“The Loneliest Whale: The Search for 52” is not your average nature documentary. In the hands of Joshua Zeman, who has tackled urban legends and serial killers in his work (“Cropsey,” “The Killing Season”), this film is a nature mystery, an unanswered question that needs to be solved. Zeman sets out to answer this question despite unbelievable odds, and like most incredible explorations into the deep, the journey is surprising, though not without reward.
As with many mysteries, this one starts with a news item that caught Zeman’s eye. In 1989, an underwater sonar system developed and used by the Navy captured the biological sonic signature of a whale registering at 52 hertz of frequency, which is unlike any other whale song. In 2004, after the death of Bill Watkins, one of the lead scientists working on tracking this whale, a paper was published that brought this curious creature to the attention of the public. Knowing only that its calls didn’t register with other whales, writers speculated that this one was roaming the seas without response. And thus, “The Loneliest Whale,” a.k.a. “52,” was born, at least in the human imagination.