Over 80 percent of ocean plastic comes from land-based sources; once plastic is discarded, it is not well managed, and thus leaks into the ocean. Over half of land-based plastic-waste leakage originates in just five countries: China, Indonesia, the Philippines, Thailand, and Vietnam.

Source: Stemming the Tide: Land-based strategies for a plastic- free ocean” by the Ocean Conservancy and the McKinsey Center for Business and Environment https://oceanconservancy.org/wp-content/uploads/2017/04/full-report-stemming-the.pdf