Expedition leader John Mitchell’s disembodied voice came over the PA system this morning just a little after 6:00 a.m. The earlier-than-normal wake up time was precipitated by the appearance of a large number of feeding humpback whales here in Frederick Sound. As we tumbled out of our bunks, some of us coming to the bow in our sleeping regalia, humpbacks dotted the glassy waters all around us. The National Geographic Sea Lion was surrounded in whale soup!
Two individual whales particularly caught our attention. Each was utilizing a feeding technique known as bubble-net foraging. Each whale would dive below its prey in the water column then slowly swim in a tight circle (always clockwise) towards the surface while releasing bubbles out of its blowholes. The cylinder of bubbles created would concentrate the prey inside the “bubble-net” and the whale then lunges through the concentrated prey for a huge mouthful!
Here in southeast Alaska there are a few whales that will co-operatively bubble-net forage in large groups. What was different about these two whales is that each was producing its own bubble-net, but joined at the outer edge of the circle ring, not sharing a single ring. From our vantage point the shape the two bubble-nets took looked like a figure eight or an infinity sign. As breakfast was called and most of us chose to stay on the bow to watch whales, a third and then a fourth whale joined the pair and each of them started setting their own bubble-nets. With water so glassy calm the bubble-nets were clearly visible and of course the sub-surface feeding whale always surfaced in the nets.
Our afternoon destination was the town of Petersburg, a fishing town not really predicated on tourism. Our afternoon activities included hiking on nearby Kupreanof Island, flight seeing over the LeConte Glacier, walking the docks to learn about Alaskan fishing vessels and how they operate, and an on-assignment photo walk through this lovely Norwegian flavored community.
Dinner tonight was all-you-can-eat fresh caught Petersburg Dungeness crab, followed by scrumptious berry crunch alamode. As the light faded and the nearly full moon rose in the east, we cruised into Thomas Bay for views of the Baird Glacier. What possibilities will we be presented tomorrow?
