Thanks to ocean pollution, the gyres have become floating, soupy, masses of microplastics, which results from the physical breakdown that begins as soon as plastic first escapes into the sea. While heavier organic materials such as wood and metal might eventually degrade or sink to the bottom, plastic breaks down near the surface as a physical response to abrasion, prolonged UV exposure, and degradation from prolonged contact to water. Having the larger pieces of plastic break into smaller chunks or pieces as a result of exposure to physical forces such as wind or waves is what creates the microplastics plaguing our oceans today. Studies have shown that these pieces can be smaller than a third of a millimetre, and they make up as much as 60% of the floating plastic debris within the North Pacific Gyre (NPG).