Review what pollution is and how it hurts the environment. Your students won't fully understand the concept ocean pollution unless they understand what pollution is and how it's harmful. Review the negative effects of littering and why it's important to recycle.
Study the ocean ecosystem before you start talking about pollution. Your students need to understand how the organisms depend on each other for survival. Show them maps of the world so they have a visual of how much water covers the Earth. Read passages about marine life and discuss the interesting animals you can find in the ocean.
Conduct an experiment using a salt water tank and plant life. Imitate the pollution of the ocean's in the salt water tank by adding a half quart of oil to the water. Add pieces of trash, fingernail polish remover or other harmful substances to the tank. For about a week, watch what happens to the plant life in the salt water tank. Tell students you are imitating what happens when pollution is added to our oceans.
Discuss the different kinds of ocean pollution. Sometimes, harmful chemicals are dumped into the water. Other times, factories located close the beach have leaks that allow harmful substances to enter the water. Oil spills are a major cause of ocean pollution. Even litter can entangle marine animals and harm or even kill them.
Give students ways to help combat ocean pollution. They can write to Congress asking for tougher laws to be enacted. If you live close by the coast line, groups of student volunteers can clean up trash and litter from the beach. Allow them to brainstorm up ways to help combat ocean pollution.