Island of the Blue Dolphins is a book about a woman named Karana. She was left behind on the island after she went to retrieve her younger brother. Her tribe had to evacuate the island because of invaders who had killed most of the tribe. Karana lives on the island by herself isolated from the rest of the world after her brother, Ramo dies.
Karana is not scared of the sea otters. Instead, she describes them in the book as playful. She becomes angry when she watches the hunters preparing to spear them in the water. She is afraid for them because she fears that the hunters will kill them all.
The animals that Karana fears are the wild dogs. The wild dogs are dangerous and forge through her encampment for food. Dozens of them snarl as they arrive to take what they want. The dogs eventually attack her brother. The wounds on the boy's body have been caused by bite marks from the wild dogs. The dogs killed her brother.
At the end of chapter five, after the many men of the tribe had been killed and winter settled upon them, the people had a lot of time to just sit and think. The book states that a sort of sickness had settled in because the people had so much time to think. The sickness was not like a disease, but it was a sense of depression and loss because the villagers no longer laughed or found joy. They did not even speak.