Report information
“Two o’clock!” The net is emerging to the right of the bow. The water starts to simmer as chased Herrings appear to dance on the surface. Boom! Eight Humpback Whales explode from the sea, open mouths lifted from the water. The previously calm, quiet sea becomes a medley of sloshing, crashing whales. Their thunderous blows echo off the peaks that surround the bays.
As they sink back down, mouths close and throats expand. The pink pleats under their jaws are stretched open to allow as big a mouthful of water and fish as possible. As the whales loll on the surface, pushing out the water through baleen-lined jaws to leave a mouthful of fish, Bonaparte’s Gulls crowd in to grab any Herrings that have escaped. The whales then start moving once more, back into formation, and soon dive again, while we’re left on deck wondering what it must feel like to have a belly full of wriggling live fish.
Humpback Whales are known as the singing whales and have a rich vocabulary of sounds. The calls used for bubble netting are not only unique to this behaviour, but also breathtakingly beautiful. To hear what was going on underwater, I’d taken along a fantastic high quality DPA hydrophone – an underwater microphone. Nothing quite prepares you for the first time you put the headphones on and plop the hydrophone into the water. A siren-like call fills your ears, a rich, droning note like an aquatic cello. One whale is singing, at times accompanied by a second, apparently harmonizing its notes.
In the depths the whales are starting to move, running the ring of bubbles beneath the shoal of Herrings. The pitch creeps up and with it the sense of suspense. Higher and higher rides the pitch, as the team of whales rises in the water. Suddenly the pitch jumps into a scream – the stun call – and moments later the whales break the surface. The stun call is thought to confuse the Herrings in the final throes of the netting, and the song is believed to chase the Herring into the net and help synchronize the team of whales to fish the net together. But why we should find the call so beautiful is a mystery.
It’s a child-like sensation to experience something so fresh and so unrelated to anything else you know. I can still hear the song in my head as I write this and at the time the crew and I sat for hours sonically spying in on the humpbacks’ world. Breath-taking.
All the best,
Joe
Further Reading:
Next report: Yves Lefevre swims with Humpbacks
Joe Stevens' last report: Humpback Whales in Alaska
How Humpback Whales migrate: Hawaiian Humpbacks