Plastic can stay in the ocean anywhere from several years to several centuries, depending on its chemical composition and the conditions of the surrounding water. Certain types of plastic, such as polyethylene terephthalate (PET) commonly used in water bottles, can take up to 400 years to decompose in the ocean. This is because plastic is not biodegradable and instead breaks down into smaller and smaller pieces through a process called photodegradation. These small plastic particles, known as microplastics, can persist in the water for even longer periods of time and can be ingested by marine animals, causing harm to their health and the entire ecosystem.
