The reasoning:
The reasoning to the great garbage patch formed gradually as a result of the ocean and marine pollution gathered by the ocean and currents, because currents capture material, wind drives all the garbage to the middle of the pacific ocean and traps it.
The effect:
The great pacific garbage patch kills marine life. 1 million seabirds and 100,000 marine animals animals are effected every year and a lot of other animals have been effected for example turtles mistake plastic bags for jellyfish.
Explanation:
For example the great pacific garbage patch is a lot of rubbish all cluttered together, where the rubbish all just sticks together. All the garbage together in the middle of the ocean has caused alot of marine animals to die... there was 1 million seabirds and 100,000 marine animals that has died, there was also alot of turtles because turtles mistake plastic bags for jelly fish. Over 1 million animals were found with plastic inside them, washed up on the beach.