The great pacific garbage patch in the north pacific ocean is about 90% plastic. why is there such a high percentage of plastic in the garbage patch?

Step-by-step explanation:

The Great Pacific Garbage Patch is located between Hawaii and California, and represents the largest accumulation of plastic in the Ocean.

The estimation is from 1.15 to 2.41 million tonnes of plastic in that area, which is an alarming fact.

The reason why that amount of plastic garbage concentrates there is North Pacific Gyre Currents, which covers the most part of the North Pacific Ocean. They North Pacific Gyre helped to concentrate the garbage at a specific point, increasing its density.