Her Sea Mates by Lark Sterling, Meg Ripley

The seas, with their beauty and dangers, were more home to me than the land could ever provide. I swam the channels each and every day, looking for the treasures that the ocean had stolen from the land born creatures. The sun and salt was my life, a beautiful place for me to pursue my future away from the pressures of the Shifter Castle. But, without warning, my mother, Queen Omera was called to the next life, and I was left with my birthright.
High Alpha, Leader of all Life, Protector of the Realms.
My sisters were waiting for me, having finished their search for their mates, and the culmination of their powers. While I had done almost everything with them growing up, this voyage was for me and me alone. I was faced with the reality that I would have to depart my sleepy little Caribbean Marine life with the humans, and go in search of my foretold future.
I thought perhaps it would be simple. Find the treasure, find the map. The map would lead me to where I needed to be. But there were dark forces beyond my understanding at play, and they didn’t want me anywhere near my fated mates, or my sisters for that matter. Sepitus lurked within the darkest parts of the ocean floor, creeping ever closer to the Castle, with a plot much larger than my demise. I had to find my mates, and I had to gather the troops, this time, the threat was coming for all of us.
Hurley, Bo, and Dylan had been swimming in the oceans their whole lives. They waited, searched, and wondered when I would arrive. I didn’t know it when they saved me from the clutches of the dark one, but they were the answer to not only my powers, but my heart as well. But when we stand upon the cliffs facing Sepitus as one, will we ever have a chance to live and grow? Or will this be the end to all living creatures of the world?