And speaking of whales, here is a story of whales speakingor more precisely, one whale, with its own, distinctive 52-hertz voice.
In 1989, a team of WHOI biologists first detected an unusual sound in the North Pacific Ocean. It had all the repetitive, low-frequency earmarks of a whale call, but at a unique frequency52 hertzfar higher than the normal 15-to-25-hertz range of blue or fin whales. They recorded it again in 1990 and 1991.
With the end of the Cold War, the U.S. Navy partially declassified its Sound Surveillance System (SOSUS), a hydrophone network built to monitor Soviet submarines. Using SOSUS, the WHOI team picked up the lone call of the same 52-hertz whale and have tracked it every year since, as it roamed widely through the North Pacific, from offshore California to the Aleutian Islands off Alaska.
“It is perhaps difficult to accept that if this was a whale, that there could have been only one of this kind in this large oceanic expanse, yet in spite of comprehensive, careful monitoring year-round, only one call with these characteristics has been found anywhere, and there has been only one source each season,” the scientists wrote in their study, published in Deep-Sea Research. The research was conducted by Mary Ann Daher, Joseph George, David Rodriquez, and William Watkins, who pioneered the field of marine mammal acoustics with William Schevill at WHOI in the 1950s, and who died in September.
The 52-hertz call may be due to a malformation, or the whale may be a hybrid of two species, the scientists speculated, but whatever the cause, it “has provided an unusual opportunity to document the seasonal activities of what we believe to be an individual whale.”
Every year over the 12-year span, the WHOI team has picked up the 52-hertz call sometime between August and December and monitored it until the whale swam out of range, always within a few weeks in January or early February. Traveling 31 to 69 kilometers per day, it was tracked over a low of 708 kilometers one season and a high of 11,062 kilometers in 2002-03.
“The usual tracking for an individual whales last hours at best,” the scientists said.
Over the years, the research has been supported by a variety of Navy sources, the U.S. Army Corps of Engineers, the Department of Defense, and the National Marine Fisheries Services. “WHOI maintained the continuity of the program between increments of formal support,” the scientists said.