When do baby seals become adults?

Besides getting larger in size its social structure changes. It will leave the side of its mother and join a group of its own gender. It will stop nursing and start foraging for its self and use a rock placed on its stomach to break open some of its food. Its fur changes from blond downy fur to a more even darker coat. It will move out to deeper and rougher water. As it grows older its fur will get coarser as its guard hairs grow. The fur around its head and face will turn white and gray. If it is a female it may get scares on its nose from mating. If its a male it might get a broken penis bone from combat with other males. As it grows older it will lose some hearing and teeth. It is common for sea otters to starve to death because over the years of eating shellfish wears down their teeth and they are unable to eat.