Humpback Whales - Bubble Net Feeding
While we were docked at Juneau we took a boat tour with nature photographer Cam Byrnes (www.flickr.com/photos/cambyrnes/) who took us to the humpback feeding areas. We saw this feeding behavior at least 4 times in a matter of about 30 minutes. He told us that watching the activity of the seagulls was also a clue as to when the humpbacks would soar upwards from the water.
From Wiki:"The humpback has the most diverse feeding repertoire of all baleen whales. Its most inventive technique is known as bubble net feeding; a group of whales swims in a shrinking circle blowing bubbles below a school of prey. The shrinking ring of bubbles encircles the school and confines it in an ever-smaller cylinder. This ring can begin at up to 30 metres (98 ft) in diameter and involve the cooperation of a dozen animals. Using a crittercam attached to a whale's back, researchers found that some whales blow the bubbles, some dive deeper to drive fish toward the surface, and others herd prey into the net by vocalizing. The whales then suddenly swim upward through the "net", mouths agape, swallowing thousands of fish in one gulp. Plated grooves in the whale's mouth allow the creature to easily drain all the water initially taken in."