This kid is throwing the trash from his soda to the ground and it started to rain/prevarication and starts to move to drains or into a runoff it and from there it makes it's way to the ocean.
Before it gets to the drain/runoff when it is rains the water is going down hill and then the water is also collecting trash/plastic and then it goes into drains /runoff.
The plastic made it to the drain and the water is going down to the drain because of the wind. It is also taking in lots of other plastics.
The plastic that went to the drain made it into the ocean. Because of the wind the plastics are getting trapped in the Gyres. Now the plastic is trapped with no way to get out and there is also lots of trash that were already in the gyres.
But then the sunlight energy is making the plastics smaller and smaller/making it into microplastic