It takes plastic approximately 450 years to decompose in the ocean.
The polymers in plastic (despite being derived from resources that can be found in nature like cellulose, salts, and natural gases,) are not naturally occurring substances, so there are no naturally occurring organisms with diets or abilities to consume and break down plastic. Because of this, it can take hundreds of years for plastic to fully decompose. Plastic production has been booming since the 1950s, so the plastic that was produced then is still around today.
