species of the whale. They speculate that it could be malformed, or a hybrid of a blue whale and another species. According to the New York Times, the research team has been contacted by deaf people who believe the whale may be deaf. Its voice has deepened slightly since 1992, suggesting that it has grown or matured. Whatever biological cause underlies its unusually high voice does not seem to be detrimental to its survival. The fact that the whale has survived and apparently matured indicates that it is probably healthy. Still, it is the only one of its kind detected anywhere, and there is only one such source per season. Because of this, the animal has been called the loneliest whale in the world.
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.
A feature length documentary entitled Finding 52: The Search for the Loneliest Whale in the World is currently in pre-production from Gigantic Pictures. Joshua Zeman (Cropsey) will be directing with Steve Bannatyne (Academy Award nominated If a Tree Falls) as the film's producer with Khush Singh as an Executive Producer. 
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