"In 1988, Robert Day, David Shaw, and Steven Ignell submitted a report to NOAA (National Oceanic and Atmospheric Administration) detailing the results of four years of sample collection and analysis of plastic fragments found floating in the Pacific Ocean. They found concentrations highest in the North Pacific Gyre. The authors cited wind and currents as the primary force driving the higher concentrations to the center of the Gyre. Concentrations of what? Number one, monofilament fishing line fragments; and number two, something called neuston plastic. Neuston plastic refers to particles that have been broken down to a small size and are now floating just at or below the surface of the water. Most plastic floating in the open ocean degrades quite quickly, due primarily to ultraviolet radiation. It becomes brittle and crumbles. When it reaches microscopic size, it competes with phytoplankton as a food source for zooplankton, and enters the food chain. That's not good for anyone. The authors used 203 sample stations, each about 450 square meters in size. 52.2% of these contained plastic fragments.
Got that? Only half of NOAA's football-field sized sample areas, in the center of the densest part of the Pacific "Garbage Patch", contain even detectable levels of microscopic plastic. Unacceptable to be sure; but hardly a solid island."