The increase in the use of plastic worldwide correlates with increasing incomes, growing economies and rising consumption in fast-growing emerging markets, compounded by under-developed waste management systems in these countries. There are 192 coastal countries, all of which contribute in some degree to oceans plastic pollution due to insufficient waste-management systems, but 10 countries in particular have been identified as the major sources of ocean’s plastic waste. These countries are:
China, Indonesia, the Philippines, Vietnam, Sri Lanka, Thailand, Egypt, Malaysia, Nigeria and Bangladesh.
Other countries that also rate poorly for their plastic waste-management systems and subsequent plastic leakage into the worlds oceans are: South Africa, India, Algeria, Turkey, Pakistan, Brazil, Burma, Morocco, North Korea and the United States of America.
Due to the currents in the world’s oceans, this plastic leakage has coalesced into five major oceanic gyres: the North and South Pacific Subtropical Gyres, the North and South Atlantic Gyre and the Indian Ocean Subtropical Gyre.
These gyres are also known as the Great Garbage Patches (although this does not mean that plastic pollution is not present in all other parts of the ocean – it is). The area in the centre of a gyre tends to be very calm and stable, therefore, all the plastic debris that is drawn into this stable centre gets trapped and circulates for years.
The most studied and notable gyre, the North Pacific Subtropical Gyre represents the boundaries of the entire Great Pacific Garbage Patch that is the biggest existing marine trash vortex. About 80% of the debris in the Great Pacific Garbage Patch comes from land-based activities in North America and Asia. Trash from the coast of North America takes about six years to reach the Great Pacific Garbage Patch, whereas trash from Japan and other Asian countries takes about a year. It then breaks down into ever smaller pieces under exposure to ultraviolet light and weathering.