Baleen Baleen Baleen is a filter-feeder system inside the mouths of baleen whales. The baleen system works by a whale opening its mouth underwater and taking in water. The whale then pushes the water out, and animals such as krill are filtered by the baleen and remain as food source for the whale. Baleen is similar to bristles and consists of keratin, the same substance found in human fingernails and hair. Baleen is a skin derivative. Some whales, such as the bowhead whale, have longer baleen than others. Other whales, such as the gray whale, only use one side of their
Whale conservation certain other species of high intelligence: humans, other great apes, bottlenose dolphins and elephants. There is an argument that whales should not be killed because of their high intelligence. Pro-whalers claim that pigs also possess high intelligence, and are routinely butchered and eaten, and that intelligence should not be the determining factor of whether an animal is acceptable to eat or not. Whale meat products from certain species have been shown to contain pollutants such as PCBs, mercury, and dioxins. Levels of pollutants in toothed-whale products are significantly higher than those of baleen whales, reflecting the fact that toothed whales