Karana is the only character that plays a major role in Island of the Blue Dolphins. For most of the novel, she is the only human being on Ghalas- at. Living alone on Ghalas-at tests her resilience, and as the story progresses, Karana grows through her experiences into harmony with herself and the world around her.

On of the most important things Karana finds on her island is a capacity for understanding and forgiveness. These come mainly through her need for companionship. By the end of chapter eight, Karana has two sworn enemies: the Aleutsand the wild dogs. When the wild dogs kill Ramo, Karana swears to herself that one day she will kill them all. Although she is motivated partially by a desire protect her own safety, there is a vindictive air to her vow. When she is on the verge of achieving this goal, however, and has the opportunity to finish off the leader of the wild dogs, she does not take it. Instead she brings the pack leader (whom she later names Rontu) back to her house and nurses him back to health. Though she admits she does not understand her own actions, she is later glad of them, for Rontu becomes Karana'a close friend and companion in a world where she is otherwise alone. In the same way, Karana repeats over and over that the Aleuts are her enemies, and that she is afraid what will happen to her if they find her on the island. However, when Karana is surprised by the Aleut girl, Tutok near her house, she does not attack, though she is in easy reach of her spear. Again, Karana does not know what stayed her hand, and is initially distrustful of Tutok, but eventually Tutok, like Rontu, becomes Karana's friend. Both of these cases highlight not only Karana's need for companionship, but also her ability to forgive and to see past the labels of those around her. She gave Rontu and Tutok a chance in spite of her fear, and her reward was friendship.

Another important aspect of Karana is her resilience. Though the white men's ship doesn't return for her for eighteen years, and though her efforts to establish a comfortable life on the island are repeatedly thwarted, she never shows signs of despair. Karana is often sad, as when her brother was killed, or frightened, as when she was injured by the sea elephant and stalked by wild dogs, but she never gives up. She is always looking ahead to her next task on the island.

Because Karana's story spans eighteen years, we are able to watch her personal and moral growth. As the only human on the island of he blue dolphins, Karana is left to develop her own moral code. We know that Karana cares deeply for others even at the very beginning of the novel, as is demonstrated when she plunges into the sea to go back to the island for her brother. Later, she is faced with different types of decisions. Faced with the necessity of hunting and defending herself from the wild dogs, Karana need to make weapons, something that the laws of her tribe forbid women to do. The stories say that weapons made by women will break just when one needs them most. After long deliberation, however, Karana decides to make a set of weapons for herself, and soon realizes that the old tales were false. Later in the novel, after Karana has befriended a number of the animals of the island, she decides for herself that she will never again kill any of these animals. This is a significant decision, because she is dependant on a number of these animals for material. However, she considers animals to be very much like people, even though they do not talk. She knows that her tribesmen would consider her resolution ridiculous, but her animal friends are so important to her that she cannot bear to kill them.