Undertow by Michael Buckley.
For three years, Lyric Walker has behaved like a model citizen - in school, at home, everywhere. The wild thing she used to be cannot come out. Her home town of Coney Island has become a refugee camp for a strange race of sentient sea creatures. The hatred and mistrust between humans and these aliens - the Alpha - grows to a fever pitch when the president demands that Alpha children enter New York's public schools.
Lyric's school is first.
But Lyric and her parents have a secret that may kill them. When Lyric is forced to befriend the Alpha prince, Fathom, things become confusing all too quickly. He is untamed - as are all the Alpha - with a sense of honor that demands quick and violent retribution for the smallest of slights. Lyric only agrees to help Fathom adjust to humans when escape from the area is offered to her for parents as well as herself.
The government, itself, is split between the locals who hate and want to exterminate these interlopers and the federal government that views them as possible allies.
A subplot about Lyric's best friend's abusive step-father, and that best friend's boy friend add pathos to an otherwise action adventure sci-fi novel.
Things start out uncomfortably in this book and quickly become ugly and then uglier. Hate and what it motivates people to do is never a pretty sight.
Things I liked best about this book:
1. Cool battle scenes.
2. Lyric and Bex, her best friend.
3. Lyric's migraines turn into something significant.
4. The trial scene - wow, that was so awesome!
5. Governmental wrangling. Don't totally trust them!! Conspiracy theorists, unite!
Possible Spoiler Alert!!
I expected an underlying theme to be the warming of the oceans. I thought that was the reason these people were forced onto land. That may crop up in subsequent titles in this series - because Fathom, Lyric, Bex and all the others will return. But the reason the Alpha left the sea is pretty freaky and scary.