Chatham Strait and Lake Eva
Watching semi-microscopic copepods that we found in the ocean where there is abundant phytoplankton and watching enormous 40-ton humpback whales lunge and bubble-net feed in the same ocean is an adventure of a lifetime! All morning long we watched a group of about 20 humpback whales (Megaptera novaeangliae) feeding probably off herring very near the rocky shore of Chichagof Island. This newly studied feeding behavior consists of a line of animals lunging forward at the surface in pursuit of vast schools of small fish such as herring, sand-lance or capelin, and of diving under another group of fish, creating a circular net of bubbles blown out of their blow-holes, and scaring the fish in this manner to the surface. The small fish do not escape from the bubble net. When this is achieved, all the whales lunge up through the net, taking most of the water with the fish into their enormous, expanded throat pouches, and pushing their heads out of the water. At the same time they have started closing their mouths almost completely, leaving them partly open to force the water out, and so retaining the prey with their baleen. This baleen hangs from the upper jaws, and is formed of the same material as our fingernails and hair. To tie all this incredible behavior together, two of these animals breeched, with their bodies almost completely out of the water.
Amid the whale activity we saw Sitka black-tailed deer on the nearby beach, as well as the most marvelous and speedy Dall’s porpoise, partaking of the same bounty as the whales. These medium-sized cetaceans are considered one of the fastest of the marine mammals, creating “rooster-tails” as their dorsal fins cut the water. This dorsal fin is mostly white, as well as their venter, part of their sides and the upper surface of the fluke or tail fin. Quite a striking animal!
During lunch we sailed south to the northeastern tip of Baranof Island, to a lovely part of Alaska: Lake Eva. Here we kayaked and hiked to an old-growth forest, as well as saw thousands of salmon in the river, en route to the lake to spawn. But as most of us were returning to our embarkation, a large brown bear was seen, fishing for salmon in the river. Most of us had the opportunity of seeing the animal quite near, as it used its complete attention to catching the elusive fish in the river. Watching it with or without binoculars, we saw it take fish to the immediate forest, consume it, and then take some leaves of devil’s club, some berries, and return to the river for more fish.
This was a fantastic wildlife-watching day!
