Fish live in the ocean because it is a place where they can find food, water, and shelter. The ocean is also home to many different fish species. Some fish live in the open ocean while others live in coral reefs. Fish live in different parts of the ocean depending on their type and size. Some fish, such as tuna, stay near the surface while others, such as swordfish, live much deeper down. Some fish live near the shoreline while others swim in the open ocean.