Little Gray's great migration

"Little Gray loved his lagoon and the humans who came to visit him there. One day, Mama announces that they must swim north to a far-away sea. At first he is sad to leave his home, but Little Gray soon realizes the importance of their journey. What happens along the way and how does Little Gray help his mother? Swim along with Little Gray as he finds the way to this special, food-filled sea"--Provided by the publisher.