People throw litter on the ground. Eventually the wind will blow it to the ocean, or the sunlight energy will turn it into micro plastics which are really small pieces of plastic.
The palstic getting turned to a microplastic.
The trash then will eventually go to the ocean from the wind and runoff. It will float along the ocean or get eaten by the fish
The trash will maybe get stuck in a gyre. A gyre is a surface current that moves in a circular pattern. The great pacific garbage patch was created by millions of tons of trash getting stuck in a gyre.
The plastic will maybe end up on a land form which is a hill or mountain. Then it will run off into the ocean.
The plastic will get blown by the wind to the ocean.