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Ocean In A Jar

In this activity, students learn about the diffusion of pesticides, plastics, and pollution on marine ecosystems.

About 70 per cent of the surface of the earth is covered with water. This includes the five oceans: Pacific, Atlantic, Indian, Southern and Arctic. However, less than one per cent of the world’s oceans are protected by law as Marine Protected Areas or Marine Parks.

Over 80 per cent of marine pollution comes from land-based activities. Oil, fertilizers, solid, garbage, sewage and toxic chemicals all drain from land into our waterways and eventually end up in the ocean.

When plastics are littered they make their way into our oceans. Plastics usually float and many marine animals get tangled up in them or confuse them for food and eat them.

As time goes by, plastics are broken down into microscopic pieces and are ingested by jellyfish, small fish and filter feeders like clams and mussels. These plastics then move up the food chain and become more concentrated in bigger fish and marine mammals.

Orcas and other whales have been classified as biohazardous because of the high concentration of these chemicals found in their blubber. 


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

  • Describe how bioaccumulation occurs in the marine environment.

  • List and describe human impacts on ocean environments.

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


  • Per Group:
    clear plastic tank filled with water (a small aquarium or clear tub is ideal)
    small container
    eye dropper
    plastic ‘litter’ that floats (Bonus: glitter or confetti works well)
    food colouring
    cooking oil
    dried herbs (oregano or basil work well)
    4-5 small sieves

Key Questions

  • How do oil and chemicals from cars, fertilizers from house yards and other chemicals end up in the ocean?
  • When the pollutants get into the water, what happens?
  • What can we do to minimize pollution ending up in the ocean?
  • What happens when animals that are filter feeders, such as grey whales, try to eat?

What To Do

    1. Fill a tank with water.
    2. Using the eye dropper, squirt a small amount of water into a small container to represent the relatively small amount of oceans protected by law in the form of marine protected areas or marine parks.
    3. Add plastic litter like glitter to the tank to represent the garbage floating on the ocean.
    4. Add cooking oil to the tank to represent the oil found in the ocean.
    5. Add food colouring to the tank to represent fertilizers and other chemicals draining into the ocean.
    6. Sprinkle the herbs in the water. They will represent the food the filter feeders want to get from the water.
    7. Using the sieve, have students try to scoop out the herbs. Can you scoop them out without getting any oil and plastic litter?
    8. Discuss how filter feeders can be affected by the pollution that ends up in our ocean.


  • Brainstorm steps that students can take to protect our oceans. Construct a food web of ocean feeding relationships
  • As a class, participate in the Great Canadian Shoreline Clean-up.
  • Construct a food web of ocean feeding relationships

Other Resources

Oceanwise | Great Canadian Shoreline Clean-up