Where Humpbacks Breach 2019 Trip Report

By Joe Van Os on Jul 02, 2019

It was heavily overcast and misty—a perfect day to visit a glacier. We headed out from Petersburg onboard the Northern Song, a luxurious motor yacht with a skilled captain who has worked in the waters of Southeast Alaska for more than 40 years. Our boat maneuvered through floating ice chunks that had calved from the face of the mile-wide LeConte Glacier and glowed like blue sapphires in the muted light.
 
The LeConte Glacier feeds into the ocean at the head of a 12-mile-long fjord at the rate of 90 feet a day! It is the southernmost tidewater glacier in the northern hemisphere, part of an extensive glacial system stretching for 120 miles between the Stikine and Whiting rivers. Along with beautiful blue ice, we photographed the stark and raw land that has recently emerged during the glacier’s inexorable retreat. Two bald eagles feasted on a newborn harbor seal pup that they had probably killed on the ice. Eagles are often attracted to seal pupping areas to feed on easily available placentas and the occasional unlucky seal pup.
 
Coastal scenery on our humpback whale adventureAs we traveled northwest through Frederick Sound the blows of humpback whales could be seen on the horizon. We could see whales diving, their flukes breaking the surface and their backs arching in the way that gave them their common name—humpbacks. That was all very exciting, but we were on a mission so we continued onward. We were heading to Tebenkof Bay in the Chatham Strait where scores of humpbacks were reportedly assembled in large bubble-net feeding groups.
 
The scene at Tebenkof was nothing short of extraordinary, one of the most spectacular whale watching events I have ever witnessed—and I operated a whale watching company on the East Coast for a number of years!
 
Imagine this scene:
 
The water of the bay is almost mirror smooth. Specific areas of the surface appear dark and rough. Upon a closer look it turns out that these rough areas are massive shoals of herring breaking the surface, and there are many of them—each probably in excess of 100 tons of fish, according to our captain who used to fish for them commercially.  While surrounded by herring, their churning numbers boiling at the surface sound like a hard rainfall.
 
Humpback Humpback whales bubble-net feedingwhales are visible in all directions. As many as 100 can be seen around the bay. The number is incredible—more than I have ever seen at one location. Not far away a cluster of perhaps a dozen whale blows seems unusually compact. “There is our first bubble-net group,” says Captain Dennis. We head in that direction, turn off the boat’s engine and drift while the first mate (a Jack-of-all-trades aboard the boat and an excellent interpretive naturalist) places a hydrophone over the side so we can listen to the whale activity below.
 
Bubble-net feeding groups are one of the most amazing examples of coordinated animal cooperation. The whales operate like a football team with upwards of 20 animals working together. The “quarterback” calls the shots and each member of the team has its own specific assignment to make each bubble-net attack on the herring balls successful.
 
The whales all disappear from the surface. Their sounding allows for numerous shots of their massive flukes with sheets of water photogenically flowing from the trailing edge. The  hydrophone allows us to hear the unseen quarterback call the play deep in the dark water. It has instructed one of the whales to create the circularHumpback whale tail fluke bubble net from the inky depths by expelling air out of its blow hole. This net is designed to surround the fish, frighten them into a compact school and keep them from escaping. The net is easily 80 feet across with bubbles the size of dinner plates rising to the surface.
 
Meanwhile, the other whales in the group have surrounded the herring ball. Their massive white pectoral flippers flash as they wave them below the surface creating even more consternation with the fish and forcing them into an ever-tightening mass. The lead whale gives a series of short, loud sonic blasts creating even more fish tension.
 
Then, following a vocal feeding call, the lead whale signals to the group to swim to the surface  With mouths wide open, the whales engulf the fish with each whale taking in as much as 15,000 gallons of seawater in their gaping maw. With their throat grooves expanded like bulging beer bellies, they push the water through their baleen plates with their tongue to strain the fish before swallowing. Each whale seems to know which direction it must go to avoid a collision during the final action.

 

Amazingly, bubble-net feeding is not instinctual—it is a learned behavior. Many times we saw inexperienced animals mess up the coordinated activity. And it seemed like after a couple of discordant times, an inexperienced animal might be driven away from the bubble-net group to forage on their own or to join one of the other bubble-net groups working in the bay.
 
Seals hauled out on rocks in AlaskaWhile nothing could top this extraordinary bubble-net behavior, our cruise also featured several photogenic Steller sea lion haul-outs, bald eagles fishing over the same herring schools that the whales were pursuing, and the spectacular pristine verdant forests and rocky shores of Tongass National Forest.
 
The meals on this boat were incredible—I could write an entire food blog about them to accompany this trip report! The chef created fabulous dishes and fresh baked goods every day.  And I missed her cooking the minute I stepped off the boat!


 Join Joe Van Os on our 2021 Where Humpbacks Breach photo tour
 
 
 

Related Tags:  Alaska, bubble-net, feeding, humpback, whales