For the last 12 years, a single solitary whale whose vocalizations match no known living species has been tracked across the Northeast Pacific. Its wanderings match no known migratory patterns of any living whale species. ...during the entire 12 year span that it has been tracked, it has been calling out for contact from others of its own kind. It has received no answer.
Lonely whale's song remains a mystery 10 December 2004
A lone whale with a voice unlike any other has been wandering the Pacific for the past 12 years... The partially declassified records show that a lone whale singing at around 52 hertz has cruised the ocean every autumn and winter since 1992. Its calls do not match those of any known species, although they are clearly those of a baleen whale, a group that includes blue, fin and humpback whales.
Twelve years of tracking 52-Hz whale calls from a unique source in the North Pacific 12 October 2004.
A unique whale call with 50-52 Hz emphasis from a single source has been tracked over 12 years in the central and eastern North Pacific. ...The species producing these calls is unknown...
One for the Marine Cryptozoologists, perhaps. (via morgan303)