Anxious to escape his day-to-day boredom, Bernie the sea turtle leaves the safety of the kelp forest to explore Garbage Island. Caught by the trash and pollution of the sea, he is knocked unconscious and swept onto the beach. There, he meets a young girl named Sophie, who discovers that a conch she finds on the beach allows her to communicate with Bernie. The two work together to return Bernie to the kelp forest where he belongs, but in the process realize the ugliness of the Garbage Island and the danger it poses to Bernie's kelp forest and other marine animals' habitats. As the young sea turtle and girl work through puzzles and meet new friends in the sea, Bernie and Sophie's quest evolves past a simple trip home to one of saving the future of marine life and the polluted oceans.