This map shows the ocean gyres that concentrate collecting plastic waste in massive ocean dumping grounds. The waste is a threat to marine life and water quality. In some cases it can even pose a problem for navigation. In 2005 an entire Russian submarine was reported entangled in discarded fishing net off the Kamchatka coast.
Plastic pollution is estimated to increase six-fold in the future with single-use plastic items such as food packaging being the largest contributor to the waste steams which include nearly indestructible construction materials and durable consumer items such as appliances. Greenpeace says 267 marine species have suffered from entanglement or ingestion of plastic. Fifty to eighty percent of sea turtles found dead are known to have ingested plastic.
There is an international treaty to prevent dumping of plastic waste from ships at sea (MARPOL), but it does not cover the 80% of waste littering coast lines from onshore waste streams. Indonesia is the worst coastline litterbug; litter there covers 90% of the upper shore and strand in highly populated areas. WWF states that five countries in Asia are the worst plastic waste offenders. If twenty countries would improve their mismanagement of solid waste, forty percent of the plastic waste stream entering the world's oceans could be stopped. The solution to this growing problem is to impose zero tolerance for ocean dumping and the conversion of consumer products away from non-degradable contents such as microbeads. Clean-up of known collection sites around the world is also important. The Northwest Hawaiian Islands, now a protected national monument, suffers contamination from derelict fishing gears deposited by the North Pacific Gyre. Efforts to clean up the affected islands and associated waters have been made since the 1980's. Research published in 2003 found 195 tons of derelict gear had been removed.