“Our hauls of plastic have been fairly consistent, and we’ve tallied about ~70 pieces per net tow, which works out to a surface concentration of around 50,000 pieces per square kilometer. These values are well within the range that we’ve found in this region before, but do not represent the super high values that define the center of the accumulation zone.
Assuming that each plastic piece weighs less than a 0.1 g, this means that within the area that we can see from the deck of our ship (about 4.5 nautical miles) there are almost 800 pounds of tiny plastic fragments floating in the surface waters. ” -Giora Proskurowski [http://www.sea.edu/plastics/science-results6-13.htm]
the above excerpt is a small part of a scientific paper published by SEA and Mr. Proskurowski and can be found on their website. it is referring to their daily sampling results that occurred on a voyage in the Atlantic during 2010. the above map is also from the study and it depicts the path that their boat took across the Atlantic paired with the varying degrees of plastic concentrations along the path. the numbers are estimates based on small samples within each area. this is their homepage for their voyage/study/report [http://www.sea.edu/plastics/].