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Plastic Waste Around 100 million tonnes of plastic are produced each year. 10 percent ends up in the sea. About 20 % of this is from ships and platforms, 80% from land. The North Pacific sub-tropical gyre covers a large area of the Pacific, including several island beaches, in which the water circulates clockwise in a slow spiral. Winds are light so the currents tend to force any floating material into the low energy central area of the gyre in astounding quantities, covering an area larger than Texas. This gyre has also been dubbed the “Asian Trash Trail” the “Trash Vortex” or the “Eastern Garbage Patch”. Not all plastic floats, around 70 percent of discarded plastic sinks to the bottom. In the North Sea, Dutch scientists have counted around 110 pieces of litter for every square kilometre of the seabed, a staggering 600,000 tonnes in the North Sea alone. (www.greenpeace.org/international/campaigns/oceans/pollution/trash-vortex) Top 20 litter Items found during MCS UK Beachwatch 2007 surveys (Plastic makes up 81% of all litter found on beaches) Small plastic pieces have been the number one item found in MCS Beachwatch surveys consecutively since 1998. Plastics consistently account for over 50% of all litter recorded. Plastics persist in the environment, and never fully disappear. Instead they turn into tiny pieces as plastic photodegrades rather than biodegrading www.adoptabeach.org.uk/pages/page.php?cust_id=10 Like other areas of concentrated marine debris in the world's oceans, the Eastern Garbage Patch has formed gradually over the last decades as a result of higher levels of marine pollution and the action of prevailing oceanic currents. The garbage patch occupies a large and relatively stationary region of the North Pacific Ocean bound by the North Pacific Gyre. The rotational pattern described by the North Pacific Gyre draws in waste material from the extremities of the North Pacific Ocean, including the coastal waters off North America and Japan. As material circulates in the current, wind-driven surface currents gradually move floating debris toward the centre. This action has produced unusually high levels of marine debris in the area. The size of the affected region is unknown, but estimates range from 700,000 km 2 to more than 15 million km2, (0.41% to 8.1% of the Pacific Ocean). Sources of pollutants Charles Moore estimates that 80% of the garbage comes from land-based sources, and 20% from ships at sea. He says that currents carry debris from the east coast of Asia to the center of the gyre in a year or less, and debris from the west coast of North America in about five years. Plastic photodegradation in the ocean The Eastern Garbage Patch has one of, if not the highest level of plastic particulate suspended in the upper water column. As a result, it is one of several oceanic regions where researchers have studied the effects and impact of plastic photodegradation in the neustonic layer. Unlike debris which biodegrades, the photodegraded plastic disintegrates into ever smaller pieces while remaining polymers, even down to the molecular level. As the plastic flotsam photodegrades into smaller and smaller pieces, it concentrates in the upper water column. As it disintegrates, the plastic ultimately becomes small enough to be ingested by aquatic organisms which reside near the ocean's surface. Plastic waste thus enters the food chain through its intense concentration in the neuston. Photodegradation Photodegradation is degradation of a photodegradable molecule caused by the absorption of photons, particularly those wavelengths found in sunlight, such as infrared radiation, visible light and ultraviolet light. However, other forms of electromagnetic radiation can cause photodegradation. Photodegradation includes photodissociation, the breakup of molecules into smaller pieces by photons. It also includes the change of a molecule's shape to make it irreversibly altered, such as the denaturing of proteins, and the addition of other atoms or molecules. A common photodegradation reaction is oxidation. This type of photodegradation is used by some drinking water and wastewater facilities to destroy pollutants. Photodegradation in the environment is part of the process by which ambergris evolves from its fatty precursor. Photo degradation also destoys paintings and other artifacts Biodegradation is the process by which organic substances are broken down by the enzymes produced by living organisms. The term is often used in relation to ecology, waste management and environmental remediation (bioremediation). Organic material can be degraded aerobically, with oxygen, or anaerobically, without oxygen. A term related to biodegradation is biomineralisation, in which organic matter is converted into minerals. Biosurfactant, an extracellular surfactant secreted by microorganism enhances the biodegradation process. Biodegradation Biodegradable matter is generally organic material such as plant and animal matter and other substances originating from living organisms, or artificial materials that are similar enough to plant and animal matter to be put to use by microorganisms. Some microorganisms have the astonishing, naturally occurring, microbial catabolic diversity to degrade, transform or accumulate a huge range of compounds including hydrocarbons (e.g. oil), polychlorinated biphenyls (PCBs), polyaromatic hydrocarbons (PAHs), pharmaceutical substances, radionuclides and metals. Major methodological breakthroughs in microbial biodegradation have enabled detailed genomic, metagenomic, proteomic, bioinformatic and other high-throughput analyses of environmentally relevant microorganisms providing unprecedented insights into key biodegradative pathways and the ability of microorganisms to adapt to changing environmental conditions (adapted from Wikipedia)