Bubble Net Feeding: An Elusive Sight to See

Nov 20, 2015

Megan Addison, Expedition Guide, Wilderness Adventurer

I had been exploring the Northern Passages route for about 10 weeks on the Wilderness Adventurer.

I was still fresh enough to find new and exciting adventures each week but seasoned enough that I could separate the typical from the spectacular.

Humpbacks diving are impressive and for a first time humpback sighting, pretty spectacular. But then comes the rare sighting of seeing humpbacks do something really wondrous.

Humpback whale breaching in Alaska

Before I started guiding, I had seen photos and videos of humpback whales bubble net feeding. In researching the whale, I read many accounts of group bubble net feeding. But after 10 weeks, I still hadn’t seen this elusive behavior with my own eyes.

I started to think that it was all one big practical joke. That the world was making up this mysterious bubble net feeding and the prank was on me.

Then one afternoon I heard the call over my radio, “Humpbacks, dead ahead!” The voice said. “If you can hear this, get out on deck right now! Bubble feeding. You’ve got to see this!”

I was just getting ready to go out on break but dropped everything, put on my dripping wet rain gear, picked up my binoculars and headed out to the bow.

Humpback whales have a variety of behaviors, many of which I had seen before.

The most typical whale sightings we get are deep dives. The whales will surface four or five times, then come up for a final breath before their sounding dive. The whale will dramatically arch its spine as the fluke comes up above the water, helping the whale descend to depths of 200 to 500 feet.

Whale tail in Alaska

Then there is lunge feeding. When the humpback doesn’t have any friends to find food, they’ll simply lunge and gulp through the slow moving prey. Watching a whale surface with its mouth open and baleen showing is quite a sight.

While lunge feeding, a humpback might take in over 500 gallons of water, expelling the water out through its baleen while capturing up to 100 pounds of food (schooling fish, krill, and other planktonic crustaceans) in a single gulp.

Individual humpbacks may also bubble net feed on their own. Underwater, they swim in a circle blowing bubbles out of their mouth and blow-hole, trapping the fish and lunging up towards the surface to catch them in their massive mouths.

These whales shoot out through the bubbles on the surface, mouth wide open and throat pleats extended. While I haven’t seen these behaviors on every trip, it happens on a relatively regular basis and I still get giddy when I see it happen.

Nevertheless, nothing compares to the communal bubble-net feeding that I finally witnessed with my own eyes.

Bubble net feeding humpback whales in Alaska

A communal bubble-net feeding frenzy can involve up to 40 whales (haven’t seen that yet) working cooperatively to catch their fastest prey, the small schooling fish. The whales will dive together and while one whale spirals below the school of fish streaming bubbles to trap their prey, the whales lunge through this confused mass of fish in one crazed feeding frenzy.

Watching six or seven whales surface with their mouths open is a sight to behold.

On that week, the great Alaskan mystery of communal bubble net feeding was revealed to me. I look forward to all the new discoveries next season in Alaska.




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