Amount of Plastic in Ocean: 700 Pieces per Human Estimate taken from 24 ocean expeditions from 2007 to 2013 By Shelley Hazen, Newser User Posted Dec 11, 2014 7:34 AM CST Updated Dec 11, 2014 8:17 AM CST 32 comments Comments This Aug. 11, 2009, file image provided shows a patch of sea garbage at sea in the Pacific Ocean. (AP Photo/ Scripps Institution of Oceanography, Mario Aguilera, File) (Newser) – Mother Earth has reached a milestone, but not the kind anyone will want to celebrate: The plastic floating in the oceans has been estimated to the tune of 5 trillion pieces in a new study. That's 250,000 tons, or some 700 pieces per person, the Washington Post reports. The 5 Gyres Institute arrived at this number by combining visual surveys and plastics hauled in by net from 24 ocean expeditions in 1,571 spots from Iceland to the Bay of Bengal, LiveScience notes. Researchers then simulated how the ocean may transport this plastic worldwide. Still, lots of plastic is unaccounted for—like 99.9% of the 288 million tons that PlasticsEurope claims is made every year. It may just be too small to see, because sun and ocean currents break down plastics into tiny pieces, the New York Times explains. These pieces—many of them found in subpolar regions, adds LiveScience—may be ending up in the bellies of marine animals. "Plastics are like a cocktail of contaminants floating around in the aquatic habitat," a marine ecologist tells the Times; these pollutants crawl up the food chain—and then back to us. And the tiniest pieces may also be hiding on the seafloor or shoreline, in the water column, or deep in the ocean. While researchers say their estimate is "highly conservative," at least one ecologist says the count is overblown, blaming unreliable visual surveys and a computer model that overestimated projections. Still, one researcher says recycling and green choices are needed right away: "The status quo is no longer acceptable."