Sea Otters
Sea Otters are marine mammals that were hunted relentlessly in the eighteenth and nineteenth centuries for their beautiful pelts. Sea otters may spend almost their entire lives in kelp beds and play a very important role in that habitat. Sea otters lack the layer of insulating blubber that is found in most other marine mammals, and therefore must consume up to twenty-five percent of their own body weight in food everyday in order to maintain their body heat. Because of this, sea otters eat many large invertebrates and occasionally a fish or two. In a kelp bed, sea otters eat mostly abalone and sea urchins. It has been discovered that when sea otters are absent from kelp beds, the sea urchin population increases in numbers and actually moves through the kelp bed eating all the kelp and algae they come across, eventually destroying the kelp bed. During the eighteenth and nineteenth centuries, when the sea otters were devastatingly over-hunted, many kelp beds disappeared off the western coast of North America. Otters are known as keystone species, meaning that they control the diversity of their habitat. Without the otters, the urchins would take over the kelp beds and destroy the habitat.