sea otter development is marked by a six-month-long dependency period. once an otter has adult-like swimming and diving behavior, can procure food by itself, and self-groom, it is considered independent. until then, otter pups spend all of their time with their mothers. this is exacerbated by the fact that for the first three months of life, otter pups cannot swim or dive effectively. they are born with a natal pelage that differs in color and structure from adult pelage and is incredibly buoyant. this prevents them from submerging their bodies underwater and must be held or anchored to kelp.