During the nineteenth century, sea otters were hunted almost to the point of extinction. when the number of sea otters became very low, it was noticed that the ecosystem of kelp bed "forests" was also disappearing. it was discovered that the sea otters were predators of sea urchins, which were, in turn, predators of the kelp. when sea otters declined, the sea urchin populations grew, destroying the kelp ecosystem and the many species that depended on it. what role did sea otters perform in this ecosystem?