My first season with Austin Adventures was the summer of ’11. I was beside myself for the opportunity to work on the Kenai Peninsula in Alaska. After 6 days of driving the 15-passenger van (while towing a trailer with a roof rack full of bikes) I was in awe of the scenery. I couldn’t believe this was my new office and playground for the next three months. The Alaska trip is, in short, amazing! Throughout the week we hike up to the Harding Icefield, bike along the Turnagain Arm and kayak the cool waters of Resurrection Bay. But my favorite experience all summer was on the Kenai Fjords boat tour.
On Mondays we leave the tranquility of Fox Island and head south in search of tidewater glaciers, bird rookeries and large mammals. Now nothing on these tours is a guarantee but you have a pretty good chance of finding all of those things. The glaciers are in fact retreating but they’re hanging in there. The waterfowl have their nesting areas and though most are migratory they usually don’t fly the coop until fall (the rainy season) begins. The large mammals, they’re a different story. Some of the animals we’re hoping to see are Steller sea lions, Harbor seals, Dall’s Porpoise, orcas and humpback whales. The humpbacks are my favorite.
In general humpbacks are solitary animals. A calf will hang around with its mother for about a year then go off on its own. They make the over 4,000 mile journey from the warm waters in Baja and Hawaii every spring to feast on herring, krill, sardines and other very small fish in south central Alaska. Along the way they pick up new methods for hunting. I like to think of it as swapping dinner recipes. A way of getting the most “bang for your buck” is called bubble net feeding.
Bubble net feeding is a collaborative feeding effort involving a number of humpbacks. They encircle a group of fish just by forcing air out of the blowholes continuously. As the circle becomes tighter the humpbacks send out a call. This call forces the fish towards the surface. The humpbacks then retreat and swim down underneath their tightly wound and now disoriented prey. They flip again and begin the ascent to the surface.
From a spectator’s point of view it’s unbelievable! Their mouths are as long as 8 feet. The fish really don’t stand a chance. The humpbacks hit the surface, jaws gaping, filling their mouths with today’s special and saltwater. They then close it up and force the water out through the rows of baleen plates that line the interior of their mouths. Unlike orcas, which have teeth, humpbacks do not chew their food but swallow it whole. The baleen acts as a filter. They open up to allow everything in then drain the rest out and enjoy their meal. As it seems, bubble net feeding is a very efficient, and luckily for us, entertaining way of eating.
The humpbacks in these waters, Resurrection and Aialik Bay had just learned the practice of BNF but we couldn’t tell they were novices. They demonstrated it beautifully and continued a couple more attempts that afternoon. On the 11 boat rides that summer I witnessed BNF less than a handful of times. When I returned to guide in AK the next summer, I felt very privileged to witness it almost every week! The effort had caught on and stuck! As it stands, my first time seeing bubble net feeding is still the most impressive session that I can recall. Seeing eight humpbacks synchronize swimming, mouths open wide enough to swallow my Honda Civic chow down on the catch of the day. It wasn’t just another Monday at the office for me.
A great, and short, video on bubble net feeding can be viewed at the link below!
Post and photos courtesy of Austin Adventures guide Pam Andrae.