Welcome to the second kitchen experiment. This one is about the pollution of marine and coastal areas by plastic waste. Microplastics in particular are a major problem. Watch the video on this topic first:

Now that you have learnt about the triggers for the amount of microplastics in the oceans, you can investigate at home in your own kitchen laboratory why exactly microplastics, which you can't even see with the naked eye, are such a big problem.

You will need the following materials:

• 2 glasses
• 1 measuring jug
• 1 deep plate / 1 salad bowl (with tap water)
• food colouring
• 1 plastic bag
• 1 sieve (as fine as possible)

Once you have all the materials in front of you, you can get started.

First, pour 50ml of tap water into a glass. Add 2-3 drops of food colouring to colour the water in the glass.

Then prepare your deep plate, which is half filled with tap water without colouring. Now carefully pour the coloured water from the glass into the uncoloured water at a point on the edge of the plate. Observe how the colour spreads. After about 2 minutes, you can start to simulate waves by gently moving the plate. Observe how this changes the distribution of the colour.

You have now created a model for seawater with microplastics. However, there is not only microplastic in the sea, but also large quantities of other plastic waste such as plastic bags. Place five to ten pieces of different sizes from a plastic bag in your plate with the colour solution. Now pour this "littered" water through a sieve into the previously unused glass. What can you observe? Does the water become "clean" again?

Tip: Download the worksheet as a PDF document!