Millions of metric tons of plastic enter the oceans every year. Some of it is highly visible in the Pacific trash vortex, also known as the Great Pacific Garbage Patch, which lies between North America and Japan.
However, the most prevalent type of debris found in our oceans — microplastics — are less visible. Microplastics are tiny bits of plastic less than 5 millimeters in length, which is about the size of a sesame seed.