A (Sperm) Whale of a Tale
When you're running whale watching tours on a daily basis your eyes get trained on minute details. The flash of white on the wing of a pigeon guillemot, the curve of a back that marks the difference between a harbor porpoise and a Dall's porpoise, or the growling, roar of a voice that tells you a Steller sea lion is expressing his opinion on something. So when our captain and marine naturalists spotted the blow of a whale in Haro Strait, shortly after leaving Friday Harbor on yesterday's whale watching tour, they noticed small details that made them pause. It wasn't the slender, rising column of an orca, nor the massive towering exhalation of a humpback whale. This was shorter, bushier, and leaned at an angle that could only mean one thing.
They had sighted the first sperm whale ever documented in the San Juan Islands.
This was not just any sperm whale though, this was Yukusam (named for the island near where he was first sighted in mid-February). He had spent weeks up in Johnstone Strait, where he had first been observed, but over the past several days had begun to move. When he was spotted off of Nanaimo local whale watchers held their breaths: would Yukusam show up in the San Juan Islands? Was there a chance this sperm whale might make history by being the first of his kind in inland Washington waters? Yesterday we found out the answer. Yes, he would.
Marked by their uniquely wrinkled look and rounded dorsal fin, an adult male sperm whale can reach lengths of 60 feet. Up to 35% of that length is their head alone! Like their smaller, toothed cousins they have only one blowhole but it is offset to the left and is s-shaped. This creates their unique angled blow that is one of their identifying features. According to whale researcher Jared Towers, who first documented the sighting of Yukusam in Johnstone Strait, the whale is estimated to be around 45 feet in length.
Yukusam showed us exactly the type of behavior we'd expect from one of his species. He would dive for 35 minutes before rising again and would remain at the surface for five to seven minutes before sounding. When he dove our hydrophone transported us to a world a thousand feet down where the darkness was all-encompassing and a single, solitary sperm whale emitted clicks at over 200 decibels. Played on our hydrophone we had to turn down the volume his voice was so loud.
Male sperm whales leave the matrilineal groups they are born into when they reach adolescence and though they often join up with other males they also wander alone. Towers mentioned to us that adult (and maybe sub-adult) male sperm whales (like Yukusam) are known to spend time in inland waterways and inlets up in southeast Alaska from time to time. And as far as anyone can tell, his appearance marks the first occasion that a sperm whale has been documented in the Salish Sea.
Perhaps Yukusam is exploring new territory or looking for areas with abundant prey. Either way our captains, crew and whale watching passengers were thrilled to see him here in the San Juan Islands.
Listen to the sperm whale's clicks from our hydrophone
