How do plastic microfibers and microplastics get into the ocean?

Microplastics are tiny plastic fragments less than 5 millimeters across, and they enter the ocean through several routes. Larger plastic items break into smaller pieces under sunlight and waves, while synthetic textiles shed microfibers during washing. Road runoff can carry tire particles, and spills of plastic pellets add another source. Once in the ocean, these particles are widespread and difficult to remove, making prevention especially important.