Bubbles: The last thing a fish sees in Alaska
I was on the bridge holding binoculars up to my eyes, scanning the smooth waters of Icy Strait for signs of life.
Sea otters floated by on their backs, stellar sea lions worked the current lines for food, and numerous species of sea birds flew in lazy circles. But I wasn’t seeing signs of our seasonal humpback whale visitors.
Mainly I was looking for their exhalation or blow, which looks like a small mist cloud when they surface.
My searching finally paid off as I caught a blow in my sight…and then another, and another, and another. There were multiple whales in a very tight group.
Could it be the holy grail of whale watching in Alaska? Did we stumble across the elusive behavior known as cooperative bubble net feeding?
We would have to alter our schedule a bit to go find out…so that’s exactly what we did.
It turned out to be seven whales in the group and sure enough they were bubble net feeding. They must have been chasing a massive school of baitfish, trapping them inside a ring of bubbles.
Once one whale sets the trap a feeding scream by another gives the signal for all the whales to swim up through the bubble net.
They open their massive mouths as they near the surface and the fish have nowhere to run as they are gulped into the maw of a hungry humpback whale along with thousands of gallons of seawater.
The throat of the whale expands to tremendous proportions allowing this amount of water and fish inside. Then as it contracts, the seawater is forced out through the baleen of the whale while the food is left trapped inside.
After a winter of fasting in the Hawaiian breeding grounds, these seven whales were making up for lost time.
We witnessed this amazing cooperative feeding behavior at least a dozen times before finally moving on towards our next adventure.
Needless to say, we were glad we had altered our schedule.