Imagine you are in SE Alaska standing alone on the deck of the Northern Song, a beautiful small boat, when you see a circle of bubbles in the water followed by what looks like a plateful of enormous mussels coming to the surface. It is the Humpback Whales feeding. The water is roiling, the sea birds are screaming and herring are jumping as if their little lives depend on it—and their little lives do. I had never heard of Bubble Netting and when I saw it only a few yards in front of me, my mouth felt like it was as open as the whales’. See for yourself: https://www.youtube.com/watch?v=Q8iDcLTD9wQ&t=41s
This is what happens when Humpback Whales Bubble Net in Southeast Alaska:
A group of whales gathers together and dives deep. Far below the surface, they swim in a circle, entrapping herring by blowing a net of bubbles around the little fish. It’s not a real net, of course. The herring could swim through it but they don’t.
As the whales circle, one of them (the same whale each time) directs the action by calling to the others (listen here). When the notes of the call drop to a lower key, it is a signal for the whales to rise to the surface, continuing to circle the bubble net. They open their enormous mouths and take in gallons of water and as many herring as possible. (Humpbacks’ lower jaws can expand to accommodate all the water and herring.)
When they reach the surface, they force the water out of their mouths but trap the herring with baleen (stiff whale bone-like hair) inside their mouths that acts like a sieve, letting water out while trapping the herring in. You can see the baleen in the photo above. It is that hairy-looking substance between the pink inside and the black edge of the whales’ mouths.
This is a simplified, unscientific description of how Humpback Whales feed themselves before heading south for the winter. I have included several links so you can read the explanation for yourself. I hope you enjoy reading this as much as I did writing (and experiencing) it.
HAVE A GOOD WEEK!