This is a comprehensive lesson plan for a group cleanup trip to a local beach, lake or stream. Learners keep track of the types and amounts of trash picked up and analyze this information. As a group, learners discuss the marine debris problem in their community and consider ways to prevent pollution. This lesson helps learners understand the effects of natural events and human influences on ecosystems. It also teaches learners several science process skills, including forming questions and answering questions by experimenting, carrying out research to validate or challenge ideas, and designing experimental tests.