Keywords: phyla, brackish, mangroves, seagrasses, International Year of the. Ocean. Lesson I: Why the Oceans are Important! In this lesson, we will introduce. you to the first of our three fall units: Year of the Ocean 98. In this unit. shows, we will discuss why the ocean. is important, the ocean biosphere, marine pollution, the methods used to. study the ocean, and the instruments. used for research. The first lesson. will focus on the importance of the.