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Introduction
 
Background
Litter Survey
Lesson 1
Lesson 2
Lesson 4
 
Lesson Three
How Harmful Is It?
 
Objective: To explore the effects of marine debris on people, animals, vessels and communities. 

Activity: Students complete a form that requires them to make decisions about how severely different types of marine debris affect people, animals, vessels and communities. As a class, results are totaled and analyzed to determine which types of marine debris are most harmful. 

Vocabulary: Ghost fishing, medical waste, entanglement, ingestion 

Materials: 

· Enough copies of "How Harmful Is It?" handout for the entire class 

Subjects: Mathematics, Science, Social Studies 

Learning Skills: Analyzing, calculating, classifying, comparing and contrasting, decision-making 

Duration: 30 minutes to compare tally; 30 minutes (preferably the next day) to analyze and discuss results. 

Grade level: 4-12 
 

Lesson Activities 

1. Distribute the "How Harmful Is It" handout to the class. Make sure students are familiar with the types of debris in the table. If possible, label and display examples of the actual debris. Review with student the instructions at the top of the page. Then have students fill out the table. 
 
2. Collect the handouts and calculate class subtotals for each type of debris on the handout (add together the students' subtotals and divide by the number of students in the class.) (Note: you can do this with the class or on your own and present the totals the next day.) Pass back to students their original handouts. 
 
3. Write the class subtotals on the board. As a class, analyze the results of the tally. Initiate discussion by asking questions such as the following: 

    · According to class results, which types of marine debris are most harmful to manatees? sea turtles? seagulls? Which types or types of debris seem to be most harmful to animals in general? (Repeat this series of questions for people, vessels, and places.) 
         
    · According to class results, which types of marine debris are the most harmful overall? Do you agree? Why or why not? 
         
    · According to these results, which type of debris is the least harmful? Do you agree? Why or why not? 
         
    · Are there any types of debris which received a low grand total, yet are very harmful to one or several of the items on the list? Which ones? 
 4. Discuss with students how their individual results might have varied from the class results. Help them to understand that people may have different opinions about how harmful certain debris is based on their own attitudes. For example, one student might think that a paper cup on a beach has little effect on the appearance or attractiveness of that beach for wading or walking, yet another student might argue that litter can make a beach so ugly that people will no longer go there. 

5. The discussion should also introduce the concept that the abundance of certain types of debris may make them more harmful on a large scale than other types that appear to be more dangerous. For example, while hospital needles are extremely dangerous, they are less common than debris such as fishing line and nets, and therefore may have a less of an overall effect on marine and coastal animals and communities. 

(Note: The numbers that students arrive at by doing this exercise do not represent objective data on marine debris effects. Instead, they help students explore the many ways that debris can harm the different components of marine and coastal communities. Students should come away with the knowledge that certain types of debris may have a greater effect on specific animals, people, vessels, and places, but that almost all marine debris can be harmful to some part of these communities.)