Ocean's Child by Christine Ford and Trish Holland, illustrated by David Diaz

From chapters.ca:
As a mother and child canoe along the Alaskan Beaufort seacoast, they observe a baby walrus held close to its mother's spotted chest, sea lions snuggling, and the Northern Lights shimmering above. David Diaz's powerful, lush illustrations bring to life the majesty of the ocean and skies - and the vulnerability of the ocean's biggest and smallest inhabitants, from the orca to the puffin. The book ends with the human mother and her sleeping child gliding home for the night. "Good night, Mother Ocean, good night."