By Dana Wright for Mongabay

NOAA

Nearly twice the size of Africa, the North Pacific seems to be endless. But somewhere in that vast ocean, 30 eastern North Pacific right whales (Eubalaena japonica) live their lives, mostly out of the view of human observers. These remaining leviathans are the survivors of past Yankee whaling – in Herman Melville’s famous words “so remorseless a havoc” – and are the most endangered population of whales on our planet. Historically this population numbered in the tens of thousands. I am one of the handful of scientists actively working toward their conservation. I also happen to be someone who’s never seen a living North Pacific right whale.

I started working with this species nearly a decade ago when I was hired to analyze underwater acoustic recordings on the presumed feeding ground of these whales in the southern Bering Sea off Alaska. Laboriously, I reviewed every minute of every recording looking for right whale calls, because computer algorithms still struggle to find right whale calls amidst the cacophony of animal sounds in this region. In total, I have analyzed tens of thousands of hours of recordings, listening and looking for right whales. As I worked through these recordings, I came to recognize the seasonal patterns of their calls on the feeding grounds, first appearing in late spring and then disappearing in late fall as the sea ice approached. I observed this rhythmic relationship with sea ice for over a dozen marine mammal species, that together create a symphony of sound that ebb

s and flows with the seasons.

Each time I stopped hearing the right whales in the fall, I wondered if that would be the last time that I would ever hear them. Would they return in the spring? Would there be any left to come back? Was this the last record of their existence?

When I began analyzing each spring recording, I’d get nervous when I didn’t hear them right away. May 15^th – nothing. May 16^th – nothing. May 26^th – nothing.

What if there is just nothing?

Then, finally, when their distinctive calls reappear, I’ve felt a rush of relief. At least one, I’d think.

There’s at least one.

Dana Wright

With so few surviving eastern North Pacific right whales in such an enormous area, scientists struggle to track their lives and movements, and lack the information needed to protect them.

“Not only are these whales exceptionally rare,” says my colleague Jessica Crance, a marine mammal biologist at the NOAA Alaska Fisheries Science Center whose been studying this species for 15 years, “but you’re dealing with survivors of a population that was decimated by whaling, so whenever a vessel approaches, they stop calling, their surfacing behavior becomes erratic and unpredictable; they’re extremely difficult to study.”

One of the greatest mysteries regarding these whales has remained unanswered for over a century. Perplexingly, outside of summer – when animals feed in the Gulf of Alaska and Bering Sea – the whales simply disappear. The location of their winter calving grounds – where whales give birth and nurse their young – has been debated by scientists for decades, with some long-standing bets still waiting to be settled.

“There are some tantalizing records of right whales off California and the Baja Peninsula,” says Dr. Phillip Clapham, Senior Scientist at Seastar Scientific, who has written seminal papers on North Pacific right whale distribution and whaling (and formerly was my boss). “While

those records are sparse, the presence of right whales in that region indicates that it may have been a major winter habitat for the population before whaling began in the 1840s. It’s worth noting that right whales had been almost wiped out from their Gulf of Alaska feeding grounds before there was any significant European settlement in California – so if they were there in big numbers before whaling, there probably wouldn’t have been settlers around to record that,” he said.