A seahorse explorer named Hippo wanders around the ocean and finds himself in the mangrove forests in the Philippines. Through Hippo we get to see and meet the different animals living in this habitat, and learn about the importance of mangroves to humankind and the environment.

Today’s Ocean Adventure Story is based on the book by Cidades Debaixo de Água, written by Ana Rita Silva, , Marta Reis, Pedro Moreira, Teresa Santos and Camille Rivera. "There are Cities Underwater" is a partnership between Cidades Debaixo de Água from Portugal and Oceanus Conservation as a guest author.