Microthread Pollution Curriculum Activity

Microthread Pollution
Curriculum Activity

Victorian Curriculum Links

Science Understanding

Solids, liquids and gases behave in different ways and have observable properties that help to classify them (VCSSU076)

Changes to materials can be reversible, including melting, freezing, evaporating, or irreversible, including burning and rusting (VCSSU077)

Scientific understandings, discoveries and inventions are used to inform personal and community decisions and to solve problems that directly affect people’s lives (VCSSU073)

The growth and survival of living things are affected by the physical conditions of their environment (VCSSU075)

Science Inquiry Skills

With guidance, pose questions to clarify practical problems or inform a scientific investigation, and predict what the findings of an investigation might be based on previous experiences or general rules (VCSIS082)

Decide which variables should be changed, measured and controlled in fair tests and accurately observe, measure and record data (VCSIS084)

Compare data with predictions and use as evidence in developing explanations (VCSIS086)

Communicate ideas and processes using evidence to develop explanations of events and phenomena and to identify simple cause-and-effect relationships (VCSIS088)

Key Learning Intentions

Students will develop a deeper understanding of what microplastics are and the impact they have on the environment. They will also understand how different materials (hard and soft plastics, liquids and oils) interact with the ocean and how this impacts our oceans.

Background

Over 6 million tonnes of rubbish makes its way into the worlds ocean each year, and scientists have concluded that 60-80% of this waste is initially discarded on land. The main component of this litter is usually plastic. Wind blows plastic rubbish out of littered streets and landfills, and from trucks and trains on their way to landfills. It gets to rivers, streams and storm drains and then gets carried by tides and currents to sea. Litter dropped by people at the beach is also a major source. Microplastics are a large portion of this waste.

Microplastics are particles of various types of plastic that is less than 5 mm in diameter. These might be broken-down pieces of larger plastic items, microthreads or fibres from clothing or microbeads originating from beauty products intended to clean skin. Because they are found in various shapes and sizes, are not predictably biodegraded, and are non-magnetic, microplastic are difficult to filter out and can easily pass through wastewater treatment plants and into waterways. Microplastics and other harmful litter are increasingly found in aquatic food webs and can be very damaging to our ecosystem and aquatic life. Microfibres and those which are created from natural sources, such as cotton, wool or hemp, can biodegrade in the atmosphere.

However, plastic microfibres (such as those produced by nylon, polyester or other synthetic materials) will not decompose over time and can cause untold damage to the internal organs of the organisms which consume them.

The remaining marine debris found in the ocean comes from boats, offshore oil rigs and large cargo ships that dump or lose debris directly into the water. The majority of this debris is fishing nets. Plastic never truly breaks down.

(Below is the information that will be useful in discussion for after the experiment is done)

Hard plastics become brittle with age and exposure to sunlight. The hard plastic breaks down by disintegrating until only tiny plastic specks remain. These microplastics are transported around the globe by currents and consumed by marine life.

Soft plastics float in the ocean currents until they are broken down into smaller fragments or sink to the bottom of the sea, these plastics can be consumed by marine creatures who mistake them for food.

Oil and chemicals spread out or disperse in the saltwater on ocean currents. Chemicals can be taken in by creatures as they filter water over their gills or in food sources. Oils can be found on the surface of the ocean.

Instructions

Materials

Hard plastics – lids, caps, bottles
Soft plastics – bafs, food packets, ziplock bags, cotton threads, clothing scraps
Cooking salt
Water
Food dye
Cooking oil
1 medium to large bowl per group
1 litre beaker or measuring cups

Tune In

https://vimeo.com/113359330

Activity
Preparation:

Organise the materials for the experiment and place these items on a separate equipment table. Each group will need a small amount of different plastic pieces - hard plastic (lids, caps,bottles) and soft plastic (bags, food packets, ziplock bags, small threads from clothing), as well as cooking salt, water, food dye, cooking oil, one medium to large bowl, 1 litre beaker or measuring cups.

During the experiment the students will be observing how different materials interact when they are added to saltwater. Provide each student with a copy of the Student Worksheet to record their own observations. As a whole class read through the instructions (below) before beginning the experiment.

Instructions:

Divide the students into groups of three or four.

Provide each group with a variety of hard and soft plastic items.

Students need to make a seawater solution of 35g of salt to 1 litre of water and fill their bowl with salty water.

Students should add two to three plastic items to the water and observe what happens. Do the plastic pieces float or sink? Does the plastic shrink or grow? Does it break apart or does it absorb the water and grow? Does the water soften the plastic and allow you to change its size or shape? Does the way the plastic moves change as the size changes?

Students record their observations on the Student Worksheet.

Students should now add their liquid pollution (e.g. food dye, cooking oil) to the bowl. These should be added one at a time. Add the food dye to one area of the bowl. Add the oil into another area of the bowl. What happens to the liquid pollution as it enters the bowl? What happens to the plastic as it come into contact with the food dye or the oil?

Students record their observations of the dye and oil on the Student Worksheet.

Discussion

Once you have completed your experiment, organise the students into a discussion circle and invite the students to share their observations and results as part of the discussion.

Discuss the observations students recorded on their Worksheets, including:

· What did you see (observe) happening in your experiment?

· What happened as you changed different parts of your experiment (variables)?

· How did the size of the plastic piece affect the experiment?

· Did it make a difference if the plastic was hard or soft?

· What happened with you added in the food dye or oil?

· How did your predictions compare with your observations?

· How would you change this experiment if you were to repeat it?

Break the class into pairs and assign pairs with two of the following questions to answer, ensuring that each question is answered (questions also available on the Student Worksheet):

1. What impact does plastic pollution have on our oceans?

2. What are some of the different ways materials may change over longer periods of time in the ocean?

3. What role might the sun have in breaking down the plastics?

4. Does the size of the plastic matter?

5. What could you do to limit plastics entering into the oceans?

6. How are single use plastics impacting our oceans? (Think about straws, ziplock bags etc.)

Once complete, engage students in a class discussion around their answers.