Stem the Tides of Trash

Discussion
Read the information provided on this page and discuss the definition and sources of marine debris.

Activity
Students use experiments to learn more about how trash ends up in waterways — and whether/how trash degrades in a marine environment.

Talk About It.
What is marine debris and where does it come from?

• Marine debris is any man-made, solid material that enters the earth's waterways.
• Trash and debris end up in oceans either directly by littering or dumping, or indirectly by being washed out to sea via storm drains, rivers or streams.
• Eighty percent of marine debris found on beaches and in waterways comes from land-based sources, such as beach users, storm water run-off, landfills and street litter.
• The other twenty percent comes from ocean sources, such as galley waste and other trash from ships, recreational boaters, fishermen and offshore industrial facilities.

Learn About It.
What happens to trash if it ends up in waterways?

1. Have students gather a variety of trash items from school and/or home and make a list of each piece of trash on the board and in student's notebooks. Be sure that there are two identical sets of each trash item for comparison in the experiment.
2. Talk about how trash might end up in waterways (blown through the air, floating in via storm water, washing in with rain). Discuss the potential problems of the trash items if they end up in the ocean.
3. Set up the experiment. Fill the containers about halfway with water. Deposit the trash into the containers, making sure that the identical pieces of each trash item is placed in each container. Cover both containers with screening or netting and secure with the rope or string. Take one container outside, and place it in an area that gets a good deal of sun. Keep the other container inside, in an undisturbed area. You may want to place signs by each container: "Science Experiment In Progress. Please Do Not Disturb."
4. Have students observe and record the condition of the trash in both containers every week, for at least two months. You could also take photos to record the progress, with the dates clearly indicated on the photos.
5. At the end of the experiment, collect both containers and set up two tables, covered with newspaper. Take the trash out of each container and spread the contents of each onto one of the tables. Observe the differences between the indoor and outdoor sets of trash. Have students wear rubber gloves while removing and examining the trash for signs of decomposition.
6. Record and discuss which pieces have degraded and which have not. Was there any difference in the trash that was kept indoors vs. outdoors? Based on the experiment, discuss the extent to which trash degrades in a marine environment. Pose this question: Is the speed of degradation the real issue, or is preventing the litter in the first place the solution?

Variation
Instead of using a variety of trash items, you could focus on only certain types of items. For example, six-pack rings are now made with photo-degradable plastic, so students could set up the experiment with that type of trash only, and compare the amount of decomposition between the indoor and outdoor samples. After the experiment, discuss the fact that plastic six-pack rings and other similar packaging should be cut up before recycling or disposal, even if they are photo-degradable, to minimize the risk of injury to wildlife.

Activity Summary