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Jellyfish in a Bottle

In this activity, students learn how garbage, like plastic bags, can be mistaken for food by marine animals.

Garbage is not a natural thing found in the environment. Animals that live in the ocean mistake garbage such as plastic bags as food, so what lands in the oceans can end up in the stomachs of animals. For instance, plastic bags can look like jellyfish and bottle caps can be mistaken for fish.

For this make and take, students will make plastic bag jellyfish in bottles. They can be used as paperweights and act as a reminder to reduce the amount of plastics we use daily.


  • List a variety of organisms which live in the marine and estuarine environment and identify feeding relationships as a connection between them.

  • List and describe human impacts on ocean environments.

  • List and describe ways in which we all can be ocean stewards.


  • Per Class:
    blue food colouring
    plastic bags (2 jellyfish can be made from one bag)
    500 mL of water for each student
    500 mL or 1L bottle for each student (Encourage students to reuse a bottle from home.)
    class set of scissors

Key Questions

  • How can garbage items look like something else?
  • How does garbage affect animals in the ocean?
  • What can we do to reduce the amount of waste we produce?

What To Do

  1. Have students cut the handles off a plastic bag
  2. Next, cut the plastic bag in half. Each student will use half a bag to create their jellyfish.
  3. Have students cut a strip from the plastic bag.
  4. Next, have them cut a square out of the plastic bag. Pinch up the center of the square, this will be the jellyfish’s head.
  5. Next, have students use the strip of plastic bag to tie the pinched section.
  6. Students can create tentacles by cutting the plastic bag with scissors.
  7. ​Have students place their completed jellyfish into a bottle.
  8. Add 2 drops of blue food colouring into the bottle and fill it up with water.
  9. Finally, students can add some glitter to the water and seal the cap of the bottle.




  • Study a marine organism and learn about its diet. Is there any garbage that may look like their food?

Other Resources

Oceanwise | Great Canadian Shoreline Clean-up