Into the Storm — Julie C. Gilbert

When a hurricane threatens to harm the underwater homes of the merpeople, it is up to India Finch, a part-human/part-mermaid teenager, to warn her ocean friends. The mer decide to seek calmer waters, and as they travel, they are  attacked by a giant squid, with India at the center of harm's way. Gravely injured, India depends on the merfolks' willingness to risk their own safety to get her ashore where her injuries can be treated. Will the prejudice many mer hold against humans leave India at the end of her journey?